Biology subjects

Jin, X.

Publications and source records attributed to Jin, X..

At least 73 records · Page 4Linked to original sources

bioRxiv2025

Cerebellum metastasis model of HER2-positive breast cancer unveils key role of IL34-induced Arg1+ macrophages.

Brain metastases occur in up to 40% of Stage IV breast cancer patients. The cerebellum is a frequent location for metastases in HER2-positive breast cancer patients, but the mechanisms for this are unknown. Here, we developed a syngeneic, immunocompetent mouse model for breast cancer brain metastases by stereotactically injecting mouse HER2-overexpressing breast cancer organoids into the cerebellum. Growth of these cerebellar metastases was monitored by MRI and trastuzumab optical imaging using a near-infrared fluorophore conjugated to trastuzumab. Spatial transcriptomics identified interleukin-34 production by breast cancer cells inducing ARG1+ macrophages at the invading edge of the metastasis. Treatment with a blocking antibody to interleukin-34s receptor, CSF1R, produced tumor shrinkage. These findings have immediate translation potential as a CSF1R-blocking antibody is FDA-approved. Further, it demonstrates that cancer-associated inflammation bordering the brain metastasis promotes metastatic growth and offers a molecularly targeted strategy to treat inflammation in brain metastasis. Graphical summary O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/660224v1_ufig1.gif" ALT="Figure 1"> View larger version (38K): org.highwire.dtl.DTLVardef@9f1a50org.highwire.dtl.DTLVardef@178acc5org.highwire.dtl.DTLVardef@196d803org.highwire.dtl.DTLVardef@3fe631_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

bioRxiv2025

ZIPcnv: accurate and efficient inference of copy number variations from shallow whole-genome sequencing

Shallow whole-genome sequencing (sWGS), a rapid and cost-effective sequencing technology, has gradually been widely adopted for CNV analyses. However, with genome-wide coverage of only 0.1-5x, sWGS data exhibit a pronounced zero-inflation phenomenon, whereby a large fraction of loci contains zero sequencing reads. Zero-inflation causes read counts to fluctuate by several-fold between adjacent windows. As a result, random upward blips in coverage can be misinterpreted as copy-number gains (false positives), and true deletions often become indistinguishable from pervasive zero-coverage noise. In addition, existing CNV detection tools developed for sWGS data often struggle to adapt across different CNV sizes. These combined effects severely constrain the accuracy of CNV inference. To address above challenges, we propose ZIPcnv, a novel CNV detection tool specifically designed for sWGS data. First, we apply a large sliding window to smooth the raw read depth signal, which transforms the original zero-inflated statistical characteristics into approximately normal distribution characteristics. We then design a statistical process model that robustly detects persistent shifts under high background noise using a cumulative sum strategy, classifying genomic regions into candidate and non-candidate CNV regions. Finally, dynamic sliding windows are used for one-pass detection of CNVs of varying lengths, with window size adapting to the CNV region size. We evaluated the performance of ZIPcnv on simulated data and 190 real whole-genome sequencing samples. Experimental results show that ZIPcnv consistently outperforms currently popular CNV detection tools. The ZIPcnv source code is freely available at https://github.com/Nevermore233/ZIPcnv.

bioinformatics↗

bioRxiv2025

Establishing a Digital PCR-Based Reference Measurement Procedure for Monkeypox Virus: An Inter-laboratory Assessment and Standardization Study

The accurate detection of monkeypox virus (MPXV) is crucial for effective viral diagnosis and epidemic prevention. Currently, the field lacks standardized reference methods for MPXV quantification, as well as reliable pseudovirus reference materials (RMs) to ensure quality control throughout the detection process. To address this, we developed a droplet digital PCR (ddPCR) reference measurement procedure (RMP) for precise quantification of MPXV genes B6R, which demonstrates excellent performance with a wide dynamic range (11-1.24x104 copies/L), strong linearity (R2=0.9984), and a low limit of quantitation (11 copies/L, CV[≤]25%). Repeatability tests confirmed high precision, with inter-laboratory CVs <10% across nine labs using different dPCR platforms. recovery efficiencies for B6R and F3L were [~]69%, with uncertainties incorporated into final measurements. The homogeneity assessment showed good results (CV=2.94%), and stability studies confirmed the stability of the sample during -70 {degrees}C and short-term storage (4 {degrees}C/-20 {degrees}C). Mandels statistical data shows that the reproducibility between laboratories is consistent. This validated ddPCR RMP provides metrological traceability, ensuring reliable and comparable results for MPXV diagnosis and supporting public health efforts.

molecular biology↗

bioRxiv2025

The piRNA PETPIR Regulates Trophoblast Function by Modulating YTHDF2-Mediated m6A Methylation of NDRG1 in Preeclampsia

Preeclampsia is marked by abnormal placental development and impaired trophoblast function. We identified Preeclampsia-associated trophoblast piRNA (PETPIR) as an important regulator of trophoblast function and m6A modifications. Placental samples from preeclamptic and healthy pregnancies were analyzed using piRNA microarrays and m6A epitranscriptomic profiling. Functional assays in trophoblast cells, transcriptomic analysis, and an in vivo PETPIR-overexpressing mouse model were employed to investigate PETPIRs mechanistic roles. We found that PETPIR was significantly upregulated in preeclamptic placentas. PETPIR inhibited trophoblast cell proliferation, migration, and invasion by inducing cell cycle arrest and apoptosis. Transcriptome analysis demonstrated that PETPIR activated hypoxia-responsive pathways. Additionally, PETPIR enhanced global m6A methylation and stabilized NDRG1 transcripts by interacting with the m6A reader YTHDF2. In vivo, PETPIR overexpression in pregnant mice recapitulated key features of preeclampsia, including maternal hypertension and fetal growth restriction. These results suggest PETPIR is a key player in the pathogenesis of preeclampsia, functioning through the PETPIR/YTHDF2/NDRG1 axis to drive hypoxia and m6A epitranscriptomic dysregulation. We provide novel insights into preeclampsias molecular mechanisms, highlighting piRNA as a promising biomarker and therapeutic target.

molecular biology↗

bioRxiv2025

Therapeutic Potential of 20E in Pulmonary Arterial Hypertension: Involvement of Mas Receptor and PI3K/Akt Pathway

BACKGROUND20-Hydroxyecdysone (20E), a natural polyhydroxylated steroid found in various edible plants, exhibits diverse pharmacological effects. This study aims to investigate the preventive and therapeutic effects of 20E on pulmonary arterial hypertension (PAH) and elucidate its underlying molecular mechanisms. METHODSA monocrotaline (MCT)-induced PAH rat model was utilized to evaluate the efficacy of 20E. The Mas receptor antagonist A779 and agonist AVE0991 were used to investigate the role of Mas in PAH progression and 20E-mediated prevention. Molecular docking and pull-down assays were conducted to confirm the interaction between 20E and the Mas receptor. In vitro, the effects of 20E on Ang II-induced proliferation and migration of human pulmonary arterial smooth muscle cells (HPASMCs) were assessed. The PI3K/Akt signaling pathway was analyzed by Western blot. RESULTS20E prevented PAH at 30 mg/kg and 90 mg/kg, while 90 mg/kg rescued pre-existing PAH. The protective effects of 20E were attenuated by A779. 20E upregulated Mas receptor expression and directly bound to it. In vitro, 20E inhibited Ang II-induced HPASMC proliferation and migration. It also downregulated p-PI3K, p-Akt, and p-mTOR while restoring P27 and P21 expression. Furthermore, knockdown of the Mas in HPASMCs abolished the effects of 20E on these processes. CONCLUSIONS20E inhibits PASMC proliferation and migration by activating the Mas receptor and modulating the downstream PI3K/Akt signaling pathway, thereby effectively preventing and rescuing PAH. It may be a promising pharmacological candidate for PAH treatment.

molecular biology↗

bioRxiv2025

Structural variants contribute to the gut microbiome, blood metabolic traits and their causal relationships

Research on genetic variants affecting the gut microbiome and blood metabolites has mainly focused on single nucleotide variants (SNPs), with structural variants (SVs) remaining largely unexamined. In this study, we utilized an advanced structural variant detection pipeline on whole-genome sequencing data from 2,002 individuals with an average sequencing depth of 42 folds, identifying 138,859 high-confidence SVs, 49.57% of which were previously unreported. We performed genome-wide association studies on 22,519 common SVs with 616 gut microbial features and 121 blood metabolic traits, uncovering 30 significant links between SVs and microbial taxa/pathways and 48 connections between SVs and blood metabolites. Notable results include 19 associations reaching study-wide significance, such as an Asian-specific 6.5k deletion at the TENT2 gene, which is strongly associated with the abundance of Coprobacillus sp. 29_1 ({beta}=0.158, p=2.5x10-9), and a deletion covering HBA1/HBA2/HBM/HBQ118 linked to nine blood metabolic traits, most significantly with mean corpuscular volume (MCV; {beta}=-0.570, p=1.22x10-91). Most SVs showed a greater impact than nearby SNPs in their associations with the microbiome/metabolites. Analysis of rare SVs also identified multiple genes associated with the microbiome/metabolites. Additionally, Mendelian randomization using SVs demonstrated causal relationships, including effects from the microbiome to metabolites, such as Clostridium ramosums impact on serum uric acid and hyperuricemia, and from metabolites to the microbiome, like the influence of mean corpuscular hemoglobin concentration on MF0064: triacylglycerol degradation. This study provides a detailed SV catalog for the Chinese population and highlights the significant role of SVs in the gut microbiome, blood metabolites, and their causal relationships. HighlightsO_LIProvides a catalog of 138,859 high-confidence SVs and 49.57% of which were novel C_LIO_LIIdentify 30 genome-wide significant "SVs--microbial taxa/pathways" and 48 "SVs--blood metabolites" associations, respectively C_LIO_LIAn Asian-specific 6.5k deletion at TENT2 gene associated with the species Coprobacillus sp. 29_1 C_LIO_LIA deletion spanning HBA1/HBA2/HBM/HBQ118 associated with 9 blood metabolic traits C_LIO_LIThe majority of SVs demonstrated a more pronounced impact than neighboring SNPs in the associations with microbiome/metabolites C_LIO_LISVs help to reveal the host-microbe causal relationships such as Clostridium ramosums causal effects on serum uric acid and hyperuricemia C_LI O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=155 SRC="FIGDIR/small/643427v2_ufig1.gif" ALT="Figure 1"> View larger version (36K): org.highwire.dtl.DTLVardef@e660d0org.highwire.dtl.DTLVardef@ddfe4dorg.highwire.dtl.DTLVardef@62a704org.highwire.dtl.DTLVardef@c31bb5_HPS_FORMAT_FIGEXP M_FIG Graphic abstract Based on a multi-omics cohort of 2,002 individuals comprising high-depth whole genome and metagenomic sequencing data, blood metabolites, and detailed questionnaires, we identified 138,859 high-confidence SVs, uncovering 36 significant associations between SVs and microbial taxa/pathways, as well as 48 associations between SVs and blood metabolites. Mendelian randomization using SVs demonstrated causal relationships, such as Clostridium ramosums causal effect on serum uric acid and hyperuricemia. This study provides a detailed SV catalog for the Chinese population and highlights the significant role of SVs in the gut microbiome, blood metabolites, and their causal relationships. C_FIG

genomics↗

bioRxiv2025

Spatial transcriptomics elucidates the central role of cerebral vasculatures in the progression of Japanese encephalitis

The cellular and molecular mechanisms underlying the neuropathology of Japanese encephalitis virus (JEV) remain obscure. Herein, we designed Stereo-seq chips to simultaneously capture the in situ transcriptomes of both the host and JEV, constructing a comprehensive spatiotemporal pathological landscape for Japanese encephalitis (JE). This study reveals the central role of the vascular system in JE pathogenesis, particularly the meninges, which displayed the strongest signal of inflammation and cell death in the JEV-infected brain. The activation of the Ackr1+ endothelial cells, disruption of the blood-brain barrier, the migration of JEV-infected monocytes, secretion of immune factors by the infected cells, and the occurrence of pyroptosis and necroptosis form a positive feedback loop, resulting in an increasing influx of immune cells and tissue damage. JEV infection leads to neurological impairments, which may be attributed to the interaction between viral proteins and host cellular factors such as Stat1, Stat3, Nfkb1, and Sp1. As the vascular system serves as a central receiver and amplifier of inflammatory signals, regulating inflammation within the vascular system is essential in mitigating JE progression.

immunology↗

bioRxiv2025

Viral Infection Detector: Ensemble Learning for Predicting Viral Infection in Single-cell Transcriptomics of Virus-Induced Cancers

Oncoviruses cause around 15-20% of all human cancers. As 3 end-based single-cell RNA-sequencing (scRNA-seq) methods become more popular, the relationship between viral infection and tumor progression at the transcriptomic level has been increasingly studied at single-cell resolution. However, the identification of infected cells is challenging as viral reads from infected cells may not be captured, leading to high false negative rates. To recover these infected cells that have been missed, we developed VID, a stacked ensemble machine-learning model that predicts virus-infected cells in scRNA-seq datasets. Using VID, we uncovered biologically meaningful differences between infected and uninfected cells across different oncovirus-mediated cancers and different cell types. Our VID tool provides a user-friendly way to study changes induced by viral infections in scRNA-seq datasets.

bioinformatics↗

bioRxiv2025

Selective depletion of cancer cells with extrachromosomal DNA via lentiviral infection

Dear Editor Extrachromosomal DNA (ecDNA), a major focal oncogene amplification mode found across cancer, has recently regained attention as an emerging cancer hallmark1,2, with a pervasive presence across cancers3,4. With technical advancements such as high-coverage sequencing and live-cell genome imaging, we can now investigate ecDNAs behaviors and functions 5-7. However, we still lack an understanding of how to eliminate ecDNA. We observed depletion of cells containing ecDNA during lentiviral but not transposon-based transduction while we sought to investigate the mechanism of ecDNA behavior. This discovery may provide critical information on utilizing a lentiviral system in emerging ecDNA research. Additionally, this observation suggests specific sensitivities for cells with ecDNA.

cancer biology↗

bioRxiv2025

The membrane skeleton density of red blood cells in MYH9-related disease patients is decreased

MYH9-related disease (MYH9-RD) is a rare autosomal dominant disorder caused by mutations in MYH9 gene, which encodes the heavy chain of nonmuscle myosin IIA. Nearly all MYH9-RD patients present with macrothrombocytopenia, characterized by decreased platelet count and increased platelet size. In this study, we collected blood samples from three MYH9-RD patients (R702S, D1424N, and R1464C) and unexpectedly found that the actin levels in the red blood cells (RBCs) from all three MYH9-RD patients are substantially lower than the healthy controls. We further revealed that the levels of two RBC membrane skeleton proteins, -spectrin and tropomodulin, are also reduced in MYH9-RD RBCs. We showed that the membrane skeleton of MYH9-RD RBCs was more porous and that MYH9-RD RBCs produced more severe deformation under hyperosmotic pressure compared to healthy controls. We conclude that MYH9-RD mutations reduce the RBC membrane skeleton density and impair its mechanical properties, and propose that defects in the membrane skeleton network in RBCs may be a common symptom in MYH9-RD. Key pointsThe levels of membrane skeleton proteins and the density of membrane skeleton network in RBCs of MYH9-RD patients are reduced. MYH9-RD RBCs produce greater deformation under hypertonic conditions compared to healthy controls.

pathology↗

bioRxiv2025

Single-Cell Genomics Elucidates Molecular Variations and Regulatory Mechanisms in Circulating Immune Cells

The human peripheral blood displays diverse molecular characteristics across populations, understanding the drivers and underlying mechanisms of which remains challenging. Here, we introduce the Chinese Immune Multi-Omics Atlas (CIMA), elucidating sex-, age-, and genetic-related molecular variations by analyzing multi-omics data from 428 adults with over 10 million immune cells. CIMA generated an enhancer-driven gene regulatory network, identifying 237 high-quality regulons and revealing cell type-specific regulatory mechanisms. Additionally, 11,521 lead cis-expression quantitative trait loci (eQTLs) and 46,339 chromatin accessibility QTLs (caQTLs) were identified at cell type level. CIMA also uncovered pleiotropic associations among immune-related disease risk loci, eQTLs, and caQTLs in a cell type-specific manner. Lastly, a novel cell language model, CIMA-CLM, was developed to predict chromatin accessibility and noncoding variant effects using chromatin sequences and gene expressions. This work represents a population-scale multi-omics resource of human immune cells, providing a valuable reference for future investigation of immune-related diseases.

immunology↗

bioRxiv2024

Accurate de novo design of a voltage-gated anion channel

Ion channels gated by environmental cues play key roles in fundamental biological processes. Designing ion channels with tailored gating mechanisms remains a significant challenge due to the complexities involved in designing conformational changes in proteins. Here we report the accurate de novo design of a voltage-gated anion channel, namely VGAC. VGAC adopts a 15-helix pentameric structure featuring a constriction composed of five arginine residues within the transmembrane span. In patch-clamp experiments, VGAC showed strictly voltage-dependent currents and demonstrated selectivity for chloride anions over iodide anions. Our data suggests that the arginine constriction undergoes voltage-induced conformational changes, serving as both the voltage sensor and selectivity filter. A 2.9-[A]-resolution cryo-electron microscopy structure of VGAC closely aligns with the design model. The ability to design ion channels with custom-designed conformational changes provides new insights into our understanding of the fundamental principles of membrane biophysics and unveils a wide range of potential applications.

synthetic biology↗

bioRxiv2024

Same-Slide Spatial Multi-Omics Integration Reveals Tumor Virus-Linked Spatial Reorganization of the Tumor Microenvironment

The advent of spatial transcriptomics and spatial proteomics have enabled profound insights into tissue organization to provide systems-level understanding of diseases. Both technologies currently remain largely independent, and emerging same slide spatial multi-omics approaches are generally limited in plex, spatial resolution, and analytical approaches. We introduce IN-situ DEtailed Phenotyping To High-resolution transcriptomics (IN-DEPTH), a streamlined and resource-effective approach compatible with various spatial platforms. This iterative approach first entails single-cell spatial proteomics and rapid analysis to guide subsequent spatial transcriptomics capture on the same slide without loss in RNA signal. To enable multi-modal insights not possible with current approaches, we introduce k-bandlimited Spectral Graph Cross-Correlation (SGCC) for integrative spatial multi-omics analysis. Application of IN-DEPTH and SGCC on lymphoid tissues demonstrated precise single-cell phenotyping and cell-type specific transcriptome capture, and accurately resolved the local and global transcriptome changes associated with the cellular organization of germinal centers. We then implemented IN-DEPTH and SGCC to dissect the tumor microenvironment (TME) of Epstein-Barr Virus (EBV)-positive and EBV-negative diffuse large B-cell lymphoma (DLBCL). Our results identified a key tumor-macrophage-CD4 T-cell immunomodulatory axis differently regulated between EBV-positive and EBV-negative DLBCL, and its central role in coordinating immune dysfunction and suppression. IN-DEPTH enables scalable, resource-efficient, and comprehensive spatial multi-omics dissection of tissues to advance clinically relevant discoveries.

systems biology↗

bioRxiv2024

NAD+ - and EVA1-C-dependent reversal of neurological deficits is mediated by differential alternative RNA splicing in tauopathic animal models

Aberrant alternative splicing (ASEs) is an aging hallmark to Alzheimers Disease (AD). Although NAD+ and related metabolites can slow down AD, NAD+ on ASEs in AD remain unclear. Mouse transcriptomic data revealed NR-induced ASEs, focusing on the Eva1-C locus. AI-based algorithms predicted EVA1-C protein structures and protein-protein interactions. AD postmortem brain samples and tauopathy models including transgenic mice and worm was used for validation. NAD+ abundance/metabolic status modulates ASEs and the expression of EVA1-C isoforms, which in turn regulate the interaction with BAG-1 and HSP70 proteins. Importantly, EVA1-C is dramatically reduced in 20 Braak 5/6 AD patients compared to cognitive normal humans in different brain regions. NAD+ metabolism modulates abundance of specific mRNA isoforms, and that ASEs influence disease progression in model tauopathies and potentially AD. These results could facilitate future development of NAD+-based splice-switching therapeutics for AD. TeaserUnveiling the Link Between NAD+ Metabolism and Alzheimers Disease: Discovering the Role of Alternative RNA Splicing in Disease Progression and Potential Therapeutic Targets

neuroscience↗

bioRxiv2024

Site of breast cancer metastasis is independent of single nutrient levels

Cancer metastasis is a major contributor to patient morbidity and mortality1, yet the factors that determine the organs where cancers can metastasize are incompletely understood. In this study, we quantify the absolute levels of over 100 nutrients available across multiple tissues in mice and investigate how this relates to the ability of breast cancer cells to grow in different organs. We engineered breast cancer cells with broad metastatic potential to be auxotrophic for specific nutrients and assessed their ability to colonize different organs. We then asked how tumor growth in different tissues relates to nutrient availability and tumor biosynthetic activity. We find that single nutrients alone do not define the sites where breast cancer cells can grow as metastases. Additionally, we identify purine synthesis as a requirement for tumor growth and metastasis across many tissues and find that this phenotype is independent of tissue nucleotide availability or tumor de novo nucleotide synthesis activity. These data suggest that a complex interplay of multiple nutrients within the microenvironment dictates potential sites of metastatic cancer growth, and highlights the interdependence between extrinsic environmental factors and intrinsic cellular properties in influencing where breast cancer cells can grow as metastases.

cancer biology↗

bioRxiv2024

Generation of cultured beef from bovine embryonic stem cells

Bovine embryonic stem cells (bESCs) serve as an optimal source for generating muscle and fat tissues. However, systematic methodologies for creating cultured beef from bESCs have not yet been reported. Here, we successfully established a bESC line and formulated a specialized culture medium that supports cell pluripotency in both two-dimensional (2D) and three-dimensional (3D) cultures. Additionally, we have also developed serum-free and transgene-free protocols that efficiently differentiate bESCs into muscle and fat cells. These differentiated cells were validated at the transcriptional and protein levels. Furthermore, we devised a method using high moisture stretched plant-based protein scaffolds for incorporating differentiated muscle and fat cells derived from bESCs, producing an innovative plant-cell hybrid cultured beef. These advancements provide a solid foundation for future cultured beef production using pluripotent stem cells.

bioengineering↗

bioRxiv2024

Data-Driven Image Analysis to Determine Antibody-Induced Dissociation of Cell-Cell Adhesion and Antibody Pathogenicity in Pemphigus Vulgaris

Pemphigus vulgaris (PV) is a blistering autoimmune disease that affects the skin and mucous membranes. The precise mechanisms by which PV antibodies induce a complete loss of cohesion of keratinocytes are not fully understood. But it is accepted that the process starts with antibody binding to desmosomal targets which leads to its disassembly and subsequent structural changes to cell-cell adhesions. In vitro immunofluorescence imaging of desmosome molecules has been used to characterize this initial phase, often qualitatively. However, there remains an untapped potential of image analysis in providing us more in-depth knowledge regarding ultrastructural changes after antibody binding. Currently, there is no such effort to establish a quantitative framework from immunofluorescence images in PV pathology. We take on this effort here in a comprehensive study to examine the effects of antibodies on key adhesion molecules and the cytoskeletal network, aiming to establish a correlation of ultrastructural changes in cell-cell adhesion with antibody pathogenicity. Specifically, we introduced a data-driven approach to quantitatively evaluate perturbations in adhesion molecules, including desmoglein 3, E-cadherin, as well as the cytoskeleton, following antibody treatment. We identify distinct immunofluorescence imaging signatures that mark the impact of antibody binding on the remodeling of the adhesion molecules and introduce a pathogenicity score to compare the relative effects of different antibodies. From this analysis, we showed that the biophysical response of keratinocytes to distinct PV associated antibodies is highly specific, allowing for accurate prediction of their pathogenicity. For instance, the high pathogenicity scores of the PVIgG and AK23 antibodies show strong agreement with their reported PV pathology. Our data-driven approach offers a more detailed framework for the action of autoantibodies in pemphigus and has the potential to pave the way for the development of effective novel diagnostic methods and therapeutic strategies. SIGNIFICANCEPemphigus vulgaris (PV) presents a critical unmet medical challenge due to its autoimmune-induced disruption of skin cell adhesion. Our study presents a data-driven approach to quantitatively analyze changes in adhesion molecules and the cytoskeleton upon exposure to various PV antibodies. By introducing a pathogenicity score, we pinpoint the specific impacts of different antibodies on various proteins, build association among these antibodies, and reveal the contribution of previously overlooked non-desmosomal antibodies, broadening the understanding of PV pathology. Although centered on PV, our method offers a versatile framework applicable for evaluating the effects of other antibodies and drugs, paving the way for new diagnostic tools for personalized medicine.

biophysics↗

bioRxiv2024

Development of Clinically Viable Non-Muscle Myosin II Small Molecule Inhibitors with Broad Therapeutic Potential

Non-muscle myosin II (NMII), a molecular motor that regulates critical processes such as cytokinesis and neuronal synaptic plasticity, has substantial therapeutic potential. However, translating this potential to in vivo use has been hampered by the lack of selective tools. The most prototypical non-selective inhibitor, blebbistatin inactivates both NMII and cardiac myosin II (CMII), a key regulator of heart function. Using rational drug design, we developed a series of NMII inhibitors that improve tolerability by selectively targeting NMII over CMII, including MT-228, which has excellent properties such as high brain penetration and efficacy in preclinical models of stimulant use disorder, which has no current FDA-approved therapies. The structure of MT-228 bound to myosin II provides insight into its 17-fold selectivity for NMII over CMII. MT-228s broad therapeutic window opens the door to new disease treatments and provides valuable tools for the scientific community, along with promising leads for future medication development. HighlightsO_LIResearch suggests numerous indications, from axon regeneration and cancer, would benefit from a small molecule inhibitor of non-muscle myosin II, a molecular motor that regulates the actin cytoskeleton. C_LIO_LICurrent chemical probe options are very limited and lack sufficient safety for in vivo C_LIO_LIstudies, which we show is primarily due to potent inhibition of cardiac myosin II. C_LIO_LIRational design that focused on improving target selectivity over the pan-myosin II inhibitor, blebbistatin, led to the identification of MT-228, a small molecule inhibitor with a wide therapeutic window. C_LIO_LIHigh-resolution structure of MT-228 bound to myosin II reveals that selectivity results from a different positioning compared to blebbistatin and an important sequence difference between cardiac and non-muscle myosin II in the inhibitor binding pocket. C_LIO_LIA single administration of MT-228 shows long-lasting efficacy in animal models of stimulant use disorder, a current unmet and rapidly escalating need with no FDA-approved treatments. C_LI

cell biology↗