Biology subjects

Feng, Y.

Publications and source records attributed to Feng, Y..

At least 181 records · Page 10Linked to original sources

bioRxiv2023

Parsing digital or analogue TCR performance through piconewton forces

{beta} T-cell receptors (TCRs) recognize aberrant peptides bound to major histocompatibility complex molecules (pMHCs) on unhealthy cells, amplifying specificity and sensitivity through physical load placed on the TCR-pMHC bond during immunosurveillance. To understand this mechanobiology, TCRs stimulated by abundantly and sparsely arrayed epitopes (NP366-374 /Db and PA224-233/Db, respectively) following in vivo influenza A virus infection were studied with optical tweezers. While certain NP repertoire CD8 T lymphocytes require many ligands for activation, others are digital, needing just few. Conversely, all PA TCRs perform digitally, exhibiting pronounced bond lifetime increases through sustained, energizing volleys of structural transitioning. Optimal digital performance is superior in vivo, correlating with ERK phosphorylation, CD3 loss, and activation marker upregulation in vitro. Given neoantigen array paucity, digital TCRs are likely critical for immunotherapies. One Sentence SummaryQuality of ligand recognition in a T-cell repertoire is revealed through application of physical load on clonal T-cell receptor (TCR)-pMHC bonds

immunology↗

bioRxiv2023

De novo design and optimization of aptamers with AptaDiff

Aptamers are single-stranded nucleic acid ligands, featuring high affinity and specificity to target molecules. Traditionally they are identified from large DNA/RNA libraries using in vitro methods, like Systematic Evolution of Ligands by Exponential Enrichment (SELEX). However, these libraries capture only a small fraction of theoretical sequence space, and various aptamer candidates are constrained by actual sequencing capabilities from the experiment. Addressing this, we proposed AptaDiff, the first in silico aptamer design and optimization method based on the diffusion model. Our Aptadiff can generate aptamers beyond the constraints of high-throughput sequencing data, leveraging motif-dependent latent embeddings from variational autoencoder, and can optimize aptamers by affinity-guided aptamer generation according to Bayesian optimization. Comparative evaluations revealed AptaDiffs superiority over existing aptamer generation methods in terms of quality and fidelity across four high-throughput screening data targeting distinct proteins. Moreover, Surface Plasmon Resonance (SPR) experiments were conducted to validate the binding affinity of aptamers generated through Bayesian optimization for two target proteins. The results unveiled a significant boost of 87.9% and 60.2% in RU values, along with a 3.6-fold and 2.4-fold decrease in KD values for the respective target proteins. Notably, the optimized aptamers demonstrated superior binding affinity compared to top experimental candidates selected through SELEX, underscoring the promising outcomes of our AptaDiff in accelerating the discovery of superior aptamers. Key PointsO_LIWe proposed AptaDiff, the first in silico aptamer design method based on the diffusion model. Aptadiff can generate aptamers beyond the constraints of high-throughput sequencing data. C_LIO_LIAptadiff can optimize aptamers through affinity-guided generation via Bayesian optimization within a motif-dependent latent space, and the affinity of the optimized aptamers to the target protein is better than the best experimental candidate from traditional SELEX screening. C_LIO_LIAptadiff consistently outperforms the current state-of-the-art method in terms of quality and fidelity across high-throughput screening data targeting distinct proteins. C_LI

bioinformatics↗

bioRxiv2023

Rapid and prolonged response of oligodendrocyte lineage cells in standard acute cuprizone demyelination model revealed by in situ hybridization

Dietary administration of a copper chelator, cuprizone (CPZ), has long been reported to induce intense and reproducible demyelination of several brain structures such as the corpus callosum (CC) in mice, followed by spontaneous remyelination after drug withdrawal. Despite the widespread use of CPZ as an animal model for demyelinating diseases such as multiple sclerosis (MS), the mechanism by which it induces demyelination and then allows robust remyelination is still unclear. An intensive mapping of the oligodendrocyte (OL) lineage cell dynamics during the de-and remyelination course would be of particular importance for a deeper understanding of this model. Here, using a panel of OL lineage cell markers as in situ hybridization (ISH) probes, including Pdgfra, Plp, Mbp, Mog, Enpp6, combined with immunofluorescence staining of CC1, SOX10, we provide a detailed dynamic profile of OL lineage cells during the entire course of the model from 3.5 days, 1, 2, 3, 4,5 weeks of CPZ treatment, i.e. the demyelination period, as well as after 1, 2, 3, 4 weeks of recovery (drug withdrawal) from 5 weeks of CPZ treatment, i.e. the remyelination period. The result showed an unexpected early death of mature OLs and response of OL progenitor cells (OPCs) in vivo upon CPZ challenge, and a prolonged upregulation of myelin-forming OLs compared to the intact control even 4 weeks after CPZ withdrawal. These data may point to the need to optimize the timing windows for the introduction of pro-remyelination therapies in demyelinating diseases such as MS, and may serve as a basic reference system for future studies of the effects of any intervention on demyelination and remyelination using the CPZ model.

neuroscience↗

bioRxiv2023

Benchmarking Machine Learning Methods for Synthetic Lethality Prediction in Cancer

Synthetic lethality (SL) is a type of genetic interaction that occurs when defects in two genes cause cell death, while a defect in a single gene does not. Targeting an SL partner of a gene mutated in cancer can selectively kill tumor cells. Traditional wet-lab experiments for SL screening are resource-intensive. Hence, many computational methods have been developed for virtual screening of SL gene pairs. This study benchmarks recent machine learning methods for SL prediction, including three matrix factorization and eight deep learning models. We scrutinize model performance using various data splitting scenarios, negative sample ratios, and negative sampling methods on both classification and ranking tasks to assess the models generalizability and robustness. Our benchmark analyzed performance differences among the models and emphasized the importance of data and real-world scenarios. Finally, we suggest future directions to improve machine learning methods for SL discovery in terms of predictive power and interpretability.

bioinformatics↗

bioRxiv2023

Suberoylanilide Hydroxamic Acid Attenuates Cognitive Impairment in Offspring Caused by Maternal Surgery during Mid-pregnancy

It is known that commonly-used anesthetics can cause long-term neurotoxicity in the developing brain. Some pregnant women have to experience non-obstetric surgery during pregnancy under general anesthesia. It is known that maternal exposure to sevoflurane, isoflurane, propofol and ketamine causes cognitive deficits in offspring. Histone acetylation has been implicated in synaptic plasticity, and abnormal histone acetylation contributes to the neonatal sevoflurane exposure induced deficits in hippocampus-dependent learning and memory. The HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) was shown to attenuate the sevoflurane-induced deficits. Propofol is commonly used in non-obstetric procedures on pregnant women. Recent evidence shows that propofol also causes neurotoxicity in developing brains. For example, previous studies in our laboratory showed that maternal propofol exposure in pregnancy impairs learning and memory in offspring by disturbing histone acetylation. The present study aims to investigate whether SAHA could also attenuate propofol-induced learning and memory deficits in offspring caused by maternal surgery during mid-pregnancy. Maternal rats were exposed to propofol or underwent abdominal surgery under propofol anesthesia during middle pregnancy. The learning and memory abilities of the offspring rats were assessed using Morris water maze (MWM) test. The protein levels of histone deacetylase 2 (HDAC2), phosphorylated cAMP response-element binding (p-CREB),brain derived neurotriphic factor (BDNF) and phosphorylated tyrosine kinase B (p-TrkB) in the hippocampus of the offspring rats were evaluated by immunofluorescence staining and western blot. Hippocampal neuroapoptosis was detected by TUNEL staining. Our results showed that maternal propofol exposure during middle pregnancy impaired the water-maze learning and memory of the offspring rats, increased the protein level of HDAC2 and reduced the protein levels of p-CREB,BDNF and p-TrkB in the hippocampus of the offspring, and such effects were exacerbated by surgery. SAHA alleviated the cognitive dysfunction and rescued the changes in the protein levels of p-CREB, BDNF and p-TrkB induced by maternal propofol exposure alone or maternal propofol exposure plus surgery. Therefore, SAHA could be a potential and promising agent for treating the learning and memory deficits in offspring caused by maternal nonobstetric surgery under propofol aneshtesia.

neuroscience↗

bioRxiv2023

Single phage proteins sequester TIR- and cGAS-generated signaling molecules

Prokaryotic anti-phage immune systems use TIR (toll/interleukin-1 receptor) and cGAS (cyclic GMP-AMP synthase) enzymes to produce 1-3/1-2 glycocyclic ADPR (gcADPR) and cyclid di-/tri-nucleotides (CDNs and CTNs) signaling molecules that limit phage replication, respectively 1-3. However, how phages neutralize these common systems is largely unknown. Here, we show that Thoeris anti-defense proteins Tad1 4 and Tad2 5 both have anti-CBASS activity by simultaneously sequestering CBASS cyclic oligonucleotides. Strikingly, apart from binding Thoeris signals 1-3 and 1-2 gcADPR, Tad1 also binds numerous CBASS CDNs/CTNs with high affinity, inhibiting CBASS systems using these molecules in vivo and in vitro. The hexameric Tad1 has six binding sites for CDNs or gcADPR, which are independent from two high affinity binding sites for CTNs. Tad2 also sequesters various CDNs in addition to gcADPR molecules, inhibiting CBASS systems using these CDNs. However, the binding pockets for CDNs and gcADPR are different in Tad2, whereby a tetramer can bind two CDNs and two gcADPR molecules simultaneously. Taken together, Tad1 and Tad2 are both two-pronged inhibitors that, alongside anti-CBASS protein 2, establish a paradigm of phage proteins that flexibly sequester a remarkable breadth of cyclic nucleotides involved in TIR- and cGAS-based anti-phage immunity.

microbiology↗

bioRxiv2023

Targeting CD74-positive macrophages improves neoadjuvant therapy in cervical cancer as revealed by single-cell transcriptomics analysis

Uterine cervical cancer (UCC) has the second-highest mortality rate among malignant tumors of the female reproductive system. Immune checkpoint inhibitors (ICIs) have emerged as a promising therapeutic strategy for cervical cancer. However, the efficacy of PD-1 (programmed cell death protein 1) blockade combined with neoadjuvant chemotherapy (NACT) and the ensuing alterations within the tumor microenvironment need further investigation. We conducted single-cell RNA sequencing using 46,950 cells from nine sequential human cervical cancer tissues representing different stages of NACT and PD-1 blockade combination therapy. We delineated the trajectory of cervical epithelial cells and unveiled crucial factors involved in the combination therapy. Cell communication analysis revealed the inferred interaction strength decreased between T cell-cancer cells, while the communication between macrophage-cancer cells intensified after NACT therapy. We verified that macrophages are necessary for PD-1 blockade combination to exert antitumor effects in vitro. Detailed analysis unraveled the CD74-positive macrophages frequently interacted with the immunoreactive Epi 3 subgroup during neoadjuvant combination therapy. CD74 upregulation limited phagocytosis and stimulated M2 polarization. The CD74 blockade enhanced macrophage phagocytosis, resulting in decreased viability of cervical cancer cells in vitro and in vivo. This study unveils the dynamic microenvironment of UCC influenced by NACT and PD-1 blockade combination therapy, and targeting CD74 was a potential strategy to augment the therapy efficacy.

cancer biology↗

bioRxiv2023

Oncogenic RAS drives rapid onset cellular plasticity and elicits a tumour-promoting neutrophil response at the inception of preneoplastic development

Oncogenic driver mutations are frequently found in normal tissues, suggesting that additional non-genetic factors are required for tumourigenesis. Phenotypic plasticity is an important gateway to malignancy and inflammation can fuel tumourigenesis, however, little is known about when and how these hallmarks first arise. Using single-cell transcriptomics and in vivo live imaging we have characterised the immediate cell intrinsic and innate immune responses during the first 24 hours following oncogenic Ras activation, in an inducible zebrafish model of HRASG12V-mediated skin tumour initiation. We found that only a subset of basal keratinocytes, but not superficial keratinocytes, are susceptible to RAS-driven phenotypic plasticity. These preneoplastic cells undergo dedifferentiation and partial EMT, resembling malignant cells observed in human squamous cell carcinoma (SCC). Strikingly, the same subset instigates the development of tumour-promoting neutrophils, which in turn enhance preneoplastic cell proliferation. Our findings demonstrate that the effects of oncogenic Ras are primarily determined by the cell of origin and reveal an association between the unlocking of phenotypic plasticity and the onset of tumour-promoting inflammation.

cancer biology↗

bioRxiv2023

One-pot virus detection based on isothermal amplificationcoupled with temperature-activated argonaute

Advances in programmable nucleases like CRISPR-associated protein (Cas) and Argonaute (Ago), combined with isothermal amplification, have made point-of-care testing (POCT) more accessible. However, the specific binding of the nuclease resulted in compatibility issues between the amplification and nuclease systems, substantially limiting the feasibility of a one-step workflow. Here, a temperature control solution based on immobilized thermotolerant Pyrococcus furiosus Ago (PfAgo) has been proposed. The use of immobilized PfAgo can effectively prevent interference with loop-mediated isothermal amplification (LAMP) at 65{degrees}C and accurately identifies amplicons when activated at 95{degrees}C. Following optimization, a sensitivity of 0.6 copies/L was achieved within 45 minutes, and high specificity was verified with no cross-reactivity among 22 other viruses. Additionally, the multiplex detection was designed for herpes virus sensing, with agreements of 86.4% for positive and 100% for negative samples. Our research presents an effective method for combining amplification and cleavage through the use of controllable nucleases, significantly improving the clinical applicability of diagnostic techniques dependent on programmable nucleases.

biochemistry↗

bioRxiv2023

Ependymocytes control cerebrospinal fluid flow to the peripheral organs through periaxonal pathway

Mechanisms controlling movement of the CSF through the central canal towards the peripheral nerves are poorly characterized. We found that fluorescent dyes injected into cisterna magna are carried with cerebrospinal fluid (CSF) through the central canal and peripheral nerves to the peripheral organs such as liver, and pancreas. We also found close connection between spinal axons and ependymocytes, suggesting synaptic interactions. Serotonin, acting through the 5-HT2B receptors abundantly expressed in ependymal cells, trigger Ca2+ signal that induces polymerization of cytoskeleton protein F-actin, consequently reducing the volume of ependymocytes. Shrinkage of the latter opens one-way route to facilitate CSF outflow from the central canal into the spinal cord parenchyma and peripheral nerves. In liver, CSF is received by stellate cells. Ependymal control over transfer of the CSF from central canal to peripheral organs by the periaxonal space (PAS) represents a novel mechanism dynamically connecting the CNS with the periphery. In briefEpendymocytes control CSF flow from CNS to peripheral organs by periaxonal pathway, and serotonin evokes the ependymal shrinkage by the aggregation of F-actin. HighlightsEpendymocytes control CSF flow from central canal to peripheral organs; CSF flows through the peripheral periaxonal space to reach the peripheral organs; Serotonin makes ependymocytes shrunk by 5-HT2B receptor-mediated Ca2+ signaling and F-actin polymerization; The hepatic stellate cells are potential collectors of CSF in the liver.

neuroscience↗

bioRxiv2023

Using the pan-genomic framework for the discovery of genomic islands in the haloarchaeon Halorubrum ezzemoulense

In this study, we use pan-genomics to characterize the organized variability from the widely dispersed halophilic archaeal species Halorubrum ezzemoulense. We include a multi-regional sampling of newly sequenced, high-quality draft genomes. Using the pan-genome graph of the species, we discover 50 genomic islands which represent rare accessory genetic capabilities available to members of the species. 19 of these islands are likely the remnant of mobile genetic elements and are enriched for genomic dark matter. 10 islands encode for niche adapting solute transporters, with a cosmopolitan but limited distribution throughout the strains. We also observe rearrangements which have led to the insertion/recombination/replacement of mutually exclusive genomic islands in equivalent genome positions ("homeocassettes"). These conflicting islands encode for similar functions, but homologs from islands located between the same core genes exhibit extreme divergence on the amino acid level. Homeocasettes provide variations for a homologous function, which may confer a greater range of adaptability to the species group. We observe some islands that appear geographically restricted; however, we also observe the coexistence of genomes, in a single geographic region, with and without certain genomic islands, demonstrating the retention and spread of rare genes in the pan-genome. ImportanceUnderstanding the evolution of genome content is a key puzzle in evolutionary biology. Despite its importance, this area hasnt received thorough investigation. This is especially true of Archaeal organisms, which constitute a large fraction of Earths diversity, but are often referred to as the "forgotten" or "third" domain of life. This study dives into those questions by finding rare genes amongst a group of closely related Archaeal species, and describes how their transfer, utilization and persistence may contribute to the speciation and specialization of the group.

microbiology↗

bioRxiv2023

Viperin immunity evolved across the tree of life through serial innovations on a conserved scaffold

Evolutionary arms races between cells and viruses drive the rapid diversification of antiviral genes in diverse life forms. Recent discoveries have revealed the existence of shared immune genes between prokaryotes and eukaryotes, showing molecular and mechanistic similarities in their response to viruses. However, the underlying evolutionary dynamics that explain the conservation and adaptation of these antiviral genes remain mostly unexplored. Here, we show that viperins constitute a highly conserved family of immune genes across diverse prokaryotes and eukaryotes, and uncover mechanisms by which they diversified in eukaryotes. Our findings indicate that viperins are enriched in Asgard archaea and widely distributed in all major eukaryotic clades, suggesting their presence in the Last Eukaryotic Common Ancestor (LECA). We show that viperins maintain their immune function by producing antiviral nucleotide analogs. We demonstrate that eukaryotic viperins diversified through serial innovations on the viperin gene, such as the emergence and selection of substrate specificity towards pyrimidine nucleotides, and through partnerships with genes maintained through genetic linkage, notably with nucleotide kinases. These findings unveil biochemical and genomic transitions underlying the adaptation of immune genes shared by prokaryotes and eukaryotes. Our study paves the way for the understanding of the conservation of immunity across domains of life.

evolutionary biology↗

bioRxiv2023

Stabilization of RRBP1 mRNA via an m6A-dependent manner in prostate cancer constitutes a therapeutic vulnerability amenable to small-peptide inhibition of METTL3

Mounting evidence has implicated the RNA m6A methylation catalyzed by METTL3 in a wide range of physiological and pathological processes, including tumorigenesis. The detailed m6A landscape and molecular mechanism of METTL3 in prostate cancer (PCa) remains ill-defined. We find that METTL3 is overexpressed in PCa and correlates with worse patient survival. Functional studies establish METTL3 as an oncoprotein dependent on its m6A enzymatic activity in both AR+ and AR- PCa cells. To dissect the regulatory network of m6A pathway in PCa, we map the m6A landscape in clinical tumor samples using m6A-seq and identify genome-wide METTL3-binding transcripts via RIP-seq. Mechanistically, we discover RRBP1 as a direct METTL3 target in which METTL3 stabilizes RRBP1 mRNA in an m6A-dependent manner. RRBP1 positively correlates with METTL3 expression in PCa cohorts and exerts an oncogenic role in aggressive PCa cells. Leveraging the 3D structural protein-protein interaction between METTL3 and METTL14, we successfully develop two potential METTL3 peptide inhibitors (RM3 and RSM3) that effectively suppress cancer cell proliferation in vitro and tumor growth in vivo. Collectively, our study reveals a novel METTL3/m6A/RRBP1 axis in enhancing aggressive traits of PCa, which can be therapeutically targeted by small-peptide METTL3 antagonists.

cancer biology↗

bioRxiv2023

A Stapled Peptide Inhibitor of METTL3-METTL14 for Cancer Therapy

METTL3, a primary methyltransferase catalyzing RNA N6-methyladenosine (m6A) modification, has been identified as an oncogene in several cancer types and thus nominated as a potentially effective target for therapeutic inhibition, although current options using this strategy are limited. In this study, we targeted protein-protein interactions at the METTL3-METTL14 binding interface to inhibit complex formation and subsequent catalysis of RNA m6A modification. Among candidate peptides, RM3 exhibited the highest anti-cancer potency, inhibiting METTL3 activity while also facilitating its proteasomal degradation. We then designed a stapled peptide inhibitor (RSM3) with enhanced peptide stability and formation of the -helical secondary structure required for METTL3 interaction. Functional and transcriptomic analysis in vivo indicated that RSM3 induced upregulation of programmed cell death-related genes while inhibiting cancer-promoting signals. Furthermore, tumor growth was significantly suppressed while apoptosis was enhanced upon RSM3 treatment, accompanied by in-creased METTL3 degradation, and reduced global RNA methylation levels in two in vivo tumor models. This peptide inhibitor thus exploits a mechanism distinct from other competitive-binding small molecules to inhibit oncogenic METTL3 activity. Our findings collectively highlight the potential of targeting METTL3 in cancer therapies through peptide-based inhibition of complex formation and proteolytic degradation.

biochemistry↗

bioRxiv2023

Metagenomic analysis of individual mosquitos reveals the ecology of insect viruses

Mosquito transmitted viruses are responsible for an increasing burden of human disease. Despite this, little is known about the diversity and ecology of viruses within individual mosquito hosts. Using a meta-transcriptomic approach, we analysed the virome of 2,438 individual mosquitos (79 species), spanning [~]4000 km along latitudes and longitudes in China. From these data we identified 393 core viral species associated with mosquitos, including seven (putative) arbovirus species. We identified potential species and geographic hotspots of viral richness and arbovirus occurrence, and demonstrated that host phylogeny had a strong impact on the composition of individual mosquito viromes. Our data revealed a large number of viruses shared among mosquito species or genera, expanding our knowledge of host specificity of insect-associated viruses. We also detected multiple virus species that were widespread throughout the country, possibly facilitated by long-distance mosquito migrations. Together, our results greatly expand the known mosquito virome, linked the viral diversity at the scale of individual insects to that at a country-wide scale, and offered unique insights into the ecology of viruses of insect vectors.

ecology↗

bioRxiv2023

BundleCleaner: Unsupervised Denoising and Subsampling of Diffusion MRI-Derived Tractography Data

We present BundleCleaner, an unsupervised multi-step frame-work that can filter, denoise and subsample bundles derived from diffusion MRI-based whole-brain tractography. Our approach considers both the global bundle structure and local streamline-wise features. We apply BundleCleaner to bundles generated from single-shell diffusion MRI data in an independent clinical sample of older adults from India using probabilistic tractography and the resulting cleaned bundles can better align with the atlas bundles with reduced overreach. In a downstream tractometry analysis, we show that the cleaned bundles, represented with less than 20% of the original set of points, can robustly localize along-tract microstructural differences between 32 healthy controls and 34 participants with Alzheimers disease ranging in age from 55 to 84 years old. Our approach can help reduce memory burden and improving computational efficiency when working with tractography data, and shows promise for large-scale multi-site tractometry.

neuroscience↗

bioRxiv2023

LncRNA SNHG16 modulates paclitaxel resistance in breast cancer by regulating Let-7a-5p/DUSP7

ObjectiveTo investigate the effect of long chain non coding RNA (lncRNA) small nucleolar RNA host gene 6 (SNHG16) on paclitaxel (PTX) resistance in breast cancer and to understand its underlying mechanism, to lay a foundation for decreasing the PTX resistance in breast cancer treatment and improving the therapeutic quality for breast cancer patients. MethodsPTX was used to induce the establishment of PTX resistant breast cancer cell lines; the control group (normal cultured MCF-7/PTX cells), si-NC group, si-SNHG16 group, si-SNHG16+anti miR-NC group, and si-SNHG16 +anti-Let-7a-5p group were set to compared the effect of SNHG16 on the PTX resistance in MCF-7 cells; MTT assay, Flow cytometry, and Transwell invasion assay were used to determine the PTX resistance, apoptosis, and invasion ability of MCF-7 cells in different groups, respectively; for further assess the effect of SNHG16 on the PTX resistance, nude mouse tumor transplantation experiment was used; and the potential mechanism of SNHG16 regulated the PTX resistance in MCF-7 cells was explored by double luciferase reporter gene detection method and gene silencing technology. ResultsThe expression of SNHG16 gene and DUSP7 protein in MCF-7 cell line was the highest, and the expression of Let-7a-5p was the lowest compared with the various breast cancer cell lines (human breast epithelial cell line MCF-10A and human breast cancer cell lines MDA-MB-468 and MDA-MB-453) (P<0.05); PTX could increase the expression of SNHG16 gene and DUSP7 protein, and reduce the expression of Let-7a-5pin MCF-7 cell line (P<0.05); the results of cell experiment and nude mouse transplantation tumor experiment demonstrated that inhibiting the expression of SNHG16 gene could reduce the invasive ability and promote cell apoptosis of MCF-7/PTX cells (P<0.05), and inhibit tumor growth and reduce the PTX resistance in breast cancer transplantation models; simultaneous inhibition of Let-7a-5p and SNHG16 had a weakening effect in MCF-7/PTX cells (P<0.05). Double luciferase reporter gene detection and gene silencing technology demonstrated that inhibiting SNHG16 gene expression could increase the expression of Let-7a-5p and decrease the expression of DUSP7 (P<0.05); inhibiting the Let-7a-5p gene could increase the expression of DUSP7. ConclusionsInhibiting SNHG16 gene could upregulate Let-7a-5p expression and downregulate the expression of DUSP7 to inhibit MCF-7 cell invasion, promote MCF-7 cell apoptosis, and reduce the PTX resistance in MCF-7 cells and nude mouse tumor transplantation models, those data demonstrated that SNHG16-Let-7a-5p-DUSP7 axis maybe a potential therapeutic strategy for decreasing the PTX resistance in breast cancer in the future.

cancer biology↗

bioRxiv2023

Actomyosin-II Proactively Shields Axons of the Central Nervous System from Mild Mechanical Stress

SummaryPan et al found that actomyosin-II-driven radial contractility underpins the resilience of central axons to mild mechanical stress by suppressing the propagation and firing of injurious Ca2+ waves. Boosting actomyosin-II activity alleviates axon degeneration in mice with traumatic brain injury. Traumatic brain injury (TBI) remains a significant and unmet health challenge. However, our understanding of how neurons, particularly their fragile axons, withstand the abrupt mechanical impacts within the central nervous system remains largely unknown. Using a microfluidic device applying discrete levels of transverse forces to axons, we identified the stress levels that most axons could resist and explored their instant responses at nanoscale resolution. Mild stress induces rapid and reversible axon beading, driven by actomyosin-II-dependent radial contraction, which restricts the spreading and bursting of stress-induced Ca2+ waves. More severe stress causes irreversible focal swelling and Ca2+ overload, ultimately leading to focal axonal swelling and degeneration. Up-regulating actomyosin-II activity prevented the progression of initial injury in vivo, protecting commissural axons from degeneration in a mice TBI model. Our study established a scalable axon injury model and uncovered the critical roles of actomyosin-II in shielding neurons against detrimental mechanical stress.

neuroscience↗