Biology subjects

Lv, Z.

Publications and source records attributed to Lv, Z..

At least 37 records · Page 2Linked to original sources

bioRxiv2025

Effects of Exercise and Konjac on Lipid Metabolism and Mechanism in Obese Rats

ObjectiveTo study the effects of exercise and konjac on body weight and lipid metabolism in obese rats, and the possible mechanism of exercise combined with konjac on body weight and lipid metabolism. MethodsFifty male Sprague Dawley rats were randomly divided into 5 groups. After six weeks of intervention, blood lipid, body weight, liver weight, inflammatory factors, oxidative stress markers and proteins were measured. ResultsWeight and liver weight in HFD group were significantly higher (P<0.05, P<0.01) than those in CON group. Compared with HFD group, blood lipid index in intervention group were significantly decreased; The levels of MDA (P<0.01, P<0.05, P<0.05) and SOD (P<0.05) in intervention group were significantly decreased; the GSH levels in HAE group and HKE group were significantly increased(P<0.01, P<0.05); the levels of IL-6, TNF-, and leptin in HAE group (P<0.05, P<0.05, P<0.01) and HKE group (P<0.01, P<0.01, P<0.05) were significantly decreased; ApoA5 in intervention group was significantly increased (P<0.01), SREBP-1c and LXR was significantly decreased (P<0.01). ConclusionKonjac or exercise alone can improve the lipid metabolism, and the comprehensive effect is better. The mechanism of regulating lipid metabolism may be related to the expression of LXR, SREBP-1c and ApoA5.

biochemistry↗

bioRxiv2024

Mechanism of NPC1L1 mediated 27-hydroxycholesterol metabolisms in the occurrence and development of osteoporosis

Cholesterol metabolism is closely related to the occurrence and development of osteoporosis, but the exact mechanism remains unclear. Niemann-Pick C1-like 1 (NPC1L1) is one of the key cholesterol transporter proteins, however, there are few reports on the functions of NPC1L1 besides regulating cholesterol transport, let alone bone homeostasis. Our preliminary research indicated that NPC1L1 may play a negative regulatory role in osteogenic differentiation. In this study, using in vitro osteogenic differentiation experiment and mouse osteoporosis model, we showed here that NPC1L1 expression was downregulated during osteogenesis, and NPC1L1 knockdown significantly enhanced osteogenic differentiation ability of osteoblasts and delayed progress of osteoporosis. Mechanistically, through RNA sequencing, NPC1L1 was found regulate cholesterol metabolism rather than transportation. It increased 27-Hydroxycholesterol (27-OHC) level through activating 27-hydroxylase (Cyp27a1), resulting in 27-OHC accumulation in osteoblasts and inhibition of osteogenesis. Moreover, C/EBP was proved mediated NPC1L1 promotes production of 27-OHC by Cyp27a1. These findings reveal that NPC1L1 inhibits osteogenesis and promotes osteoporosis via regulate cholesterol metabolism. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=100 SRC="FIGDIR/small/615783v1_ufig1.gif" ALT="Figure 1"> View larger version (59K): org.highwire.dtl.DTLVardef@11a62bforg.highwire.dtl.DTLVardef@148fb9aorg.highwire.dtl.DTLVardef@7e486eorg.highwire.dtl.DTLVardef@c53116_HPS_FORMAT_FIGEXP M_FIG NPC1L1 inhibits osteogenic differentiation and promotes the progression of OP through the C/EBP/Cyp27a1/27-OHC axis. C_FIG

molecular biology↗

bioRxiv2024

Developmental control of E-cadherin junctions by mechanical contractility in Drosophila embryos

Adherens junctions are very plastic structures that change their composition and structure depending on the state of the epithelial tissue, involving mechanical stress and tissue dynamics. In Drosophila embryos, adherens junctions mature only during gastrulation following their formation a few minutes before during cellularization. Although the developmental maturation is obvious during gastrulation, the factors and conditions controlling it have remained unclear. Here, we assay the levels, distribution pattern, and mobility of E-cadherin during Drosophila gastrulation. Indicating a maturation, we find an increase in total levels at junctions and a drop in the mobile fraction of E-cadherin molecules. Both developmental changes depend on Myo-II contractility. Consistent with stereotypic Myo-II regulation, we find that interference with Rho signaling leads to corresponding changes in E-cadherin levels and mobility, at least in part. Besides Rho signaling, Src42A contributes to junction maturation, as tested by both loss-function and gain-of-function situations. Together, we demonstrate developmental maturation of adherens junctions and identify Rho signaling and Src42A as upstream regulatory pathways.

developmental biology↗

bioRxiv2024

Different Roles of D1/D2 Medium Spiny Neurons in the Nucleus Accumbens in Pair Bond Formation of Male Mandarin Voles

The mesolimbic dopamine (DA) system has been implicated in pair bond formation. However, involvements of DA release, real time activities, and electrophysiological activities of D1/D2 medium spiny neurons (MSNs) in the nucleus accumbens (NAc) shell in pair bonding remain unclear. This work verified that male mandarin voles after pair bonding released higher levels of DA in the NAc shell and displayed higher levels of D1 MSNs activity and lower levels of D2 MSNs activity upon sniffing their partners compared to upon sniffing an unknown female. Moreover, pair bonding induced differential alterations in both synaptic plasticity and neuronal intrinsic excitability in both D1 MSNs and D2 MSNs. In addition, chemogenetic inhibition of ventral pallidum (VP) -projecting D2 MSNs in the NAc shell enhanced pair bond formation, while chemogenetic activation of VP-projecting D2 MSNs in the NAc shell inhibited pair bond formation. These findings suggest that different neuronal activity of NAc shell D1 MSNs / D2 MSNs regulated by increasing DA release after pair bonding may be a neurobiological mechanism underlying pair bond formation.

neuroscience↗

bioRxiv2024

PVN-mPFC OT projections modulates pup-directed pup care or attacking in virgin mandarin voles

In many species, adult animals may exhibit caregiving or aggression towards conspecific offspring. The neural mechanisms underlying the infanticide and pup care remain poorly understood. Here, using monogamous virgin mandarin voles (Microtus mandarinus) that may exhibit pup care or infanticide, we found that more oxytocin (OT) neurons in the paraventricular nucleus (PVN) were activated during pup caring than infanticide. Optogenetic activation of OT neurons in the PVN facilitated pup-caring in male and female mandarin voles. In infanticide voles, optogenetic activation of PVN OT cells prolonged latency to approach and attack pups, whereas inhibition of these OT neurons facilitated approach and infanticide. In addition, OT release in the medial prefrontal cortex (mPFC) in pup-care voles increased upon approaching and retrieving pups, and decreased in infanticide voles upon attacking pups. Optogenetic activation of PVN OT neuron projections to the mPFC shortened the latency to approach and retrieve pups and facilitated the initiation of pup care, whereas inhibition of these projections had little effect. For pup-care females, neither activation nor inhibition of the fibers affected their behavior towards pups. In infanticide male and female voles, optogenetic activation of PVN-mPFC OT projection fibers prolonged the latency to approach and attack pups and suppressed the initiation of infanticide, whereas inhibition of these projections promoted approach and infanticide. Finally, we found that intraperitoneal injection of OT promoted pup care and inhibited infanticide behavior. It is suggested that the OT system, especially PVN OT neurons projecting to mPFC, modulates pup-directed behaviors and OT can be used to treat abnormal behavioral responses associated with some psychological diseases such as depression and psychosis.

neuroscience↗

bioRxiv2023

mTORC1/S6K1 signaling promotes sustained oncogenic translation through modulating CRL3IBTK-mediated non-degradative ubiquitination of eIF4A1

Enhanced protein synthesis is a crucial molecular mechanism that allows cancer cells to survive, proliferate, metastasize, and develop resistance to anti-cancer treatments, and often arises as a consequence of increased signaling flux channeled to mRNA-bearing eukaryotic initiation factor 4F (eIF4F). However, the post-translational regulation of eIF4A1, an ATP-dependent RNA helicase and subunit of the eIF4F complex, is still poorly understood. Here, we demonstrate that IBTK, a substrate-binding adaptor of Cullin 3-RING ubiquitin ligase (CRL3) complex, interacts with eIF4A1. The non-degradative ubiquitination of eIF4A1 catalyzed by CRL3IBTK complex promotes cap-dependent translational initiation, nascent protein synthesis, oncogene expression, and tumor cell growth both in vivo and in vitro. Moreover, we show that mTORC1 and S6K1, two key regulators of protein synthesis, directly phosphorylate IBTK to augment eIF4A1 ubiquitination and sustained oncogenic translation. This link between the CRL3IBTK complex and the mTORC1/S6K1 signaling pathway, which is frequently dysregulated in cancer, represents a promising target for anti-cancer therapies. Statement of Significance: Overexpression of IBTK contributes to the process of tumorigenesis by amplifying translation, and represents a promising target for anti-cancer therapies.

cancer biology↗

bioRxiv2023

O-GlcNAcylation of YTHDF2 antagonizes ERK-dependent phosphorylation and inhibits lung carcinoma

The intracellular O-linked N-acetylglucosamine (O-GlcNAc) glycosylation mediates many signal transduction events and regulates tumorigenesis. Previously the RNA N6-methyladenosine (m6A) reader, YTH (YT521-B homology) domain 2 (YTHDF2), has been shown to be O-GlcNAcylated on Ser-263 during Hepatitis B virus (HBV) infection and promote HBV-related hepatocellular carcinoma. Herein we mapped YTHDF2 O-GlcNAcylation at Thr-49 via electron-transfer dissociation mass spectrometry under unperturbed conditions. We show that YTHDF2 Thr-49 O-GlcNAcylation antagonizes Extracellular-signal regulated kinase (ERK)-dependent phosphorylation at Ser-39 and promotes YTHDF2 degradation. The downstream signaling pathway of YTHDF2 in lung carcinoma are thus upregulated, which leads to the downregulation of c-Myc. We further used mouse xenograft models to show that YTHDF2-T49A mutants increased lung cancer mass and size. Our work reveals a key role of YTHDF2 O-GlcNAcylation in tumorigenesis and suggests that O-GlcNAcylation exerts distinct functions under different biological stress.

biochemistry↗

bioRxiv2023

SRSF1-mediated alternative splicing of Tial1/Tiar is essential for homing and self-renewal in mouse spermatogonial stem cells

AbstractSpermatogonial stem cells (SSCs) are essential for continuous spermatogenesis and male fertility. The underlying mechanisms of alternative splicing (AS) in mouse SSCs are still largely unclear. We demonstrated that SRSF1 is essential for gene expression and splicing in mouse SSCs. Crosslinking immunoprecipitation and sequencing (CLIP-seq) data revealed that spermatogonia-related genes (e.g., Plzf, Id4, Setdb1, Stra8, Tial1/Tiar, Bcas2, Ddx5, Srsf10, Uhrf1, and Bud31) were bound by SRSF1 in the mouse testes. Specific deletion of Srsf1 in mouse germ cells impairs homing of precursor SSCs leading to male infertility. Whole-mount staining data showed the absence of germ cells in the testes of adult conditional knockout (cKO) mice, which indicates Sertoli cell-only syndrome (SCOS) in cKO mice. The expression of spermatogonia-related genes (Gfra1, Pou5f1, Plzf, Dnd1, Stra8, and Taf4b) was significantly reduced in the testes of cKO mice. Moreover, multiomics analysis suggests that SRSF1 may affect survival of spermatogonia by directly binding and regulating Tial1/Tiar expression through AS. In addition, immunoprecipitation mass spectrometry (IP-MS) and co-immunoprecipitation (Co-IP) data showed that SRSF1 interacts with RNA splicing-related proteins (SART1, RBM15, and SRSF10). Collectively, our data reveal the critical role of SRSF1 in spermatogonia survival, which may provide a framework to elucidate the molecular mechanisms of the posttranscriptional network underlying homing of precursor SSCs.

developmental biology↗

bioRxiv2023

Airway secretory cell-derived p63+ progenitors contribute to alveolar regeneration after sterile lung injury

Lung injury activates epithelial stem or progenitor cells for alveolar repair and regeneration. However, the origin and fate of injury-induced progenitors are poorly defined. Here, we report that p63-expressing progenitors emerge upon bleomycin-induced lung injury. These p63+ progenitors proliferate rapidly and differentiate into alveolar type 1 (AT1) and type 2 (AT2) cells through distinct trajectories. Dual recombinase-mediated sequential genetic lineage tracing reveals that p63+ progenitors originate from airway secretory cells and subsequently generate alveolar cells. Functionally, p63 activation is required for efficient alveolar regeneration from secretory cells. Our study identifies a secretory cell-derived p63+ progenitor that contributes to alveolar repair, indicating a potential therapeutic avenue for lung regeneration after injury.

cell biology↗

bioRxiv2023

Host-microbe interactions mediate doramectin-promoted metabolic reprogramming of CD8+ T-cells and amplify antitumor immunity

The intestinal microbiota and its metabolites influence the host metabolic environment and CD8+ T-cell function. Metabolic changes in T-cells are thought to enhance the antitumor immune response. Here, we show that doramectin (DOR), a macrocyclic lactone (ML) of the avermectin (AVM) family, can modify CD8+ T-cell metabolism to increase and accelerate effector function. However, the functional capability of DOR depends mainly on the accessibility of gut microbiota. Using metagenomic and metabolomic techniques, we describe for the first time the interplay between gut microbiota and host metabolism involved in metabolic reprogramming of CD8+-T cells following DOR administration. Interestingly, we found that, after DOR administration, Firmicutes phylum not only impact DOR transport and absorption, but also boost amino acid levels in CD8+ T-cells, consistent with increased production of tumor necrosis factor alpha (TNF-) and, in particular, interferon gamma (IFN-{gamma}), which together play an important role in antitumor immunity. In contrast, the dysbiotic microbial community may abrogate the anticancer efficacy of DOR and lead to enhanced tumor growth and decreased survival. This finding likely supports the view that the presence of certain bacteria in the gut governs extra-intestinal immune responses and may be associated with metabolic adaptations necessary for efficient function of CD8+ T-cells upon DOR administration.

cancer biology↗

bioRxiv2022

Cryo-EM complex structure of active GPR75 with a nanobody

Although there has been enormous progress in the last half-century in the drug discovery targeting obesity and associated co-morbidities, the clinical treatment of obesity remains tremendously challenging. GPR75 is an orphan receptor and is suggested to be a potential novel target for the control of obesity and related metabolic disorders. Inhibition of the GPR75 signaling pathway by small molecules, antibodies, or genetic manipulations may provide a therapeutic strategy for obesity. Here, we report the active-like Cryo-EM structure of human GPR75 with an intracellular nanobody, which reveals the receptor activation mechanism. The extensive interaction network required to achieve the active structure helps explain the allosteric coupling between the orthosteric pocket and the G-protein coupling domain. The well-defined orthosteric ligand binding pocket of human GPR75 provides a structural basis for anti-obesity drug discovery.

biophysics↗

bioRxiv2022

Development of Equine Polyclonal Antibodies as a Broad-Spectrum Therapy Against SARS-CoV-2 Variants

The Coronavirus disease 19 (COVID-19) pandemic has accumulated over 550 million confirmed cases and more than 6.34 million deaths worldwide. Although vaccinations has largely protected the population through the last two years, the effect of vaccination has been increasingly challenged by the emerging SARS-CoV-2 variants. Although several therapeutics including both monoclonal antibodies and small molecule drugs have been used clinically, high cost, viral escape mutations, and potential side effects have reduced their efficacy. There is an urgent need to develop a low cost treatment with wide-spectrum effect against the novel variants of SARS-CoV-2. Here we report a product of equine polyclonal antibodies that showed potential broad spectrum neutralization effect against the major variants of SARS-CoV-2. The equine polyclonal antibodies were generated by horse immunization with the receptor binding domain (RBD) of SARS-CoV-2 spike protein and purified from equine serum. A high binding affinity between the generated equine antibodies and the RBD was observed. Although designed against the RBD of the early wild type strain sequenced in 2020, the equine antibodies also showed a highly efficient neutralization capacity against the major variants of SARS-CoV-2, including the recent BA.2 Omicron variant (IC50 =1.867g/ml) in viral neutralization assay in Vero E6 cells using live virus cultured. The broad-spectrum neutralization capacity of the equine antibodies was further confirmed using pseudovirus neutralization assay covering the major SARS-CoV-2 variants including wild type, alpha, beta, delta, and omicron, showing effective neutralization against all the tested strains. Ex vivo reconstructed human respiratory organoids representing nasal, bronchial, and lung epitheliums were employed to test the treatment efficacy of the equine antibodies. Antibody treatment protected the human nasal, bronchial, and lung epithelial organoids against infection of the novel SARS-CoV-2 variants challenging public health, the Delta and Omicron BA.2 isolates, by reducing >95% of the viral load. The equine antibodies were further tested for potential side effects in a mouse model by inhalation and no significant pathological feature was observed. Equine antibodies, as a mature medical product, have been widely applied in the treatment of infectious diseases for more than a century, which limits the potential side effects and are capable of large scale production at a low cost. A cost-effective, wide-spectrum equine antibody therapy effective against the major SARS-CoV-2 variants can contribute as an affordable therapy to cover a large portion of the world population, and thus potentially reduce the transmission and mutation of SARS-CoV-2.

immunology↗

bioRxiv2022

Study on endogenous inhibitors against PD-L1: cAMP as a potential candidate

The discovery of new anticancer drugs targeting the PD-1/PD-L1 pathway has been research hotspots. In this study, a combination of biological affinity ultrafiltration (BAU), UPLC-HRMS, molecular dynamic (MD) simulations and molecular docking methods were applied to search for endogenous active compounds that can inhibit the binding of PD-L1 and PD-1. We screened dozens of potential cancer related endogenous compounds. The results showed that cyclic adenosine monophosphate (cAMP) had a direct inhibition effect on the PD-1/PD-L1 binding with an in vitro IC50 value of about 2.7 {micro}M determined by homogeneous time-resolved fluorescence (HTRF) assay. The binding mode analyses for the cAMP - dimeric/monomeric PD-L1 complex indicated that cAMP was likely to bind to the dimeric PD-L1, since the binding free energies of the cAMP - dimeric and monomeric PD-L1 complex were about 23.6 and 15.1 kcal/mol, respectively, from MD simulations. The direct binding assay using surface plasmon resonance (SPR) method showed that cAMP could also bind to monomeric PD-L1 fixed on the sensor chip surface with a KD value of about 1.72 mM. Our findings suggested that cAMP may directly inhibit the PD-1/PD-L1 interaction.

molecular biology↗

bioRxiv2021

Screening of cell-virus, cell-cell, gene-gene interactions among kingdoms of life at single cell resolution

The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) issued a significant and urgent threat to global health. The exact animal origin of SARS-CoV-2 remains obscure and understanding its host range is vital for preventing interspecies transmission. Previously, we have assessed the target cell profiles of SARS-CoV-2 in pets, livestock, poultry and wild animals. Herein, we expand this investigation to a wider range of animal species and viruses to provide a comprehensive source for large-scale screening of potential virus hosts. Single cell atlas for several mammalian species (alpaca, hamster, hedgehog, chinchilla etc.), as well as comparative atlas for lung, brain and peripheral blood mononuclear cells (PBMC) for various lineages of animals were constructed, from which we systemically analyzed the virus entry factors for 113 viruses over 20 species from mammalians, birds, reptiles, amphibians and invertebrates. Conserved cellular connectomes and regulomes were also identified, revealing the fundamental cell-cell and gene-gene cross-talks between these species. Overall, our study could help identify the potential host range and tissue tropism of SARS-CoV-2 and a diverse set of viruses and reveal the host-virus co-evolution footprints.

cell biology↗

bioRxiv2021

Viral receptor profiles of masked palm civet revealed by single-cell transcriptomics

Civets are small mammals belonging to the family Viverridae. The masked palm civets (Paguma larvata) served as an intermediate host in the bat-to-human transmission of severe acute respiratory syndrome coronavirus (SARS-CoV) in 20031. Because of their unique role in the SARS outbreak, civets were suspected as a potential intermediate host of SARS-CoV-2, the etiological pathogen of the COVID-19 pandemic. Besides their susceptibility to coronaviruses, civets can also be infected by other viruses, such as canine distemper viruses2, parvoviruses3, influenza viruses4, etc. Regarding the ecological and economical role of civets, it is vital to evaluate the potential threats from different pathogens to these animals. Receptor binding is a necessary step for virus entry into host cells. Understanding the distribution of receptors of various viruses provides hints to their potential tissue tropisms. Herein, we characterized the cell atlas of five important organs (the frontal lobe, lung, liver, spleen and kidney) of masked palm civets (Paguma larvata) and described the expression profiles of receptor associated genes of 132 viruses from 25 families, including 16 viruses from 10 families reported before that can attack civets and 116 viruses with little infection record.

immunology↗

bioRxiv2021

ICER controls HIV-1 infection and replication in elite controllers

A rare subset of HIV-infected individuals, termed elite controllers (ECs), can maintain long-term control over HIV replication in the absence of antiretroviral therapy (ART). To elucidate the biological mechanism of resistance to HIV replication at the molecular and cellular levels, we performed RNA sequencing and identified alternative splicing variants from ECs, HIV-infected individuals undergoing ART, ART-naive HIV-infected individuals, and healthy controls. Differential gene expression patterns that are specific to ECs and may influence HIV resistance were identified, including alternative RNA splicing and exon usage variants of the CREM/ICER gene (cAMP-responsive element modulator/inducible cAMP early repressors). The knockout and knockdown of specific ICER exons that were found to be upregulated in ECs resulted in significantly increased HIV infection in CD4+ T cell line and primary CD4+ T cells. Overexpression of ICER isoforms decreased HIV infection in primary CD4+ T cells. Furthermore, ICER regulated HIV-1 LTR promoter activity in a Tat-dependent manner. Together, these results suggest that ICER is an HIV host factor that may contribute to HIV resistance of ECs. These findings will help elucidate the mechanisms of HIV control by ECs and may yield a new approach for treatment of HIV.

immunology↗

bioRxiv2021

TRANSFER ENTROPY BASED CAUSALITY FROM HEAD MOTION TO EYE MOVEMENT

Eye movement behavior, which provides the visual information acquisition and processing, plays an important role in performing sensorimotor tasks, such as driving, by human beings in everyday life. In the procedure of performing sensorimotor tasks, eye movement is contributed through a specific coordination of head and eye in gaze changes, with head motions preceding eye movements. Notably we believe that this coordination in essence indicates a kind of causality. In this paper, we investigate transfer entropy to set up a quantity for measuring an unidirectional causality from head motion to eye movement. A normalized version of the proposed measure, demonstrated by virtual reality based psychophysical studies, behaves very well as a proxy of driving performance, suggesting that quantitative exploitation of coordination of head and eye may be an effective behaviometric of sensorimotor activity.

bioinformatics↗

bioRxiv2020

Double Lock of a Potent Human Monoclonal Antibody against SARS-CoV-2

Receptor recognition and subsequent membrane fusion are essential for the establishment of successful infection by SARS-CoV-2. Halting these steps can cure COVID-19. Here we have identified and characterized a potent human monoclonal antibody, HB27, that blocks SARS-CoV-2 attachment to its cellular receptor at sub-nM concentrations. Remarkably, HB27 can also prevent SARS-CoV-2 membrane fusion. Consequently, a single dose of HB27 conferred effective protection against SARS-CoV-2 in two established mouse models. Rhesus macaques showed no obvious adverse events when administrated with 10-fold of effective dose of HB27. Cryo-EM studies on complex of SARS-CoV-2 trimeric S with HB27 Fab reveal that three Fab fragments work synergistically to occlude SARS-CoV-2 from binding to ACE2 receptor. Binding of the antibody also restrains any further conformational changes of the RBD, possibly interfering with progression from the prefusion to the postfusion stage. These results suggest that HB27 is a promising candidate for immuno-therapies against COVID-19. HighlightsO_LISARS-CoV-2 specific antibody, HB27, blocks viral receptor binding and membrane fusion C_LIO_LIHB27 confers prophylactic and therapeutic protection against SARS-CoV-2 in mice models C_LIO_LIRhesus macaques showed no adverse side effects when administered with HB27 C_LIO_LICryo-EM studies suggest that HB27 sterically occludes SARS-CoV-2 from its receptor C_LI

biophysics↗