Biology subjects

Zhang, L.

Publications and source records attributed to Zhang, L..

At least 847 records · Page 47Linked to original sources

bioRxiv2023

Covalent Targeting of Glutamate Cysteine Ligase to Inhibit Glutathione Synthesis

Dysregulated oxidative stress plays a major role in cancer pathogenesis and some types of cancer cells are particularly vulnerable to inhibiting cellular antioxidant capacity. Glutamate-cysteine ligase (GCL) is the first and rate-limiting step in the synthesis of the major cellular antioxidant glutathione (GSH). Developing a GCL inhibitor may be an attractive therapeutic strategy for certain cancer types that are particularly sensitive to oxidative stress. In this study, we reveal a cysteine-reactive covalent ligand EN25 that covalently targets an allosteric cysteine C114 on GCLM, the modifier subunit of GCL, leading to inhibition of GCL activity, lowering of cellular GSH levels, and impaired cell viability in ARID1A-deficient cancer cells that are particularly vulnerable to glutathione depletion, but not in ARID1A-positive cancer cells. Our studies uncover a novel potential ligandable site within GCLM that can be targeted to inhibit the GSH synthesis in cancer cells to target vulnerable cancer cell types.

biochemistry↗

bioRxiv2023

SMYD5 is a novel epigenetic gatekeeper of the mild hypothermia response

The mild hypothermia response (MHR) maintains organismal homeostasis during cold exposure and is thought to be critical for the neuroprotection documented with therapeutic hypothermia. To date, little is known about the transcriptional regulation of the MHR. We utilize a forward CRISPR-Cas9 mutagenesis screen to identify the histone lysine methyltransferase SMYD5 as a regulator of the MHR. SMYD5 represses the key MHR gene SP1 at euthermia. This repression correlates with temperature-dependent levels of H3K36me3 at the SP1-locus and globally, indicating that the mammalian MHR is regulated at the level of histone modifications. We have identified 37 additional SMYD5 regulated temperature-dependent genes, suggesting a broader MHR-related role for SMYD5. Our study provides an example of how histone modifications integrate environmental cues into the genetic circuitry of mammalian cells and provides insights that may yield therapeutic avenues for neuroprotection after catastrophic events.

genetics↗

bioRxiv2023

Co-engagement of TIGIT+ immune cells to PD-L1+ tumours by a bispecific antibody potentiates T-cell response and tumour control

Co-targeting PD-1/PD-L1 and TIGIT/CD226 is being pursued to broaden the efficacy of current immunotherapy. Here we demonstrate that a bispecific antibody (BsAb) targeting PD-L1 and TIGIT, HB0036, shows major advantages over the combination of the two parental monoclonal Abs (mAbs). We demonstrated that HB0036 co-engages PD-L1+ tumour cells and TIGIT+ T cells, and thereby upregulates CD226 on T cells and induces a greater T-cell proliferative response compared to the combination of the parental antibodies in vitro. In vivo, HB0036 recruits greater amounts of TIGIT antibody in PD-L1+ tumours but not in PD-L1- tumours, compared with therapy using the two parental antibodies. We also observed improved tumour control and favourable immunological signatures with HB0036 in syngeneic and xenograft tumour models. Collectively, these findings demonstrate that bispecific antibodies targeting PD-L1 and TIGIT offer superior benefits in cancer immunotherapy compared with therapy using the two parental antibodies. Based on these studies, a phase I clinical trial with HB0036 has been initiated in patients with solid tumours (NCT05417321).

immunology↗

bioRxiv2023

Adaptation invariant concentration discrimination in an insect olfactory system

Neural responses evoked by a stimulus reduce upon repetition. While this adaptation allows the sensory system to attend to novel cues, does information about the recurring stimulus, particularly its intensity, get compromised? We explored this issue in the locust olfactory system. We found that locusts innate behavioral response to odorants varied with repetition and stimulus intensity. Counter-intuitively, the stimulus-intensity dependent differences became significant only after adaptation had set in. Adaptation altered responses of individual neurons in the antennal lobe (neural network downstream to insect antenna). These response variations to repetitions of the same stimulus were unpredictable and inconsistent across intensities. Although both adaptation and intensity decrements resulted in an overall reduction in spiking activities across neurons, these changes could be disentangled, and information about stimulus intensity was robustly maintained by ensemble neural responses. In sum, these results show how information about odor intensity can be preserved in an adaptation-invariant manner.

neuroscience↗

bioRxiv2023

Copine-6 is a Ca2+ sensor for activity-induced AMPA receptor exocytosis

The recruitment of synaptic AMPA (-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid) receptors underlies the strengthening of neuronal connectivity during learning and memory. This process is triggered by NMDA (N-methyl-D-aspartate) receptor-dependent postsynaptic Ca2+ influx. Synaptotagmin (Syt)-1 and -7 have been proposed as Ca2+-sensors for AMPA receptor exocytosis, but are functionally redundant. Here we identify a cytosolic C2 domain-containing Ca2+-binding protein Copine-6 that forms a complex with AMPA receptors. Loss of Copine-6 expression impairs activity-induced exocytosis of AMPA receptors in primary hippocampal neurons, which is rescued by wild-type Copine-6, but not Ca2+-binding mutants. In contrast, Copine-6 loss-of-function has no effects on steady-state expression or tetrodotoxin-induced synaptic upscaling of surface AMPA receptors. Loss of Syt-1/-7 significantly reduces Copine-6 protein expression. Interestingly, overexpression of wild-type Copine-6, but not the Ca2+-binding mutant, restores activity-dependent exocytosis of AMPA receptors in Syt-1/-7 double-knockdown neurons. We conclude that Copine-6 is a postsynaptic Ca2+-sensor that mediates AMPA receptor exocytosis during synaptic potentiation.

neuroscience↗

bioRxiv2023

Population genomics reveals extensive inbreeding and purging of mutational load in wild Amur tigers

The inbreeding is a big threat for the persistence of genetic diversity in small and isolated populations of endangered species. The homozygous genome could exacerbate inbreeding depression by introducing homozygous deleterious alleles in the population. However, purging of inbreeding loads as they become homozygotes in small populations could alleviate the depression. The Amur tiger (Panthera tigris altaica) is typically exists in small population living in forests in Northeast Asia and is among the most endangered animals on the planet with great symbolic significance of conservation. By comparing with captive individuals, we revealed substantially higher and more extensive inbreeding in the wild Amur tiger population (FROH=0.51) than in captive Amur tigers (FROH=0.26). We further found much less mutational loads in wild populations when compared with captive Amur tigers. However, the frequency of loss of function and deleterious nonsynonymous mutations inside ROH regions are much lower than that in non-ROH regions in both wild and captive Amur tigers, indicating the purging may had occurred in both populations but much effective in the wild population. In addition, we found the average frequency of deleterious alleles was much lower than that of neutral alleles in the wild population, indicating that the purifying selection contributed to the purging of mutational loads in the wild Amur tigers. These findings provide valuable genome-wide evidence to support the making of future conservation plans of wild Amur tigers.

genomics↗

bioRxiv2023

Sleep is required for neural network plasticity in the jellyfish Cassiopea

Sleep in animals plays roles that appear specific to the brain, including synaptic homeostasis [1], neurotransmitter regulation [2], cellular repair [3], memory consolidation [4], and neural plasticity [5,6]. Would any of these functions of sleep be relevant to an animal without a brain? The upside-down jellyfish Cassiopea xamachana, like other cnidarians, lacks a centralized nervous system, yet the animal sleeps [7]. By tracking the propensity of the radially spaced ganglia to initiate muscle contractions over several days we determined how neural activity changes between sleep and wake in a decentralized nervous system. Ganglia-network sleep/ wake activity patterns range from being highly specialized to a few ganglia, to being completely unspecialized. Ganglia specialization also changes over time, indicating a high degree of plasticity in the neural network. The ganglia that lead activity can persist or switch between sleep/wake transitions, signifying a level of local control of the behavioral state in a decentralized nervous system. Following sleep deprivation, ganglia usage becomes far more sleep specialized, demonstrating reduced network plasticity. Together, these findings identify a novel behavioral control system that is decentralized and yet displays temporal specialization and centralization, and show a role for sleep in maintaining neural network plasticity, revealing a conserved function of sleep in this brain-less animal.

neuroscience↗

bioRxiv2023

The soluble guanylyl cyclase pathway is inhibited to evade androgen deprivation-induced senescence and enable progression to castration resistance

Castration-resistant prostate cancer (CRPC) is fatal and therapeutically under-served. We describe a novel CRPC-restraining role for the vasodilatory soluble guanylyl cyclase (sGC) pathway. We discovered that sGC subunits are dysregulated during CRPC progression and its catalytic product, cyclic GMP (cGMP), is lowered in CRPC patients. Abrogating sGC heterodimer formation in castration-sensitive prostate cancer (CSPC) cells inhibited androgen deprivation (AD)-induced senescence, and promoted castration-resistant tumor growth. We found sGC is oxidatively inactivated in CRPC. Paradoxically, AD restored sGC activity in CRPC cells through redox-protective responses evoked to protect against AD-induced oxidative stress. sGC stimulation via its FDA-approved agonist, riociguat, inhibited castration-resistant growth, and the anti-tumor response correlated with elevated cGMP, indicating on-target sGC activity. Consistent with known sGC function, riociguat improved tumor oxygenation, decreasing the PC stem cell marker, CD44, and enhancing radiation-induced tumor suppression. Our studies thus provide the first evidence for therapeutically targeting sGC via riociguat to treat CRPC. Statement of significanceProstate cancer is the second highest cancer-related cause of death for American men. Once patients progress to castration-resistant prostate cancer, the incurable and fatal stage, there are few viable treatment options available. Here we identify and characterize a new and clinically actionable target, the soluble guanylyl cyclase complex, in castration-resistant prostate cancer. Notably we find that repurposing the FDA-approved and safely tolerated sGC agonist, riociguat, decreases castration-resistant tumor growth and re-sensitizes these tumors to radiation therapy. Thus our study provides both new biology regarding the origins of castration resistance as well as a new and viable treatment option.

cancer biology↗

bioRxiv2023

Genome-wide coancestry reveals details of ancient and recent male-driven reticulation in baboons

Baboons (genus Papio) are a morphologically and behaviorally diverse clade of catarrhine monkeys that have experienced hybridization between phenotypically and genetically distinct phylogenetic species. We used high coverage whole genome sequences from 225 wild baboons representing 19 geographic localities to investigate population genomics and inter-species gene flow. Our analyses provide an expanded picture of evolutionary reticulation among species and reveal novel patterns of population structure within and among species, including differential admixture among conspecific populations. We describe the first example of a baboon population with a genetic composition that is derived from three distinct lineages. The results reveal processes, both ancient and recent, that produced the observed mismatch between phylogenetic relationships based on matrilineal, patrilineal, and biparental inheritance. We also identified several candidate genes that may contribute to species-specific phenotypes. One-Sentence SummaryGenomic data for 225 baboons reveal novel sites of inter-species gene flow and local effects due to differences in admixture.

evolutionary biology↗

bioRxiv2023

An inverse agonist of orphan receptor GPR61 reveals a novel allosteric mechanism

GPR61 is a biogenic amine receptor-related orphan GPCR associated with phenotypes relating to appetite and thus, is of interest as a druggable target to treat disorders of metabolism and body weight, such as obesity and cachexia. To date, lack of structural information or a known biological ligand or tool compound has hindered comprehensive efforts to study its structure and function. Here, we report the first ever structural characterization of GPR61, in both its active-like complex with heterotrimeric G protein and in its inactive state. Moreover, we report the discovery of a potent and selective small-molecule inverse agonist against GPR61 and structural elucidation of its unprecedented allosteric site and mode of action. These findings offer key mechanistic insights into an orphan GPCR, while providing both a new structural framework and tool compound to support further studies of GPR61 function and modulation.

biophysics↗

bioRxiv2023

Assessing Genetic Diversity in Critically Endangered Chieniodendron hainanense Populations within Fragmented Habitats in Hainan

AbstractHabitat fragmentation engenders a reduction in the geographic distribution of species, thereby rendering diminutive populations susceptible to extinction due to environmental, demographic, and genetic factors. Chieniodendron hainanense (henceforth C. hainanense) exemplifies a wild plant with extremely small populations (WPESP) and faces endangerment, necessitating urgent national conservation efforts. Elucidating the genetic diversity of C. hainanense is crucial for uncovering underlying mechanisms and devising protective strategies. In the present study, 35 specimens from six distinct cohort groups were genotyped utilizing genotyping-by-sequencing (GBS) and single nucleotide polymorphism (SNP) methodologies. The results indicated that C. hainanense exhibits limited genetic diversity. Observed heterozygosity within C. hainanense populations spanned from 10.79% to 14.55%, with an average value of 13.15%. The six C. hainanense populations can be categorized into two distinct groups: (1) Diaoluoshan and Baishaling, and (2) Wuzhishan, Huishan, Bawangling, and Jianfengling. The degree of genetic differentiation among C. hainanense populations is relatively weak. The observed loss of diversity can be attributed to the effects of natural selection.

ecology↗

bioRxiv2023

Time, Space and Single-Cell Resolved Molecular Trajectory of Cell Populations and the Laterality of the Body Plan at Gastrulation

Understanding of the molecular drivers of lineage diversification and tissue patterning during primary germ layer development requires in-depth knowledge of the dynamic molecular trajectories of cell lineages across a series of developmental stages of gastrulation1-7. Through computational modeling, we constructed at single-cell resolution a spatio-temporal compendium of the molecular trajectories of germ-layer derivatives in gastrula-stage mouse embryos. This molecular atlas infers the developmental trajectories of single-cell populations and the molecular network activity underpinning the specification and differentiation of the germ-layer lineages. Analysis of the heterogeneity of cellular composition of cell populations at defined positions in the epiblast revealed progressive diversification of cell types, mirroring the process of lineage allocation during gastrulation. A novel observation is the difference in the contribution of cells on contralateral sides of the epiblast to mesoderm derivatives of the early organogenesis embryo, and the enhanced BMP signaling activity in right-side mesoderm of E7.5 embryo. Perturbation of BMP signaling activity at late gastrulation led to randomization of left-right (L-R) molecular asymmetry in the lateral mesoderm of early-somite-stage embryo. Our findings indicate the asymmetric BMP activity during gastrulation may be critical for the symmetry breaking process associated with specification of L-R body asymmetry ahead of the acquisition of functionality of the L-R organizer.

developmental biology↗

bioRxiv2023

Metabolic Reprogramming via targeting ACOD1 promotes polarization and anti-tumor activity of human CAR-iMACs in solid tumors

The pro-inflammatory state of macrophages is crucial in conferring its role in combating tumor cells. That state is closely associated with metabolic reprogramming. Here we identified key metabolic genes regulating macrophage pro-inflammatory activation in a pooled metabolic gene knockout CRISPR screen. We found that KEAP1 and ACOD1 are strong regulators of the pro-inflammatory state, and therefore developed human ACOD1 knockout macrophages with our induced pluripotent stem cell-derived CAR-macrophage (CAR-iMAC) platform. The engineered iMACs showed stronger and more persistent polarization toward the pro-inflammatory state, more ROS production, and more potent phagocytosis and cytotoxic functions against cancer cells in vitro. Upon transplantation to ovarian or pancreatic cancer mouse models, ACOD1 depleted CAR-iMACs exhibited enhanced capacity in repressing tumors in vivo and prolonged the lifespan of mice. In addition, combining ACOD1-depleted CAR-iMACs with immune check point inhibitors (ICIs), such as the anti-CD47 antibody or anti-PD1 antibody resulted in stronger tumor suppressing effect. Mechanistically, the depletion of ACOD1 reduced the immunometabolite itaconate, allowing KEAP1 to prevent NRF2 from entering the nucleus to activate the anti-inflammatory program. This study demonstrates that ACOD1 is a new myeloid target for cancer immunotherapy and metabolically engineered human iPSC-derived CAR-iMACs exhibit enhanced polarization and anti-tumor functions in adoptive cell transfer therapies.

immunology↗

bioRxiv2023

A Logic-incorporated Gene Regulatory Network Deciphers Principles in Cell Fate Decisions

Organisms utilize gene regulatory networks (GRNs) to make fate decisions, but the regulatory mechanisms of transcription factors (TFs) in GRNs are exceedingly intricate. A longstanding question in this field is how these tangled interactions synergistically contribute to decision- making procedures. To comprehensively understand the role of regulatory logic in cell fate decisions, we constructed a logic-incorporated GRN model and examined its behavior under two distinct driving forces (noise-driven and signal-driven). Under the noise-driven mode, we distilled the relationship among fate bias, regulatory logic, and noise profile. Under the signal-driven mode, we bridged regulatory logic and progression-accuracy trade-off, and uncovered distinctive trajectories of reprogramming influenced by logic motifs. In differentiation, we characterized a special logic-dependent priming stage by the solution landscape. Finally, we applied our findings to decipher three biological instances: hematopoiesis, embryogenesis, and trans-differentiation. Orthogonal to the classical analysis of expression profile, we harnessed noise patterns to construct the GRN corresponding to fate transition. Our work presents a generalizable framework for top- down fate-decision studies and a practical approach to the taxonomy of cell fate decisions.

systems biology↗

bioRxiv2023

A novel simian adenovirus vectored COVID-19 vaccine elicits effective mucosal and systemic immunity in mice by intranasal and intramuscular vaccination regimens

The failure of COVID-19 vaccines to prevent SARS-CoV-2 infection and transmission, a possibly critical reason was the lack of protective mucosal immunity in respiratory tract. Here, we evaluated the effects of mucosal and systemic immunity from a novel simian adenovirus vectored COVID-19 vaccine (Sad23L- nCoV-S) in mice in comparison with Ad5-nCoV-S by intranasal (IN) drip and intramuscular (IM) injection vaccinations. As good as the well-known Ad5-nCoV-S vaccine, a single-dose IN inoculation of 1x109 PFU Sad23L-nCoV-S vaccine induced a similar level of IgG S-binding antibody (S-BAb) and neutralizing antibody (NAb) and higher IgA in serum, while IN route raised significantly higher IgG and IgA S- BAb and NAb in bronchoalveolar lavage (BAL), and specific IFN-{gamma} secreting T cell response in lung compared with IM route, but lower T cell response in spleen. By prime-boost vaccination regimens with different combination of IN and IM inoculations of Sad23L-nCoV-S vaccine, the IN involved vaccinations stimulated higher protective mucosal or local immunity in BAL and lung, while the IM involved immunizations induced higher systemic immunity in serum and spleen. A long-term sustained systemic and mucosal NAb and T cell immunity to SARS-CoV-2 was maintained at high levels over 32 weeks by prime-boost vaccination regimens with IN and IM routes. In conclusion, priming or boosting immunization with IN inoculation of Sad23L-nCoV-S vaccine could induced effective mucosal immunity and in combination of IM route could additionally achieve systemic immunity, which provided an important reference for vaccination regimens against respiratory virus infection. IMPORTANCEThe essential goal of vaccination is to generate potent and long-term protection against diseases. Several factors including type of vector, delivery route, boosting regimen influence the outcome of prime-boost immunization approaches. The immunization regimen by constructing a novel simian adenovirus vectored COVID-19 vaccine and employing combination of intranasal and intramuscular inoculations, could elicit mucosal neutralizing antibodies against five mutant strains in the respiratory tract, and strong systemic immunity. Immune protection could last for more than 32 weeks. Vectored vaccine construction and immunization regimens have positively impacted respiratory disease prevention.

immunology↗

bioRxiv2023

Compensation or preservation? Different roles of functional lateralization in speech perception in older non-musicians and musicians

Musical training can offset age-related decline of speech perception in noisy environments. However, whether functional compensation or functional preservation the older musicians adopt to counteract the adverse effects of aging is unclear yet, so do older non-musicians. Here, we employed the fundamental brain organization feature named functional lateralization, and calculated network-based lateralization indices (LIs) of resting-state functional connectivity (FC) in 23 older musicians (OM), 23 older non-musicians (ONM), and 24 young non-musicians (YNM). OM outperformed ONM and almost equalized YNM in speech-in-noise/speech tasks. In parallel, ONM exhibited reduced lateralization than YNM in LI of intrahemispheric FC (LI_intra) in cingulo-opercular network (CON) and interhemispheric heterotopic FC (LI_he) in language network (LAN). Moreover, OM showed higher neural alignment to YNM (i.e., similar lateralization pattern) than ONM in LI_intra in CON, LAN, frontoparietal network (FPN) and default mode network (DMN) and LI_he in DMN. These findings suggest that musical training contributes to the preservation of youth-like lateralization in older adults. Furthermore, stronger left-lateralized and lower alignment-to-young of LI_intra in somatomotor network (SMN) and dorsal attention network (DAN) and LI_he in DMN correlated with better speech performance in ONM. In contrast, stronger right-lateralized LI_intra in FPN and DAN and higher alignment-to-young of LI_he in LAN correlated with better performance in OM. Thus, functional preservation and compensation of lateralization may play different roles in speech perception in noise for the elderly with and without musical expertise, respectively. Our findings provide insight into successful aging theories from the unique perspective of functional lateralization and speech perception. Significance statementAs a positive lifestyle which contributes to neural resource enrichment, musical training experience may mitigate age-related decline in speech perception in noise through both functional compensation and preservation. What is unknown is whether older musicians rely more on one of these mechanisms, and how is it different from older non-musicians. From a unique perspective of functional lateralization, we found that high-performing older musicians showed stronger preservation of youth-like lateralization with a more right-lateralized pattern whereas high-performing older non-musicians were associated with stronger scaffolding of compensatory networks with a more left-lateralized pattern. Our findings suggest that older musicians and non-musicians exhibit different coping strategies in terms of functional lateralization against aging, which would largely enrich aging theories and inspire training intervention.

neuroscience↗

bioRxiv2023

Cytomixis and aberrant phenomena during meiosis in pollen mother cells of Camellia sinensis var. sinensis cv 'Fudingdabai'

Tea plant (Camellia sinensis) is an economically essential crop in China, Japan and other countries. The present study reports the meiotic behavior, including microsporogenesis of the Fudingdabai cultivar in Camellia sinensis var. sinensis. Most of the investigated pollen mother cells undergo normal meiosis processes. In contrast, a few of the pollen mother cells showed some abnormal phenomena such as cytomixis, monovalent, laggard chromosomes, unsynchronized division, micronucleus, and so on. Among which, spontaneous cytomixis is the most common phenomenon, which mainly occurred in early prophase I but also in meiosis II. Other abnormal phenomena were less than cytomixis. The results of this study laid a foundation for exploring the meiosis and cytogenetics study of the tea plants.

plant biology↗

bioRxiv2023

ANP rescues the preeclamptic symptoms in Axl knockout mice by improving trophoblast function

Pre-eclampsia (PE) is characterized by maternal hypertension and/or proteinuria after 20 weeks of gestation. Shallow trophoblast invasion into spiral artery (SpA) and defective decidualization have been implicated in the pathogenesis of PE. However, the underlying mechanisms remain unclear. AXL receptor tyrosine kinase is a biomarker and therapeutic target for a variety of metastatic cancers while tumorigenesis and placentation share many features. In this study, a new function of AXL in promoting SpA remodeling and trophoblast invasion were demonstrated. The pregnant Axl knockout (Axl-/-) mice exhibited typical PE symptoms, including increased blood pressure and proteinuria. Artificially induced decidualization experiments showed that appeared normal, however, RNA-seq results of Axl-/- deciduoma revealed abnormal expression of a number of transcripts, including Corin, which encodes a cardiac protease that activates atrial natriuretic peptide (ANP). Treatment with ANP reversed the PE symptoms. Moreover, in decidua from women afflicted with PE, AXL level was significantly lower than that in normal pregnancies. These data show that the abnormality of decidua-derived AXL-CORIN-ANP affects maternal-fetal crosstalk and contributes to PE.

pathology↗