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Zhou, F.

Publications and source records attributed to Zhou, F..

At least 91 records · Page 5Linked to original sources
bioRxiv2024

Targeting GFPT2 to reinvigorate immunotherapy in EGFR-mutated NSCLC

In the evolving field of cancer immunotherapy, EGFR-mutated NSCLC presents a significant challenge, demonstrating marked innate resistance to established treatments. An effective method to counter this resistance remains elusive. Through comprehensive genetic and pharmacological analyses across various models, we have identified glutamine fructose-6-phosphate transaminase 2 (GFPT2) as a key facilitator of immune evasion in EGFR-mutated NSCLC. Mechanistically, under EGFR mutation condition, GFPT2 expression, which is typically low in normal tissues, is highly induced via EGFR/IRE1/Xbp1s signaling axis, leading to a significant increase in intracellular UDP-GlcNAc and consequently, an altered N-glycosylation profile. GFPT2 escalates the expression and glycosylation of PD-L1, PVR and CD276, bolstering their interactions with CD8+T cells, and amplifies CD73 glycosylation, thereby intensifying adenosine-mediated CD8+T cells suppression. These actions collectively reduce tumor cell vulnerability to CD8+T cell-mediated death. Moreover, GFPT2 regulates EGFR glycosylation, which consequentially modulates the EGFR-dependent secretion of CXCL10 and VEGF, thus impeding CD8+T cell infiltration within tumors. We further identified a GFPT2 isoform-specific inhibitor that potentiates PD-1 blockade therapy beyond that of existing strategy, corroborated by results in xenografts and patient-derived organoids. Together, these findings illuminate the promising therapeutic potential of GFPT2 as a metabolic checkpoint, offering an innovative approach to invigorate immunotherapy in NSCLC with EGFR mutations.

cancer biology↗
bioRxiv2024

LRRK2 G2019S mutation suppresses differentiation of Th9 and Treg cells via JAK/STAT3

The Leucine-rich repeat kinase-2 (LRRK2) G2019S mutation, resulting in aberrantly enhanced kinase activity, is one of the well-recognized genetic risk factors in Parkinsons Disease (PD). Increased LRRK2 activity was also observed in immune cells from PD patients. Emerging results have also unveiled an upsurge in -synuclein (-syn)-specific CD4+ T cell responses in PD patients. Given that LRRK2 mutations in PD are germline mutations, there are unmet meets to explore whether LRRK2 G2019S mutation contributes to the pathogenesis of PD via altering CD4+ T-cell functions. To fill this knowledge gap, we generated a new T cell receptor (TCR) transgenic mouse strain bearing LRRK2 G2019S knock-in mutation, OT-II/LRRK2 (Refer to Mut). As CD4+ T cells from OT-II mice specifically recognize ovalbumin, this new strain enables us to explore the impact of LRRK2 G2019S mutation on T-cell functions in an antigen-specific manner. We found that the abundance and proliferation of major immune subsets in spleen tissue from Mut mice are comparable to wild-type (OT-II, Refer to WT) control. However, when we characterized T cell differentiation in these two strains, T cells derived from Mut mice displayed increased Th2 differentiation (IL-4) and decreased Th9 (IL-9) and Treg (Foxp3+ %) differentiation. LRRK2 G2019S mutation significantly altered the expression levels of master transcription factors (TFs) for T cell differentiation. Specifically, Mut T cells displayed an increase in mRNA expression of Gata3 (TF for Th2), a decrease in expression of Irf4 and Foxp3 (TFs for Th9 and Treg, respectively). Mechanistically, LRRK2 mutation decreased IL-9 production and Treg cell population through the JAK/STAT3 signaling. In conclusion, LRRK2 plays a critical role in regulating T cell differentiation, warranting further studies to evaluate the impacts of altered T cell differentiation led by LRRK2 mutation in dopaminergic neuron damages.

immunology↗
bioRxiv2024

Magnesium Transporter MgtA revealed as a Dimeric P-type ATPase

Magnesium (Mg2+) uptake systems are present in all domains of life given the vital role of this ion. Bacteria acquire Mg2+ via conserved Mg2+ channels and transporters. The transporters are required for growth when Mg2+ is limiting or during bacterial pathogenesis, but, despite their significance, there are no known structures for these transporters. Here we report the first structure of the Mg2+ transporter MgtA solved by single particle cryo-electron microscopy (cryo-EM). Using mild membrane extraction, we obtained high resolution structures of both a homodimeric form (2.9 [A]), the first for a P-type ATPase, and a monomeric form (3.6 [A]). Each monomer unit of MgtA displays a structural architecture that is similar to other P-type ATPases with a transmembrane domain and two soluble domains. The dimer interface consists of contacts between residues in adjacent soluble nucleotide binding and phosphotransfer regions of the haloacid dehalogenase (HAD) domain. We suggest oligomerization is a conserved structural feature of the diverse family of P-type ATPase transporters. The ATP binding site and conformational dynamics upon nucleotide binding to MgtA were characterized using a combination of cryo-EM, molecular dynamics simulations, hydrogen-deuterium exchange mass spectrometry, and mutagenesis. Our structure also revealed a Mg2+ ion in the transmembrane segments, which, when combined with sequence conservation and mutagenesis studies, allowed us to propose a model for Mg2+ transport across the lipid bilayer. Finally, our work revealed the N-terminal domain structure and cytoplasmic Mg2+ binding sites, which have implications for related P-type ATPases defective in human disease.

biophysics↗
bioRxiv2024

Mechanical confinement induces ferroptosis through mitochondrial dysfunction

Cells exist in highly crowded environments where they are exposed to fluctuating mechanical forces arising from surrounding cells and the extracellular matrix microenvironment. In these settings, external forces are transmitted to intracellular organelles including the nucleus. While cells can survive confinement, extended duration of confinement or confinement in settings where cells are unable to escape, can result in cell death. How cells sense and respond to prolonged confinement to trigger cell death remains unclear. Here, we demonstrate that nuclear deformation generated by axial confinement triggers the programmed cell death pathway - ferroptosis. We show that axial confinement results in Drp1-dependent mitochondrial fragmentation and cPLA2 translocation to mitochondria, where Drp1 undergoes acute phase separation. Ensuing mitochondrial ROS accumulation and arachidonic acid production concertedly leads to lipid peroxidation evoking ferroptosis. Finally, of clinical relevance, we find that in human osteoarthritis tissue cPLA2 exhibits mitochondrial localization and high ROS levels. Together, our findings unveil a pivotal role for Drp1 and cPLA2 in linking mechanical confinement with mitochondrial dysfunction resulting in ferroptosis, which sheds new light on a mechanical mechanism of pathophysiology in osteoarthritis.

cell biology↗
bioRxiv2024

TLR9 activation in large wound induces tissue repair and hair follicle regeneration via gamma delta T cells

The mechanisms underlying tissue repair in response to damage have been one of main subjects of investigation. In this study, we leveraged the wound-induced hair neogenesis (WIHN) models in adult mice to explore the inner correlation. Our investigation revealed that heightened release of mitochondrial DNA (mtDNA) accompanying tissue damage activated the toll-like receptor 9 (TLR9) pathway, influencing the repair process and the ultimate number of regenerated hair follicles. Furthermore, our analysis of single-cell RNA sequencing comparisons demonstrated increased TLR9 activation was associated with the recruitment of gamma delta T cells ({gamma}{delta}T). Inhibition of {gamma}{delta}T cell recruitment led to a reduction in the population of {gamma}{delta}T cells and a more fibrotic healing outcome. Notably, these {gamma}{delta}T cells exhibited distinctive high production of AREG, contributing to the rapid increase of local AREG levels around the epidermis and influencing the fate commitment of keratinocytes. These findings provide new insights into the roles of TLRs as critical mediators in the sense of tissue damage, the modulation of immune cell activity, and the ultimate influence on healing outcomes. TeaserStarting with how tissue injury stimulates downstream tissue repair and regeneration through relevant signals, this study explored the phenomenon and correlation between tissue damage and TLR9, and the effect of TLR9 on {gamma}{delta}T, keratinocytes and the healing outcomes.

cell biology↗
bioRxiv2024

A Prodrug Strategy to Reposition Atovaquone as a Long-Acting Injectable for Malaria Chemoprotection

Recent malaria drug discovery approaches have been extensively focused on the development of oral, smallmolecule inhibitors for disease treatment whereas parenteral routes of administration have been avoided due to limitations in deploying a shelf-stable injectable even though it could be dosed less frequently. However, an updated target candidate profile from Medicines for Malaria Venture (MMV) and stakeholders have advocated for long-acting injectable chemopreventive agents as an important interventive tool to improve malaria prevention. Here, we present strategies for the development of a long-acting, intramuscular, injectable atovaquone prophylactic therapy. We have generated three prodrug approaches that are contrasted by their differential physiochemical properties and pharmacokinetic profiles: mCBK068, a docosahexaenoic acid ester of atovaquone formulated in sesame oil, mCKX352, a heptanoic acid ester of atovaquone formulated as a solution in sesame oil, and mCBE161, an acetic acid ester of atovaquone formulated as an aqueous suspension. As a result, from a single 20 mg/kg intramuscular injection, mCKX352 and mCBE161 maintain blood plasma exposure of atovaquone above the minimal efficacious concentration for >70 days and >30 days, respectively, in cynomolgus monkeys. The differences in plasma exposure are reflective of the prodrug strategy, which imparts altered chemical properties that ultimately influence aqueous solubility and depot release kinetics. On the strength of the pharmacokinetic and safety profiles, mCBE161 is being advanced as a first-in-class clinical candidate for first-in-human trials.

pharmacology and toxicology↗
bioRxiv2024

Multiple layers of innate immune response antagonism of SARS-CoV-2

Several SARS-CoV-2 proteins have been shown to counteract the host innate immune response, mostly using in vitro protein expression, which may not fully reflect their role in the context of viral infection. In addition, while each viral protein was characterized in a different experimental system, their relative contribution in immunosuppression remains unclear. Here we used a SARS-CoV-2 bacterial artificial chromosome with en passant mutagenesis to recover a panel of twelve infectious recombinant SARS-CoV-2 viruses, each with mutations in either NSP1, NSP2, NSP3, NSP6, NSP12, NSP13, NSP14, NSP15, NSP16, ORF3a, ORF6 or ORF8. We used the interferon-stimulated response element (ISRE)-driven luciferase assay in 293T-ACE2/TMPRSS2 cells to test the panel, demonstrating that mutations in many proteins, especially in NSP1 and NSP15, increased the type I interferon response relative to the parental wild-type virus. RNA-seq analysis of mutant-virus infected Calu-3 cells showed that the mutations in NSP1 or NSP15 lead to higher expression of multiple genes involved in innate immune response, cytokine-mediated signaling and regulation of lymphocyte proliferation. Furthermore, mutations in either NSP1 or NSP15 resulted in a greater maturation of human monocyte-derived dendritic cells in vitro. Infection of K18 hACE2 transgenic mice with either NSP1 or NSP15 mutated viruses demonstrated attentuated respiratory tract replication. Analysis of lung immune cells from infected mice by single-cell RNA-seq identified 15 populations of major myeloid and lymphoid cells with changes in the pattern of their activation associated with viral infection. The effects of mutations in NSP1 or NSP15 on these responses are consistent with differences in the immunosuppressive mechanisms utilized by the two proteins. Overall, these data demonstrate different and redundant mechanisms of innate immune antagonism by SARS-CoV-2 and suppression of activation of antigen presenting cells and T and B lymphocytes mediated by multiple viral proteins. AUTHOR SUMMARYThe mechanisms by which SARS-CoV-2 and its proteins modulate host immunity, specifically the interferon response, are still not clear. We generated twelve infectious SARS-CoV-2 viruses with mutations in individual proteins and demonstrated that many of them have interferon-antagonizing activity and immunosuppressive effects in human cells and in the K18 hACE mouse model of infection. We idemtified distinct and redundant mechanisms of immunosuppression of SARS-CoV-2 mediated by multiple individual viral proteins, with 9 out of the 12 tested proteins showing some immunosuppressive effect in at least one experimental system. The demonstrated immunosuppressive effects extend from the innate response to immune cells to pathologic changes in vivo. Importantly, this work shows, for the first time, a comparison of the effects of multiple viral proteins in the context of authentic viral infection, rather than in a surrogate system, and shows the relative contribution of each viral protein under identical experimental conditions. Overall, our data indicates that SARS-CoV-2 antagonizes multiple immune mechanisms, particularly type I interferon signaling, activation of innate immune cells and T and B lymphocyte functions with the greatest effects due to NSP1 and NSP15.

microbiology↗
bioRxiv2024

Polymer-solubilized structure of the mechanosensitive channel MscS suggests the role of protein-lipid interactions in the functional gating cycle

Interpretations of experimental conformations of mechanosensitive channels gated by force from lipids become more reliable when native lipids are preserved in the structures. Escherichia coli MscS is an adaptive osmolyte release valve that regulates turgor in osmotically stressed cells. MscS promptly opens under abrupt super-threshold tensions in the membrane, but at lower and more gradually applied tensions, it silently inactivates from the closed state. A central question has been whether to assign the commonly observed non-conductive conformation with splayed peripheral helices to a closed or inactivated state. We present a 3-[A] MscS cryo-EM structure obtained in Glyco-DIBMA polymers, which avoid complete lipid removal. Within the complex, we observe densities for endogenous phospholipids intercalating between the peripheral and pore-lining helices. The lipidomic analysis shows a 2-3 fold enrichment of phosphatidylglycerol in Glyco-DIBMA-extracted MscS samples. The computed pressure of these lipids on the protein surface enforces the characteristic kinks in the pore-lining helices, sterically stabilizing the separation of the peripheral helices. Mutations of residues coordinating lipids in the crevices eliminate inactivation, allowing us to classify this group of structures as the inactivated state. Our study reveals a novel inactivation mechanism in which intercalated lipids physically decouple the tension-sensing helices from the gate.

biophysics↗
bioRxiv2024

Regulatory T cells and IFN-γ-producing Th1 cells play a critical role in the pathogenesis of Sjögren's Syndrome

ObjectivesSjogrens Disease (SjD) is an autoimmune disorder characterized by progressive dysfunction, inflammation and destruction of salivary and lacrimal glands, and by extraglandular manifestations. Its etiology and pathophysiology remain incompletely understood, though a role for autoreactive B cells has been considered key. Here, we investigated the role of effector and regulatory T cells in the pathogenesis of SjD. MethodsHistological analysis, RNA-sequencing and flow cytometry were conducted on glands, lungs, eyes and lymphoid tissues of mice with regulatory T cell-specific deletion of stromal interaction proteins (STIM) 1 and 2 (Stim1/2Foxp3), which play key roles in calcium signaling and T cell function. The pathogenicity of T cells from Stim1/2Foxp3mice was investigated through adoptively transfer into lymphopenic host mice. Additionally, single-cell transcriptomic analysis was performed on peripheral blood mononuclear cells (PBMCs) of patients with SjD and control subjects. ResultsStim1/2Foxp3 mice develop a severe SjD-like disorder including salivary gland (SG) and lacrimal gland (LG) inflammation and dysfunction, autoantibodies and extraglandular symptoms. SG inflammation in Stim1/2Foxp3 mice is characterized by T and B cell infiltration, and transcriptionally by a Th1 immune response that correlates strongly with the dysregulation observed in patients with SjD. Adoptive transfer of effector T cells from Stim1/2Foxp3 mice demonstrates that the SjD-like disease is driven by interferon (IFN)-{gamma} producing autoreactive CD4+ T cells independently of B cells and autoantiboodies. scRNA-seq analysis identifies increased Th1 responses and attenuated memory Treg function in PBMCs of patients with SjD. ConclusionsWe report a more accurate mouse model of SjD while providing evidence for a critical role of Treg cells and IFN-{gamma} producing Th1 cells in the pathogenesis of SjD, which may be effective targets for therapy.

immunology↗
bioRxiv2024

Loss of STIM1 and STIM2 in salivary glands disrupts ANO1 function but does not induce Sjogren's disease

Sjogrens disease (SjD) is an autoimmune disease characterized by xerostomia (dry mouth), lymphocytic infiltration into salivary glands and the presence of SSA and SSB autoantibodies. Xerostomia is caused by hypofunction of the salivary glands and has been involved in the development of SjD. Saliva production is regulated by parasympathetic input into the glands initiating intracellular Ca2+ signals that activate the store operated Ca2+ entry (SOCE) pathway eliciting sustained Ca2+ influx. SOCE is mediated by the STIM1 and STIM2 proteins and the ORAI1 Ca2+ channel. However, there are no studies on the effects of lack of STIM1/2 function in salivary acini in animal models and its impact on SjD. Here we report that male and female mice lacking Stim1 and Stim2 (Stim1/2K14Cre) in salivary glands showed reduced intracellular Ca2+ levels via SOCE in parotid acini and hyposalivate upon pilocarpine stimulation. Bulk RNASeq of the parotid glands of Stim1/2K14Cre mice showed a decrease in the expression of Stim1/2 but no other Ca2+ associated genes mediating saliva fluid secretion. SOCE was however functionally required for the activation of the Ca2+ activated chloride channel ANO1. Despite hyposalivation, ageing Stim1/2K14Cre mice showed no evidence of lymphocytic infiltration in the glands or elevated levels of SSA or SSB autoantibodies in the serum, which may be linked to the downregulation of the toll-like receptor 8 (Tlr8). By contrast, salivary gland biopsies of SjD patients showed increased STIM1 and TLR8 expression, and induction of SOCE in a salivary gland cell line increased the expression of TLR8. Our data demonstrate that SOCE is an important activator of ANO1 function and saliva fluid secretion in salivary glands. They also provide a novel link between SOCE and TLR8 signaling which may explain why loss of SOCE does not result in SjD.

physiology↗
bioRxiv2024

Multi-omic characterization of allele-specific regulatory variation in hybrid pigs

Genetic variation in the regulation of gene expression contributes substantially to phenotypic variation. Understanding how variation in DNA sequences and epigentic modifications leads to gene expression variation remains a challenging task. In hybrid animals where cellular environments are homogeneous, differences between the expression of paternal and maternal alleles must be due to cis sequence or epigenic differences. Therefore, hybrid mapping is a powerful approach to efficiently identify and characterize genes under regulation through mechanisms in cis. In this study, using reciprocal crosses of the phenotypically divergent Duroc and Lulai pig breeds, we performed a comprehensive multi-omic characterization of regulatory variation across brain, liver, muscle, and placenta in four developmental stages. We produced one of the largest multi-omic datasets to date in pigs, including 16 whole genome sequenced genomes, 48 whole genome bisulfite sequencing, 168 ATAC-Seq and 168 RNA-Seq samples. We developed a novel read count-based method to reliably assess allele-specific methylation, chromatin accessibility, and RNA expression. We showed that tissue specificity was much stronger than developmental stage specificity in all of DNA methylation, chromatin accessibility, and gene expression. We identified 573 genes showing allele specific expression, including those influenced by parent-of-origin as well as allele genotype effects. By integrating methylation, chromatin accessibility, and gene expression data, many of these allele specific expression can be explained by allele specific methylation and/or chromatin accessibility. This study provides one of the most comprehensive characterizations of regulatory variation across multiple tissues and developmental stages in pigs and offers new opportunity of genetic improvement for this important food animal species.

developmental biology↗
bioRxiv2024

Decoding of resting-state using task-based multivariate pattern analysis supports the Incentive-Sensitization Theory in nicotine use disorder

BackgroundThe Incentive-Sensitization Theory postulates that addiction is primarily driven by the sensitization of the brains reward system to addictive substances, such as nicotine. According to this theory, exposure to such substances leads to an increase in wanting, while liking the experience remains relatively unchanged. Although this candidate mechanism has been well substantiated through animal brain research, its translational validity for humans has only been partially demonstrated so far, with evidence from human neuroscience data being very limited. MethodsFrom fMRI data of N=31 individuals with Nicotine Use Disorder, we created multivoxel patterns capable of capturing wanting and liking-related dimensions from a smoking cue-reactivity task. Using these patterns, we then designed a novel resting-state reading method to evaluate how much wanting or liking still persist as a neural trace after watching the cues. ResultsWe found that the persistence of wanting-related brain patterns at rest increases with longer smoking history but this was not the case for liking-related patterns. Interestingly, such behavior has not been observed for non-temporal measures of smoking intensity. ConclusionThis study provides basic human neuroscience evidence that the dissociation between liking and wanting escalates over time, further substantiating the Incentive-Sensitization Theory, at least for Nicotine Use Disorder. These results suggest that treatment approaches could be personalized to account for the variability in individuals neural adaptation to addiction by considering how individuals differ in the extent to which their incentive salience system is sensitized.

neuroscience↗
bioRxiv2023

Fully flexible molecular alignment enables accurate ligand structure modelling

Accurate protein-ligand binding poses are the prerequisites of structure-based binding affinity prediction, and also provide the structural basis for in depth lead optimization in small molecule drug design. Ligand-based modeling approaches primarily extract valuable information from the structural features of small molecules to assess their potential as drug candidates against specific targets. However, it is challenging to provide reasonable predictions of binding poses for different molecules, due to the complexity and diversity of the chemical space of small molecules. Similarity-based molecular alignment techniques can effectively narrow the search range, as structurally similar molecules are likely to have similar binding modes, with higher similarity usually correlating to higher success rates. However, molecular similarity isnt consistently high because molecules often require changes to achieve specific purposes, leading to reduced alignment precision. To address this issue, we propose a new alignment method--Z-align. This method uses topological structural information as a criterion for evaluating similarity, reducing the reliance on molecular fingerprint similarity. Our method has achieved significantly higher success rates than other methods at moderate levels of similarity. Additionally, our approach can comprehensively and flexibly optimize bond lengths and angles of molecules, maintaining high accuracy even when dealing with larger molecules. Consequently, our proposed solution helps in achieving more accurate binding poses in protein-ligand docking problems, facilitating the development of small molecule drugs.

bioinformatics↗
bioRxiv2023

Glycodiversification of gentamicins through in vivo glycosyltransferase swapping enabled the creation of novel hybrid aminoglycoside antibiotics with potent activity and low ototoxicity

Aminoglycosides (AGs) are a class of potent antibiotics with a broad spectrum of activity. However, their use is limited by safety concerns associated with nephrotoxicity and ototoxicity, as well as drug resistance. To address these issues, semi-synthetic approaches for modifying natural AGs have successfully generated new generations of AGs, however, with limited types of modification due to significant challenges in synthesis. This study explores a novel approach that harness the bacterial biosynthetic machinery of gentamicins and kanamycins to create hybrid AGs, installing extensive natural modifications from gentamicins onto kanamycins. This was achieved by glycodiversification of gentamicins via swapping the glycosyltransferase (GT) in their producer with the GT from kanamycins biosynthetic pathway and resulted in the creation of a series of novel AGs with combined structural features of two, therefore referred to as genkamicins (GKs). The manipulation of the hybrid metabolic pathway enabled the target accumulation of different GK species and the successful isolation and characterization of six GK components. These compounds display retained antimicrobial activity against a panel of World Health Organization (WHO) critical priority pathogens, and GK-C2a, in particular, demonstrates low ototoxicity compared to clinical drugs in zebrafish embryos. This study provides a new strategy for diversifying the structure of AGs and a potential avenue for developing less toxic AG drugs to combat infectious diseases.

synthetic biology↗
bioRxiv2023

Obesity status and its relative factors of captive Asian elephants (Elephas maximus) in China based on body condition assessment

Obesity is a common health problem in captive wildlife. Since the obesity status of captive Asian elephants (Elephas maximus) in China has not previously been investigated, we recorded seven relevant variables (sex, age, daily feed supply, proportion of high-calorie feed, outdoor enclosure area, outdoor time, and foot disorder) related to obesity in 204 captive Asian elephants through field investigation of 43 elephant-raising facilities. Assessment of obesity was based on visual body condition scoring for each individual. It revealed that obesity was prevalent for captive Asian elephants (especially elephants in zoos) in China. Over 70% of captive Asian elephants in China were overweight or in obesity to various degrees. Statistical analysis showed that for elephants in zoos, insufficient outdoor time might be the primary potential cause of obesity. We suggested facilities to extend the outdoor time and control the supply of high-calorie feed (e.g., fruits, vegetables, pellets, etc.) for captive elephants, thereby alleviating obesity through increased exercise and a suitable energy intake. Moreover, all facilities should implement positive reinforcement training to facilitate regular physical examinations, including foot health checks and blood sampling. This training would improve the ability to collect more precise information relating to elephant health, obesity, and the evaluation of animal welfare.

zoology↗
bioRxiv2023

USP7 Inhibition Promotes Mesenchymal Stem cell-Macrophage Crosstalk in Age-related Osteoporosis via Efferocytosis and Senolysis

Although elderly osteoporotic patients have similar implant survival rates compared to those of normal individuals, they require longer healing periods to achieve proper osseointegration. This may be related to chronic inflammatory responses and impaired stem cell repair functions in the osteoporotic bone microenvironment. Recently, the deubiquitinating enzyme, ubiquitin-specific peptidase 7 (USP7), was found to regulate macrophage immune response and modulate stem cell osteogenic differentiation. The selective inhibitor of USP7, P5091, has also been found to promote bone repair and homeostasis in osteoporotic conditions. However, the roles of USP7 and P5091 in osteoimmunology and dental implant osseointegration under senile osteoporotic conditions remain unclear. In this study, USP7 depletion and P5091 were showed to inhibit inflammation in senescent bone marrow derived macrophages (BMDMs) and promote osteogenic differentiation in aged BMSCs. Furthermore, mRNA-Seq revealed that USP7 depletion could enhance efferocytosis in senescent BMDMs through the EPSIN1/ low-density lipoprotein receptor-related protein 1 (LRP1) pathway and selectively induce apoptosis (senolysis) in aged BMSCs. In senile osteoporotic mice, we found that the osseointegration period was prolonged compared to young mice, and P5091 promoted the early stage of osseointegration, which may be related to macrophage efferocytosis around the implant. Collectively, this study suggests that USP7 inhibition may accelerate the osseointegration process in senile osteoporotic conditions by promoting macrophage efferocytosis and aged BMSCs apoptosis. This has implications for understanding the cellular interactions and signaling mechanisms in the peri-implant bone microenvironment under osteoporotic conditions. It may also provide clinical significance in developing new therapies to enhance osseointegration quality and shorten the edentulous period in elderly osteoporotic patients.

cell biology↗
bioRxiv2023

Urine proteomic analysis of patients with schizophrenia

We tried to explore the difference of urinary proteome between unmedicated schizophrenia patients and normal people through a small number of cases. The results showed that a total of 35 differential proteins were screened in the schizophrenia group compared with the healthy control group. Through random grouping evaluation, it has 91.4 % credibility. Fifteen of the differentially expressed proteins were reported to be related to schizophrenia mechanism, drug target or nervous system regulation. Among them, the aromatic amino acid decarboxylase related to the pathogenesis of schizophrenia can distinguish all 10 patients and 9 normal people with 100 % accuracy in this study, and the AUC value of 17 proteins is greater than or equal to 0.9. The biological pathways enriched by differentially expressed proteins include ephrin receptor signaling pathway, positive regulation of long-term potentiation (LTP), etc. This study shows that urine proteomics can reflect the difference between schizophrenia and healthy controls, and has the potential as a diagnostic marker.

biochemistry↗