Biology subjects

Bai, Q.

Publications and source records attributed to Bai, Q..

16 recordsLinked to original sources

bioRxiv2026

Substrate recognition and ion coupling mechanism of the human VIAAT

Inhibitory neurotransmission, essential for neural circuit homeostasis and proper neurological function, depends on the efficient sequestration of {gamma}-aminobutyric acid (GABA) and glycine into synaptic vesicles. This critical process is mediated exclusively by the vesicular inhibitory amino acid transporter (VIAAT). Despite extensive biochemical and physiological investigation, the molecular mechanism governing VIAAT-mediated transport has remained incompletely understood. Here, we determined structures of human VIAAT in multiple functional states, including apo, GABA-bound, and glycine-bound states, as well as apo state in chloride-free condition. VIAAT adopts a classical LeuT-fold and we elucidated how its large, electronegative binding pocket accommodates both GABA and glycine. Moreover, we resolved two previously unidentified chloride-binding sites. Through integrative molecular dynamics simulations and functional mutagenesis, our results support roles for chloride and the conserved residue E213 in substrate binding and proton-coupled transport. Together, our findings establish a structural framework for VIAAT-mediated inhibitory neurotransmitter transport that illuminates the molecular basis of inhibitory synaptic transmission and provides a foundation for understanding VIAAT dysfunction in epilepsy and related neurodevelopmental disorders.

neuroscience↗

bioRxiv2026

Salmonella exploits metal-responsive UMPylation to enable intracellular biphasic growth and antibiotic tolerance

Salmonella develops profound antibiotic tolerance during in vivo infection, directly contributing to antimicrobial treatment failure. Although phenotypic heterogeneity in bacterial growth rates underlies this tolerance, the exact mechanisms remain elusive. Here, we reveal that Salmonella exhibits a biphasic growth pattern within macrophages, with initial antibiotic levels modulating lag phase duration. Crucially, this growth plasticity is orchestrated by metal ion homeostasis and a reversible PTM-mediated protein phase transitions. Mechanistically, under stress conditions, enhanced Mn2+ uptake activates the UMPylator YdiU, which modifies critical translational machinery components such as elongation factor TufA. These modifications induce protein aggregation, leading to translational arrest and growth stasis. Conversely, upon stress alleviation, Salmonella accumulates Mg2+ and effluxes Mn2+, then the de-UMPylase YdiV is activated, which resolves protein aggregates to enable rapid bacterial resuscitation and proliferation. This metal-responsive proteostatic switch represents an evolutionarily conserved strategy for bacterial stress adaptation, with broad implications for combating antimicrobial tolerance. SIGNIFICANCE STATEMENTAntibiotic tolerance, a key cause of treatment failure in chronic infections, is often linked to bacterial phenotypic heterogeneity, yet the underlying regulatory mechanisms remain largely understood. This study uncovers a fundamental survival strategy employed by intracellular pathogen Salmonella, where host-derived manganese acts as a critical signal to induce a reversible, dormant state. We demonstrate that stress-induced Mn2+ influx activates widespread protein UMPylation, which functions as a molecular glue to drive the aggregation of essential proteins, thereby halting bacterial growth and conferring antibiotic tolerance. Crucially, this state is reversible upon stress relief through Mn2+ efflux and subsequent de-UMPylation, enabling rapid bacterial resuscitation. As an evolutionarily conserved mechanism of adaptive tolerance, this metal-ion-responsive switch, mediated by reversible protein UMPylation, identifies a key target for developing therapeutics against persistent bacterial infections.

microbiology↗

bioRxiv2026

Ventral anterior foregut endoderm cells as progenitors for airway epithelial cell replacement in primary ciliary dyskinesia

BackgroundLung transplantation remains the ultimate treatment option for patients with end-stage lung disease, but has many limitations. This underlines the urgent need of developing alternative approaches to treat lung disorders. Among the emergent strategies, gene therapy holds great potential for the treatment of monogenic lung diseases. However, so far, aerosolized viral vector-based delivery for gene therapy has failed likely because of difficulties in accessing the target cells. Combined gene and cell therapy approaches could be a promising alternative. Trials using basal cell transplantation already showed encouraging results. Moreover, the induced pluripotent stem cell (iPSC) technology broadens the scope of personalized therapies by paving the way for autologous approaches. Our group previously derived iPSC lines from patients with Primary Ciliary Dyskinesia (PCD) and found that their correction by gene conversion allows functional recovery. This study aimed to identify the best progenitors and airway conditioning technique to develop an autologous cell replacement strategy for PCD. MethodsAirway epithelial cells were differentiated from induced pluripotent stem cell (iPSC) lines from a healthy donor (parental Hy03) and Hy03 in which MCIDAS was knocked out (PCD model) and maintained in air-liquid interface (iALI). The engraftment of GFP+ ventral Anterior Foregut Endoderm (vAFE) cells, differentiated from GFP-expressing Hy03 iPSCs, was assessed after conditioning of the recipient iALI. The efficacy (epithelial cell shedding) and toxicity (cell death) of different conditioning strategies were compared. Cilia functional repair was assessed using microbead motion tracking. ResultsGFP+ vAFE cells can successfully integrate and repair trypsin- or EDTA-conditioned airway epithelia derived from the parental and MCIDAS-/- Hy03 iPSC lines. EDTA showed optimal efficacy/safety balance. Progenitor integration and differentiation were confirmed by E-cadherin, tubulin-IV, KRT5 and MUC5AC co-expression in GFP+ engrafted cells at day 35 post-graft (immunofluorescence analysis). The engrafted GFP+ population reached 35-45% of the total epithelial population, as indicated by flow cytometry quantification of EpCAM+/GFP+ cells. Functional analysis demonstrated cilia motion restoration after GFP+ cell engraftment onto MCIDAS-/- iALI. ConclusionsOur study shows that vAFE cells can integrate and differentiate to repair epithelial models of PCD. EDTA conditioning is promising for the clinical application of this therapeutic strategy.

cell biology↗

bioRxiv2026

Large-scale Visuomotor Reaction Time Self-Testing Reveals Subtle Motor Changes in Older Adults with Subjective Cognitive Impairment

IntroductionAffordable tools for early Alzheimers disease (AD) detection could support drug development and early intervention. Subtle motor changes may indicate preclinical AD, but hand response selection and initiation speeds are understudied. This study assessed whether unsupervised, online visuomotor reaction time (RT) tests relate to subjective cognitive impairment (SCI), a validated high risk state for future conversion to AD MethodsA total of 910 participants (age 66.3{+/-}7.5, 70.8% female) completed assessments of simple and choice visuomotor RT tests at home as part of the online TAS Test protocol; they also completed the Cambridge Neuropsychological Test Automated Battery (CANTAB) episodic memory and executive function tests. Among them, 142 participants reported SCI. ResultsOn the TAS Test visuomotor tests, SCI was associated with 8.4% [1.4%, 15.4%] longer RT ( (p = .008; adjusted for task complexity), greater odds of time-out failure (OR = 1.35 [1.01, 1.81]; p = .037), and greater variance in RT (log-variance (SCI - comparison) = .094 [.028, .159]; p < .001). There were no significant differences between the SCI and comparison groups on any of the CANTAB tests. After adjusting for SCI status, none of the CANTAB tests were significantly associated with RT. DiscussionSCI was associated with longer and more variable visuomotor RT, and greater odds of time-out failure, while not being associated with tests of memory and executive function. Cognitive test scores did not explain a significant amount of variance in visuomotor RT. Taken together, these results support a hypothesis that people with SCI may be experiencing earlier visuomotor deficits that are distinct from (or precede) decline in episodic memory and executive function. Visuomotor tasks that record RT may be more sensitive to preclinical manifestations of cognitive decline than more traditional tests of cognitive function.

bioinformatics↗

bioRxiv2025

Hepatitis E ORF2 blocks trophoblast autophagy to induce miscarriage via LC3B binding rather than PI3K/Akt/mTOR pathway suppression

Hepatitis E virus (HEV) is a zoonotic pathogen that can infect pregnant women and cause adverse pregnancy outcomes, including miscarriage and preterm delivery. The previous study demonstrated that HEV genotype 3 (HEV-3) inhibits complete autophagic flux in both mouse placental tissue and human trophoblast cells (JEG-3), evidenced by reduced expression of ATG proteins (including LC3, Beclin1, ATG4B, ATG5, and ATG9A) and accumulation of p62. However, the specific regulatory pathway involved remains unclear. Thus, eukaryotic expression vectors for HEV open reading frames (ORFs) were constructed, and ORF2 and ORF3 proteins were transiently overexpressed in JEG-3 cells via liposome transfection.. While both ORF2 and ORF3 significantly reduced LC3B protein levels (p < 0.01), only ORF2 induced p62 accumulation (p < 0.01), indicative of autophagic inhibition, which indicates that ORF2 was the key viral protein mediating autophagy suppression in JEG-3. The results of WB and RT-qPCR show that ORF2 suppressed the PI3K/Akt/mTOR pathway while enhancing nuclear translocation of TFEB (p < 0.01) and AMPK phosphorylation (p < 0.01), suggesting paradoxical activation of upstream autophagy regulators. Through co-transfection of mCherry-LC3 with ORF2, co-localization studies, and AlphaFold 3-based intermolecular interaction predictions, we proposed that ORF2 directly binds LC3B to block autophagosome formation. Finally, co-immunoprecipitation confirmed physical interaction between HEV ORF2 and LC3B, elucidating the molecular mechanism of HEV-induced autophagy suppression in trophoblasts. These findings reveal the molecular mechanism by which HEV inhibits autophagy leading to miscarriage in mice, providing new insights into HEV-induced reproductive damage.

pathology↗

bioRxiv2025

Control of leaflet movement pattern by a novel PP2C phosphatase DLM1 in Medicago truncatula

Sessile plants exhibit diverse movement behaviors that have long intrigued the scientists. The legume plants display a rhythmic leaflet movement pattern characterized by horizontal opening during the day and vertical closure at night. However, the underlying mechanisms remain largely enigmatic. Here, we isolated a mutant designated as dlm1 (downward leaflet movement1) from Medicago truncatula that displays leaflets downward opening during daytime while upward closure at night. Cellular analyses reveal that this aberrant phenotype correlates with abnormal volume changes of motor cells within the pulvinus. DLM1 exhibits high expression level in the motor organ pulvinus and encodes an unreported nuclear-localized PP2C phosphatase. Notably, phylogenetic analysis demonstrates that species exhibiting rhythmic leaflet movements consistently retain DLM1 homologs, suggesting the possibility of its functionally conserved role in regulating leaflets movement pattern. Structural characterization reveals that DLM1 possesses both phosphatase and kinase domains. Functional complementation assays demonstrate that the phosphatase domain is necessary and sufficient for maintaining the leaflet movement pattern. Collectively, our work uncovers a novel PP2C protein that governs the leaflet movement, providing mechanistic insights into this intriguing plant behavior.

plant biology↗

bioRxiv2025

The Pesticide Chlorpyrifos Increases the Risk of Parkinson's Disease

Background and PurposePesticides have been associated with an increased risk of Parkinsons disease (PD), but it is unclear which specific pesticides contribute to this association and whether it is causal. Since chlorpyrifos (CPF) exposure has been implicated as a risk factor for PD, we investigated its association to incident PD and if this association is biologically plausible using human, rodent, and zebrafish (ZF) studies. MethodsThe association of CPF with PD was assessed using the UCLA PEG study (829 PD and 824 control subjects), and proximity-based exposure estimates from living or working near agricultural CPF use. For the mammalian studies, 6 months old male C57BL/6 mice were divided into two groups, CPF and controls, for open field, rotarod, and wire hang behavioral testing. Mice were then exposed to CPF in an inhalation chamber (0.65-2.9 mg/m3/day) for 6 hrs./day 5 days/wk., whereas control mice were exposed to vehicle alone. Behavioral tests were performed before and 2.5 months after CPF exposure following a 3-day washout. Mice were then perfused for immunohistochemical analysis. For the mechanistic studies, ZF embryos were treated with CPF (250 nM) 24 hours post fertilization for 5-7 days. Behavioral testing was performed using the Viewpoint Imaging System. Neuronal loss and microglial activation were determined using immunohistochemistry. Neuronal autophagic flux was determined using autophagy modulators in GFP-LC3 transgenic ZF and Western blots. ResultsLong-term residential CPF exposure was linked to an increased risk of developing PD with an odds ratio of 2.68 (CI 1.58-4.55). Mice exposed to aerosolized CPF developed motor impairment and a significant loss of dopaminergic neurons in the substantia nigra and activation of microglia. TH positive neurons in the substantia nigra (SN) had significantly higher levels of phosphoserine 129 (pS129) -synuclein (-syn), a marker for pathological phosphorylated -syn, and ubiquitin. In contrast, neither pS129 -syn or ubiquitin accumulated in TH neurons in the VTA after CPF exposure. Consistent with the mice data, CPF exposure resulted in impairment of locomotor activity and selective loss of aminergic neurons in ZF. We also found an increase in neuronal apoptosis and microglial activation. Importantly, dopamine neuron loss was found to be at least partially dependent on {gamma}1-synuclein (closest functional homologue to human -syn) as neuronal loss did not occur in {gamma}1-synuclein knockout ZF. Using an in vivo ZF assay, we found impaired autophagic flux and an increase in lysosomal labelling within the zebrafish brain. CPF exposure also led to elevated {gamma}1-synuclein and p62 (autophagic cargo protein) levels consistent with impaired degradation. Furthermore, induction of autophagy was protective, supporting the hypothesis that impaired autophagic flux is at least partially responsible for neuron loss following CPF exposure. ConclusionsCPF exposure is associated with an increased risk of developing PD and this association is likely causal since PD-like pathology was recapitulated in animal models. Furthermore, impaired autophagic flux appears to underly this toxicity, a pathway implicated in the pathogenesis of PD.

neuroscience↗

bioRxiv2024

An adaptive autoregressive diffusion approach to design active humanized antibody and nanobody

Humanization is a critical process for designing efficiently specific antibodies and nanobodies prior to clinical trials. Developing widely recognized deep learning techniques or frameworks for humanizing conventional antibodies and nanobodies presents a valuable yet challenging task. Inspired by the effectiveness of diffusion models across various applications, we introduce HuDiff, an adaptive diffusion approach for humanizing antibodies and nanobodies from scratch, referred to as HuDiff-Ab and HuDiff-Nb, respectively. This approach begins the humanization process exclusively with complementarity-determining region (CDR) sequences, eliminating the need for humanized templates. On public benchmark datasets, the results of HuDiff-Abs humanized antibodies are more similar to experimentally humanized antibodies than to those of the Sapiens humanization model. Besides, humanized nanobodies produced by HuDiff-Nb exhibit a higher humanness score and greater nativeness than those generated by the Lammanade pipeline for humanization nanobody. We apply HuDiff to humanize a mouse antibody and an alpaca nanobody, both targeting the SARS-CoV-2 RBD, and validate the binding affinity of humanized sequences through Bio-Layer Interferometry (BLI) experiments. The results show the binding affinity of the best humanized antibody is nearly equal to that of the parental mouse antibody (0.15 nM vs. 0.12 nM). Remarkably, the top-performing humanized nanobody exhibits a significantly enhanced binding affinity compared to the parental alpaca nanobody (2.52 nM vs. 5.47 nM), representing a 54% increase. These findings indicate that our approach HuDiff is highly effective in enhancing the humanness of antibodies and nanobodies while maintaining or potentially improving the binding affinity of the designed humanized sequences. The code and checkpoints of HuDiff are available at https://github.com/TencentAI4S/HuDiff.

bioinformatics↗

bioRxiv2024

Tau load in select brainstem neurons predicts the severity and nature of balance deficits in the absence of cell death

Patients with tauopathies present with profoundly different clinical symptoms1, even within the same disorder2. A central hypothesis in the field, well-supported by biomarker studies3,4 and post-mortem pathology5-7, is that clinical heterogeneity reflects differential degeneration of vulnerable neuronal populations responsible for specific neurological functions. Recent work has revealed mechanisms underlying susceptibility of particular cell types8-10, but relating tau load to disrupted behavior -- es- pecially before cell death -- requires a targeted circuit-level approach. Here we studied two distinct balance behaviors in larval zebrafish11 expressing a human 0N/4R-tau allele12 in select populations of evolutionarily-conserved and well-characterized brainstem vestibular circuits13,14. We observed that human tau load predicted the severity of circuit-specific deficits in posture and navigation in the ab- sence of cell death. Targeting expression to either mid- or hindbrain balance neurons recapitulated these particular deficits in posture and navigation. By parametrically linking tau load in specific neu- rons to early behavioral deficits, our work moves beyond cell type to close the gap between pathological and neurological conceptions of tauopathy.

neuroscience↗

bioRxiv2023

A versatile framework for drug-target interaction prediction by considering domain specific features

Predicting drug-target interaction (DTI) is a critical and rate-limiting step in drug discovery. Traditional wet-lab experiments are reliable but expensive and time-consuming. Recently, deep learning has revealed itself as a new and promising tool for accelerating the DTI prediction process because its powerful performance. Due to the vast chemical space, the DTI prediction models are typically expected to discover drugs or targets that are absent from the training set. However, generalizing prediction performance to novel drug-target pairs that belong to different distributions is a challenge for deep learning methods. In this work, we propose an Ensemble of models that capture both Domain-generIc and domain-Specific features (E-DIS) to learn diversity domain features and adapt to out-of-distribution (OOD) data. We employed Mixture-of-Experts (MOE) as a domain-specific feature extractor for the raw data to prevent the loss of any crucial features by the encoder during the learning process. Multiple experts are trained on different domains to capture and align domain-specific information from various distributions without accessing any data from unseen domains. We evaluate our approach using four benchmark datasets under both in-domain and cross-domain settings and compare it with advanced approaches for solving OOD generalization problems. The results demonstrate that E-DIS effectively improves the robustness and generalizability of DTI prediction models by incorporating diversity domain features.

bioinformatics↗

bioRxiv2022

ZBTB20 is Essential for Cochlear Maturation and Hearing in Mice

The mammalian cochlear epithelium undergoes substantial remodeling and maturation before the onset of hearing. However, very little is known about the transcriptional network governing cochlear late-stage maturation and particularly the differentiation of its lateral non-sensory region. Here we establish ZBTB20 as an essential transcription factor required for cochlear terminal differentiation and maturation and hearing. ZBTB20 is abundantly expressed in the developing and mature cochlear non-sensory epithelial cells, with transient expression in immature hair cells and spiral ganglion neurons. Otocyst-specific deletion of Zbtb20 causes profound deafness with reduced endolymph potential in mice. The subtypes of cochlear epithelial cells are normally generated but their postnatal development is arrested in the absence of ZBTB20, as manifested by an immature appearance of the organ of Corti, malformation of tectorial membrane, a flattened spiral prominence, and a lack of identifiable Boettcher cells. Furthermore, these defects are related with a failure in the terminal differentiation of the non-sensory epithelium covering the outer border Claudius cells, outer sulcus root cells and spiral prominence epithelial cells. Transcriptome analysis shows ZBTB20 regulates genes coding for tectorial membrane proteins in the greater epithelial ridge, and those preferentially expressed in root cells and spiral prominence epithelium. Our results point to ZBTB20 as an essential regulator for postnatal cochlear maturation and particularly for the terminal differentiation of cochlear lateral non-sensory domain.

developmental biology↗

bioRxiv2021

A multiepitope fusion protein-based p-ELISA method for diagnosing bovine and goat brucellosis

In recent years, the incidence of brucellosis has increased annually, which has caused tremendous economic losses in agriculture and husbandry in various countries. Therefore, developing rapid, sensitive and specific diagnostic techniques for brucellosis has become critical brucellosis research. Bioinformatics technology was used to predict the B cell epitopes of the main antigen proteins of Brucella, and the validity of each epitope was verified by indirect enzyme-linked immunosorbent assay (iELISA). The verified epitopes were connected in series to construct a multiepitope fusion protein, goat, bovine brucellosis sera, and rabbit sera were collected to verify the antigenicity and specificity of this protein. Then, the fusion protein was used as a diagnostic antigen to construct paper-based ELISA (p-ELISA) technology. A total of 22 effective epitopes were predicted, and a fusion protein was successfully constructed, which showed good antigenicity and specificity. The constructed p-ELISA method was used for the simultaneous detection of bovine and goat brucellosis. ROC curve analysis showed that the sensitivity and specificity of protein detection in goat serum were 98.85% and 98.51%, respectively. The positive and the negative predictive value was 99.29% and 98.15%, respectively. When assessing bovine serum, the sensitivity and specificity were 97.85% and 96.61%, respectively. The positive and the negative predictive value was 98.28% and 97.33%, respectively. This study combined bioinformatics, fusion protein development and p-ELISA technologies to establish a sensitive and specific rapid diagnosis technology for brucellosis that can be used to assess the serum of bovine, goats and other livestock. IMPORTANCEBrucellosis has caused tremendous economic losses in agriculture and husbandry in various countries. Therefore, developing rapid, sensitive and specific diagnostic techniques for brucellosis has become critical brucellosis research. In this study, we used immunoinformatic technology to predict the B cell epitopes in the major outer membrane proteins of Brucella, synthesized polypeptides and coupled them with KLH, screened these polypeptides by iELISA methods, selected effective polypeptides as diagnostic antigens, and established a p-ELISA for brucellosis diagnosis based on a multiepitope fusion protein that can be used to assess the serum of bovine, goats and other livestock.

microbiology↗

bioRxiv2020

Proinflammatory S100A9 Regulate Differentiation and Aggregation of Neural Stem Cells

Inflammation is the primary pathological feature of neurodegenerative diseases such as Alzheimers (AD) and Parkinsons disease. Proinflammatory molecules (e.g. S100A9) play important roles during progression of the diseases by regulating behavior and fate of multiple cell types in the nervous system (1). Our earlier studies reveal that S100A9 is toxic to neurons, and its interaction with A{beta} peptides leads to the formation of large non-toxic amyloidogenic aggregates, suggesting a protective role of A{beta} amyloids (2). We herein, demonstrate that S100A9 interacts with neural stem cells (NSCs) and causes NSC differentiation. In the brain of transgenic AD mouse models, we found large quantities of proinflammatory S100A9, which colocalizes with the differentiated NSCs. NSC sphere formation, which is a representative character of NSC stemness, is also substantially inhibited by S100A9. These results suggest that S100A9 is a representative marker for the inflammatory conditions in AD, and it promotes NSC differentiation. Intriguingly, in contrast to the death of both stem and differentiated NSCs caused by high S100A9 doses, S100A9 at a moderate concentration is toxic only to the early differentiated NSCs (i.e. progenitor cells and immature neurons), but not the stem cells. We therefore postulate that at the early stage of AD, expression of S100A9 leads to NSC differentiation, which remedies the neuron damages. The application drugs, which help maintain NSC stemness (e.g. PDGF), may help overcome the acute inflammatory conditions and improve the efficacy of NSC transplantation therapy.

cell biology↗

bioRxiv2020

Seizures are a druggable mechanistic link between TBI and subsequent tauopathy

Traumatic brain injury (TBI) is a prominent risk factor for neurodegenerative diseases and dementias including chronic traumatic encephalopathy (CTE). TBI and CTE, like all tauopathies, are characterized by accumulation of Tau into aggregates that progressively spread to other brain regions in a prion-like manner. The mechanisms that promote spreading and cellular uptake of tau seeds after TBI are not fully understood, in part due to lack of tractable animal models. Here, we test the putative roles for excess neuronal activity and dynamin-dependent endocytosis in promoting the in vivo spread of tauopathy. We introduce tauopathy reporter zebrafish expressing a genetically-encoded fluorescent Tau biosensor that reliably reports accumulation of human tau species when seeded via intra-ventricular brain injections. Subjecting zebrafish larvae to a novel TBI paradigm produced various TBI symptoms including cell death, hemorrhage, blood flow abnormalities, post-traumatic seizures, and Tau inclusions. Bath application of anticonvulsant drugs rescued TBI-induced tauopathy and cell death; these benefits were attributable to inhibition of post-traumatic seizures because co-application of convulsants reversed these beneficial effects. However, one convulsant drug, 4-Aminopyridine, unexpectedly abrogated TBI-induced tauopathy - this was due to its inhibitory action on endocytosis as confirmed via additional dynamin inhibitors. These data suggest a role for seizure activity and dynamin-dependent endocytosis in the prion-like seeding and spreading of tauopathy following TBI. Further work is warranted regarding anti-convulsants that dampen post-traumatic seizures as a route to moderating subsequent tauopathy. Moreover, the data highlight the utility of deploying in vivo Tau biosensor and TBI methods in larval zebrafish, especially regarding drug screening and intervention. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=117 SRC="FIGDIR/small/091819v1_ufig1.gif" ALT="Figure 1"> View larger version (24K): org.highwire.dtl.DTLVardef@34a2caorg.highwire.dtl.DTLVardef@1ab916borg.highwire.dtl.DTLVardef@d83bf2org.highwire.dtl.DTLVardef@47bf90_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIIntroduces first Traumatic Brain Injury (TBI) model in larval zebrafish, and its easy C_LIO_LITBI induces clinically relevant cell death, haemorrhage & post-traumatic seizures C_LIO_LICa2+ imaging during TBI reveals spike in brain activity concomitant with seizures C_LIO_LITau-GFP Biosensor allows repeated in vivo measures of prion-like tau aggregation C_LIO_LIpost-TBI, anticonvulsants stop tauopathies akin to Chronic Traumatic Encephalopathy C_LI

neuroscience↗

bioRxiv2019

Antigenicity and Potential Use of A Novel Brucella Multiepitope Recombinant Protein in the Diagnosis of Brucellosis

Currently, brucellosis is a reemerged zoonotic infectious disease with an increased incidence in recent years. A simple, rapid and sensitive method for diagnosing brucellosis has important significance for early diagnosis and early treatment, which can help to reduce medical burden and economic loss. Previously, a multiple epitope recombinant protein was constructed based on linear B-cell epitope prediction tools. In this study, the recombinant protein was used as an antigen to study the immune response produced by immunized mice, and goat serum was used to verify its diagnostic accuracy.The production of antibodies was successfully induced in the vaccinated mice. Through analyzing the serum antibody subtypes, the primary antibody was identified as IgG. Flow cytometric analysis revealed that the percentage of CD4+, CD8+ and the CD4+/CD8+ ratios were increased by T cell subsets in mouse splenocytes, indicating that the recombinant protein induced a strong immune response in mice and that it had strong immunoreactivity. Using indirect ELISA, the recombinant protein correctly diagnosed positive and negative brucellosis samples. Compared with the whole bacterial antigen, the recombinant protein had a weaker sensitivity but a stronger specificity.In this study, animal experiments showed that the recombinant protein had good antigenicity, and indirect ELISA indicates that it can be used as an antigen to diagnose brucellosis. Therefore, the recombinant protein is a potential candidate antigen for brucellosis vaccine development and serological diagnosis.

zoology↗

bioRxiv2017

Direct Conversion Of Human Fibroblasts Into Osteoblasts And Osteocytes With Small Molecules And A Single Factor, Runx2

Human osteoblasts can be induced from somatic cells by introducing defined factors, however, the strategy limits cells therapeutic applications for its multi-factor and complicated genetic manipulations that may bring uncertainty into the genome. Another important cell type in bone metabolism, osteocytes, which play a central role in regulating the dynamic nature of bone in all its diverse functions, have not been obtained from transdifferetiation so far. Herein, we have established procedures to convert human fibroblast directly into osteocyte-like and osteoblast-like cells using a single transcription factor, Runx2 and chemical cocktails by activating Wnt and cAMP/PKA pathways. These induced osteoblast-like cells express osteogenic markers and generate mineralized nodule deposition. A good performance of bone formation from these cells was observed in subcutaneous site of mouse at 4 weeks post-transplantation. Moreover, further studies convert human fibroblasts into osteocyte-like cells by orchestrating timing of the aforementioned chemical cocktails exposure. These osteocyte-like cells express osteocyte-specific markers and display characteristic morphology features of osteocytes. In summary, this study provides a promising strategy for cell-based therapy in bone regenerative medicine by direct reprogramming of fibroblasts into osteocytes and osteoblasts.

cell biology↗