Biology subjects

Du, J.

Publications and source records attributed to Du, J..

At least 127 records · Page 7Linked to original sources

bioRxiv2023

TIPE drives a cancer stem-like phenotype by promoting glycolysis via PKM2/HIF-1alpha axis in melanoma

TIPE (TNFAIP8) has been identified as an oncogene and participates in tumor biology. However, how its role in the metabolism of tumor cells during melanoma development remains unclear. Here, we demonstrated that TIPE promoted glycolysis by interacting with pyruvate kinase M2 (PKM2) in melanoma. We found that TIPE induced PKM2 dimerization, thereby facilitating its translocation from the cytoplasm to the nucleus. TIPE-mediated PKM2 dimerization consequently promoted HIF-1 activation and glycolysis, which contributed to melanoma progression and increased its stemness features. Notably, TIPE specifically phosphorylated PKM2 at Ser 37 in an ERK-dependent manner. Consistently, the expression of TIPE was positively correlated with the levels of PKM2 Ser37 phosphorylation and cancer stem cell markers in melanoma tissues from clinical samples and tumor bearing mice. In summary, our findings indicate that the TIPE/PKM2/HIF-1 signaling pathway plays a pivotal role in promoting cancer stem cell properties by facilitating the glycolysis, which would provide a promising therapeutic target for melanoma intervention.

cancer biology↗

bioRxiv2023

Photobodies enable the phase-separation and counterbalance of phytochrome B mediated PIF5 degradation and stabilization

Photoactivation of the plant photoreceptor and thermosensor phytochrome B (PHYB) triggers its condensation into subnuclear photobodies (PBs). However, the function of PBs remains frustratingly elusive. Here, we found that PHYB recruits PHYTOCHROME-INTERACTING FACTOR5 (PIF5) to PBs. Surprisingly, PHYB exerts opposing roles in degrading and stabilizing PIF5. Perturbing PB size by overproducing PHYB provoked a biphasic PIF5 response: while a moderate increase in PHYB enhanced PIF5 degradation, further elevating the PHYB level stabilized PIF5 by retaining more of it in enlarged PBs. These results reveal a PB-mediated light and temperature sensing mechanism, in which PHYB condensation confers the co-occurrence and competition of two antagonistic phase-separated PHYB signaling actions--PIF5 stabilization in PBs and PIF5 degradation in the surrounding nucleoplasm-- thereby enabling an environmentally-sensitive counterbalancing mechanism to titrate nucleoplasmic PIF5 and its transcriptional output. This PB-enabled signaling mechanism provides a framework for regulating a plethora of PHYB-interacting signaling molecules in diverse plant environmental responses.

plant biology↗

bioRxiv2023

Super-Resolution Imaging of Fast Morphological Dynamics of Neurons in Behaving Animals

Neurons are best studied in their native working states in which their functional and morphological dynamics support animals natural behaviors. Super-resolution microscopy can potentially reveal these dynamics in much higher details but has been challenging in behaving animals due to severe motion artifacts. Here, we report multiplexed line-scanning structured illumination microscopy, which could tolerate motions of up to 50 m/s while achieving 150 and 100 nm lateral resolutions in its linear and nonlinear forms respectively over large fields-of-view. We continuously imaged the dynamics of spinules in dendritic spines and axonal boutons volumetrically over thousands of frames and tens of minutes in mouse brains during sleep-wake cycles. Super-resolution imaging of axonal boutons revealed their prevalent spinule dynamics on a scale of seconds. Simultaneous two-color imaging further enabled analyses of the correlation between the spatial distributions of diverse PSD-95 clusters and the structural dynamics of dendrites in the brains of awake mice.

neuroscience↗

bioRxiv2023

Microglia facilitate and stabilize the response to general anesthesia

General anesthesia leads to a loss of consciousness and an unarousable state in patients. Although general anesthetics are widely used in clinical practice, their underlying mechanisms remain elusive. The potential involvement of nonneuronal cells is unknown. Microglia are important immune cells in the central nervous system (CNS) that play critical roles in CNS function and dysfunction. We unintentionally observed delayed anesthesia induction and early anesthesia emergence in microglia-depleted mice. We found that microglial depletion differentially regulates neuronal activities by suppressing the neuronal network of anesthesia-activated brain regions and activating emergence-activated brain regions. Thus, microglia facilitate and stabilize the anesthesia status. This influence is not mediated by dendritic spine plasticity. Instead, it relies on the activation of microglial P2Y12 and subsequent calcium influx, which facilitates the general anesthesia response. Together, we elucidate the regulatory role of microglia in general anesthesia, extending our knowledge of how nonneuronal cells modulate neuronal activities.

neuroscience↗

bioRxiv2023

DRG Explant Model: Elucidating Mechanisms of Oxaliplatin-Induced Peripheral Neuropathy and Identifying Potential Therapeutic Targets

Oxaliplatin triggered chemotherapy induced peripheral neuropathy (CIPN) is a common and debilitating side effect of cancer treatment which limits the efficacy of chemotherapy and negatively impacts patients quality of life dramatically. For better understanding the mechanisms of CIPN and screen for potential therapeutic targets, it is critical to have reliable in vitro assays that effectively mirror the neuropathy in vivo. In this study, we established a dorsal root ganglia (DRG) explant model. This model displayed dose-dependent inhibition of neurite outgrowth in response to oxaliplatin, while oxalic acid exhibited no significant impact on the regrowth of DRG. The robustness of this assay was further demonstrated by the inhibition of OCT2 transporter, which facilitates oxaliplatin accumulation in neurons, fully restoring the neurite regrowth capacity. Using this model, we revealed that oxaliplatin triggered a substantial increase of oxidative stress in DRG. Notably, inhibition of TXNIP with verapamil significantly reduced oxidative stress level. Our results demonstrated the use of DRG explants as an efficient model to study the mechanisms of CIPN and screen for potential treatments.

neuroscience↗

bioRxiv2023

The serine/threonine kinase CcAkt regulates the fertility of Coridius chinensis

Akt (also known as protein kinase B) belongs to the multifunctional serine/threonine kinase family and is an important component of the insulin signaling pathway that plays a key role in many biological processes such as cell growth, proliferation, and survival. However, few studies have reported the effect of Akt on reproduction in Hemiptera. In this study, we cloned and characterized the Akt gene from Coridius chinensis (CcAkt). The open reading frame of CcAkt has a length of 1,563 bp and encodes 520 amino acids. It has a conserved pleckstrin homology domain, a serine/threonine protein kinase catalytic domain, and a serine/threonine protein kinase domain. Phylogenetic analysis showed that CcAkt and HhAkt of Halyomorpha halys had the highest similarity. Analysis of temporal and spatial expression patterns revealed that CcAkt is expressed throughout development and in various tissues of C. chinensis adults. CcAkt expression was high in female adult and the fourth instar nymph stage of C. chinensis. In C. chinensis adult, CcAkt expression was highest in the testis and ovary. Injection of bovine insulin induced CcAkt expression, whereas that of 20-hydroxyecdysone significantly reduced CcAkt expression. Both hormones, however, induced the expression of vitellogenin (Vg) and vitellogenin receptor (VgR). In unmated females, CcAkt knockout resulted in decreased expression of CcVg and CcVgR, stunted the development of the ovarioles, decreased the number of eggs and hatching rate. These findings suggest that CcAkt may be involved in regulating the reproduction of C. chinensis.

molecular biology↗

bioRxiv2023

SARS-CoV-2 neurotropism-induced anxiety and depression-like behaviors require Microglia activation

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been associated with a wide range of "long COVID" neurological symptoms. However, the mechanisms governing SARS-CoV-2 neurotropism and its effects on long-term behavioral changes remain poorly understood. Using a highly virulent mouse-adapted SARS-CoV-2 strain, denoted as SARS2-N501YMA30, we demonstrated that intranasal inoculation of SARS2-N501YMA30 results in viral dissemination to multiple brain regions, including the amygdala and hippocampus. Behavioral assays indicated a marked elevation in anxiety- and depression-like behaviors post infection. A comparative analysis of RNA expression profiles disclosed alterations in the post-infected brains. Additionally, we observed dendritic spine remodeling on neurons within the amygdala after infection. Infection with SARS2-N501YMA30 was associated with microglial activation and a subsequent increase in microglia-dependent neuronal activity in the amygdala. Pharmacological inhibition of microglial activity subsequent to viral spike inoculation mitigates microglia-dependent neuronal hyperactivity. Transcriptomic analysis of infected brains revealed the upregulation of inflammatory and cytokine-related pathways, implicating microglia-driven neuroinflammation in the pathogenesis of neuronal hyperactivity and behavioral abnormality. Overall, these data provide critical insights into the neurological consequences of SARS-CoV-2 infection and underscore microglia as a potential therapeutic target for ameliorating virus-induced neurobehavioral abnormalities.

neuroscience↗

bioRxiv2023

Human Striatal Association Megaclusters

The striatum receives projections from multiple regions of the cerebral cortex consistent with its role in diverse motor, affective, and cognitive functions. Supporting cognitive functions, the caudate receives projections from cortical association regions. Building on recent insights about the details of how multiple cortical networks are specialized for distinct aspects of higher-order cognition, we revisited caudate organization using within-individual precision neuroimaging (n=2, each participant scanned 31 times). Detailed analysis revealed that the caudate has side-by-side zones that are coupled to at least Give distinct distributed association networks, paralleling the specialization observed in the cerebral cortex. Examining correlation maps from closely juxtaposed seed regions in the caudate recapitulated the Give distinct cerebral networks including their multiple spatially distributed regions. These results extend the general notion of parallel specialized basal ganglia circuits, with the additional discovery that even within the caudate, there is Gine-grained separation of multiple distinct higher-order networks.

neuroscience↗

bioRxiv2023

The circadian clock regulates PIF3 protein stability in parallel to red light

The circadian clock is an endogenous oscillator, but its importance lies in its ability to impart rhythmicity on downstream biological processes or outputs. Focus has been placed on understanding the core transcription factors of the circadian clock and how they connect to outputs through regulated gene transcription. However, far less is known about posttranslational mechanisms that tether clocks to output processes through protein regulation. Here, we identify a protein degradation mechanism that tethers the clock to photomorphogenic growth. By performing a reverse genetic screen, we identify a clock-regulated F-box type E3 ubiquitin ligase, CLOCK-REGULATED F-BOX WITH A LONG HYPOCOTYL 1 (CFH1), that controls hypocotyl length. We then show that CFH1 functions in parallel to red light signaling to target the transcription factor PIF3 for degradation. This work demonstrates that the circadian clock is tethered to photomorphogenesis through the ubiquitin proteasome system and that PIF3 protein stability acts as a hub to integrate information from multiple environmental signals.

plant biology↗

bioRxiv2023

Human Pannexin 1 Channel is NOT Phosphorylated by Src Tyrosine Kinase at Tyr199 and Tyr309

Protein phosphorylation is one of the major molecular mechanisms regulating protein activity and function throughout the cell. Pannexin 1 (PANX1) is a large-pore channel permeable to ATP and other cellular metabolites. Its tyrosine phosphorylation and subsequent activation have been found to play critical roles in diverse cellular conditions, including neuronal cell death, acute inflammation, and smooth muscle contraction. Specifically, the non-receptor kinase Src has been reported to phosphorylate Tyr198 and Tyr308 of mouse PANX1 (equivalent to Tyr199 and Tyr309 of human PANX1), resulting in channel opening and ATP release. Although the Src-dependent PANX1 activation mechanism has been widely discussed in the literature, independent validation of the tyrosine phosphorylation of PANX1 has been lacking. Here, we show that commercially available antibodies against the two phosphorylation sites mentioned above--which were used to identify endogenous PANX1 phosphorylation at these two sites-- are nonspecific and should not be used to interpret results related to PANX1 phosphorylation. We further provide evidence that neither tyrosine residue is a major phosphorylation site for Src kinase in heterologous expression systems. We call on the field to re-examine the existing paradigm of tyrosine phosphorylation-dependent activation of the PANX1 channel.

biochemistry↗

bioRxiv2023

Neuronal acid-sensing ion channel 1a regulates neuron-to-glioma synapses

Neuronal activity promotes high-grade glioma progression via secreted proteins and neuron-to-glioma synapses, and glioma cells boost neuronal activity to further reinforce the malignant cycle. Whereas strong evidence supports that the activity of neuron-to-glioma synapses accelerates tumor progression, the molecular mechanisms that modulate the formation and function of neuron-to-glioma synapses remain largely unknown. Our recent findings suggest that a proton (H+) signaling pathway actively mediates neuron-to-glioma synaptic communications by activating neuronal acid-sensing ion channel 1a (Asic1a), a predominant H+ receptor in the central nervous system (CNS). Supporting this idea, our preliminary data revealed that local acid puff on neurons in high-grade glioma-bearing brain slices induces postsynaptic currents of glioma cells. Stimulating Asic1a knockout (Asic1a-/-) neurons results in lower AMPA receptor-dependent excitatory postsynaptic currents (EPSCs) in glioma cells than stimulating wild-type (WT) neurons. Moreover, glioma-bearing Asic1a-/- mice exhibited reduced tumor size and survived longer than the glioma-bearing WT mice. Finally, pharmacologically targeting brain Asic1a inhibited high-grade glioma progression. In conclusion, our findings suggest that the neuronal H+-Asic1a axis plays a key role in regulating the neuron-glioma synapse. The outcomes of this study will greatly expand our understanding of how this deadly tumor integrates into the neuronal microenvironment.

neuroscience↗

bioRxiv2023

Acid-sensing ion channel 1a contributes to the prefrontal cortex ischemia-enhanced neuronal activities in the amygdala

Following a stroke, the emergence of amygdala-related disorders poses a significant challenge, with severe implications for post-stroke mental health, including conditions such as anxiety and depression. These disorders not only hinder post-stroke recovery but also elevate mortality rates. Despite their profound impact, the precise origins of aberrant amygdala function after stroke remain elusive. As a target of reduced brain pH in ischemia, acid-sensing ion channels (ASICs) have been implicated in synaptic transmission after ischemia, hinting at their potential role in reshaping neural circuits following a stroke. This study delves into the intriguing relationship between post-stroke alterations and ASICs, specifically focusing on postsynaptic ASIC1a enhancement in the amygdala following prefrontal cortex (PFC) ischemia induced by endothelin-1 (ET-1) injection. Our findings intriguingly illustrate that mPFC ischemia not only accentuates the PFC to amygdala circuit but also implicates ASIC1a in fostering augmented synaptic plasticity after ischemia. In contrast, the absence of ASIC1a impairs the heightened induction of long-term potentiation (LTP) in the amygdala induced by ischemia. This pivotal research introduces a novel concept with the potential to inaugurate an entirely new avenue of inquiry, thereby significantly enhancing our comprehension of the intricate mechanisms underlying post-stroke neural circuit reconfiguration. Importantly, these revelations hold the promise of paving the way for groundbreaking therapeutic interventions.

neuroscience↗

bioRxiv2023

Cooperative progression of colitis and leukemia modulated by clonal hematopoiesis via PTX3/IL-1β pro-inflammatory signaling

Clonal hematopoiesis (CH) is considered an important risk factor for all-cause mortality and the development of multiple chronic diseases including hematological neoplasms, cardiovascular diseases, and potentially a range of autoimmune or immune-deficiency diseases. Mutations in TET2 are one of the first identified, most important, and prevalent genetic drivers of CH. However, cooperative factors and mechanisms underlying TET2-deficiency related CH (TedCH) remain largely unknown. Recently, it has been suggested that certain diseases occurred before TedCH and promote TedCH trajectory on the contrary, indicating that diseases in non-hematopoietic organs may act as environmental non-genetic drivers of CH. To clarify the relationships between immune-dysfunctional diseases and CH, here we tested the impact of various challenges on TedCH. We found that expedited TedCH depended on establishment of an inflammatory environment. Primary or chimeric Tet2-mutant mice spontaneously developed co-symptoms reminiscent of human chronic colitis and myeloid leukemia, which was exacerbated by feeding with DSS, an experimental inducer of ulcerative colitis. Single cell RNA-seq (scRNA-seq) analysis reveals in depth the damage of colon in the Tet2-mutant mice in physiological conditions or fed with DSS, along with increase of dysbacteriosis indicated by gut microbiome analysis. Results from colon scRNA-seq from both mouse and human highlight the important roles of PTX3/IL-1{beta} pro-inflammatory signaling in promoting colitis or leukemia. Finally, TedCH trajectory and inflammation in colon and bone marrow were ameliorated by treatment of IL-1R1 inhibitor Anakinra. Our study suggests that PTX3/IL-1{beta} signaling and clonal hematopoiesis cooperate and play important roles in gut-bone marrow axis and related diseases including colitis and leukemia. HighlightsO_LICertain environmental factors, such as Dextran Sulfate Sodium (DSS), an experimental inducer of ulcerative colitis, promote TedCH C_LIO_LIColitis and leukemia are spontaneously and simultaneously developed in Tet2-defficient primary or chimeric mice, along with increased pathogenic gut microbiomes, indicating an aberrant gut-bone marrow axis in the mutant mice. C_LIO_LISingle cell RNA-seq analysis reveals enhanced PTX3, a soluble pattern recognition molecule and IL-1{beta} pro-inflammatory signaling in colitis and leukemia. C_LIO_LIThe In vivo function of the PTX3/IL-1{beta} pro-inflammatory signaling in TedCH is indicated in human colitis and validated in experimental settings. C_LI

immunology↗

bioRxiv2023

Within-Individual Organization of the Human Cerebral Cortex: Networks, Global Topography, and Function

The human cerebral cortex is populated by specialized regions that are organized into networks. Here we estimated networks using a Multi-Session Hierarchical Bayesian sModel (MS-HBM) applied to intensively sampled within-individual functional MRI (fMRI) data. The network estimation procedure was initially developed and tested in two participants (each scanned 31 times) and then prospectively applied to 15 new participants (each scanned 8 to 11 times). Detailed analysis of the networks revealed a global organization. Locally organized first-order sensory and motor networks were surrounded by spatially adjacent second-order networks that also linked to distant regions. Third-order networks each possessed regions distributed widely throughout association cortex. Moreover, regions of distinct third-order networks displayed side-by-side juxtapositions with a pattern that repeated similarly across multiple cortical zones. We refer to these as Supra-Areal Association Megaclusters (SAAMs). Within each SAAM, two candidate control regions were typically adjacent to three separate domain-specialized regions. Independent task data were analyzed to explore functional response properties. The somatomotor and visual first-order networks responded to body movements and visual stimulation, respectively. A subset of the second-order networks responded to transients in an oddball detection task, consistent with a role in orienting to salient or novel events. The third-order networks, including distinct regions within each SAAM, showed two levels of functional specialization. Regions linked to candidate control networks responded to working memory load across multiple stimulus domains. The remaining regions within each SAAM did not track working memory load but rather dissociated across language, social, and spatial / episodic processing domains. These results support a model of the cerebral cortex in which progressively higher-order networks nest outwards from primary sensory and motor cortices. Within the apex zones of association cortex there is specialization of large-scale networks that divides domain-flexible from domain-specialized regions repeatedly across parietal, temporal, and prefrontal cortices. We discuss implications of these findings including how repeating organizational motifs may emerge during development.

neuroscience↗

bioRxiv2023

A Combination of Machine Learning and PBPK Modeling Approach for Pharmacokinetics Prediction of Small Molecules in Humans

Recently, there has been rapid development in model-induced drug development, which has the potential to reduce animal experiments and accelerate drug discovery. Physiologically based pharmacokinetic (PBPK) and machine learning (ML) models are commonly used in early drug discovery to predict drug properties. However, basic PBPK models require a large number of molecule-specific inputs from in vitro experiments, which hinders the efficiency and accuracy of these models. To address this issue, this paper introduces a new computational platform that combines ML and PBPK models. The platform predicts molecule PK profiles with high accuracy and without the need for experimental data. This study developed a whole-body PBPK model and ML models of plasma protein unbinding (fup), Caco-2 cell permeability, and total plasma clearance to predict the PK of small molecules. Pharmacokinetic profiles were simulated using a "bottom-up" PBPK modeling approach with ML inputs. Additionally, 40 compounds were used to evaluate the platforms accuracy. Results showed that the ML-PBPK model predicted the area under the concentration-time curve (AUC) with 62.5% accuracy within a 2-fold range, which was higher than using in vitro inputs with 47.5% accuracy. The ML-PBPK model platform provides high accuracy in prediction and reduces the number of experiments and time required compared to traditional PBPK approaches. The platform successfully predicts human PK parameters without in vitro and in vivo experiments and can potentially guide early drug discovery and development.

pharmacology and toxicology↗

bioRxiv2023

New germline Cas9 promoters show improved performance for homing gene drive

Gene drive systems could be a viable strategy to prevent pathogen transmission or suppress vector populations by propagating drive alleles with super-Mendelian inheritance. CRISPR-based homing gene drives, perhaps the most powerful gene drive strategy, convert wild type alleles into drive alleles in heterozygotes with the help of Cas9 and gRNA. However, achieving successful outcomes with these drives often requires high performance. Specifically, it is desirable to identify Cas9 promoters that yield high drive conversion rates, minimize the formation rate of resistance alleles in both the germline and the early embryo, and limit somatic Cas9 expression. Thus far, high-performance promoters have only been discovered in Anopheles species. In Drosophila, the nanos promoter avoids leaky somatic expression, but at the cost of high embryo resistance from maternally deposited Cas9. To improve drive efficiency, we tested eleven Drosophila melanogaster germline promoters in several configurations. Some of the new promoters achieved higher drive conversion efficiency with minimal embryo resistance, but none could completely avoid somatic expression like nanos. However, such somatic expression often did not carry detectable fitness costs when the promoter-Cas9 elements supported a rescue homing drive targeting a haplolethal gene, suggesting somatic drive conversion. Based on our findings, we selected two Cas9 promoter lines for cage experiments with a 4-gRNA suppression drive. While one promoter exhibited substantial somatic effects, leading to a low drive equilibrium frequency, the other outperformed nanos, resulting in the successful suppression of the cage population. Overall, these novel Cas9 promoters hold potential advantages for homing drives in Drosophila species and may also possess valuable homologs in other organisms.

genetics↗

bioRxiv2023

Defining Vaginal Community Dynamics: daily microbiome transitions, the role of menstruation, bacteriophages and bacterial genes

BackgroundThe composition of the vaginal microbiota during the menstrual cycle is dynamic, with some women remaining eu- or dysbiotic and others transitioning between these states. What defines these dynamics, and whether these differences are microbiome-intrinsic or mostly driven by the host is unknown. To address this, we characterized 49 healthy, young women by metagenomic sequencing of daily vaginal swabs during a menstrual cycle. We classified the dynamics of the vaginal microbiome and assessed the impact of host behavior as well as microbiome differences at the species, strain, gene and phage levels. ResultsBased on the daily shifts in community state types (CSTs) during a menstrual cycle the vaginal microbiome was classified into four Vaginal Community Dynamics (VCDs) and reported in a classification tool, named VALODY: constant eubiotic, constant dysbiotic, menses-related and unstable dysbiotic. The abundance of bacteria, phages, and bacterial gene content was compared between the four VCDs. Women with different VCDs showed significant differences in relative phage abundance and bacterial composition even when assigned to the same CST. Women with unstable VCDs had higher phage counts and were more likely dominated by L. iners. Their Gardnerella spp. strains were also more likely to harbour bacteriocin-coding genes. ConclusionsThe VCDs present a novel time series classification which highlights the complexity of varying degrees of vaginal dysbiosis. Knowing the differences in phage levels and the genomic strains present allows a deeper understanding of the initiation and maintenance of permanent dysbiosis. Applying the VCDs to further characterize the different types of microbiome dynamics qualifies the investigation of disease and enables comparisons at individual and population levels. Based on our data, to be able to classify a dysbiotic sample into the accurate VCD, clinicians would need two-three mid-cyclical samples and two samples during menses. In the future, it will be important to address whether transient VCDs pose a similar risk profile to persistent dysbiosis with similar clinical outcomes. This framework may aid interdisciplinary translational teams in deciphering the role of the vaginal microbiome in womens health and reproduction.

microbiology↗

bioRxiv2023

Hypoxia Bi-directionally Regulates Gut Vascular Barrier through HIF-1α-dependent Mechanism in vitro

ObjectiveThe gut vascular barrier (GVB) is the key checkpoint for pathogens to enter the blood circulation through the intestine, which is crucial for maintaining the intestinal barrier function. However, the effect and molecular mechanism of hypoxia on GVB remains unclear. Here, we show a role of the transcription factor hypoxia inducible factor-1 (HIF-1) in hypoxia-induced bi-directional regulation of GVB. Approach and ResultsAn in vitro GVB model composed of rat intestinal microvascular endothelial cells was studied. Evans blue-albumin efflux assay showed that the experimentally severe hypoxia induced by cobalt chloride (500 M, 24 h) markedly disrupted the GVB in vitro, while mild hypoxia induced by cobalt chloride (500 M, 6 h) evidently enhanced the GVB, revealing hypoxia-induced bi-directional regulation of the GVB for the first-time. Importantly, knockdown of HIF-1 largely abolished the bi-directional changes of GVB caused by hypoxia. Furthermore, experimentally severe hypoxia exacerbated the inflammatory GVB disruption induced by LPS or TNF-, while the mild hypoxia promoted the repair. ConclusionCollectively, our data indicate that hypoxia bi-directionally regulates GVB in a HIF-1-dependent manner.

cell biology↗