Transcription Of Marker Genes Research Articles

A single-cell transcriptomic study of heterogeneity in human embryonic tanycytes

Disruptions in energy homeostasis can lead to diseases like obesity and diabetes, affecting millions of people each year. Tanycytes, the adult stem cells in the hypothalamus, play crucial roles in assisting hypothalamic neurons in maintaining energy balance. Although tanycytes have been extensively studied in rodents, our understanding of human tanycytes remains limited. In this study, we utilized single-cell transcriptomics data to explore the heterogeneity of human embryonic tanycytes, investigate their gene regulatory networks, analyze their intercellular communication, and examine their developmental trajectory. Our analysis revealed the presence of two clusters of β tanycytes and three clusters of α tanycytes in our dataset. Surprisingly, human embryonic tanycytes displayed significant similarities to mouse tanycytes in terms of marker gene expression and transcription factor activities. Trajectory analysis indicated that α tanycytes were the first to be generated, giving rise to β tanycytes in a dorsal–ventral direction along the third ventricle. Furthermore, our CellChat analyses demonstrated that tanycytes generated earlier along the developmental lineages exhibited increased intercellular communication compared to those generated later. In summary, we have thoroughly characterized the heterogeneity of human embryonic tanycytes from various angles. We are confident that our findings will serve as a foundation for future research on human tanycytes.

LncRNA CARMN inhibits abdominal aortic aneurysm formation and vascular smooth muscle cell phenotypic transformation by interacting with SRF

Phenotypic transformation of vascular smooth muscle cells (VSMCs) plays a crucial role in abdominal aortic aneurysm (AAA) formation. CARMN, a highly conserved, VSMC-enriched long noncoding RNA (lncRNA), is integral in orchestrating various vascular pathologies by modulating the phenotypic dynamics of VSMCs. The influence of CARMN on AAA formation, particularly its mechanisms, remains enigmatic. Our research, employing single-cell and bulk RNA sequencing, has uncovered a significant suppression of CARMN in AAA specimens, which correlates strongly with the contractile function of VSMCs. This reduced expression of CARMN was consistent in both 7- and 14-day porcine pancreatic elastase (PPE)-induced mouse models of AAA and in human clinical cases. Functional analyses disclosed that the diminution of CARMN exacerbated PPE-precipitated AAA formation, whereas its augmentation conferred protection against such formation. Mechanistically, we found CARMN's capacity to bind with SRF, thereby amplifying its role in driving the transcription of VSMC marker genes. In addition, our findings indicate an enhancement in CAMRN transcription, facilitated by the binding of NRF2 to its promoter region. Our study indicated that CARMN plays a protective role in preventing AAA formation and restrains the phenotypic transformation of VSMC through its interaction with SRF. Additionally, we observed that the expression of CARMN is augmented by NRF2 binding to its promoter region. These findings suggest the potential of CARMN as a viable therapeutic target in the treatment of AAA.Graphical abstract

CALMODULIN-LIKE16 and PIN-LIKES7a cooperatively regulate rice seedling primary root elongation under chilling.

Low-temperature sensitivity at the germination stage is a challenge for direct seeding of rice in Asian countries. How Ca2+ and auxin (IAA) signaling regulate primary root growth under chilling remains unexplored. Here, we showed that OsCML16 interacted specifically with OsPILS7a to improve primary root elongation of early rice seedlings under chilling. OsCML16, a subgroup 6c member of the OsCML family, interacted with multiple cytosolic loop regions of OsPILS7a in a Ca2+-dependent manner. OsPILS7a localized to the endoplasmic reticulum membranes and functioned as an auxin efflux carrier in a yeast growth assay. Transgenics showed that presence of OsCML16 enhanced primary root elongation under chilling, whereas the ospils7a knockout mutant lines showed the opposite phenotype. Moreover, under chilling conditions, OsCML16 and OsPILS7a-mediated Ca2+ and IAA signaling and regulated the transcription of IAA signaling-associated genes (OsIAA11, OsIAA23, and OsARF16) and cell division marker genes (OsRAN1, OsRAN2, and OsLTG1) in primary roots. These results show that OsCML16 and OsPILS7a cooperatively regulate primary root elongation of early rice seedlings under chilling. These findings enhance our understanding of the crosstalk between Ca2+ and IAA signaling and reveal insights into the mechanisms underlying cold-stress response during rice germination.

Transcription Factor GmERF105 Negatively Regulates Salt Stress Tolerance in Arabidopsis thaliana.

The Ethylene Response Factor (ERF) transcription factors form a subfamily of the AP2/ERF family that is instrumental in mediating plant responses to diverse abiotic stressors. Herein, we present the isolation and characterization of the GmERF105 gene from Williams 82 (W82), which is rapidly induced by salt, drought, and abscisic acid (ABA) treatments in soybean. The GmERF105 protein contains an AP2 domain and localizes to the nucleus. GmERF105 was selectively bound to GCC-box by gel migration experiments. Under salt stress, overexpression of GmERF105 in Arabidopsis significantly reduced seed germination rate, fresh weight, and antioxidant enzyme activity; meanwhile, sodium ion content, malonic dialdehyde (MDA) content, and reactive oxygen species (ROS) levels were markedly elevated compared to the wild type. It was further found that the transcription levels of CSD1 and CDS2 of two SOD genes were reduced in OE lines. Furthermore, the GmERF105 transgenic plants displayed suppressed expression of stress response marker genes, including KIN1, LEA14, NCED3, RD29A, and COR15A/B, under salt treatment. Our findings suggest that GmERF105 can act as a negative regulator in plant salt tolerance pathways by affecting ROS scavenging systems and the transcription of stress response marker genes.

Mapping visual functions onto molecular cell types in the mouse superior colliculus

The superficial superior colliculus (sSC) carries out diverse roles in visual processing and behaviors, but how these functions are delegated among collicular neurons remains unclear. Here, using single-cell transcriptomics, we identified 28 neuron subtypes and subtype-enriched marker genes from tens of thousands of adult mouse sSC neurons. We then asked whether the sSC's molecular subtypes are tuned to different visual stimuli. Specifically, we imaged calcium dynamics in single sSC neurons invivo during visual stimulation and then mapped marker gene transcripts onto the same neurons exvivo. Our results identify a molecular subtype of inhibitory neuron accounting for ∼50% of the sSC's direction-selective cells, suggesting a genetic logic for the functional organization of the sSC. In addition, our studies provide a comprehensive molecular atlas of sSC neuron subtypes and a multimodal mapping method that will facilitate investigation of their respective functions, connectivity, and development.

DOCK2 Promotes Asthma Development by Eliciting Airway Epithelial-Mesenchymal Transition.

Epithelial-mesenchymal transition (EMT) contributes to airway remodeling, a predominant feature of asthma. DOCK2 (dedicator of cytokinesis 2) is an innate immune signaling molecule involved in vascular remodeling. However, it is unknown if DOCK2 plays a role in airway remodeling during asthma development. In this study, we found that DOCK2 is highly induced in both normal human bronchial epithelial cells treated with house dust mite (HDM) extract and human asthmatic airway epithelium. DOCK2 is also upregulated by TGF-β1 (transforming growth factor β1) during EMT of human bronchial epithelial cells. Importantly, knockdown of DOCK2 inhibits, and overexpression of DOCK2 promotes, TGF-β1-induced EMT. Consistently, DOCK2 deficiency suppresses the EMT of airway epithelium, attenuates the subepithelial fibrosis, and improves pulmonary function in HDM-induced asthmatic lungs. These data suggest that DOCK2 plays an important role in EMT and asthma development. Mechanistically, DOCK2 interacts with transcription factor FoxM1 (forkhead box M1), which enhances FoxM1 binding to mesenchymal marker gene promoters and further promotes mesenchymal marker gene transcription and expression, leading to EMT. Taken together, our study identifies DOCK2 as a novel regulator for airway EMT in an HDM-induced asthma model, thus providing a potential therapeutic target for treatment of asthma.

Effect of Mir-4270 Inhibitor and Mimic on Viability and Stemness in Gastric Cancer Stem-Like Cells Derived from MKN-45 Cell Line.

MicroRNAs (miRNAs) are significant regulatory factors in stem cell proliferation, and change in miRNA expression influences the cancer stem cell viability and gene expression. Herein, we evaluated the effect of the hsa-miR-4270 inhibitor and its mimic on the expression of stem cell markers in gastric cancer (GC) stem-like cells. GC stem-like cells were isolated from the MKN-45 cell line by a non-adherent surface system. The cells were confirmed by differentiation assays using dexamethasone and insulin as adipogenesis-inducing agents and also Staurosporine as a neural-inducing agent. Isolated GC stem-like cells were treated with different concentrations (0, 15, 20, 25, 30, 40, 50, and 60 nM) of hsa-miR-4270 inhibitor and its mimic. The quantity of cell viability was determined by trypan blue method. Transcription of the stem cell marker genes, including CD44, OCT3/4, SOX2, Nanog, and KLF4, was evaluated by real-time RT-PCR. The results showed that GC stem-like cells were differentiated into both adipose cells using dexamethasone and insulin and neural cells by Staurosporine. Treatment of GC stem-like cells with hsa-miR-4270 inhibitor decreased cell viability and downregulated OCT3/4, CD44, and Nanog to 86%, 79%, and 91% respectively. Also, SOX2 and KLF4 were overexpressed to 8.1- and 1.94-folds, respectively. However, hsa-miR-4270 mimic had opposite effects on the cell viability and gene expression of the stem cell markers. The effect of hsa-miR-4270 inhibitor and its mimic on the expression of the stem cell markers in GCSCs indicated that hsa-miR-4270 stimulates the stemness property of GCSCs, likely through stimulating the development of gastric stem cells.

Circulating Extracellular Vesicle-Propagated microRNA Signature as a Vascular Calcification Factor in Chronic Kidney Disease.

Chronic kidney disease (CKD) accelerates vascular calcification via phenotypic switching of vascular smooth muscle cells (VSMCs). We investigated the roles of circulating small extracellular vesicles (sEVs) between the kidneys and VSMCs and uncovered relevant sEV-propagated microRNAs (miRNAs) and their biological signaling pathways. We established CKD models in rats and mice by adenine-induced tubulointerstitial fibrosis. Cultures of A10 embryonic rat VSMCs showed increased calcification and transcription of osterix (Sp7), osteocalcin (Bglap), and osteopontin (Spp1) when treated with rat CKD serum. sEVs, but not sEV-depleted serum, accelerated calcification in VSMCs. Intraperitoneal administration of a neutral sphingomyelinase and biogenesis/release inhibitor of sEVs, GW4869 (2.5 mg/kg per 2 days), inhibited thoracic aortic calcification in CKD mice under a high-phosphorus diet. GW4869 induced a nearly full recovery of calcification and transcription of osteogenic marker genes. In CKD, the miRNA transcriptome of sEVs revealed a depletion of 4 miRNAs, miR-16-5p, miR-17~92 cluster-originated miR-17-5p/miR-20a-5p, and miR-106b-5p. Their expression decreased in sEVs from CKD patients as kidney function deteriorated. Transfection of VSMCs with each miRNA-mimic mitigated calcification. In silico analyses revealed VEGFA (vascular endothelial growth factor A) as a convergent target of these miRNAs. We found a 16-fold increase in VEGFA transcription in the thoracic aorta of CKD mice under a high-phosphorus diet, which GW4869 reversed. Inhibition of VEGFA-VEGFR2 signaling with sorafenib, fruquintinib, sunitinib, or VEGFR2-targeted siRNA mitigated calcification in VSMCs. Orally administered fruquintinib (2.5 mg/kg per day) for 4 weeks suppressed the transcription of osteogenic marker genes in the mouse aorta. The area under the curve of miR-16-5p, miR-17-5p, 20a-5p, and miR-106b-5p for the prediction of abdominal aortic calcification was 0.7630, 0.7704, 0.7407, and 0.7704, respectively. The miRNA transcriptomic signature of circulating sEVs uncovered their pathologic role, devoid of the calcification-protective miRNAs that target VEGFA signaling in CKD-driven vascular calcification. These sEV-propagated miRNAs are potential biomarkers and therapeutic targets for vascular calcification.

Microbial communities mediating net methylmercury formation along a trophic gradient in a peatland chronosequence.

Peatlands are generally important sources of methylmercury (MeHg) to adjacent aquatic ecosystems, increasing the risk of human and wildlife exposure to this highly toxic compound. While microorganisms play important roles in mercury (Hg) geochemical cycles where they directly and indirectly affect MeHg formation in peatlands, potential linkages between net MeHg formation and microbial communities involving these microorganisms remain unclear. To address this gap, microbial community composition and specific marker gene transcripts were investigated along a trophic gradient in a geographically constrained peatland chronosequence. Our results showed a clear spatial pattern in microbial community composition along the gradient that was highly driven by peat soil properties and significantly associated with net MeHg formation as approximated by MeHg concentration and %MeHg of total Hg concentration. Known fermentative, syntrophic, methanogenic and iron-reducing metabolic guilds had the strong positive correlations to net MeHg formation, while methanotrophic and methylotrophic microorganisms were negatively correlated. Our results indicated that sulfate reducers did not have a key role in net MeHg formation. Microbial activity as interpreted from 16S rRNA sequences was significantly correlated with MeHg and %MeHg. Our findings shed new light on the role of microbial community in net MeHg formation of peatlands that undergo ontogenetic change.

Ozone and nitrogen dioxide regulate similar gene expression responses in Arabidopsis but natural variation in the extent of cell death is likely controlled by different genetic loci.

High doses of ozone (O3) and nitrogen dioxide (NO2) cause damage and cell death in plants. These two gases are among the most harmful air pollutants for ecosystems and therefore it is important to understand how plant resistance or sensitivity to these gases work at the molecular level and its genetic control. We compared transcriptome data from O3 and NO2 fumigations to other cell death related treatments, as well as individual marker gene transcript level in different Arabidopsis thaliana accessions. Our analysis revealed that O3 and NO2 trigger very similar gene expression responses that include genes involved in pathogen resistance, cell death and ethylene signaling. However, we also identified exceptions, for example RBOHF encoding a reactive oxygen species producing RESPIRATORY BURST OXIDASE PROTEIN F. This gene had increased transcript levels by O3 but decreased transcript levels by NO2, showing that plants can identify each of the gases separately and activate distinct signaling pathways. To understand the genetics, we conducted a genome wide association study (GWAS) on O3 and NO2 tolerance of natural Arabidopsis accessions. Sensitivity to both gases seem to be controlled by several independent small effect loci and we did not find an overlap in the significantly associated regions. Further characterization of the GWAS candidate loci identified new regulators of O3 and NO2 induced cell death including ABH1, a protein that functions in abscisic acid signaling, mRNA splicing and miRNA processing. The GWAS results will facilitate further characterization of the control of programmed cell death and differences between oxidative and nitrosative stress in plants.

Oilseed rape MPK1 mediates reactive oxygen species-dependent cell death and jasmonic acid-induced leaf senescence

Leaf senescence is the terminal phase of leaf development, which involves remobilization of nutrients from leaves to other organs and is affected by many different endogenous (e.g. hormonal) and external stimuli. A proper control of leaf senescence is essential for fitness of annual plants. Although great progress has been made in identifying key genes or proteins controlling leaf senescence in Arabidopsis and several other plants, the relevant genes controlling leaf senescence in oilseed rape ( Brassica napus ) remain largely elusive. In this study, we found that a Mitogen-activated Protein Kinase, BnaMPK1 from oilseed rape positively modulated reactive oxygen species (ROS) -dependent cell death and jasmonic acid (JA)-induced leaf senescence. The expression of BnaMPK1 dramatically increased in senescing leaves of oilseed rape. Transient expression of BnaMPK1 in Nicotiana benthamiana and rapeseed protoplasts resulted in accumulation of ROS and cell death. Moreover, ectopic expression of BnaMPK1 in Arabidopsis exhibited accelerated JA-induced leaf senescence while atmpk1 mutants showed delayed leaf senescence. Furthermore, the expression of chlorophyll degradation and senescence marker genes Non-Yellowing 1 ( NYE1 , SGR1 ), Non-Yellow Coloring 1 ( NYC1 ), Senescence-Associated Gene 29 ( SAG29 ) and two well-known gene mediating JA-induced senescence ORESARA ( ORE ) 1 and ORE9 were induced in BnaMPK1 overexpression lines, whereas most of them were repressed in the atmpk1 mutant. A bimolecular fluorescence complementation (BiFC) and co-immunoprecipitation (Co-IP) assay revealed that BnaMKK3 interacted with BnaMPK1 and, constitutively active BnaMKK3 phosphorylated BnaMPK1 whereas inactive BnaMKK3 can not. Taken together, these results indicate that BnaMPK1 acts as a positive regulator of ROS- and JA-dependent leaf senescence. • BnaMPK1 expression level is up-regulated in senescing leaves. • BnaMPK1 expression induces ROS-dependent cell death in leaves and protoplasts of oilseed rape. • BnaMPK1 modulates jasmonic acid (JA)-induced leaf senescence. • BnaMPK1 expression induces the transcription of a few senescence-associated marker genes. • BnaMPK1 interacts with upstream BnaMKK3 and is phosphorylated by BnaMKK3.

CRHR1 mediates the transcriptional expression of pituitary hormones and their receptors under hypoxia.

Hypothalamus-pituitary-adrenal (HPA) axis plays critical roles in stress responses under challenging conditions such as hypoxia, via regulating gene expression and integrating activities of hypothalamus-pituitary-targets cells. However, the transcriptional regulatory mechanisms and signaling pathways of hypoxic stress in the pituitary remain to be defined. Here, we report that hypoxia induced dynamic changes in the transcription factors, hormones, and their receptors in the adult rat pituitary. Hypoxia-inducible factors (HIFs), oxidative phosphorylation, and cAMP signaling pathways were all differentially enriched in genes induced by hypoxic stress. In the pituitary gene network, hypoxia activated c-Fos and HIFs with specific pituitary transcription factors (Prop1), targeting the promoters of hormones and their receptors. HIF and its related signaling pathways can be a promising biomarker during acute or constant hypoxia. Hypoxia stimulated the transcription of marker genes for microglia, chemokines, and cytokine receptors of the inflammatory response. Corticotropin-releasing hormone receptor 1 (CRHR1) mediated the transcription of Pomc, Sstr2, and Hif2a, and regulated the function of HPA axis. Together with HIF, c-Fos initiated and modulated dynamic changes in the transcription of hormones and their receptors. The receptors were also implicated in the regulation of functions of target cells in the pituitary network under hypoxic stress. CRHR1 played an integrative role in the hypothalamus-pituitary-target axes. This study provides new evidence for CRHR1 involved changes of hormones, receptors, signaling molecules and pathways in the pituitary induced by hypoxia.

Ursolic Acid Enhances Myelin Repair in Adult Mice Brains and Stimulates Exhausted Oligodendrocyte Progenitors to Remyelinate.

In multiple sclerosis patients, long-term inflammation makes the oligodendrocyte progenitor cells (OPCs) exhausted; therefore, a new therapy that makes them responsive to insults to participate in remyelination is highly in demand. Here, we investigated the effect of ursolic acid (UA) on myelin repair after mid-term and long-term demyelination periods induced by 6 or 12weeks of cuprizone treatment followed by 2weeks of recovery with or without UA. Immunohistochemistry studies and myelin genes expression assessment were used to evaluate the myelination status of mouse corpora callosa and the cellular mechanisms of myelin repair. Results showed that UA significantly promoted recovery from myelin loss after discontinuing 6 or 12weeks of cuprizone feeding, as measured by luxol fast blue (LFB), fluoroMyelin (FM), anti-myelin basic protein (MBP) staining, and oligodendrocyte progenitor cell counts. It led to reduced inflammation and gliosis as evaluated by glial fibrillary acidic protein (GFAP), Iba1, or other marker gene transcripts. Following long-term demyelination, gliosis and TNF-α were observed as potential players in lesion pathology, which were restored by UA. An increased IL-10 may contribute to UA anti-inflammatory effect and making responsive the exhausted OPCs. UA increased the number of new oligodendrocyte lineage cells and myelination. Our findings indicated that UA can enhance myelin repair after cuprizone challenge through the prevention of gliosis and increasing the newly generated myelin.

Cross talk between lysine methyltransferase Smyd2 and TGF-β-Smad3 signaling promotes renal fibrosis in autosomal dominant polycystic kidney disease.

Autosomal dominant polycystic kidney disease (ADPKD) is an inherited genetic disorder that is caused by mutations in PKD1 or PKD2 genes and is characterized by renal fluid-filled cyst formation and interstitial fibrosis. PKD1 gene mutation results in the upregulation of SET (suppressor of variegation, enhancer of zeste, trithorax) and MYND (myeloid-nervy-DEAF1) domain-containing lysine methyltransferase 2 (SMYD2) in kidneys from Pkd1 mutant mice and patients with ADPKD. However, the role and mechanism of Smyd2 in the regulation of renal fibrosis in ADPKD remains elusive. In the present study, we showed that 1) expression of Smyd2 can be regulated by transforming growth factor (TGF)-β-Smad3 in normal rat kidney 49F (NRK-49F) cells and mouse fibroblast NIH3T3 cells; 2) knockdown of Smyd2 and inhibition of Smyd2 with its specific inhibitor, AZ505, decreases TGF-β-induced expression of α-smooth muscle actin, fibronectin, collagen type 1 and 3, and plasminogen activator inhibitor-1 in NRK-49F cells; 3) Smyd2 regulates the transcription of fibrotic marker genes through binding on the promoters of those genes or through methylating histone H3 to indirectly regulate the expression of those genes; and 4) knockout and inhibition of Smyd2 significantly decreases renal fibrosis in Pkd1 knockout mice, supporting that targeting Smyd2 can not only delay cyst growth but also attenuate renal fibrosis in ADPKD. This study identified a cross talk between TGF-β signaling and Smyd2 in the regulation of fibrotic gene transcription and activation of fibroblasts in cystic kidneys, suggesting that targeting Smyd2 with AZ505 is a potential therapeutic strategy for ADPKD treatment.NEW & NOTEWORTHY Here, we identified a cross talk between SET and MYND domain-containing lysine methyltransferase 2 (Smyd2) and transforming growth factor (TGF)-β-Smad3 signaling and a synergistic feedback loop between them, in which TGF-β stimulates expression of Smyd2 in a Smad3-dependent manner, and upregulation of Smyd2 regulates the transcription of TGF-β and other fibrotic marker genes through direct binding on their promoters or methylating histone H3 indirectly to regulate the transcription of those genes in fibroblasts. Thus, the Smyd2-TGF-β-Smad3-Smyd2 signaling axis plays an important role in promoting renal fibrosis, and targeting Smyd2 with its specific inhibitor should not only delay cyst growth but also ameliorate renal fibrosis in ADPKD.

Proteasome-Mediated Regulation of GATA2 Expression and Androgen Receptor Transcription in Benign Prostate Epithelial Cells.

GATA2 has been shown to be an important transcription factor together with androgen receptor (AR) in prostate cancer cells. Less is known about GATA2 in benign prostate epithelial cells. We have investigated if GATA2 exogenous expression in prostate epithelial basal-like cells could induce AR transcription or luminal differentiation. Prostate epithelial basal-like (transit amplifying) cells were transduced with lentiviral vector expressing GATA2. Luminal differentiation markers were assessed by RT-qPCR, Western blot and global gene expression microarrays. We utilized our previously established AR and androgen-dependent fluorescence reporter assay to investigate AR activity at the single-cell level. Exogenous GATA2 protein was rapidly and proteasome-dependently degraded. GATA2 protein expression was rescued by the proteasome inhibitor MG132 and partly by mutating the target site of the E3 ligase FBXW7. Moreover, MG132-mediated proteasome inhibition induced AR mRNA and additional luminal marker gene transcription in the prostate transit amplifying cells. Different types of intrinsic mechanisms restricted GATA2 expression in the transit amplifying cells. The appearance of AR mRNA and additional luminal marker gene expression changes following proteasome inhibition suggests control of essential cofactor(s) of AR mRNA expression and luminal differentiation at this proteolytic level.

Mucosal Mast Cell-Specific Gene Expression Is Promoted by Interdependent Action of Notch and TGF-β Signaling.

Rodent mast cells are classified into two major subsets, mucosal mast cells (MMCs) and connective tissue mast cells. MMCs arise from mast cell progenitors that are mobilized from the bone marrow to mucosal tissues in response to allergic inflammation or helminth infection. TGF-β is known as an inducer of MMC differentiation in mucosal tissues, but we have previously found that Notch receptor-mediated signaling also leads to the differentiation. Here, we examined the relationship between Notch and TGF-β signaling in MMC differentiation using mouse bone marrow-derived mast cells (BMMCs). We found that the coexistence of Notch and TGF-β signaling markedly upregulates the expression of MMC markers, mouse mast cell protease (mMCP)-1, mMCP-2, and αE integrin/CD103, more than Notch or TGF-β signaling alone, and that their signals act interdependently to induce these marker expressions. Notch and TGF-β-mediated transcription of MMC marker genes were both dependent on the TGF-β signaling transducer SMAD4. In addition, we also found that Notch signaling markedly upregulated mMCP-1 and mMCP-2 expression levels through epigenetic deregulation of the promoter regions of these genes, but did not affect the promoter of the CD103-encoding gene. Moreover, forced expression of the constitutively active Notch2 intracellular domain in BMMCs showed that Notch signaling promotes the nuclear localization of SMADs 3 and 4 and causes SMAD4-dependent gene transcription. These findings indicate that Notch and TGF-β signaling play interdependent roles in inducing the differentiation and maturation of MMCs. These roles may contribute to the rapid expansion of the number of MMCs during allergic mucosal inflammation.

Imidacloprid and thiamethoxam affect synaptic transmission in zebrafish

Imidacloprid (IMI) and thiamethoxam (THM) are two commonly applied neonicotinoid insecticides. IMI and THM could cause negative impacts on non-target organisms like bees. However, the information about neurotoxicity of IMI and THM in fish is still scarce. Here we investigated the effects of IMI and THM on locomotor behavior, AChE activity, and transcription of genes related to synaptic transmission in zebrafish exposed to IMI and THM with concentrations of 50 ng L−1 to 50,000 ng L−1 at 14 day post fertilization (dpf), 21 dpf, 28 dpf and 35 dpf. Our results showed that IMI and THM significantly influenced the locomotor activity in larvae at 28 dpf and 35 dpf. THM elevated AChE activity at 28 dpf. The qPCR data revealed that IMI and THM affected the transcription of marker genes belonging to the synapse from 14 dpf to 35 dpf. Furthermore, IMI and THM mainly affected transcription of key genes in γ-aminobutyric acid, dopamine and serotonin pathways in larvae at 28 dpf and 35 dpf. These results demonstrated the neurotoxicity of IMI and THM in zebrafish. The findings from this study suggested that IMI and THM in the aquatic environment may pose potential risks to fish fitness and survival.

Nanotube-decorated hierarchical tantalum scaffold promoted early osseointegration

This study aimed to fabricate a hierarchical tantalum scaffold mimicking natural bone structure to enhance osseointegration. Porous tantalum scaffolds (p-Ta) with microgradients were fabricated by selective laser melting according to a computer-aided design model. Electrochemical anodization produced nanotubes on the p-Ta surface (p-Ta-nt). SEM verified the construction of a unique nanostructure on p-Ta-nt. Contact angle and protein adsorption measurements demonstrated that p-Ta-nt have enhanced hydrophilicity and protein absorption. MC3T3-E1 preosteoblasts showed increased filamentous pseudopods and comparable cell proliferation when cultured on p-Ta-nt. Osteogenic marker gene (Osterix, Runx2, COL-I) transcription was significantly upregulated in MC3T3-E1 cells cultured on p-Ta-nt after 7 days. After implantation into the femurs of New Zealand white rabbits for 2 weeks, histological examination found improved early osseointegration in the p-Ta-nt group. This study showed that a hierarchical tantalum structure could enhance early osteogenic effects in vitro and in vivo.

Dydrogesterone Affects the Transcription of Genes in Innate Immune and Coagulation Cascade in Zebrafish Embryos

Dydrogesterone (DDG) acts on the reproduction but also affects the functioning of non-reproductive system. So far, the knowledge about other effects of DDG remains limited. Here we investigated the effects of DDG on the transcription of genes in innate immune and coagulation cascade in zebrafish embryos. The zebrafish embryos were exposed to DDG at 49.0, 527 and 5890 ng L- 1 for 144 hour post fertilization (hpf). The results showed that DDG significantly decreased the transcription of marker genes (e.g. tnfa, il8 and cc-chem) involved in the innate immune response at environmental concentrations. Moreover, DDG also down-regulated the transcription of genes in coagulation cascade (e.g. fga, fgb, fgg and f2). These results indicated that DDG had potential effects on the innate immune and coagulation cascade functions in the early life zebrafish, thus further affecting fish growth and health.

TWIST1 induces phenotypic switching of vascular smooth muscle cells by downregulating p68 and microRNA-143/145.

TWIST1 is an important basic helix‐loop‐helix protein linked to multiple physiological and pathological processes. Although TWIST1 is believed to be involved in vascular pathogenesis, its effects on homeostasis of smooth muscle cells (SMCs) remain poorly understood. Here, we show that TWIST1 protein levels were significantly elevated during SMC phenotypic switching in vivo and in vitro. TWIST1 overexpression promoted phenotypic switching of SMCs, while siRNA targeting of TWIST1 prevented cell transition. Mechanistically, TWIST1 decreased the level of microRNA‐143/145, which governs smooth muscle marker gene transcription. In addition, TWIST1 repressed p68 mRNA and protein expression, a crucial modulator of SMC behavior and microRNA biogenesis. Our co‐immunoprecipitation assay demonstrated a previously unrecognized molecular interaction between TWIST1 and p68 protein. Finally, we found that TWIST1 triggered SMC phenotypic switching and suppressed microRNA‐143/145 expression by promoting the proteasomal degradation of p68. These data suggest a novel role of TWIST1 in the regulation of SMC homeostasis by modulating p68/microRNA‐143/145 axis.