The transcription factor PAX5 activates human LINE1 retrotransposons to induce cellular senescence.

As a hallmark of senescent cells, the derepression of Long Interspersed Elements 1 (LINE1) transcription results in accumulated LINE1 cDNA, which triggers the secretion of the senescence-associated secretory phenotype (SASP) and paracrine senescence in a cGAS-STING pathway-dependent manner. However, transcription factors that govern senescence-associated LINE1 reactivation remain ill-defined. Here, we predict several transcription factors that bind to human LINE1 elements to regulate their transcription by analyzing the conserved binding motifs in the 5'-untranslated regions (UTR) of the commonly upregulated LINE1 elements in different types of senescent cells. Further analysis reveals that PAX5 directly binds to LINE1 5'-UTR and the binding is enhanced in senescent cells. The enrichment of PAX5 at the 5'-UTR promotes cellular senescence and SASP by activating LINE1. We also demonstrate that the longevity gene SIRT6 suppresses PAX5 transcription by directly binding to the PAX5 promoter, and overexpressing PAX5 abrogates the suppressive effect of SIRT6 on stress-dependent cellular senescence. Our work suggests that PAX5 could serve as a potential target for drug development aiming to suppress LINE1 activation and treat senescence-associated diseases.

EAF2 Downregulation Recruits Tumor-associated Macrophages in Prostate Cancer through Upregulation of MIF.

BACKGROUND: The role of tumor inflammatory microenvironment in the advancement of cancer, particularly prostate cancer, is widely acknowledged. ELL-associated factor 2 (EAF2), a tumor suppressor that has been identified in the prostate, is often downregulated in prostate cancer. Earlier investigations have shown that mice with EAF2 gene knockout exhibited a substantial infiltration of inflammatory cells into the prostatic stroma. METHODS: A cohort comprising 38 patients who had been diagnosed with prostate cancer and subsequently undergone radical prostatectomy (RP) was selected. These patients were pathologically graded according to the Gleason scoring system and divided into two groups. The purpose of this selection was to investigate the potential correlation between EAF2 and CD163 using immunohistochemistry (IHC) staining. Additionally, in vitro experimentation was conducted to verify the relationship between EAF2 expression, macrophage migration and polarization. RESULTS: Our study demonstrated that in specimens of human prostate cancer, the expression of EAF2 was notably downregulated, and this decrease was inversely associated with the number of CD163-positive macrophages that infiltrated the cancerous tissue. Cell co-culture experiments revealed that the chemotactic effect of tumor cells towards macrophages was intensified and that macrophages differentiated into tumor-associated macrophages (TAMs) when EAF2 was knocked out. Additionally, the application of cytokine protein microarray showed that the expression of chemokine macrophage migration inhibitory factor (MIF) increased after EAF2 knockout. CONCLUSIONS: Our findings suggested that EAF2 was involved in the infiltration of CD163-positive macrophages in prostate cancer via MIF.

Synthesis and Upconversion Luminescence Fine-tuning of Yb3+/Ho3+-Doped Indium and Gallium Oxide Nanoparticles.

Rare earth (RE) dopants can modulate the bandgap of oxides of indium and gallium and provide extra upconversion luminescence (UCL) abilities. However, relevant UCL fine-tuning strategies and energy mechanisms have been less studied. In this research, InGaO, Ho3+ monodoped and Yb3+/Ho3+ codoped In2O3, and Ho3+ monodoped Yb3Ga5O12 nanoparticles (NPs) were synthesized by a solvothermal method. The effects of Yb3+ and Ho3+ dopants on the crystal structures, UCL properties, and optical bandgaps of the oxides were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), UCL spectroscopy, and measurements of decay times, pump power dependence, and transmittance spectra. The crystal structures of oxide products of indium and gallium were significantly modified with RE dopants. In2O3 and Yb3Ga5O12 were selected as the host materials. For Yb3+/Ho3+ codoped In2O3 NPs, there existed energy transfers from the defect states of In2O3 to Ho3+ and from Yb3+ to Ho3+. With a fixed Ho3+ concentration, In2O3:0%Yb3+,2%Ho3+ NPs showed the optimal UCL properties mainly due to In2O3-Ho3+ energy transfer and Ho3+-Yb3+ energy-back-transfer, while with a fixed Yb3+ concentration, In2O3:5%Yb3+,3%Ho3+ NPs with a slight Yb2O3 impurity and Yb3Ga5O12:2%Ho3+ NPs did mainly due to Ho3+-Ho3+ cross-relaxation. Besides, the optical bandgaps of In2O3 and Yb3Ga5O12 were noticeably broadened with RE dopants. These findings can offer feasible directions for the synthesis and UCL fine-tuning of RE-doped oxides of indium and gallium and improve their multifunction application prospects in the fields of semiconductor and UCL nanomaterials.

Schistosome egg-derived extracellular vesicles deliver Sja-miR-71a inhibits host macrophage and neutrophil extracellular traps via targeting Sema4D.

BACKGROUND: Macrophages and neutrophils are rapidly recruited around Schistosome eggs to form granulomas. Extracellular traps (ETs) of macrophages and neutrophils are part of the pathogen clearance armamentarium of leukocytes. Schistosome eggs possess the ability to resist attack by the host's immune cells and survive by employing various immune evasion mechanisms, including the release of extracellular vesicles (EVs). However, the specific mechanisms by which Schistosome egg-derived EVs (E-EVs) evade the immune response and resist attack from macrophage and neutrophil ETs remain poorly understood. In this study, we aimed to investigate the association between E-EVs and macrophage/neutrophil ETs. METHODS: EVs were isolated from the culture supernatant of S. japonicum eggs and treated macrophages and neutrophils with E-EVs and Sja-miR-71a. The formation of ETs was then observed. Additionally, we infected mice with S. japonicum, administered HBAAV2/9-Sja-miR-71a, and the formation of macrophage ETs (METs) and neutrophil ETs (NETs) in the livers was measured. Sema4D-knockout mice, RNA sequencing, and trans-well assay were used to clarify Sja-miR-71a in E-EVs inhibits METs and NETs formation via the Sema4D/ PPAR-γ/ IL-10 axis. RESULTS: Our findings revealed that E-EVs were internalized by macrophages and neutrophils, leading to the inhibition of METs and NETs formation. The highly expressed Sja-miR-71a in E-EVs targeted Sema4D, resulting in the up-regulation of IL-10 and subsequent inhibition of METs and NETs formation. Sema4D knockout up-regulated IL-10 expression and inhibited the formation of METs and NETs. Furthermore, we further demonstrated that Sja-miR-71a inhibits METs and NETs formation via the Sema4D/ PPAR-γ/ IL-10 axis. CONCLUSIONS: In summary, our findings provide new insights into the immune evasion abilities of Schistosome eggs by demonstrating their ability to inhibit the formation of METs and NETs through the secretion of EVs. This study enhances our understanding of the host-pathogen interaction and may have implications for the development of novel therapeutic approaches. Video Abstract.

Simultaneous thulium laser resection of the prostate and transperineal prostate biopsy in clinically diagnosed metastatic prostate cancer with bladder outlet obstruction.

Metastatic prostate cancer (mPCa) patients complicated with bladder outlet obstruction (BOO) are often referred to a urologist. Androgen deprivation therapy (ADT) combined with indwelling catheter usually be the initial management. To retrospectively analysis the safety and efficacy of simultaneous thulium laser resection of the prostate (TmLRP) and transperineal prostate biopsy in metastatic prostate cancer with bladder outlet obstruction. From January 2016 to December 2021, 67 clinically diagnosed mPCa with BOO patients were included in this study. All patients were preoperatively assessed with international prostate symptom score (IPSS), QoL, serum prostate-specific antigen (PSA), prostate volume evaluation by transrectal ultrasound, postvoid residual urine volume (PVR), and maximum flow rate (Qmax). Preoperative and perioperative parameters at 1-, 3-, and 6-month follow-up were also evaluated. All complications were recorded. Simultaneous TmLRP and transperineal prostate biopsy had obvious advantages for clinically diagnosed mPCa patients with BOO, including short overall operation time (52 ± 23.3 min), little hemoglobin decrease (0.6 ± 0.7 g/l), and short hospital stay (average 3.8 days). In addition, simultaneous TmLRP and transperineal prostate biopsy also brought them significant improvement on IPSS, QoL score, Qmax, and PVR volume (P < 0.001) at 1-, 3-, and 6-month follow-up after operation compared to preoperative parameters. Complications were in a low incidence. Simultaneous TmLRP and transperineal prostate biopsy is a bloodless operation with immediate effect and little perioperative complication. Importantly, it is a promising technology in the diagnosis and treatment of clinically diagnosed mPCa patients with BOO.

HAAN: Learning a Hierarchical Adaptive Alignment Network for Image-Text Retrieval.

Image-text retrieval aims to search related results of one modality by querying another modality. As a fundamental and key problem in cross-modal retrieval, image-text retrieval is still a challenging problem owing to the complementary and imbalanced relationship between different modalities (i.e., Image and Text) and different granularities (i.e., Global-level and Local-level). However, existing works have not fully considered how to effectively mine and fuse the complementarities between images and texts at different granularities. Therefore, in this paper, we propose a hierarchical adaptive alignment network, whose contributions are as follows: (1) We propose a multi-level alignment network, which simultaneously mines global-level and local-level data, thereby enhancing the semantic association between images and texts. (2) We propose an adaptive weighted loss to flexibly optimize the image-text similarity with two stages in a unified framework. (3) We conduct extensive experiments on three public benchmark datasets (Corel 5K, Pascal Sentence, and Wiki) and compare them with eleven state-of-the-art methods. The experimental results thoroughly verify the effectiveness of our proposed method.

Identification and Alternative Splicing Profile of the Raffinose synthase Gene in Grass Species.

Raffinose synthase (Rafs) is an important enzyme in the synthesis pathway of raffinose from sucrose and galactinol in higher plants and is involved in the regulation of seed development and plant responses to abiotic stresses. In this study, we analyzed the Rafs families and profiled their alternative splicing patterns at the genome-wide scale from 10 grass species representing crops and grasses. A total of 73 Rafs genes were identified from grass species such as rice, maize, foxtail millet, and switchgrass. These Rafs genes were assigned to six groups based the phylogenetic analysis. We compared the gene structures, protein domains, and expression patterns of Rafs genes, and also unraveled the alternative transcripts of them. In addition, different conserved sequences were observed at these putative splice sites among grass species. The subcellular localization of PvRafs5 suggested that the Rafs gene was expressed in the cytoplasm or cell membrane. Our findings provide comprehensive knowledge of the Rafs families in terms of genes and proteins, which will facilitate further functional characterization in grass species in response to abiotic stress.

Noninvasive radiomic biomarkers for predicting pseudoprogression and hyperprogression in patients with non-small cell lung cancer treated with immune checkpoint inhibition.

This study aimed to develop a computed tomography (CT)-based radiomics model capable of precisely predicting hyperprogression and pseudoprogression (PP) in patients with non-small cell lung cancer (NSCLC) treated with immunotherapy. We retrospectively analyzed 105 patients with NSCLC, from three institutions, treated with immune checkpoint inhibitors (ICIs) and categorized them into training and independent testing set. Subsequently, we processed CT scans with a series of image-preprocessing techniques, and 6008 radiomic features capturing intra- and peritumoral texture patterns were extracted. We used the least absolute shrinkage and selection operator logistic regression model to select radiomic features and construct machine learning models. To further differentiate between progressive disease (PD) and hyperprogressive disease (HPD), we developed a new radiomics model. The logistic regression (LR) model showed optimal performance in distinguishing PP from HPD, with areas under the receiver operating characteristic curve (AUC) of 0.95 (95% confidence interval [CI]: 0.91-0.99) and 0.88 (95% CI: 0.66-1) in the training and testing sets, respectively. Additionally, the support vector machine model showed optimal performance in distinguishing PD from HPD, with AUC of 0.97 (95% CI: 0.93-1) and 0.87 (95% CI: 0.72-1) in the training and testing sets, respectively. Kaplan‒Meier survival curves showed clear stratification between PP predicted by the radiomics model and true progression (HPD and PD) (hazard ratio = 0.337, 95% CI: 0.200-0.568, p < 0.01) in overall survival. Our study demonstrates that radiomic features extracted from baseline CT scans are effective in predicting PP and HPD in patients with NSCLC treated with ICIs.

Using MRI radiomics to predict the efficacy of immunotherapy for brain metastasis in patients with small cell lung cancer.

BACKGROUND: Brain metastases (BMs) are common in small cell lung cancer (SCLC), and the efficacy of immune checkpoint inhibitors (ICIs) in these patients is uncertain. In this study we aimed to develop and validate a radiomics nomogram based on magnetic resonance imaging (MRI) for intracranial efficacy prediction of ICIs in patients with BMs from SCLC. METHODS: The training and validation cohorts consisted of 101 patients from two centers. The interclass correlation coefficient (ICC), logistic univariate regression analysis, and random forest were applied to select the radiomic features, generating the radiomics score (Rad-score) through the formula. Using multivariable logistic regression analysis, a nomogram was created by the combined model. The discrimination, calibration, and clinical utility were used to assess the performance of the nomogram. Kaplan-Meier curves were plotted based on the nomogram scores. RESULTS: Ten radiomic features were selected for calculating the Rad-score as they could differentiate the intracranial efficacy in the training (area under the curve [AUC], 0.759) and the validation cohort (AUC, 0.667). A nomogram was created by combining Rad-score, treatment lines, and neutrophil-to-lymphocyte ratio (NLR). The training cohort obtained an AUC of 0.878 for the combined model, verified in the validation cohort (AUC = 0.875). Kaplan-Meier analyses showed the nomogram was associated with progression-free survival (PFS) (p = 0.0152) and intracranial progression-free survival (iPFS) (p = 0.0052) but not overall survival (OS) (p = 0.4894). CONCLUSION: A radiomics nomogram model for predicting the intracranial efficacy of ICIs in SCLC patients with BMs can provide suggestions for exploring individual-based treatments for patients.

Development and validation of an MRI-Based nomogram to predict the effectiveness of immunotherapy for brain metastasis in patients with non-small cell lung cancer.

Introduction: The variability and unpredictability of immune checkpoint inhibitors (ICIs) in treating brain metastases (BMs) in patients with advanced non-small cell lung cancer (NSCLC) is the main concern. We assessed the utility of novel imaging biomarkers (radiomics) for discerning patients with NSCLC and BMs who would derive advantages from ICIs treatment. Methods: Data clinical outcomes and pretreatment magnetic resonance images (MRI) were collected on patients with NSCLC with BMs treated with ICIs between June 2019 and June 2022 and divided into training and test sets. Metastatic brain lesions were contoured using ITK-SNAP software, and 3748 radiomic features capturing both intra- and peritumoral texture patterns were extracted. A clinical radiomic nomogram (CRN) was built to evaluate intracranial progression-free survival, progression-free survival, and overall survival. The prognostic value of the CRN was assessed by Kaplan-Meier survival analysis and log-rank tests. Results: In the study, a total of 174 patients were included, and 122 and 52 were allocated to the training and validation sets correspondingly. The intratumoral radiomic signature, peritumoral radiomic signature, clinical signature, and CRN predicted intracranial objective response rate. Kaplan-Meier analyses showed a significantly longer intracranial progression-free survival in the low-CRN group than in the high-CRN group (p < 0.001). The CRN was also significantly associated with progression-free survival (p < 0.001) but not overall survival. Discussion: Radiomics biomarkers from pretreatment MRI images were predictive of intracranial response. Pretreatment radiomics may allow the early prediction of benefits.

Perioperative immunotherapy for patients with EGFR mutant non-small cell lung cancer: Unexpected potential benefits.

Given that immunotherapy has resulted in a significant overall survival (OS) benefit in advanced-stage disease, it is of notable interest to determine the effectiveness of these agents in early-stage non-small cell lung cancer (NSCLC). The potential exists for the immunotherapeutic approach in early-stage NSCLC to mirror the paradigm seen in advanced NSCLC, wherein survival enhancements have notably benefited the majority of patients. However, their performance in early-stage epidermal growth factor receptor (EGFR) mutant NSCLC is controversial. In the limited studies that included patients with EGFR mutation status, we found unexpected, good survival benefits of perioperative immune checkpoint inhibitors (ICIs) in resectable EGFR-positive NSCLC, which is controversial with those in advanced EGFR-mutant NSCLC. It is possible because of the shift toward immunosuppression that the immune environment undergoes during tumor progression. In the early disease stages, the anti-tumor immune response can be activated with fewer hindrances. In the context of EGFR mutant tumors, intratumor genetic heterogeneity can generate treatment-sensitive and -resistant subclones. The subclonality of the resistant subclone is pivotal in therapy response, with tyrosine kinase inhibitors (TKIs) selectively controlling EGFR-mutant cell proliferation and "competitive release" potentially explaining lower pathological responses in adjuvant TKIs trials. This review delves into emerging data on perioperative treatment modalities for early-stage EGFR mutant NSCLC, exploring unique mechanisms and predictive biomarkers to guide perioperative management strategies.

Enhanced kinase translocation reporters for simultaneous real-time measurement of PKA, ERK, and Ca2.

Kinase translocation reporters (KTRs) are powerful tools for single-cell measurement of time-integrated kinase activity but suffer from restricted dynamic range and limited sensitivity, particularly in neurons. To address these limitations, we developed enhanced KTRs (eKTRs) for protein kinase A (PKA) and extracellular signal-regulated kinase (ERK) that display high sensitivity, rapid response kinetics, broad dynamic range, cell type-specific tuning, and an ability to detect PKA and ERK activity in primary sensory neurons. Moreover, co-expression of optically separable eKTRs for PKA and ERK revealed the kinetics of expected and unexpected crosstalk between PKA, ERK, protein kinase C, and calcium signaling pathways, demonstrating the utility of eKTRs for live cell monitoring of diverse and interacting signaling pathways. These results open the door to improved live-cell and in vivo measurements of key signaling pathways in neurons, while at the same time demonstrating the importance of KTR size and NLS strength to KTR dynamics.

Endocytosis blocks the vesicular secretion of exosome marker proteins.

Exosomes are secreted vesicles of ~30 to 150 nm diameter that play important roles in human health and disease. To better understand how cells release these vesicles, we examined the biogenesis of the most highly enriched human exosome marker proteins, the exosomal tetraspanins CD81, CD9, and CD63. We show here that endocytosis inhibits their vesicular secretion and, in the case of CD9 and CD81, triggers their destruction. Furthermore, we show that syntenin, a previously described exosome biogenesis factor, drives the vesicular secretion of CD63 by blocking CD63 endocytosis and that other endocytosis inhibitors also induce the plasma membrane accumulation and vesicular secretion of CD63. Finally, we show that CD63 is an expression-dependent inhibitor of endocytosis that triggers the vesicular secretion of lysosomal proteins and the clathrin adaptor AP-2 mu2. These results suggest that the vesicular secretion of exosome marker proteins in exosome-sized vesicles occurs primarily by an endocytosis-independent pathway.

Metabolic Engineering of Pichia pastoris for the Production of Triacetic Acid Lactone.

Triacetic acid lactone (TAL) is a promising renewable platform polyketide with broad biotechnological applications. In this study, we constructed an engineered Pichia pastoris strain for the production of TAL. We first introduced a heterologous TAL biosynthetic pathway by integrating the 2-pyrone synthase encoding gene from Gerbera hybrida (Gh2PS). We then removed the rate-limiting step of TAL synthesis by introducing the posttranslational regulation-free acetyl-CoA carboxylase mutant encoding gene from S. cerevisiae (ScACC1*) and increasing the copy number of Gh2PS. Finally, to enhance intracellular acetyl-CoA supply, we focused on the introduction of the phosphoketolase/phosphotransacetylase pathway (PK pathway). To direct more carbon flux towards the PK pathway for acetyl-CoA generation, we combined it with a heterologous xylose utilization pathway or endogenous methanol utilization pathway. The combination of the PK pathway with the xylose utilization pathway resulted in the production of 825.6 mg/L TAL in minimal medium with xylose as the sole carbon source, with a TAL yield of 0.041 g/g xylose. This is the first report on TAL biosynthesis in P. pastoris and its direct synthesis from methanol. The present study suggests potential applications in improving the intracellular pool of acetyl-CoA and provides a basis for the construction of efficient cell factories for the production of acetyl-CoA derived compounds.

Effective Use of Sugarcane-Bagasse-Derived KOH-Activated Biochar for Remediating Norfloxacin-Contaminated Water.

Bagasse-derived biochar (SCB750) was prepared at 750 °C using Chinese sugarcane bagasse as a carbon source and then modified with KOH for the removal of the antibiotic norfloxacin (NOR) from aqueous solutions. 3K-SCB750, prepared using a solid-to-liquid mass ratio of bagasse:KOH = 1:3, was found to have the best adsorption performance for NOR. Under the conditions of pH 5, 25 °C, 2.4 g L-1 adsorbent, and 300 mg L-1 NOR, its adsorption of NOR reached equilibrium (97.5% removal) after 60 min. The adsorption behaviours were in line with the quasi-second-order kinetic and Langmuir isotherm models, respectively. The maximum theoretical adsorption capacity reached up to 157.4 mg·g-1 at 40 °C. The thermodynamic parameters showed that the adsorption of NOR onto 3K-SCB750 was a spontaneous, endothermic, and physical process. In addition, Brunauer-Emmett-Teller analysis (BET), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Raman spectroscopy were conducted to investigate the structural and adsorption properties of 3K-SCB750. Fourier transform infrared spectroscopy (FTIR) was also applied to understand the mechanism of adsorption of NOR onto 3K-SCB750. All of the results indicated that 3K-SCB750 had a large specific surface area of 1038.8 m2·g-1, an average pore size of 1.9 nm, and hierarchical structures with random pores and cracks for efficient removal of NOR. NOR adsorption mechanisms on 3K-SCB750 were related to the pore-filling effect and electrostatic attraction. Therefore, 3K-SCB750 biochar may be used as a promising adsorbent of antibiotics in wastewaters.

Rapamycin and Low-dose IL-2 Mediate an Immunosuppressive Microenvironment to Inhibit Benign Prostatic Hyperplasia.

Benign prostatic hyperplasia (BPH) is a condition that becomes more common with age and manifests itself primarily as the expansion of the prostate and surrounding tissues. However, to date, the etiology of BPH remains unclear. In this respect, we performed single-cell RNA sequencing of prostate transition zone tissues from elderly individuals with different prostate volumes to reveal their distinct tissue microenvironment. Ultimately, we demonstrated that a reduced Treg/CD4+ T-cell ratio in the large-volume prostate and a relatively activated immune microenvironment were present, characterized partially by increased expression levels of granzymes, which may promote vascular growth and profibrotic processes and further exacerbate BPH progression. Consistently, we observed that the prostate gland of patients taking immunosuppressive drugs usually remained at a smaller volume. Furthermore, in mouse models, we confirmed that both suppression of the immune system with rapamycin and induction of Treg proliferation with low doses of IL-2 therapy indeed prevented the progression of BPH. Taken together, our findings suggest that an activated immune microenvironment is necessary for prostate volume growth and that Tregs can reverse this immune activation state, thereby inhibiting the progression of BPH.

Syntenin and CD63 Promote Exosome Biogenesis from the Plasma Membrane by Blocking Cargo Endocytosis.

Exosomes are small extracellular vesicles important in health and disease. Syntenin is thought to drive the biogenesis of CD63 exosomes by recruiting Alix and the ESCRT machinery to endosomes, initiating an endosome-mediated pathway of exosome biogenesis. Contrary to this model, we show here that syntenin drives the biogenesis of CD63 exosomes by blocking CD63 endocytosis, thereby allowing CD63 to accumulate at the plasma membrane, the primary site of exosome biogenesis. Consistent with these results, we find that inhibitors of endocytosis induce the exosomal secretion of CD63, that endocytosis inhibits the vesicular secretion of exosome cargo proteins, and that high-level expression of CD63 itself also inhibits endocytosis. These and other results indicate that exosomes bud primarily from the plasma membrane, that endocytosis inhibits their loading into exosomes, that syntenin and CD63 are expression-dependent regulators of exosome biogenesis, and that syntenin drives the biogenesis of CD63 exosomes even in Alix knockout cells.

Active Tuning and Anisotropic Strong Coupling of Terahertz Polaritons in Van der Waals Heterostructures.

Electromagnetic field confinement is significant in enhancing light-matter interactions as well as in reducing footprints of photonic devices especially in Terahertz (THz). Polaritons offer a promising platform for the manipulation of light at the deep sub-wavelength scale. However, traditional THz polariton materials lack active tuning and anisotropic propagation simultaneously. In this paper, we design a graphene/α-MoO3 heterostructure and simulate polariton hybridization between isotropic graphene plasmon polaritons and anisotropic α-MoO3 phonon polaritons. The physical fundamentals for polariton hybridizations depend on the evanescent fields coupling originating from the constituent materials as well as the phase match condition, which can be severely affected by the α-MoO3 thickness and actively tuned by the gate voltages. Hybrid polaritons propagate with in-plane anisotropy that exhibit momentum dispersion characterized by elliptical, hyperboloidal and even flattened iso-frequency contours (IFCs) in the THz range. Our results provide a tunable and flexible anisotropic polariton platform for THz sensing, imaging, and modulation.

Synthetic Biology Toolkit for Marker-Less Integration of Multigene Pathways into Pichia pastoris via CRISPR/Cas9.

Pichia pastoris, an important methylotrophic yeast, is currently mainly used for the expression of recombinant proteins and has great potential applications in the production of value-added compounds (e.g., chemical and natural products). However, the construction of P. pastoris cell factories is largely hindered by the lack of genetic tools for the manipulation of multigene biosynthetic pathways. Therefore, the present study aimed to establish a CRISPR-based synthetic biology toolkit for the integration and assembly of multigene biosynthetic pathways into the chromosome of P. pastoris. First, 23 intergenic regions were selected and characterized as potential integration sites, with a focus on the integration efficiency and heterologous gene expression levels. In addition, a panel of constitutive and methanol-inducible promoters with different strengths (weak, medium, and strong promoters) were characterized to control the expression of biosynthetic pathway genes to the desirable levels. With a series of gRNA plasmids (for single-locus, two-loci, and three-loci integration) and donor plasmids (containing homology arms for integration and promoters and terminators for driving heterologous gene expression) as major components, a CRISPR-based synthetic biology toolkit was established, which enabled the integration of one locus, two loci, and three loci with efficiencies as high as ∼100, ∼93, and ∼75%, respectively, in P. pastoris GS115 strain. Finally, the application of the toolkit was demonstrated by the construction of a series of P. pastoris cell factories, which could produce 2,3-butanediol, ß-carotene, zeaxanthin, and astaxanthin with methanol as the sole carbon and energy source. The P. pastoris synthetic biology toolkit is highly standardized and can be employed to construct P. pastoris cell factories with high efficiency.

De Novo Biosynthesis of Vindoline and Catharanthine in Saccharomyces cerevisiae.

Vinblastine has been used clinically as one of the most potent therapeutics for the treatment of several types of cancer. However, the traditional plant extraction method suffers from unreliable supply, low abundance, and extremely high cost. Here, we use synthetic biology approach to engineer Saccharomyces cerevisiae for de novo biosynthesis of vindoline and catharanthine, which can be coupled chemically or biologically to vinblastine. On the basis of a platform strain with sufficient supply of precursors and cofactors for biosynthesis, we reconstituted, debottlenecked, and optimized the biosynthetic pathways for the production of vindoline and catharanthine. The vindoline biosynthetic pathway represents one of the most complicated pathways ever reconstituted in microbial cell factories. Using shake flask fermentation, our engineered yeast strains were able to produce catharanthine and vindoline at a titer of 527.1 and 305.1 µg·liter-1, respectively, without accumulating detectable amount of pathway intermediates. This study establishes a representative example for the production of valuable plant natural products in yeast.