Intratumor injected gold molecular clusters for NIR-II imaging and cancer therapy.

Surgical resections of solid tumors guided by visual inspection of tumor margins have been performed for over a century to treat cancer. Near-infrared (NIR) fluorescence labeling/imaging of tumor in the NIR-I (800 to 900 nm) range with systemically administrated fluorophore/tumor-targeting antibody conjugates have been introduced to improve tumor margin delineation, tumor removal accuracy, and patient survival. Here, we show Au25 molecular clusters functionalized with phosphorylcholine ligands (AuPC, ~2 nm in size) as a preclinical intratumorally injectable agent for NIR-II/SWIR (1,000 to 3,000 nm) fluorescence imaging-guided tumor resection. The AuPC clusters were found to be uniformly distributed in the 4T1 murine breast cancer tumor upon intratumor (i.t.) injection. The phosphocholine coating afforded highly stealth clusters, allowing a high percentage of AuPC to fill the tumor interstitial fluid space homogeneously. Intra-operative surgical navigation guided by imaging of the NIR-II fluorescence of AuPC allowed for complete and non-excessive tumor resection. The AuPC in tumors were also employed as a photothermal therapy (PTT) agent to uniformly heat up and eradicate tumors. Further, we performed in vivo NIR-IIb (1,500 to 1,700 nm) molecular imaging of the treated tumor using a quantum dot-Annexin V (QD-P3-Anx V) conjugate, revealing cancer cell apoptosis following PTT. The therapeutic functionalities of AuPC clusters combined with rapid renal excretion, high biocompatibility, and safety make them promising for clinical translation.

High-precision tumor resection down to few-cell level guided by NIR-IIb molecular fluorescence imaging.

In vivo fluorescence/luminescence imaging in the near-infrared-IIb (NIR-IIb, 1,500 to 1,700 nm) window under <1,000 nm excitation can afford subcentimeter imaging depth without any tissue autofluorescence, promising high-precision intraoperative navigation in the clinic. Here, we developed a compact imager for concurrent visible photographic and NIR-II (1,000 to 3,000 nm) fluorescence imaging for preclinical image-guided surgery. Biocompatible erbium-based rare-earth nanoparticles (ErNPs) with bright down-conversion luminescence in the NIR-IIb window were conjugated to TRC105 antibody for molecular imaging of CD105 angiogenesis markers in 4T1 murine breast tumors. Under a ∼940 ± 38 nm light-emitting diode (LED) excitation, NIR-IIb imaging of 1,500- to 1,700-nm emission afforded noninvasive tumor­to­normal tissue (T/NT) signal ratios of ∼40 before surgery and an ultrahigh intraoperative tumor-to-muscle (T/M) ratio of ∼300, resolving tumor margin unambiguously without interfering background signal from surrounding healthy tissues. High-resolution imaging resolved small numbers of residual cancer cells during surgery, allowing thorough and nonexcessive tumor removal at the few-cell level. NIR-IIb molecular imaging afforded 10-times-higher and 100-times-higher T/NT and T/M ratios, respectively, than imaging with IRDye800CW-TRC105 in the ∼900- to 1,300-nm range. The vastly improved resolution of tumor margin and diminished background open a paradigm of molecular imaging-guided surgery.

Phase III clinical trial comparing the efficacy and safety of adamgammadex with sugammadex for reversal of rocuronium-induced neuromuscular block.

BACKGROUND: Preliminary clinical trials of adamgammadex, a new cyclodextrin-based selective reversal agent, have demonstrated its efficacy in reversing neuromuscular block by rocuronium. METHODS: This multicentre, randomised, double-blind, positive-controlled, non-inferiority phase III clinical trial compared the efficacy and safety of adamgammadex and sugammadex. We randomised 310 subjects to receive adamgammadex (4 mg kg-1) or sugammadex (2 mg kg-1) at reappearance of the second twitch of the train-of-four (TOF), and standard safety data were collected. RESULTS: For the primary outcome, the proportion of patients with TOF ratio ≥0.9 within 5 min was 98.7% in the adamgammadex group vs 100% in the sugammadex group, with a point estimate and 95% confidence interval (CI) of 1.3% (-4.6%, +1.3%); the lower limit was greater than the non-inferiority margin of -10%. For the key secondary outcome, the median (inter quartile range) time from the start of administration of adamgammadex or sugammadex to recovery of TOF ratio to 0.9 was 2.25 (1.75, 2.75) min and 1.75 (1.50, 2.00) min, respectively. The difference was 0.50 (95% CI: 0.25, 0.50); the upper limit was lower than the non-inferiority margin of 5 min. In addition, there were no inferior results observed in secondary outcomes. Adamgammadex had a lower incidence of adverse drug reactions compared with sugammadex (anaphylactic reaction, recurarisation, decreased heart rate, and laryngospasm; P=0.047). CONCLUSIONS: Adamgammadex was non-inferior to sugammadex with a possible lower incidence of adverse drug reactions compared with sugammadex. Adamgammadex may have a potential advantage in terms of its overall risk-benefit profile. CLINICAL TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR2000039525. Registered October 30, 2020. https://www.chictr.org.cn/showproj.html?proj=56825.

Xanthomonas chitinilytica sp. nov., a novel chitinolytic bacterium isolated from a microbial fermentation bed material.

A Gram-stain-negative bacterium, H13-6T, was isolated from a microbial fermentation bed material collected from a pig farm located in Yan'an, Shaanxi, China. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain H13-6T was affiliated with the genus Xanthomonas and showed highest similarity to strain Xanthomonas maliensis M97T (98.38%), Xanthomonas prunicola CFBP 8353T (98.26%) and Xanthomonas oryzae ATCC 35933T (98.11%). The pairwise ortho Average Nucleotide Identity values and the digital DNA-DNA hybridization values between strain H13-6T and the other Xanthomonas species were all below their respective cut-offs. Two genes encoding for chitinase were found and the strain showed a strong chitin-degrading activity. The major fatty acids were Iso-C15:0 (55.9%), Antesio-C15:0 (7.4%) and Iso-C11:0 (5.5%) and the major polar lipids were diphosphatidylglycerol, phosphatidyglycerol and phosphatidylethanolamine. Based on the phenotypic properties and phylogenetic distinctiveness, Xanthomonas chitinilytica was proposed as a novel species of the genus Xanthomonas, with strain H13-6T (= CGMCC 1.61317T = NBRC 115641T) as type strain.

Kaistella yananensis sp. nov., a Novel Indoleacetic Acid-Producing Bacterium Isolated from the Root Nodules of Sophora davidii (Franch.) Skeels.

A novel endophytic bacterium, designated strain BT6-1-3T, was isolated from the root nodules of a leguminous shrub named Sophora davidii (Franch.) Skeels, found growing wild in Yan'an, Shaanxi Province, China. Cells were Gram-staining-negative, non-motile, catalase-positive, oxidase-positive, and did not produce H2S. Strain BT6-1-3T grew at 15-40 °C (optimum 30 °C), at pH 6.0-10.0 (optimum pH 9.0), and with 0-1% (w/v) NaCl (optimum 0.5%). The quinone system was menaquinone 6. The major fatty acids present in BT6-1-3T were iso-C11:0, iso-C15:0, and C16:0. The G+C content of genomic DNA was 39.4 mol% by whole genome sequencing. According to the analysis of 16S rRNA gene sequence, the closest relative was Kaistella montana WG4 (nucleotide identity was 97.6%). The genome of strain BT6-1-3T was sequenced, and the genome similarity was calculated using average nucleotide identity and genome-to-genome distance analysis with the genomes of other strains of Kaistella. Both strongly supported that the strain BT6-1-3T belonged to the genus Kaistella as a representative of a new species. Based on phylogenetic analysis, chemotaxonomic data, and physiological and biochemical characteristics, strain BT6-1-3T represents a new species of the genus Kaistella and is named as Kaistella yananensis sp. nov. Type strain is BT6-1-3T (= NBRC 115452T = CGMCC 1.60032T).

Diabetic kidney disease screening status and related factors: a cross-sectional study of patients with type 2 diabetes in six provinces in China.

OBJECTIVE: To understand the awareness and practice of diabetic kidney disease (DKD) or nephropathy screening among community-based patients with type 2 diabetes in six provinces and cities in China, and to analyse the related factors affecting screening practices. METHODS: From December 2021 to March 2022, a cross-sectional survey was conducted using a structured questionnaire in 6230 patients with type 2 diabetes aged 18 years and older. The content of the questionnaire includes three parts: the general situation of diabetic patients (gender, age, ethnicity, marriage, education, occupation, etc.), DKD screening practices, and the evaluation of DKD screening services. RESULTS: 89.70% of the patients had their fasting blood glucose measured every six months, 21.12% of the patients had their glycosylated hemoglobin measured every six months, and only 13.11% and 9.34% of the patients had a urine protein-creatinine ratio test and estimated glomerular filtration rate test every 12 months. The proportions of glycosylated hemoglobin, urine protein-creatinine ratio, and estimated glomerular filtration rate were relatively high in young, northern, highly educated, and long-duration type 2 diabetic patients. CONCLUSION: The results of this survey found that the proportion of urine protein-creatinine ratio testing, estimated glomerular filtration rate testing, and glycosylated hemoglobin testing in Chinese patients with type 2 diabetes was very low. Patients with type 2 diabetes in rural areas, southern areas, with low education level, and short course of disease have lower detection rates for DKD, and hence lower rates of prevention and treatment.

Serum HBV RNA is associated with liver fibrosis regression in HBeAg-positive chronic hepatitis B patients treated with nucleos(t)ide analogues.

Noninvasive methods for assessing hepatic fibrosis are clinically necessary. This study aims to explore HBV markers correlated with liver fibrosis and capable of diagnosing significant fibrosis and predicting fibrosis regression. Seventy-four HBeAg-positive chronic hepatitis B (CHB) patients were enrolled and started on entecavir or adefovir therapy. Serum HBV RNA, HBV DNA, HBsAg and hepatitis B core-related antigen (HBcrAg) levels were measured at baseline and during treatment. Liver fibrosis was assessed at baseline and month 60 by liver biopsy. Fibrosis regression was defined as Ishak fibrosis score decreased ≥1-point. At baseline, HBsAg, HBcrAg and HBV RNA levels had a stronger correlation with Ishak fibrosis score (r = -.441, p = .002; r = -.469, p = .001; r = -.398, p = .001) than APRI and FIB-4 (r = .321 p = .006; r = .371, p = .001). HBsAg >4 log10 IU/ml plus HBcrAg >7 log10 IU/ml or HBsAg >4 log10 IU/ml plus HBV RNA >5 log10 copies/ml exhibited the same excellent diagnostic ability for significant fibrosis with the AUROC of 0.857. After 60 months of antiviral treatment, 66.7% of patients who suffered significant fibrosis at baseline achieved fibrosis regression, and an HBV RNA decline from baseline to month 6 greater than 0.63 log10 copies/ml could predict the fibrosis regression at month 60. In conclusion, serum HBsAg, HBcrAg and HBV RNA are potential markers for predicting significant liver fibrosis. HBV RNA measurement would be particularly useful for monitoring hepatic fibrosis changes in HBeAg-positive CHB patients.

Design, synthesis and biological evaluation of 2,4,6- trisubstituted triazine derivatives as new nonpeptide small-molecule SIRT5 inhibitors.

Human sirtuin 5 (SIRT5) participates in a variety of metabolic disorder-associated diseases, including cancer. Inhibition of SIRT5 has been confirmed to provide a new strategy for treatment of related diseases. Previously, we discovered a pyrimidine skeleton inhibitor XIV, which showed low micromolar inhibitory activity against SIRT5. Herein, we utilized the scaffold-hopping strategy to design and synthesize a series of 2,4,6- trisubstituted triazine derivatives. The SAR analysis led to the discovery of several new SIRT5 inhibitors with low micromolar inhibition levels. The most potent compounds 10 (IC50 = 5.38 µM), and 14 (IC50 = 4.07 µM) were further confirmed to be the substrate-competitive SIRT5 inhibitors through enzyme kinetic assays, which is consistent with the molecular docking analyses. Fluorescence-based thermal shift assays proved that these compounds may stabilize SIRT5 by binding withprotein.. In addition, compounds 10 and 14 were also revealed to have moderate selectivity to SIRT5 over SIRT1-3. This study will aid further efforts to develop highly potent and selective SIRT5 inhibitors for the treatment of cancer and other related diseases.

lncRNA lnc-POP1-1 upregulated by VN1R5 promotes cisplatin resistance in head and neck squamous cell carcinoma through interaction with MCM5.

Cisplatin resistance is a major therapeutic challenge in advanced head and neck squamous cell carcinoma (HNSCC). Here, we aimed to investigate the key signaling pathway for cisplatin resistance in HNSCC cells. Vomeronasal type-1 receptor 5 (VN1R5) was identified as a cisplatin resistance-related protein and was highly expressed in cisplatin-resistant HNSCC cells and tissues. The long noncoding RNA (lncRNA) lnc-POP1-1 was confirmed to be a downstream target induced by VN1R5. VN1R5 transcriptionally regulated lnc-POP1-1 expression by activating the specificity protein 1 (Sp1) transcription factor via the cyclic AMP (cAMP)/protein kinase A (PKA) pathway. VN1R5 promoted cisplatin resistance in HNSCC cells in a lnc-POP1-1-dependent manner. Mechanistically, lnc-POP1-1 bound to the minichromosome maintenance deficient 5 (MCM5) protein directly and decelerated MCM5 degradation by inhibiting ubiquitination of the MCM5 protein, which facilitated the repair of DNA damage caused by cisplatin. In summary, we identified the cisplatin resistance-related protein VN1R5 and its downstream target lnc-POP1-1. Upon upregulation by VN1R5, lnc-POP1-1 promotes DNA repair in HNSCC cells through interaction with MCM5 and deceleration of its degradation.

Enhanced mild-temperature photothermal therapy by pyroptosis-boosted ATP deprivation with biodegradable nanoformulation.

BACKGROUND: Mild-temperature photothermal therapy (mild PTT) is a safe and promising tumor therapeutic modality by alleviating the damage of healthy tissues around the tumor due to high temperature. However, its therapeutic efficiency is easily restricted by heat shock proteins (HSPs). Thus, exploitation of innovative approaches of inhibiting HSPs to enhance mild PTT efficiency is crucial for the clinical application of PTT. RESULTS: Herein, an innovative strategy is reported: pyroptosis-boosted mild PTT based on a Mn-gallate nanoformulation. The nanoformulation was constructed via the coordination of gallic acid (GA) and Mn2+. It shows an acid-activated degradation and releases the Mn2+ and GA for up-regulation of reactive oxygen species (ROS), mitochondrial dysfunction and pyroptosis, which can result in cellular ATP deprivation via both the inhibiton of ATP generation and incresed ATP efflux. The reduction of ATP and accumulation of ROS provide a powerful approach for inhibiting the expression of HSPs, which enables the nanoformulation-mediated mild PTT. CONCLUSIONS: Our in-vitro and in-vivo results demonstrate that this strategy of pyroptosis-assited PTT can achieve efficient mild PTT efficiency for osteosarcoma therapy.

Secondary leaflet tethering in patients with severe degenerative mitral regurgitation and its association with the severity of mitral regurgitation.

BACKGROUND: The purpose of the study was to determine the association between vena contracta area (VCA) and secondary leaflet tethering among mitral valve prolapse (MVP) patients, and thus to further identify and characterize an MVP with pathological leaflet tethering (MVPt+) phenotype. METHODS: We prospectively evaluated 94 consecutive MVP patients with significant mitral regurgitation (MR) and 21 healthy controls. MVPt+ group was defined as tenting volume index (TVi) > .7 mL/m2 . The three-dimensional (3D) geometry of mitral valve apparatus and VCA was measured with dedicated quantification software. RESULTS: Of the 94 patients with MVP and significant MR, 31 patients showed a TVi > .7 mL/m2 and entered the MVP with leaflet tethering (MVPt+) group. In stepwise multivariate analysis, only prolapse volume index and TVi were independently associated with 3D VCA. 3D VCA, annular area index, and plasma levels of NT-proBNP were independently correlated with the severity of leaflet tethering. ROC curve revealed that a 3D VCA ≥ .55 cm2 is the optimal cutoff point to predict MVPt+ phenotype. CONCLUSIONS: Secondary leaflet tethering is a significant mechanism behind severe degenerative MR, resulting in an MVPt+ phenotype featuring more advanced morphological and hemodynamical characteristics.

Longitudinal development of children's sharing behaviour: Only children versus children with siblings from rural China.

This study examined the development of children's sharing behaviour towards friends and strangers using dictator games with a longitudinal design in a sample of rural Chinese children (n = 589, 47.0% girls) at 3-4 years old and 2 years later (n = 453, 44.2% girls). Results showed that the willingness to share and the amount of sharing changed over time and were affected by family structure. Only children shared fewer stickers than non-only children at ages 3-4, but the amount they shared did not differ at ages 5-6. Only children may develop reciprocal friendships at an older age due to their lack of experience with siblings. Children shared more stickers with friends than strangers at ages 3-4, and such ingroup bias became stronger at ages 5-6.

Construction and validation of a risk prediction model for acute kidney injury in patients after cardiac arrest.

OBJECTIVE: Identifying patients at high risk for cardiac arrest-associated acute kidney injury (CA-AKI) helps in early preventive interventions. This study aimed to establish and validate a high-risk nomogram for CA-AKI. METHODS: In this retrospective dataset, 339 patients after cardiac arrest (CA) were enrolled and randomized into a training or testing dataset. The Student's t-test, non-parametric Mann-Whitney U test, or χ2 test was used to compare differences between the two groups. Optimal predictors of CA-AKI were determined using the Least Absolute Shrinkage and Selection Operator (LASSO). A nomogram was developed to predict the early onset of CA-AKI. The performance of the nomogram was assessed using metrics such as area under the curve (AUC), calibration curves, decision curve analysis (DCA), and clinical impact curve (CIC). RESULTS: In total, 150 patients (44.2%) were diagnosed with CA-AKI. Four independent risk predictors were identified and integrated into the nomogram: chronic kidney disease, albumin level, shock, and heart rate. Receiver operating characteristic (ROC) analyses showed that the nomogram had a good discrimination performance for CA-AKI in the training dataset 0.774 (95%CI, 0.715-0.833) and testing dataset 0.763 (95%CI, 0.670-0.856). The AUC values for the two groups were calculated and compared using the Hanley-McNeil test. No statistically significant differences were observed between the groups. The calibration curve demonstrated good agreement between the predicted outcome and actual observations. Good clinical usefulness was identified using DCA and CIC. CONCLUSION: An easy-to-use nomogram for predicting CA-AKI was established and validated, and the prediction efficiency of the clinical model has reasonable clinical practicability.

Transcriptome Analysis of Rice Embryo and Endosperm during Seed Germination.

Seed germination is a complex, multistage developmental process that is an important step in plant development. In this study, RNA-Seq was conducted in the embryo and endosperm of unshelled germinating rice seeds. A total of 14,391 differentially expressed genes (DEGs) were identified between the dry seeds and the germinating seeds. Of these DEGs, 7109 were identified in both the embryo and endosperm, 3953 were embryo specific, and 3329 were endosperm specific. The embryo-specific DEGs were enriched in the plant-hormone signal-transduction pathway, while the endosperm-specific DEGs were enriched in phenylalanine, tyrosine, and tryptophan biosynthesis. We categorized these DEGs into early-, intermediate-, and late-stage genes, as well as consistently responsive genes, which can be enriched in various pathways related to seed germination. Transcription-factor (TF) analysis showed that 643 TFs from 48 families were differentially expressed during seed germination. Moreover, 12 unfolded protein response (UPR) pathway genes were induced by seed germination, and the knockout of OsBiP2 resulted in reduced germination rates compared to the wild type. This study enhances our understanding of gene responses in the embryo and endosperm during seed germination and provides insight into the effects of UPR on seed germination in rice.

Calcium Phosphate-Based Nanomaterials: Preparation, Multifunction, and Application for Bone Tissue Engineering.

Calcium phosphate is the main inorganic component of bone. Calcium phosphate-based biomaterials have demonstrated great potential in bone tissue engineering due to their superior biocompatibility, pH-responsive degradability, excellent osteoinductivity, and similar components to bone. Calcium phosphate nanomaterials have gained more and more attention for their enhanced bioactivity and better integration with host tissues. Additionally, they can also be easily functionalized with metal ions, bioactive molecules/proteins, as well as therapeutic drugs; thus, calcium phosphate-based biomaterials have been widely used in many other fields, such as drug delivery, cancer therapy, and as nanoprobes in bioimaging. Thus, the preparation methods of calcium phosphate nanomaterials were systematically reviewed, and the multifunction strategies of calcium phosphate-based biomaterials have also been comprehensively summarized. Finally, the applications and perspectives of functionalized calcium phosphate biomaterials in bone tissue engineering, including bone defect repair, bone regeneration, and drug delivery, were illustrated and discussed by presenting typical examples.

Are they equivalent? An examination of task variants of approximate number comparison.

Nonverbal numerical ability supports individuals' numerical information processing in everyday life and is also correlated with their learning of mathematics. This ability is typically measured with an approximate number comparison paradigm, in which participants are presented with two sets of objects and instructed to choose the numerically larger set. This paradigm has multiple task variants, where the two sets are presented in different ways (e.g., two sets are presented either simultaneously or sequentially, or two sets are presented either intermixed or separately). Despite the fact that different task variants have often been used interchangeably, it remains unclear whether these variants measure the same aspects of nonverbal numerical ability. Using a latent variable modeling approach with 270 participants (Mage = 20.75 years, SDage = 2.03, 94 males), this study examined the degree to which three commonly used task variants tapped into the same construct. The results showed that a bi-factor model corresponding to the hypothesis that task variants had both commonalities and uniqueness was a better fit for the data than a single-factor model, corresponding to the hypothesis that task variants were construct equivalent. These findings suggested that task variants of approximate number comparison did not measure the same construct and cannot be used interchangeably. This study also quantified the extent to which general cognitive abilities were involved in both common and unique parts of these task variants.

Long noncoding RNA lnc-H2AFV-1 promotes cell growth by regulating aberrant m6A RNA modification in head and neck squamous cell carcinoma.

Head and neck squamous cell carcinoma (HNSCC) is the most common malignant tumor in the oral and maxillofacial regions, and long noncoding RNAs (lncRNAs) play crucial roles in the occurrence and progression of HNSCC. The lncRNA lnc-H2AFV-1 was found to be upregulated in HNSCC tissues; however, the function of lnc-H2AFV-1 in regulating HNSCC proliferation and the potential molecular mechanism is unclear. The present study evaluated the expression of lnc-H2AFV-1 in HNSCC tissues using quantitative real-time PCR (qPCR) and associated abundant lnc-H2AFV-1 expression with tumor size. Functionally, lnc-H2AFV-1 significantly promoted the proliferation of HNSCC cells in vitro and in vivo. Quantified N6-methyladenosine (m6A) RNA methylation and dot blot assays revealed that total m6A methylation in HNSCC cells was accompanied by lnc-H2AFV-1 expression. Western blotting showed that the expression of methyltransferase-like (METTL) 3 and METTL14 was consistent with that of lnc-H2AFV-1, whereas the expression of demethylase fat mass and obesity-associated (FTO) was contrary to that of lnc-H2AFV-1. Methylated RNA immunoprecipitation sequencing (MeRIP-seq) and MeRIP-qPCR revealed that lnc-H2AFV-1 overexpression led to the elevated expression and maximal m6A methylation of intraflagellar transport (IFT) 80 in HNSCC. In addition, METTL3/14 knockdown decreased IFT80 expression. Thus, our findings suggested that lnc-H2AFV-1 might be a biomarker that alters m6A modification by regulating the m6A methylases METTL3/14 and FTO and then mediating the downstream target IFT80 to promote HNSCC progression.

A novel CREB5/TOP1MT axis confers cisplatin resistance through inhibiting mitochondrial apoptosis in head and neck squamous cell carcinoma.

BACKGROUND: Cisplatin resistance is one of the main causes of treatment failure and death in head and neck squamous cell carcinoma (HNSCC). A more comprehensive understanding of the cisplatin resistance mechanism and the development of effective treatment strategies are urgent. METHODS: RNA sequencing, RT-PCR, and immunoblotting were used to identify differentially expressed genes associated with cisplatin resistance. Gain- and loss-of-function experiments were performed to detect the effect of CREB5 on cisplatin resistance and mitochondrial apoptosis in HNSCC. Chromatin immunoprecipitation (ChIP) assay, dual-luciferase reporter assay, and immunoblotting experiments were performed to explore the underlying mechanisms of CREB5. RESULTS: CREB5 was significantly upregulated in cisplatin-resistant HNSCC (CR-HNSCC) patients, which was correlated with poor prognosis. CREB5 overexpression strikingly facilitated the cisplatin resistance of HNSCC cells in vitro and in vivo, while CREB5 knockdown enhanced cisplatin sensitivity in CR-HNSCC cells. Interestingly, the activation of AKT signaling induced by cisplatin promoted nucleus translocation of CREB5 in CR-HNSCC cells. Furthermore, CREB5 transcriptionally activated TOP1MT expression depending on the canonical motif. Moreover, CREB5 silencing could trigger mitochondrial apoptosis and overcome cisplatin resistance in CR-HNSCC cells, which could be reversed by TOP1MT overexpression. Additionally, double-targeting of CREB5 and TOP1MT could combat cisplatin resistance of HNSCC in vivo. CONCLUSIONS: Our findings reveal a novel CREB5/TOP1MT axis conferring cisplatin resistance in HNSCC, which provides a new basis to develop effective strategies for overcoming cisplatin resistance.

Whole-Cell Biotransformation of Penicillin G by a Three-Enzyme Co-expression System with Engineered Deacetoxycephalosporin†C Synthase.

Deacetoxycephalosporin C synthase (DAOCS) catalyzes the transformation of penicillin G to phenylacetyl-7-aminodeacetoxycephalosporanic acid (G-7-ADCA) for which it depends on 2-oxoglutarate (2OG) as co-substrate. However, the low activity of DAOCS and the expense of 2OG restricts its practical applications in the production of G-7-ADCA. Herein, a rational design campaign was performed on a DAOCS from Streptomyces clavuligerus (scDAOCS) in the quest to construct novel expandases. The resulting mutants showed 25∼58 % increase in activity compared to the template. The dominant DAOCS variants were then embedded into a three-enzyme co-expression system, consisting of a catalase and an L-glutamic oxidase for the generation of 2OG, to convert penicillin G to G-7-ADCA in E. coli. The engineered whole-cell enzyme cascade was applied to an up-scaled reaction, exhibiting a yield of G-7-ADCA up to 39.21 mM (14.6 g ⋅ L-1 ) with a conversion of 78.42 mol %. This work highlights the potential of the integrated whole-cell system that may inspire further research on green and efficient production of 7-ADCA.

Biosynthesis of ß-lactam nuclei in yeast.

We have engineered brewer's yeast as a general platform for de novo synthesis of diverse ß-lactam nuclei starting from simple sugars, thereby enabling ready access to a number of structurally different antibiotics of significant pharmaceutical importance. The biosynthesis of ß-lactam nuclei has received much attention in recent years, while rational engineering of non-native antibiotics-producing microbes to produce ß-lactam nuclei remains challenging. Benefited by the integration of heterologous biosynthetic pathways and rationally designed enzymes that catalyze hydrolysis and ring expansion reactions, we succeeded in constructing synthetic yeast cell factories which produce antibiotic cephalosporin C (CPC, 170.1 ± 4.9 µg/g DCW) and the downstream ß-lactam nuclei, including 6-amino penicillanic acid (6-APA, 5.3 ± 0.2 mg/g DCW), 7-amino cephalosporanic acid (7-ACA, 6.2 ± 1.1 µg/g DCW) as well as 7-amino desacetoxy cephalosporanic acid (7-ADCA, 1.7 ± 0.1 mg/g DCW). This work established a Saccharomyces cerevisiae platform capable of synthesizing multiple ß-lactam nuclei by combining natural and artificial enzymes, which serves as a metabolic tool to produce valuable ß-lactam intermediates and new antibiotics.