Pharmacotherapy for adults with overweight and obesity: a systematic review and network meta-analysis of randomised controlled trials.

BACKGROUND: Pharmacotherapy provides an option for adults with overweight and obesity to reduce their bodyweight if lifestyle modifications fail. We summarised the latest evidence for the benefits and harms of weight-lowering drugs. METHODS: This systematic review and network meta-analysis included searches of PubMed, Embase, and Cochrane Library (CENTRAL) from inception to March 23, 2021, for randomised controlled trials of weight-lowering drugs in adults with overweight and obesity. We performed frequentist random-effect network meta-analyses to summarise the evidence and applied the Grading of Recommendations Assessment, Development, and Evaluation frameworks to rate the certainty of evidence, calculate the absolute effects, categorise interventions, and present the findings. The study was registered with PROSPERO, CRD 42021245678. FINDINGS: 14 605 citations were identified by our search, of which 132 eligible trials enrolled 48 209 participants. All drugs lowered bodyweight compared with lifestyle modification alone; all subsequent numbers refer to comparisons with lifestyle modification. High to moderate certainty evidence established phentermine-topiramate as the most effective in lowering weight (odds ratio [OR] of ≥5% weight reduction 8·02, 95% CI 5·24 to 12·27; mean difference [MD] of percentage bodyweight change -7·98, 95% CI -9·27 to -6·69) followed by GLP-1 receptor agonists (OR 6·33, 95% CI 5·00 to 8·00; MD -5·79, 95% CI -6·34 to -5·25). Naltrexone-bupropion (OR 2·69, 95% CI 2·10 to 3·44), phentermine-topiramate (2·40, 1·68 to 3·44), GLP-1 receptor agonists (2·22, 1·74 to 2·84), and orlistat (1·71, 1·42 to 2·05) were associated with increased adverse events leading to drug discontinuation. In a post-hoc analysis, semaglutide, a GLP-1 receptor agonist, showed substantially larger benefits than other drugs with a similar risk of adverse events as other drugs for both likelihood of weight loss of 5% or more (OR 9·82, 95% CI 7·09 to 13·61) and percentage bodyweight change (MD -11·40, 95% CI -12·51 to -10·29). INTERPRETATION: In adults with overweight and obesity, phentermine-topiramate and GLP-1 receptor agonists proved the best drugs in reducing weight; of the GLP-1 agonists, semaglutide might be the most effective. FUNDING: 1.3.5 Project for Disciplines of Excellence, West China Hospital, Sichuan University.

Nanobodies and chemical cross-links advance the structural and functional analysis of PI3Kα.

Nanobodies and chemical cross-linking were used to gain information on the identity and positions of flexible domains of PI3Kα. The application of chemical cross-linking mass spectrometry (CXMS) facilitated the identification of the p85 domains BH, cSH2, and SH3 as well as their docking positions on the PI3Kα catalytic core. Binding of individual nanobodies to PI3Kα induced activation or inhibition of enzyme activity and caused conformational changes that could be correlated with enzyme function. Binding of nanobody Nb3-126 to the BH domain of p85α substantially improved resolution for parts of the PI3Kα complex, and binding of nanobody Nb3-159 induced a conformation of PI3Kα that is distinct from known PI3Kα structures. The analysis of CXMS data also provided mechanistic insights into the molecular underpinning of the flexibility of PI3Kα.

Time-dependent risk of fracture in adults with type 2 diabetes receiving anti-diabetic drug: A one-stage network meta-analysis.

AIMS: To assess the time-dependent risk of fracture in adults with type 2 diabetes receiving anti-diabetic drugs. MATERIALS AND METHODS: We searched MEDLINE, EMBASE, and Cochrane Library up to 18 November 2021, for randomized controlled trials (RCTs) and propensity-score-matched non-randomized studies (NRSs) comparing all anti-diabetic drugs with standard treatment or with each other on fracture in adults with type 2 diabetes. The study performed a one-stage network meta-analysis using discrete-time hazard regression with reconstructed individual time-to-event data. RESULTS: This network meta-analysis involved seven RCTs (65,051 adults with type 2 diabetes) with a median follow-up of 36 months and three propensity-score-based NRSs (17,954 participants) with a median follow-up of 27.3 months. Among anti-diabetic drugs, thiazolidinediones increased the overall hazard of fracture by 42% (95% credible interval [CrI], 3%-97%) and almost tripled the risk after 4 years (hazard ratio [HR], 2.74; 95% CrI, 1.53-4.80). Credible subgroup analysis suggested that thiazolidinediones increased the hazard of fracture only in females (HR, 2.19; 95% CrI, 1.26-3.74) but not among males (HR, 0.81; 95% CrI, 0.45-1.40). Moderate certainty evidence established that thiazolidinediones increase 92 fractures in five years per 1000 female patients. We did not find the risk of fractures with other anti-diabetic drugs including metformin, sulfonylureas, sodium-glucose cotransporter-2 (SGLT2) inhibitors, and dipeptidyl peptidase-4 (DPP-4) inhibitors. CONCLUSIONS: Long-term use of thiazolidinediones elevates the risk of fracture among females with type 2 diabetes. There is no evidence eliciting fracture risk associated with other anti-diabetic drugs.

Cryo-EM structures of PI3Kα reveal conformational changes during inhibition and activation.

Phosphoinositide 3-kinases (PI3Ks) are lipid kinases essential for growth and metabolism. Their aberrant activation is associated with many types of cancers. Here we used single-particle cryoelectron microscopy (cryo-EM) to determine three distinct conformations of full-length PI3Kα (p110α-p85α): the unliganded heterodimer PI3Kα, PI3Kα bound to the p110α-specific inhibitor BYL-719, and PI3Kα exposed to an activating phosphopeptide. The cryo-EM structures of unbound and of BYL-719-bound PI3Kα are in general accord with published crystal structures. Local deviations are presented and discussed. BYL-719 stabilizes the structure of PI3Kα, but three regions of low-resolution extra density remain and are provisionally assigned to the cSH2, BH, and SH3 domains of p85. One of the extra density regions is in contact with the kinase domain blocking access to the catalytic site. This conformational change indicates that the effects of BYL-719 on PI3Kα activity extend beyond competition with adenosine triphosphate (ATP). In unliganded PI3Kα, the DFG motif occurs in the "in" and "out" positions. In BYL-719-bound PI3Kα, only the DFG-in position, corresponding to the active conformation of the kinase, was observed. The phosphopeptide-bound structure of PI3Kα is composed of a stable core resolved at 3.8 Å. It contains all p110α domains except the adaptor-binding domain (ABD). The p85α domains, linked to the core through the ABD, are no longer resolved, implying that the phosphopeptide activates PI3Kα by fully releasing the niSH2 domain from binding to p110α. The structures presented here show the basal form of the full-length PI3Kα dimer and document conformational changes related to the activated and inhibited states.

Molecular insights into differentiated ligand recognition of the human parathyroid hormone receptor 2.

The parathyroid hormone receptor 2 (PTH2R) is a class B1 G protein-coupled receptor (GPCR) involved in the regulation of calcium transport, nociception mediation, and wound healing. Naturally occurring mutations in PTH2R were reported to cause hereditary diseases, including syndromic short stature. Here, we report the cryogenic electron microscopy structure of PTH2R bound to its endogenous ligand, tuberoinfundibular peptide (TIP39), and a heterotrimeric Gs protein at a global resolution of 2.8 Å. The structure reveals that TIP39 adopts a unique loop conformation at the N terminus and deeply inserts into the orthosteric ligand-binding pocket in the transmembrane domain. Molecular dynamics simulation and site-directed mutagenesis studies uncover the basis of ligand specificity relative to three PTH2R agonists, TIP39, PTH, and PTH-related peptide. We also compare the action of TIP39 with an antagonist lacking six residues from the peptide N terminus, TIP(7-39), which underscores the indispensable role of the N terminus of TIP39 in PTH2R activation. Additionally, we unveil that a disease-associated mutation G258D significantly diminished cAMP accumulation induced by TIP39. Together, these results not only provide structural insights into ligand specificity and receptor activation of class B1 GPCRs but also offer a foundation to systematically rationalize the available pharmacological data to develop therapies for various disorders associated with PTH2R.

Constitutive signal bias mediated by the human GHRHR splice variant 1.

Alternative splicing of G protein-coupled receptors has been observed, but their functions are largely unknown. Here, we report that a splice variant (SV1) of the human growth hormone-releasing hormone receptor (GHRHR) is capable of transducing biased signal. Differing only at the receptor N terminus, GHRHR predominantly activates Gs while SV1 selectively couples to ß-arrestins. Based on the cryogenic electron microscopy structures of SV1 in the apo state or GHRH-bound state in complex with the Gs protein, molecular dynamics simulations reveal that the N termini of GHRHR and SV1 differentiate the downstream signaling pathways, Gs versus ß-arrestins. As suggested by mutagenesis and functional studies, it appears that GHRH-elicited signal bias toward ß-arrestin recruitment is constitutively mediated by SV1. The level of SV1 expression in prostate cancer cells is also positively correlated with ERK1/2 phosphorylation but negatively correlated with cAMP response. Our findings imply that constitutive signal bias may be a mechanism that ensures cancer cell proliferation.

Similar toxicity potential of glyphosate and glyphosate-based herbicide on cerebellar development after maternal exposure in rats.

Studies on the effects of glyphosate (GlyP) and glyphosate-based herbicides (GBHs) on cerebellar development are extremely limited. This study examined the effects of maternal exposure to GlyP and GBH on rat cerebellar development in male offspring. From day 6 of gestation until day 21 postpartum at weaning, dams were given GlyP at 1.5% or 3.0% in diet or GBH at 1.0% in drinking water (corresponding to 0.36% GlyP). At weaning, GBH exposure was linked to increased numbers of DCX+ migrating granule cells in the cortex and TUNEL+ apoptotic cells in the internal granular layer (IGL), suggesting the disappearance of mismigrated granule cells via apoptosis. GBH also upregulated Nr4a3 and downregulated Cdk5 in the cerebellar vermis, suggesting a causal relation with the impaired granule cell development at this time. GlyP (3.0%) tended to increase in the number of DCX+ migrating granule cells in the IGL and upregulated Nr4a3 at weaning. Both compounds also upregulated genes related to granule cell migration (Astn1, Astn2, Nfia, and/or Nfix) at weaning and in adulthood, which might be an ameliorative response to delayed granule cell migration. Moreover, GBH induced Purkinje cell misalignment at weaning, which could be the result of delayed granule cell migration. In adulthood, GBH was associated with upregulation of the reelin signaling-related genes Reln, Dab1, and Efnb1, suggesting a compensatory response to Purkinje cell misalignment. GlyP induced the same gene expression changes. These results suggest that GBH reversibly disrupts cerebellar development, primarily by targeting granule cell migration and differentiation, whereas GlyP exhibited similar toxic potential as GBH.

Pharmacotherapy for adults with overweight and obesity: a systematic review and network meta-analysis of randomised controlled trials.

BACKGROUND: Pharmacotherapy provides an option for adults with overweight and obesity to reduce their bodyweight if lifestyle modifications fail. We summarised the latest evidence for the benefits and harms of weight-lowering drugs. METHODS: This systematic review and network meta-analysis included searches of PubMed, Embase, and Cochrane Library (CENTRAL) from inception to March 23, 2021, for randomised controlled trials of weight-lowering drugs in adults with overweight and obesity. We performed frequentist random-effect network meta-analyses to summarise the evidence and applied the Grading of Recommendations Assessment, Development, and Evaluation frameworks to rate the certainty of evidence, calculate the absolute effects, categorise interventions, and present the findings. The study was registered with PROSPERO, CRD 42021245678. FINDINGS: 14 605 citations were identified by our search, of which 143 eligible trials enrolled 49 810 participants. Except for levocarnitine, all drugs lowered bodyweight compared with lifestyle modification alone; all subsequent numbers refer to comparisons with lifestyle modification. High to moderate certainty evidence established phentermine-topiramate as the most effective in lowering weight (odds ratio [OR] of ≥5% weight reduction 8·02, 95% CI 5·24 to 12·27; mean difference [MD] of percentage bodyweight change -7·97, 95% CI -9·28 to -6·66) followed by GLP-1 receptor agonists (OR 6·33, 95% CI 5·00 to 8·00; MD -5·76, 95% CI -6·30 to -5·21). Naltrexone-bupropion (OR 2·69, 95% CI 2·11 to 3·43), phentermine-topiramate (2·40, 1·69 to 3·42), GLP-1 receptor agonists (2·17, 1·71 to 2·77), and orlistat (1·72, 1·44 to 2·05) were associated with increased adverse events leading to drug discontinuation. In a post-hoc analysis, semaglutide, a GLP-1 receptor agonist, showed substantially larger benefits than other drugs with a similar risk of adverse events as other drugs for both likelihood of weight loss of 5% or more (OR 9·82, 95% CI 7·09 to 13·61) and percentage bodyweight change (MD -11·41, 95% CI -12·54 to -10·27). INTERPRETATION: In adults with overweight and obesity, phentermine-topiramate and GLP-1 receptor agonists proved the best drugs in reducing weight; of the GLP-1 agonists, semaglutide might be the most effective. FUNDING: 1.3.5 Project for Disciplines of Excellence, West China Hospital, Sichuan University.

Molecular identification and validation of four stable QTL for adult-plant resistance to powdery mildew in Chinese wheat cultivar Bainong 64.

KEY MESSAGE: Four stable QTL for adult-plant resistance (APR) to powdery mildew were identified on chromosome arms 1DL, 2BS, 2DL, and 6BL in the widely grown Chinese wheat cultivar Bainong 64. These QTL had no effect on response to stripe rust or leaf rust. Wheat powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt), is a devastating fungal disease. Seedlings of Chinese wheat Bainong 64 are susceptible to Bgt, but adult plants have maintained resistance since it was released in 1996. A population of 171 recombinant inbred lines (RILs) developed from cross Jingshuang 16/Bainong 64 (JS16/BN64) was used to dissect genetic components of powdery mildew resistance. A genetic map comprising 5383 polymorphic markers was constructed using the 15 K SNP chip and kompetitive allele-specific PCR (KASP) markers. Composite interval mapping identified four stable QTL with favorable alleles all from BN64 on chromosome arms 1DL, 2BS, 2DL, and 6BL in at least four environments. They accounted for 8.3%, 13.8%, 14.4%, and 9.0% of the total phenotypic variation explained (PVE) in maximum, respectively. QPmjbr.caas-1DL, situated about 22 Mb from centromere, is probably a new QTL. QPmjbr.caas-2DL located near the end of arm 2DL and explained the largest PVE. Using genetic maps populated with KASP markers, QPmjbr.caas-2BS and QPmjbr.caas-6BL were fine mapped to a 1.8 cM genetic intervals spanning 13.6 Mb (76.0-89.6 Mb) and 1.7 cM and 4.9 Mb (659.9-664.8 Mb), respectively. The four QTL independent of stripe rust and leaf rust resistance were validated for powdery mildew resistance in another RIL population related to BN64 and a cultivar panel using representative KASP markers. Since BN64 has been a leading cultivar and an important breeding parent in China, the QTL and markers reported in this study will be useful for marker-assisted selection of APR.

Identification of genes showing altered DNA methylation and gene expression in the renal proximal tubular cells of rats treated with ochratoxin A for 13 weeks.

Ochratoxin A (OTA) is a mycotoxin that causes renal carcinogenicity following the induction of karyomegaly in proximal tubular cells after repeated administration to rats. Here, we performed gene profiling regarding altered DNA methylation and gene expression in the renal tubules focusing on the mechanism of OTA-induced carcinogenesis. For this purpose, OTA or 3-chloro-1,2-propanediol (3-MCPD), a renal carcinogen not inducing karyomegaly, was administered to rats for 13 weeks, and DNA methylation array and RNA sequencing analyses were performed on proximal tubular cells. Genes for which OTA altered the methylation status and gene expression level, after excluding genes showing similar expression changes by 3-MCPD, were subjected to confirmation analysis of the transcript level by real-time reverse-transcription PCR. Gene Ontology (GO)-based functional annotation analysis of validated genes revealed a cluster of hypermethylated and downregulated genes enriched under the GO term "mitochondrion," such as those associated with metabolic reprogramming in carcinogenic process (Clpx, Mrpl54, Mrps34, and Slc25a23). GO terms enriched for hypomethylated and upregulated genes included "response to arsenic-containing substance," represented by Cdkn1a involved in cell cycle arrest, and "positive regulation of IL-17 production," represented by Osm potentiating cell proliferation promotion. Other genes that did not cluster under any GO term included Lrrc14 involved in NF-κB-mediated inflammation, Gen1 linked to DNA repair, Has1 related to chromosomal aberration, and Anxa3 involved in tumor development and progression. In conclusion, a variety of genes engaged in carcinogenic processes were obtained by epigenetic gene profiling in rat renal tubular cells specific to OTA treatment for 13 weeks.

Sodium-Glucose Cotransporter-2 Inhibitors in Patients With Heart Failure : A Systematic Review and Meta-analysis.

BACKGROUND: Randomized controlled trials established the cardiac protection of sodium-glucose cotransporter-2 (SGLT2) inhibitors among adults with type 2 diabetes. New evidence suggests that these results could extend to people without diabetes. PURPOSE: To evaluate the effect of SGLT2 inhibitors in patients with heart failure, regardless of the presence of type 2 diabetes. DATA SOURCES: PubMed, Web of Science, Cochrane Library, and Embase (OVID interface). STUDY SELECTION: Eligible trials randomly assigned adults with heart failure to SGLT2 inhibitors or control. DATA EXTRACTION: Time-to-event individual patient data were reconstructed from published Kaplan-Meier plots; time-varying risk ratios (RRs) were calculated in half-, 1-, and 2-year time frames; and anticipated absolute benefits were calculated using simple models applying relative effects to baseline risks. DATA SYNTHESIS: Sodium-glucose cotransporter-2 inhibitors reduce hospitalization for heart failure by 37% (95% CI, 25% to 47%) at 6 months, 32% (CI, 20% to 42%) at 1 year, and 26% (CI, 10% to 40%) at 2 years (all high certainty) and reduce cardiovascular death by 14% (CI, 1% to 25%) at 1 year (high certainty). Nevertheless, low-certainty evidence did not indicate protection against all-cause death, kidney disease progression, or kidney failure. Anticipated absolute benefits are greater for patients treated in the first year and for those with poorer prognoses, such as those newly diagnosed with heart failure in the hospital. In addition, SGLT2 inhibitors doubled the risk for genital infections (RR, 2.69 [CI, 1.61 to 4.52]; high certainty). LIMITATION: Covariates were unavailable in meta-analyses with reconstructed individual patient data. CONCLUSION: Among people with heart failure, SGLT2 inhibitors reduce hospitalizations for heart failure regardless of the presence of diabetes; absolute benefits are most pronounced in first-year treatment and vary with prognostic factors. Clinicians should note the increased risk for genital infection in patients receiving SGLT2 inhibitors. PRIMARY FUNDING SOURCE: 1.3.5 Project for Disciplines of Excellence, West China Hospital of Sichuan University. (PROSPERO: CRD42021255544).

Progressive disruption of neurodevelopment by mid-gestation exposure to lipopolysaccharides and the ameliorating effect of continuous alpha-glycosyl isoquercitrin treatment.

We investigated the effect of lipopolysaccharide (LPS)-induced maternal immune activation used as a model for producing neurodevelopmental disorders on hippocampal neurogenesis and behaviors in rat offspring by exploring the antioxidant effects of alpha-glycosyl isoquercitrin (AGIQ). Pregnant Sprague-Dawley rats were intraperitoneally injected with LPS (50 µg/kg body weight) at gestational days 15 and 16. AGIQ was administered in the diet to dams at 0.5% (w/w) from gestational day 10 until weaning at postnatal day 21 and then to offspring until adulthood at postnatal day 77. During postnatal life, offspring of LPS-injected animals did not show neuroinflammation or oxidative stress in the brain. At weaning, LPS decreased the numbers of type-2b neural progenitor cells (NPCs) and PCNA+ proliferating cells in the subgranular zone, FOS-expressing granule cells, and GAD67+ hilar interneurons in the dentate gyrus. In adulthood, LPS decreased type-1 neural stem cells, type-2a NPCs, and GAD67+ hilar interneurons, and downregulated Dpysl3, Sst, Fos, Mapk1, Mapk3, Grin2a, Grin2b, Bdnf, and Ntrk2. In adults, LPS suppressed locomotor activity in the open field test and suppressed fear memory acquisition and fear extinction learning in the contextual fear conditioning test. These results indicate that mid-gestation LPS injections disrupt programming of normal neurodevelopment resulting in progressive suppression of hippocampal neurogenesis and synaptic plasticity of newborn granule cells by suppressing GABAergic and glutamatergic neurotransmitter signals and BDNF/TrkB signaling to result in adult-stage behavioral deficits. AGIQ ameliorated most aberrations in hippocampal neurogenesis and synaptic plasticity, as well as behavioral deficits. Effective amelioration by continuous AGIQ treatment starting before LPS injections may reflect both anti-inflammatory and anti-oxidative stress effects during gestation and neuroprotective effects of continuous exposure through adulthood.

QTL Mapping Reveals Both All-Stage and Adult-Plant Resistance to Powdery Mildew in Chinese Elite Wheat Cultivars.

Powdery mildew caused by Blumeria graminis f. sp. tritici is a threat to wheat production in China. Mapping quantitative trait loci (QTL) for resistance to powdery mildew and developing breeder-friendly markers are important initial steps in breeding resistant cultivars. An all-stage resistance gene and several QTL were identified using a population of 254 recombinant inbred lines developed from a Jingdong 8/Aikang 58 cross. The population was evaluated for powdery mildew resistance across six field environments over three consecutive growing seasons utilizing two different mixtures of B. graminis f. sp. tritici isolates, named #Bgt-HB and #Bgt-BJ. Using genotypic data obtained from the Wheat TraitBreed 50K single-nucleotide polymorphism array, seven stable QTL were identified on chromosome arms 1DL, 2AL, 2DS, 4DL, 5AL, 6BL.1, and 6BL.2. The QTL on 2AL conferred all-stage resistance to B. graminis f. sp. tritici race E20 in greenhouse tests and explained up to 52% of the phenotypic variance in field trials but was resistant only against #Bgt-HB. The gene involved in this QTL was predicted to be Pm4a based on genome location and gene sequence. QPmja.caas-1DL, QPmja.caas-4DL, and QPmja.caas-6BL.1 were identified as potentially new QTL for powdery mildew resistance. QPmja.caas-2DS and QPmja.caas-6BL.1 were effective against both B. graminis f. sp. tritici mixtures, indicating their probable broad-spectrum resistance. A Kompetitive allele-specific PCR marker closely linked to QPmja.caas-2DS was developed and validated in a panel of 286 wheat cultivars. Because both Jingdong 8 and Aikang 58 have been leading cultivars and breeding parents, the QTL and marker reported represent valuable resources for wheat researchers and breeders.

DABCO-Catalyzed Mono-/Diallylation of N-Unsubstituted Isatin N,N'-Cyclic Azomethine Imine 1,3-Dipoles with Morita-Baylis-Hillman Carbonates.

Allylation of N-unsubstituted isatin N,N'-cyclic azomethine imines with Morita-Baylis-Hillman carbonates in the presence of 1-10 mol% DABCO in DCM at room temperature, rapidly gave N-allylated and N, ß-diallylated isatin N,N'-cyclic azomethine imine 1,3-dipoles in moderate to high yields. The reaction features mild reaction conditions, easily practical operation, and short reaction times in most cases. Furthermore, the alkylated products were transformed into novel bicyclic spiropyrrolidine oxoindole derivatives through the [3+2] or [3+3]-cycloaddition with maleimides or Knoevenagel adducts.

Discovery of 2,4-diarylaminopyrimidine derivatives bearing dithiocarbamate moiety as novel ALK inhibitors.

To overcome drug resistance caused by ALK kinase mutations especially G1202R, two series of novel 2,4-diarylaminopyrimidine derivatives bearing dithiocarbamate moiety were designed, synthesized and evaluated for their biological activities. Among all the target compounds, B10 efficiently inhibited the proliferation of ALK-positive Karpas299 and H2228 cells both with IC50 values of 0.07 µM. In addition, B10 exhibited remarkable enzymatic inhibitory potency with IC50 values of 4.59 nM, 2.07 nM and 5.95 nM toward ALKWT, ALKL1196M and ALKG1202R, respectively. Furthermore, B10 induced apoptosis in H2228 cell and caused cell cycle arrest in G2/M phase. Ultimately, the binding modes of B10 with ALKWT and ALKG1202R were ideally established, which further confirmed the structural basis in accordance with the SARs analysis. These results indicated that B10 was a potent ALK inhibitor for ALKG1202R mutation treatment and deserved for further investigation.

Calcined ZnTi-Layered Double Hydroxide Intercalated with H3 PW12 O40 with Efficiently Photocatalytic and Adsorption Performances.

Wastewater treatment is of great significance to environmental remediation. The exploration of efficient and stable methods for wastewater treatment is still a challenging issue. Herein, a heterojunction material with photocatalysis and adsorption properties has been designed to remove the complex pollutants from wastewater. The heterojunction material (ZnO/TiO2 -PW12 , PW12 =[PW12 O40 ]3- ) was synthesized by calcining the ZnTi-layered double hydroxide (ZnTi-LDH) intercalated with the Keggin-type polyoxometalate H3 PW12 O40 . In the construction of ZnO/TiO2 -PW12 it was found that the polyanionic PW12 remained unchanged in the process of forming the proposed heterojunction. The photochemical properties verify that heterojunction synergistic with PW12 facilitated the separation of photoproduced electron-hole pairs and thus suppressed the recombination. Therefore, ZnO/TiO2 -PW12 exhibits excellent photocatalytic property, and the efficiency of Cr(VI) photoreduction reached more than 90 % in the first 3 min. Furthermore, the electrostatic force between the PW12 and cationic dyes makes ZnO/TiO2 -PW12 having an outstanding adsorption performance for cationic dyes, such as rhodamine B, crystal violet and methyl blue. Such heterojunction material combined with polyoxometalate puts forward new insights for the design of functional materials for water treatment with low cost and high efficiency.

Pathway construction and metabolic engineering for fermentative production of ß-alanine in Escherichia coli.

ß-Alanine is a naturally occurring ß-amino acid that has been widely applied in the life and health field. Although microbial fermentation is a promising method for industrial production of ß-alanine, an efficient microbial cell factory is still lacking. In this study, a new metabolically engineered Escherichia coli strain for ß-alanine production was developed through a series of introduction, deletion, and overexpression of genes involved in its biosynthesis pathway. First, the L-aspartate a-decarboxylase gene, BtADC, from Bacillus tequilensis, with higher catalytic activity to produce ß-alanine from aspartate, was constitutively expressed in E. coli, leading to an increased production of ß-alanine up to 2.76 g/L. Second, three native aspartate kinase genes, akI, akII, and akIII, were knocked out to promote the production of ß-alanine to a higher concentration of 4.43 g/L by preventing from bypass loss of aspartate. To increase the amount of aspartate, the native AspC gene was replaced with PaeAspDH, a L-aspartate dehydrogenase gene from Pseudomonas aeruginosa, accompanied with the overexpression of the native AspA gene, to further improve the production level of ß-alanine to 9.27 g/L. Last, increased biosynthesis of oxaloacetic acid (OAA) was achieved by a combination of overexpression of the native PPC, introduction of CgPC, a pyruvate decarboxylase from Corynebacterium glutamicum, and deletion of ldhA, pflB, pta, and adhE in E. coli, to further enhance the production of ß-alanine. Finally, the engineered E. coli strain produced 43.12 g/L ß-alanine in fed-batch fermentation. Our study will lay a solid foundation for the promising application of ß-alanine in the life and health field. KEY POINTS: • Overexpression of BtADC resulted in substantial accumulation of ß-alanine. • The native AspC was replaced with PaeAspDH to catalyze the transamination of OAA. • Deletion of gluDH prevented from losing carbon flux in TCA recycle. • A 43.12-g/L ß-alanine production in fed-batch fermentation was achieved. Graphical abstract.

First Report of Fusarium fujikuroi Causing Black Stem Rot of Zanthoxylum bungeanum in China.

Chinese prickly ash (Zanthoxylum bungeanum Maxim.), native to China, is an important tree species for soil and water conservation, barren mountain afforestation, and garden greening. Its fruit is commonly used for seasoning and medicine. In August 2016, black stem rot of Z. bungeanum was first observed in Hanyuan County, Ya'an City. In June 2019, the symptoms were observed on > 60% of 10,000 plants in Hanyuan County. At its early stage, the bark was wet and rotten, slightly concave, and accompanied by gummosis. The lesions were dark brown and long oval, peeling off the rotten bark covered with white hyphae. At the later stage, the lesions shrunk and cracked, with many orange-red particles (conidia) and dense black particles (ascospores). Larger lesions often caused large-scale bark necrosis. After the lesions girdled the trunk, the plants rapidly died. A total of 36 isolates were isolated from 320 infested tissue fragments (5 × 5 mm) that were surface sterilized for 60 s in 3% sodium hypochlorite, and 60 s in 75% ethanol, rinsed three times in sterilized water, placed onto potato dextrose agar (PDA) amended with streptomycin sulfate (50 µg/ml), and incubated in the dark at 25°C. Among them, 28 exhibited morphological characteristics described as Fusarium fujikuroi Nirenberg. On PDA, the fungus produced white to grey orange, circular colonies. On carnation leaf agar (CLA), the microconidia were club shaped with a flattened base and 0 to 1 septum, 5 to 15 × 2 to 4 µm in size, whereas macroconidia were relatively slender, medium length with no significant curvature, and had a tapered apical cell and a poorly developed, notched basal cell, 3 to 5 septa, 20 to 50 × 3 to 5 µm in size. For molecular identification, DNA was extracted from a representative isolate using a fungus genomic DNA extraction kit (Solarbio, Beijing). PCRs were performed with primers EF1f/EF2r for translation elongation factor 1α (EF-1α) region, and primers 5f2/7cr for RNA polymerase II genes (RPB2) region. PCRs were amplified and their products (GenBank accession nos. MT448248 and MT448247) were sequenced and blasted, showing 99 to 100% sequence homology with known F. fujikuroi isolates (GenBank accession nos. MN102101.1 and MN193888.1). To conduct pathogenicity test, twigs of 42 three-year-old potted Z. bungeanum plants were superficially wounded with a needle on the cortex, and each twig was inoculated by dropping a 100 µl conidial suspension (1×106 conidia/ml) of the fungus onto its wound surface. The inoculated areas were bandaged with gauze moistened with sterilized water. The wounded wigs that were inoculated with sterilized water served as the controls. Treated plants were maintained in a greenhouse with temperature ranging from 22 to 29°C and RH from 70% to 80%. One month later, 100% of inoculated plants showed the symptoms similar to those observed in the field, with the size of lesions ranging from 0.5 to 1.0 cm2. The fungus was re-isolated from the branch cortexes and confirmed morphologically and molecularly. To our knowledge, this is the first report of F. fujikuroi as a causal agent of black stem rot disease on Z. bungeanum in China. These results will help correctly identify this disease and develop proper strategies to manage the disease.

Decorating of 2D indium oxide onto 2D bismuth oxybromide to enhance internal electric field and stimulate artificial photosynthesis.

CO2 photocatalytic reduction is an excellent strategy for promoting solar-to-chemical energy conversion and alleviating the severe environmental crisis. In this study, 2D indium oxide (IO) is decorated on 2D bismuth oxybromide (BOB) nanosheets to gain BOB/IO (BxIy) heterojunction. The optimal B3I1 composite affords a CO production rate of 54.2 µmol⋅g-1, about 2.2 times and 11.3 times higher than those of the pristine BOB and IO, respectively. The introduction of IO significantly enhances the internal electric field (IEF), leading to accelerated charge transfer and prolonged lifetime of the photogenerated carriers. In the BxIy composite, the BOB and IO serve as the electron acceptor and donor, respectively, facilitating the reduction of CO2 and oxidation of H2O. In-situ DRIFTs spectra are used to confirm the catalytic active sites and provide insights into the mechanism of CO2 photoreduction. The results suggest *COOH and *CO2- species played a crucial role in the formation of CO. This work presents a valuable perspective on understanding the charge transfer route and developing highly efficient photocatalysts for CO2 photoreduction.

In vitro and in vivo induction of ochratoxin A exposure-related micronucleus formation in rat proximal tubular epithelial cells and expression profiling of chromosomal instability-related genes.

Ochratoxin A (OTA) is a renal carcinogen in rats, and repeated administration induces karyomegaly in proximal tubular epithelial cells (PTECs) of the outer stripe of the outer medulla (OSOM) before inducing proliferative lesions. To investigate whether OTA induces micronuclei (MN) in PTECs, we performed an in vitro MN assay using rat renal NRK-52E PTECs after treatment for ≤21 days, and an in vivo OSOM MN assay in rats treated with OTA, other renal carcinogens, or non-carcinogenic renal toxicants for 4 or 13 weeks. The in vitro assay revealed an increased frequency of micronucleated cells from the acceptable dose level for cell viability, even after 21 days of treatment. The in vivo assay also revealed a dose- and treatment period-dependent increase in PTECs with γ-H2AX+ MN. OTA-specific gene expression profiling by OSOM RNA sequencing after week 13 revealed the altered expression of genes related to microtubule-kinetochore binding, the kinesin superfamily, centriole assembly, DNA damage repair, and cell cycle regulation. MN formation was also observed with other renal carcinogens that induce karyomegaly similarly to OTA. These results imply that γ-H2AX+ MN formation by OTA treatment is related to the induction of chromosomal instability accompanying karyomegaly formation before proliferative lesions form, providing a new insight into the carcinogenic mechanism that may be relevant to humans.