A rat model of adenoid hypertrophy constructed by using ovalbumin and lipopolysaccharides to induce allergy, chronic inflammation, and chronic intermittent hypoxia.

BACKGROUND: Adenoid hypertrophy (AH) is a common pediatric disease that significantly impacts the growth and quality of life of children. However, there is no replicable and valid model for AH. METHODS: An AH rat model was developed via comprehensive allergic sensitization, chronic inflammation induction, and chronic intermittent hypoxia (CIH). The modeling process involved three steps: female Sprague-Dawley rats (aged 4-5 weeks) were used for modeling. Allergen sensitization was induced via intraperitoneal administration and intranasal provocation using ovalbumin (OVA); chronic nasal inflammation was induced through intranasal lipopolysaccharide (LPS) administration for sustained nasal irritation; CIH akin to obstructive sleep apnea/hypopnea syndrome was induced using an animal hypoxia chamber. Postmodel establishment, behaviors, and histological changes in nasopharynx-associated lymphoid tissue (NALT) and nasal mucosa were assessed. Arterial blood gas analysis and quantification of serum and tissue levels of (interleukin) IL-4 and IL-13, OVA-specific immunoglobulin E (sIgE), eosinophil cationic protein (ECP), tumor necrosis factor (TNF-α), IL-17, and transforming growth factor (TGF)-ß were conducted for assessment. The treatment group received a combination of mometasone furoate and montelukast sodium for a week and then was evaluated. RESULTS: Rats exhibited notable nasal symptoms and hypoxia after modeling. Histopathological analysis revealed NALT follicle hypertrophy and nasal mucosa inflammatory cell infiltration. Elevated IL-4, IL-13, IL-17, OVA-sIgE, ECP, and TNF-α levels and reduced TGF-ß levels were observed in the serum and tissue of model-group rats. After a week of treatment, the treatment group exhibited symptom and inflammatory factor improvement. CONCLUSION: The model effectively simulates AH symptoms and pathological changes. But it should be further validated for genetic, immunological, and hormonal backgrounds in the currently used and other strains and species.

Research progress on small molecule inhibitors targeting KRAS G12C with acrylamide structure and the strategies for solving KRAS inhibitor resistance.

KRAS (Kirsten-RAS) is a highly mutated gene in the RAS (rat sarcoma) gene family that acts as a critical switch in intracellular signaling pathways, regulating cell proliferation, differentiation, and survival. The continuous activation of KRAS protein resulting from mutations leads to the activation of multiple downstream signaling pathways, inducing the development of malignant tumors. Despite the significant role of KRAS in tumorigenesis, targeted drugs against KRAS gene mutations have failed, and KRAS was once considered an undruggable target. The development of KRAS G12C mutant conformational modulators and the introduction of Sotorasib (R&D code: AMG510) have been a breakthrough in this field, with its remarkable clinical outcomes. Consequently, there is now a great number of KRAS G12C mutations. Patent applications for mutant GTPase KRAS G12C inhibitors, which are said to be covalently modified by cysteine codon 12, have been submitted since 2014. This review classifies KRAS G12C inhibitors based on their chemical structure and evaluates their biological properties. Additionally, it discusses the obstacles encountered in KRAS inhibitor research and the corresponding solutions.

Design, Synthesis, and Biological Evaluation of Pyrido [1,2-α] Pyrimidinone Mesoionic Derivatives Bearing Propenylbenzene as the Vector Control Insecticide.

A series of novel pyrido [1,2-α] pyrimidinone mesoionic derivatives bearing a propenylbenzene group at the 1-position were synthesized on the basis of the structure of mesoionic insecticides triflumezopyrim and dicloromezotiaz via a rationally conceived pharmacophore model and evaluated for their insecticidal activities against three insect vectors. The bioassay results showed that some compounds exerted remarkable insecticidal activities against M. domestica, Ae. albopictus, and B. germanica. Particularly, compound 26l displayed outstanding insecticidal activity against Ae. Albopictus, with an LC50 value of 0.45 µg/mL, far superior to that of imidacloprid (LC50 = 1.82 µg/mL) and equivalent to that of triflumezopyrim (0.35 µg/mL). Meanwhile, compound 34l presented a broad insecticidal spectrum, with LC50 values of 1.51 µg/g sugar, 0.52 µg/mL and 0.14 µg/adult, which were about 2.88, 3.50, and 1.50 times better than that of imidacloprid (LC50 = 4.35 µg/g sugar, 1.82 µg/mL and 0.21 µg/adult against M. domestica, Ae. albopictus, and B. germanica, respectively) and equivalent to that of triflumezopyrim against M. domestica (1.13 µg/g sugar) and Ae. albopictus (0.35 µg/mL) but lower than the potency against B. germanica (0.06 µg/g sugar). The molecular docking study by energy minimizations revealed that introducing propenylbenzene at the 1-position of compounds 26l and 34l could embed into the binding pocket of nicotinic acetylcholine receptors and form pi-alkyl interaction with LEU306. These results demonstrated that compounds 26l and 34l could be promising candidates for vector control insecticides, which deserved further investigation.

Functional assessment of lysosomal Rab7 and RILP with RNA interference and overexpression in Spodoptera frugiperda Sf9 cell lines.

The interaction manner and biological function of Rab7 and its effector, Rab-interacting lysosomal protein (RILP), remain unclear in invertebrates. We provide a protocol for detecting the effects of Rab7 and RILP terminals on lysosome and autophagy in Spodoptera frugiperda Sf9 cells with overexpression and RNA interference. We describe steps for overexpressing plasmids, generating long double-stranded RNA, and transfecting them into Sf9 cells. We then detail procedures for cell immunofluorescence imaging with harmine treatment and fluorescence analysis. For complete details on the use and execution of this protocol, please refer to Cui et al. (2023).1.

Evolutional insights into the interaction between Rab7 and RILP in lysosome motility.

Lysosome motility is critical for the cellular function. However, Rab7-related transport elements showed genetic differences between vertebrates and invertebrates, making the mechanism of lysosomal motility mysterious. We suggested that Rab7 interacted with RILP as a feature of highly evolved organisms since they could interact with each other in Spodoptera frugiperda but not in Drosophila melanogaster. The N-terminus of Sf-RILP was identified to be necessary for their interaction, and Glu61 was supposed to be the key point for the stability of the interaction. A GC-rich domain on the C-terminal parts of Sf-RILP hampered the expression of Sf-RILP and its interaction with Sf-Rab7. Although the corresponding vital amino acids in the mammalian model at the C-terminus of Sf-RILP turned to be neutral, the C-terminus would also help with the homologous interactions between RILP fragments in insects. The significantly different interactions in invertebrates shed light on the biodiversity and complexity of lysosomal motility.

Smoothened antagonist sonidegib affects the development of D. melanogaster larvae via suppression of epidermis formation.

Hedgehog (Hh) signaling is essential for the regulation of embryonic growth and development, the maintenance of stem cell autostasis, and tissue formation, whether in vertebrates or invertebrates. However, exploration into the Hh pathway antagonists in Drosophila or other pests of agricultural importance has been scant. In order to gain a better understanding of the potential utility of the antagonists in insect investigations, a conventional Hh antagonist, sonidegib, was used to evaluate the effects on the development of Drosophila larvae. The results showed that early instar larvae exposed to sonidegib exhibited new epidermal abnormalities and decreased motility after molting. Transcriptome analysis revealed that Sonidegib had a profound effect on chitin-based cuticle development throughout all stages of larvae. Physiological experiments revealed that sonidegib suppressed the epidermis formation and decreased the chitin content. The results of this study shed new light on the potential use of Hh antagonists in agricultural pest management.

Diagnostic value of serum LDH in children with refractory Mycoplasma pneumoniae pneumoniae: A systematic review and meta-analysis.

Background: To investigate the relationship between serum Lactate dehydrogenase (LDH) and refractory Mycoplasma pneumoniae pneumonia (RMPP) in juvenile individuals. Methods: Search Chinese databases and English databases. The retrieval time limit is from the establishment of the database to 2022-04-27. And screening and inclusion of relevant diagnostic test literature. The QUADAS-2 method was used to evaluate the quality of the included literature. The random effects model was used to combine sensitivity, specificity, likelihood ratio, diagnostic odds ratio, summary receiver operating characteristic curve, and area under summary receiver operating characteristic curve to evaluate the prediction value of LDH for RMPP. Subgroup analyses were used to explore sources of heterogeneity. Results: ① A total of 29 literatures that met the criteria were included in the study, and the quality of the literature was medium and high, with a total of 702,2 patients. ② The combined sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and area under the curve of the studies were: 0.75 (95% CI = 0.73-0.76), 0.73 (95% CI = 0.72-0.74), 3.61 (95% CI = 2.86-4.56), 0.30 (95% CI = 0.23-0.39), 13.04 (95% CI = 8.24-20.63), and 0.85(95% CI = 0.82-0.88). ③ The results of subgroup analysis showed that Compared with the subgroup with LDH threshold ≤400 IU/L, the AUC increased from 0.84 (95% CI = 0.80-0.87) to 0.89 (95% CI = 0.86-0.91). Conclusions: The serum LDH has good accuracy for the diagnosis of RMPP and can serve as a diagnostic marker for RMPP.

Network pharmacology, molecular docking, and experimental validation to explore the potential mechanism of Long Mu Qing Xin mixture for the treatment of attention deficit hyperactivity disorder.

Background: Long Mu Qing Xin Mixture (LMQXM) has shown potentially positive effects in alleviating attention deficit hyperactivity disorder (ADHD); however, the action mechanism is still not fully understood. This study aimed to predict the potential mechanism of LMQXM for ADHD using network pharmacology and molecular docking, which were then validated using animal experiments. Methods: Network pharmacology and molecular docking techniques were used to predict the core targets and potential pathways of LMQXMQ for ADHD, and KEGG pathway enrichment analysis revealed the potential significance of dopamine (DA) and cyclic adenosine monophosphate (cAMP) signaling pathways. To verify the hypothesis, we conducted an animal experiment. In the animal experiment, the young spontaneously hypertensive rats (SHRs) were randomly divided into the model group (SHR), the methylphenidate hydrochloride group (MPH, 4.22 mg/kg), and 3 LMQXM groups (low-dose (LD) group, 5.28 ml/kg; medium-dose (MD) group, 10.56 ml/kg; and high-dose (HD) group, 21.12 ml/kg), and administered by gavage for 4 weeks; the WKY rats were set as the control group. The open field test and Morris water maze test were used to evaluate the behavioral performance of rats, high performance liquid chromatography mass spectrometry (LC-MS) was used to analyze DA levels in the prefrontal cortex (PFC) and striatum of rats, ELISA was used to detect cAMP concentrations in the PFC and striatum, and immunohistochemistry and qPCR were used to analyze positive cell expression and mRNA expression for indicators related to DA and cAMP pathways. Results: The results showed that beta-sitosterol, stigmasterol, rhynchophylline, baicalein, and formononetin might be key components of LMQXM for ADHD and that these components bind well to the core targets, DA receptors (DRD1 and DRD2). Furthermore, LMQXM might act through the DA and cAMP signaling pathways. In the animal experiment, we found that MPH and LMQXM-MD controlled hyperactivity and improved learning and memory in SHRs, while LMQXM-HD only controlled hyperactivity in SHRs; meanwhile, MPH and LMQXM-MD upregulated DA and cAMP levels, mean optical density (MOD) of cAMP, and MOD and mRNA expression of DRD1 and PKA in the prefrontal cortex (PFC) and striatum of SHRs, while LMQXM-LD and LMQXM-HD upregulated DA and cAMP levels in the striatum, MOD of cAMP in the PFC, and mRNA expression of PKA in the PFC. However, we did not find a significant regulatory effect of LMQXM on DRD2. Conclusion: To sum up, this study demonstrated that LMQXM may increase DA levels mainly by activating the cAMP/PKA signaling pathway through DRD1, thereby controlling the behavioral disorders of SHRs, which is most effective at moderate doses, and this may be a key mechanism for LMQXM in the treatment of ADHD.

Design, synthesis and antitumor activity of novel thiophene- triazine derivatives bearing arylurea unit as potent PI3K/mTOR inhibitorss.

In this article, we designed and synthesized a series of novel thiophene-triazine derivatives bearing arylurea unit as potent dual PI3K/mTOR inhibitors. The cytotoxicity of all the target compounds were evaluated against nine cancer cell lines (breast cancer cell line MCF-7, lung cancer cell lines A549, NCI-H460, H2228 and H1975, cervical cancer cell lines Hela and Hela-MDR, ovarian cancer cell lines Ovcar-2 and glioma U87MG) and the kinase inhibitory activity against PI3K/mTOR kinases was also tested. The results demonstrated that most of the target compounds exhibited moderate to excellent activity and high selectivity against one or more cancer cell lines. Among them, seven compounds displayed better activity than lead compound GDC-0941. The inhibitory activity of the most promising compound on nine cancer cell lines was 302.5 times better than that of GDC-0941 with the IC50 values as low as 0.008 ± 0.002 µM, and the inhibitory activity against PI3Kα and mTOR kinase was excellent, with the IC50 values of 177.41 and 12.24 nM, respectively, indicating that it was a potential dual PI3Kα/mTOR inhibitor. The Structure-Activity Relationships (SARs) indicated that the introduction of the arylurea group significantly improved the cellular and kinase activities of the target compounds. Moreover, the results of toxicity and hemolysis experiments demonstrated that the most promising compound had low toxicity and good safety. The results of PCR assay and molecular docking modes showed that it was a potential PI3K/mTOR inhibitor, which was worthy of further study.

Group housing enhances mating and increases the sensitization of chemical cues in Bactrocera dorsalis.

BACKGROUND: Changes in population density have profound impacts on mating behaviors in group-living animals. The plasticity of mating behavior enables insects to respond to social signals and adjust mating frequency in accordance with rival competition and reproductive opportunity. RESULTS: In this study, we found that low levels of cis-vaccenyl acetate (cVA), a Drosophila pheromone, increased mating rates of Bactrocera dorsalis, but high concentrations of cVA inhibited mating, indicating a functional role of cVA in regulating mating behaviors in insect species other than Drosophila. Moreover, we demonstrated that group housing conditions had positive effects for B. dorsalis on their mating rates, responses toward cVA and cVA-mediated mating behaviors, which are dependent on the activity of c-AMP reponse element binding protein (CREB) binding protein (CBP). CONCLUSIONS: Our data suggest that CBP-mediated plasticity in mating behavior and chemical recognition enables insects to adapt to different housing conditions and highlight the potential of cVA as an efficient agent in regulating mating behaviors in insect species other than Drosophila. © 2022 Society of Chemical Industry.

Childhood obesity and central precocious puberty.

Childhood obesity is a major public health problem worldwide, and the relationship between obesity and central precocious puberty has long been confirmed, however, the mechanisms underlying this association remain elusive. This review provides an overview of the recent progress regarding how childhood obesity impacts on hypothalamic-pituitary-gonadal axis and pubertal onset, focusing on adipokines (leptin and ghrelin), hormone (insulin), and lipid (ceramide), as well as critical signaling pathways (AMPK/SIRT, mTOR) that integrate the peripheral metabolism and central circuits. Notably, prevention of obesity and CPP is beneficial for the adult life of the children, thus we further summarize the potential strategies in treating and preventing childhood obesity and CPP. The updated understanding of metabolic stress and pediatric endocrine disease will arise the attention of society, and also contribute to preventing more serious comorbidities in the later period of life in children.

Hypoxia-Induced Downregulation of miR-29 in Renal Tumor Cells Affects Collagen IV Subunit Expression through Multiple Sites.

Multiple tumor exacerbations and treatment procedures, such as extracellular matrix remodeling, metabolic reprogramming, immunological evasion, and resistance to chemotherapy and radiotherapy, are influenced by intratumoral hypoxia. It is becoming increasingly clear how hypoxia interacts with the extracellular matrix and how this affects the growth of cancer. We analyzed the published sequencing results of hypoxia-stressed mouse kidney tumor cells and found that the expression of miR-29b was significantly downregulated. There are several sites that are complementary to the miR-29 seed sequence in the 3' non-coding regions (3'UTRs) of various extracellular matrix-related genes, including collagen IV. We analyzed the sequences of the 3'UTRs of different subunits of collagen IV in different species and constructed the corresponding phylogenetic trees. We found that the 3'UTRs of Col4a1 and Col4a4 may have been subjected to particular evolutionary pressures. By cloning the 3'UTRs of collagen IV subunits into the psiCHECKTM-2 vector, we found that seven of the eight sites in the Col4a3-Col4a6 gene complementary to miR-29 were significantly repressed by miR-29a, b (except for the 7774-7781 of Col4a3 gene). The inhibitory efficiency of miR-29a, b on these seven sites was between 27% and 57%. The research on the regulation of miR-29 and extracellular matrix by hypoxia can provide a theoretical basis for tumor and fibrosis research and treatment.

Qingfei Tongluo Formula Mitigates Mycoplasma pneumoniae Infection via the PERK Signaling Pathway.

Mycoplasma pneumoniae pneumonia (MPP) is usually found in school-aged children and relapses easily because of antibiotic resistance. The Qingfei Tongluo formula (QTF) is a clinically used traditional Chinese medicine to treat MPP. Our previous study demonstrated that QTF exhibited ameliorative effects on the experimental MPP mice model. In this study, the function and underlying QTF mechanism in MPP was attempted to be further explored. Mycoplasma pneumoniae (MP) was applied to infect A549 cells and BALB/c mice to mimic MPP in vitro and in vivo. Cytokine release and reactive oxygen species (ROS) production were analyzed using enzyme-linked immunosorbent assay (ELISA) assay and flow cytometry. Western blot analysis was used to detect the protein involved in ER stress. MP infection was found to enhance cytokine release and ER stress in vitro and in vivo, and this effect could be alleviated by QTF. Moreover, protein kinase RNA-like endoplasmic reticulum kinase (PERK) knockdown alleviated MP infection-induced cytokine release, ROS production, and ER stress in A549 cells while the PERK overexpression exhibited the opposite effects. In conclusion, QTF alleviated MP infection-induced cytokine release, ROS production, and ER stress via PERK signaling pathway inhibition.

XS-2, a novel potent dual PI3K/mTOR inhibitor, exhibits high in vitro and in vivo anti-breast cancer activity and low toxicity with the potential to inhibit the invasion and migration of triple-negative breast cancer.

Breast cancer has become the most commonly diagnosed cancer, surpassing lung cancer, with 2.26 million new breast cancers worldwide in 2020. Hence, there is an urgent need to develop effective molecularly targeted therapeutic drugs to treat breast cancer. In this paper, we designed, synthesized and screened a novel thiophene-triazine derivative, XS-2, as a potent dual PI3K/mTOR inhibitor for the treatment of breast cancer. Also, XS-2 was found to be potentially effective against triple-negative breast cancer (TNBC) in vitro during the investigation. We evaluated the in vitro inhibitory effect of XS-2 on 10 cancer cell lines by MTT and 6 kinases to investigated its in vivo antitumor activity in MCF-7 xenograft tumor-bearing BALB/c nude mice. In addition, the in vitro/in vivo toxicity to mice was also assessed by hemolytic toxicity, H&E staining and blood biochemical analysis. In order to investigate the antitumor mechanism of XS-2, a series of experiments were carried out in vitro/in vivo animal model and molecular biological levels such as the cell cycle and the apoptosis assay, real-time PCR, western blot, docking and molecular simulations analysis, etc. What's more, wound healing assay, Transwell and Western Blot were applied to explore the ability of XS-2 to inhibit the cell invasion and migration. The results showed that XS-2 exhibited strong antitumor activity both in vitro and in vivo. The inhibitory activities of XS-2 on ten cancer cell lines were ranging from 1.07 ± 0.11 to 0.002 ± 0.001 µM, which were 1565 times better than that of the lead compound GDC-0941, inhibitory activities against PI3Kα and mTOR kinases were 291.0 and 60.8 nM, respectively. Notably, XS-2 not only showed significant in vivo antitumor activity and low toxicity, with the tumor inhibition rate of 57.0 %, but also exhibited strong inhibitory in the expression of related proteins of PI3K pathway in tumor tissues. In addition, XS-2 significantly inhibited breast cancer MCF-7 and MDA-MB-231 cells in a concentration- and time-dependent manner, and inhibited the migration and invasion ability of MDA-MB-231 and MCF-7 cells. More than that, XS-2 could inhibit the increase of the expression levels of N-cadherin and vimentin upregulated by EGF and reversed the E-cadherin expression down regulated by EGF, resulting in inhibiting EMT in MCF-7 and MDA-MB-231 cells. The results showed that XS-2 was expected to be successfully developed as a high-efficiency and low-toxicity breast cancer therapeutic drug with the potential to inhibit the invasion and migration of TNBC. This provides a new research idea for the treatment of TNBC, which is of great significance.

Kukoamine A inhibits C-C motif chemokine receptor 5 to attenuate lipopolysaccharide-induced lung injury.

The aim of this study was to elucidate the mechanism underlying the effects of Kukoamine A (KuA) treatment on endotoxin-induced lung injury/inflammation. The study was performed in lipopolysaccharide (LPS)-exposed mouse models of lung injury and LPS-induced alveolar epithelial cell model. Relevant kits were used to detect levels of inflammation-related indicators, oxidative stress indicators, and mitochondrial function. Hematoxylin and eosin staining was to detect lung injury. Then, C-C motif chemokine receptor 5 (CCR5) overexpression plasmid was transfected into alveolar epithelial cells to investigate the mechanism of KuA in lung injury. The results showed that LPS induction increased the expression of inflammatory factors, oxidative stress markers, and mitochondrial dysfunction in both animal and cellular models. In the mouse model, KuA treatment improved lung tissue injury, decreased wet-to-dry ratio and MPO levels, reduced the expression of inflammatory factors, and ameliorated oxidative stress and mitochondrial dysfunction. The protective effect of KuA in the cell model remained whereas was markedly reversed after CCR5 overexpression. Taken together, KuA might improve LPS-induced lung injury by inhibiting CCR5. This might also provide a novel theory for KuA in the treatment of lung injury.

Kukoamine A Improves Mycoplasma pneumoniae Pneumonia by Regulating miR-222-3p/Superoxide Dismutase 2.

Mycoplasma pneumoniae pneumonia (MPP) represents a common respiratory disease in children patients. Kukoamine A (KuA) is a spermine alkaloid found in the Chinese herb Cortex Lycii radices, which has a variety of pharmacological properties. However, no study has been reported on the role of KuA in MPP. Exosomes, a type of lipid bilayer-enclosed extracellular vesicles, can be delivered to the target cells, where they regulate function and physiology. With the use of human alveolar basal epithelial cells (HABECs) as an in vitro model, in this study, we sought to characterize the changes in levels of superoxide dismutase 2 (SOD2) and proinflammatory cytokines including IL-6 and TNF-α in HABECs in response to exosomes, which were isolated from peripheral blood serum of MPP patients. We found that, compared to normal, MPP patients exhibited a significant up-regulated miR-222-3p. Further, exosomal miR-222-3p downregulated SOD2 activity but promoted nuclear NF-κB activity and expression of IL-6 and TNF-α in HABECs, ultimately leading to an oxidative stress condition. Interestingly, such stimulating effects were attenuated by the pretreatment of KuA. This study suggests a critical role possessed by KuA in MPP by regulating the miR-222-3p/SOD2 axis, which represents a promising strategy for the treatment of MPP.

Indole-Based Tubulin Inhibitors: Binding Modes and SARs Investigations.

Tubulin inhibitors can interfere with normal cell mitosis and inhibit cell proliferation through interfering with the normal structure and function of microtubules, forming spindle filaments. Indole, as a privileged pharmacological skeleton, has been widely used in anti-cancer inhibitors. A variety of alkaloids containing an indole core obtained from natural sources have been proven to inhibit tubulin polymerization, and an ever-increasing number of synthetic indole-based tubulin inhibitors have been reported. Among these, several kinds of indole-based derivatives, such as TMP analogues, aroylindoles, arylthioindoles, fused indole, carbazoles, azacarbolines, alkaloid nortopsentin analogues and bis-indole derivatives, have shown good inhibition activities towards tubulin polymerization. The binding modes and SARs investigations of synthetic indole derivatives, along with a brief mechanism on their anti-tubulin activity, are presented in this review.

The Potential Binding Interaction and Hydrolytic Mechanism of Carbaryl with the Novel Esterase PchA in Pseudomonas sp. PS21.

Microbial bioremediation is a very potent and eco-friendly approach to alleviate pesticide pollution in agricultural ecosystems, and hydrolase is an effective element for contaminant degradation. In the present study, a novel Mn2+-dependent esterase, PchA, that efficiently hydrolyzes carbamate pesticides with aromatic structures was identified from Pseudomonas sp. PS21. The hydrolytic activity was confirmed to be related closely to the core catalytic domain, which consists of six residues. The crucial residues indirectly stabilized the position of carbaryl via chelating Mn2+ according to the binding model clarified by molecular simulations, and the additional hydrophobic interactions between carbaryl with several hydrophobic residues also stabilized the binding conformation. The residue Glu398, by serving as the general base, might activate a water molecule and facilitate PchA catalysis. This work offers valuable insights into the binding interaction and hydrolytic mechanism of carbaryl with the hydrolase PchA and will be crucial to designing strategies leading to the protein variants that are capable of degrading related contaminants.

Five questions toward mRNA degradation in oocytes and preimplantation embryos: when, who, to whom, how, and why?†.

RNA-the primary product of the genome-is subject to various biological events during its lifetime. During mammalian gametogenesis and early embryogenesis, germ cells and preimplantation embryos undergo marked changes in the transcriptome, including mRNA turnover. Various factors, including specialized proteins, RNAs, and organelles, function in an intricate degradation system, and the degradation selectivity is determined by effectors and their target mRNAs. RNA homeostasis regulators and surveillance factors function in the global transcriptome of oocytes and somatic cells. Other factors, including BTG4, PABPN1L, the CCR4-NOT subunits, CNOT6L and CNOT7, and TUTs, are responsible for two maternal mRNA avalanches: M- and Z-decay. In this review, we discuss recent advances in mRNA degradation mechanisms in mammalian oocytes and preimplantation embryos. We focused on the studies in mice, as a model mammalian species, and on RNA turnover effectors and the cis-elements in targeting RNAs.

Synthesis of fluorenes and their related compounds from biaryls and Meldrum's acid derivatives.

A new synthetic method for preparing fluorenes from amino group-containing biaryls and Meldrum's acid derivatives was developed. The reaction proceeded without a catalyst and loss of functional groups. The corresponding six- and seven-membered cyclic products were obtained using biaryl ether and ortho-terphenyl as substrates, respectively.