A novel nucleic acid linker for multi-gene expression enhances plant and animal synthetic biology.

The production of compact vectors for gene stacking is hindered by a lack of effective linkers. Here, we report that a 26-nt nucleic acid linker, NAL1, from the fungus Glarea lozoyensis and its truncated derivatives could connect two genes as a bicistron, enabling independent translation in a maize protoplast transient expression system and human 293 T cells. The optimized 9-nt NAL10 linker was then used to connect four genes driven by a bidirectional promoter; this combination was successfully used to reconstruct the astaxanthin biosynthesis pathway in transgenic maize. The short and efficient nucleic acid linker NAL10 can be widely used in multi-gene expression and synthetic biology in animals and plants.

Direct Formation of Amide-Linked C-Glycosyl Amino Acids and Peptides via Photoredox/Nickel Dual Catalysis.

Glycoproteins account for numerous biological processes including those associated with diseases and infections. The advancement of glycopeptides has emerged as a promising strategy for unraveling biological pathways and discovering novel medicines. In this arena, a key challenge arises from the absence of efficient synthetic strategies to access glycopeptides and glycoproteins. Here, we present a highly concise approach to bridging saccharides with amino acids and peptides through an amide linkage. Our amide-linked C-glycosyl amino acids and peptides are synthesized through cooperative Ni-catalyzed and photoredox processes. The catalytic process generates a glycosyl radical and an amide carbonyl radical, which subsequently combine to yield the C-glycosyl products. The saccharide reaction partners encompass mono-, di-, and trisaccharides. All 20 natural amino acids, peptides, and their derivatives can efficiently undergo glycosylations with yields ranging from acceptable to high, demonstrating excellent stereoselectivities. As a substantial expansion of applications, we have shown that simple C-glycosyl amino acids can function as versatile building units for constructing C-glycopeptides with intricate spatial complexities.

Supramolecular Adhesive Hydrogels for Tissue Engineering Applications.

Tissue engineering is a promising and revolutionary strategy to treat patients who suffer the loss or failure of an organ or tissue, with the aim to restore the dysfunctional tissues and enhance life expectancy. Supramolecular adhesive hydrogels are emerging as appealing materials for tissue engineering applications owing to their favorable attributes such as tailorable structure, inherent flexibility, excellent biocompatibility, near-physiological environment, dynamic mechanical strength, and particularly attractive self-adhesiveness. In this review, the key design principles and various supramolecular strategies to construct adhesive hydrogels are comprehensively summarized. Thereafter, the recent research progress regarding their tissue engineering applications, including primarily dermal tissue repair, muscle tissue repair, bone tissue repair, neural tissue repair, vascular tissue repair, oral tissue repair, corneal tissue repair, cardiac tissue repair, fetal membrane repair, hepatic tissue repair, and gastric tissue repair, is systematically highlighted. Finally, the scientific challenges and the remaining opportunities are underlined to show a full picture of the supramolecular adhesive hydrogels. This review is expected to offer comparative views and critical insights to inspire more advanced studies on supramolecular adhesive hydrogels and pave the way for different fields even beyond tissue engineering applications.

Retrospective clinical and microbiologic analysis of metagenomic next-generation sequencing in the microbiological diagnosis of cutaneous infectious granulomas.

BACKGROUND: Cutaneous infectious granulomas (CIG) are localized and chronic skin infection caused by a variety of pathogens such as protozoans, bacteria, worms, viruses and fungi. The diagnosis of CIG is difficult because microbiological examination shows low sensitivity and the histomorphological findings of CIG caused by different pathogens are commonly difficult to be distinguished. OBJECTIVE: The objective of this study is to explore the application of mNGS in tissue sample testing for CIG cases, and to compare mNGS with traditional microbiological methods by evaluating sensitivity and specificity. METHODS: We conducted a retrospective study at the Department of Dermatology of Sun Yat-sen Memorial Hospital, Sun Yat-sen University from January 1st, 2020, to May 31st, 2024. Specimens from CIG patients with a clinical presentation of cutaneous infection that was supported by histological examination were retrospectively enrolled. Specimens were delivered to be tested for microbiological examinations and mNGS. RESULTS: Our data show that mNGS detected Non-tuberculosis mycobacteria, Mycobacterium tuberculosis, fungi and bacteria in CIG. Compared to culture, mNGS showed a higher positive rate (80.77% vs. 57.7%) with high sensitivity rate (100%) and negative predictive value (100%). In addition, mNGS can detect more pathogens in one sample and can be used to detect variable samples including the samples of paraffin-embedded tissue with shorter detective time. Of the 21 patients who showed clinical improvement within a 30-day follow-up, eighteen had their treatments adjusted, including fifteen who continued treatment based on the results of mNGS. CONCLUSIONS: mNGS could provide a potentially rapid and effective alternative detection method for diagnosis of cutaneous infectious granulomas and mNGS results may affect the clinical prognosis resulting from enabling the patients to initiate timely treatment.

Metagenomic Next-Generation Sequencing Contributes to the Early Diagnosis of Mixed Infections in Central Nervous System.

Central nervous system (CNS) infections represent a challenge due to the complexities associated with their diagnosis and treatment, resulting in a high incidence rate and mortality. Here, we presented a case of CNS mixed infection involving Candida and human cytomegalovirus (HCMV), successfully diagnosed through macrogenomic next-generation sequencing (mNGS) in China. A comprehensive review and discussion of previously reported cases were also provided. Our study emphasizes the critical role of early pathogen identification facilitated by mNGS, underscoring its significance. Notably, the integration of mNGS with traditional methods significantly enhances the diagnostic accuracy of CNS infections. This integrated approach has the potential to provide valuable insights for clinical practice, facilitating early diagnosis, allowing for treatment adjustments, and ultimately, improving the prognosis for patients with CNS infections.

Upgrade of chrysomycin A as a novel topoisomerase II inhibitor to curb KRAS-mutant lung adenocarcinoma progression.

A primary strategy employed in cancer therapy is the inhibition of topoisomerase II (Topo II), implicated in cell survival. However, side effects and adverse reactions restrict the utilization of Topo II inhibitors. Thus, investigations focus on the discovery of novel compounds that are capable of inhibiting the Topo II enzyme and feature safer toxicological profiles. Herein, we upgrade an old antibiotic chrysomycin A from Streptomyces sp. 891 as a compelling Topo II enzyme inhibitor. Our results show that chrysomycin A is a new chemical entity. Notably, chrysomycin A targets the DNA-unwinding enzyme Topo II with an efficient binding potency and a significant inhibition of intracellular enzyme levels. Intriguingly, chrysomycin A kills KRAS-mutant lung adenocarcinoma cells and is negligible cytotoxic to normal cells at the cellular level, thus indicating a capability of potential treatment. Furthermore, mechanism studies demonstrate that chrysomycin A inhibits the Topo II enzyme and stimulates the accumulation of reactive oxygen species, thereby inducing DNA damage-mediated cancer cell apoptosis. Importantly, chrysomycin A exhibits excellent control of cancer progression and excellent safety in tumor-bearing models. Our results provide a chemical scaffold for the synthesis of new types of Topo II inhibitors and reveal a novel target for chrysomycin A to meet its further application.

Epidemiology and Clinical Findings of Tinea Capitis: A 23-Year Retrospective, Single-Center Study in Guangzhou, China.

BACKGROUND: Tinea capitis (TC) is one of the most common public health concerns due to its high incidence in preadolescent children. The epidemiological and clinical characteristics of TC vary depending on geographical regions and have changed over the past decades. OBJECTIVES: This study aimed to identify epidemiological changes in recent decades, including the prevalence and clinical and mycological characteristics of TC in southern China. METHODS: We conducted a retrospective study at the Department of Dermatology of Sun Yat-sen Memorial Hospital, Sun Yat-sen University from June 1997 to August 2020. RESULTS: We retrospectively evaluated 401 TC patients. Of these, 157 patients (39.2%) were preschool children aged 3-7 years and the majority were males. However, the prevalence in children under 3 years old is on the rise (from 19.67% during 1997-2010 to 32.49% during 2011-2020). Grey patches were the most common clinical pattern and mostly occurred in children (71.3%), while the proportion of grey patches and black dots was almost the same in adults. Although Microsporum canis (76%) was the most common causative organism, the number of the T. mentagrophytes complex, as a zoophilic fungus, has increased more than that of the anthropophilic fungi T. violaceum in the recent decade. There was a significant difference in the portion of sex among different age groups, and the gender difference was more notable in the adult group, which showed that the TC prevalence in females was 9 times that in males. In males, M. canis and the T. mentagrophytes complex were the two most common causative fungi, while M. canis and T. violaceum were the two most common causative fungi in females. Additionally, approximately 61.7% of black dot TCs occurred in females. For treatment, oral antifungal therapeutics were widely used in most patients with different treatment durations, although without a significant difference in efficacy (P = 0.106). CONCLUSIONS: In the last decade, the prevalence of TC in children under 3 years old increased, and boys dramatically outnumbered girls. In adults, the TC prevalence in females is nine times that in males, and most TCs occurring in females are presented as black dots. Moreover, the zoophilic T. mentagrophytes complex has replaced T. violaceum and is now the second most prevalent organism, followed by M. canis of TC.

Natural Anticancer Molecules and Their Therapeutic Potential.

Cancer poses a significant global public health challenge [...].

6-Shogaol as a Novel Thioredoxin Reductase Inhibitor Induces Oxidative-Stress-Mediated Apoptosis in HeLa Cells.

Inhibition of thioredoxin reductase (TrxR) is a crucial strategy for the discovery of antineoplastic drugs. 6-Shogaol (6-S), a primary bioactive compound in ginger, has high anticancer activity. However, its potential mechanism of action has not been thoroughly investigated. In this study, we demonstrated for the first time that 6-S, a novel TrxR inhibitor, promoted oxidative-stress-mediated apoptosis in HeLa cells. The other two constituents of ginger, 6-gingerol (6-G) and 6-dehydrogingerduone (6-DG), have a similar structure to 6-S but fail to kill HeLa cells at low concentrations. 6-Shogaol specifically inhibits purified TrxR1 activity by targeting selenocysteine residues. It also induced apoptosis and was more cytotoxic to HeLa cells than normal cells. The molecular mechanism of 6-S-mediated apoptosis involves TrxR inhibition, followed by an outburst of reactive oxygen species (ROS) production. Furthermore, TrxR knockdown enhanced the cytotoxic sensitivity of 6-S cells, highlighting the physiological significance of targeting TrxR by 6-S. Our findings show that targeting TrxR by 6-S reveals a new mechanism underlying the biological activity of 6-S and provides meaningful insights into its action in cancer therapeutics.

The Effect of Epimedium Isopentenyl Flavonoids on the Broiler Gut Health Using Microbiomic and Metabolomic Analyses.

Epimedium (EM), also known as barrenwort, is a traditional medicinal plant rich in isopentenyl flavonols, which have beneficial biological activities and can improve human and animal health, but its mechanism is still unclear. In this study, ultra-high-performance liquid chromatography/quadrupole-time-of-flight-mass spectrometry (UHPLC-Q-TOF/MS) and ultra-high-performance liquid chromatography triple-quadrupole mass spectrometry (UHPLC-QqQ-MS/MS) were used to analyse the main components of EM, and isopentenyl flavonols such as Epimedin A, B, and C as well as Icariin were the major components of EM. Meanwhile, broilers were selected as model animals to illuminate the mechanism of Epimedium isopentenyl flavonols (EMIE) on gut health. The results showed that supplementation with 200 mg/kg EM improved the immune response, increased cecum short-chain fatty acids (SCFAs) and lactate concentrations, and improved nutrient digestibility in broilers. In addition, 16S rRNA sequencing showed that EMIE altered the composition of cecal microbiome, increasing the relative abundance of beneficial bacteria (Candidatus Soleaferrea and Lachbospiraceae NC2004 group and Butyricioccus) and reducing that of harmful bacteria (UBA1819, Negativibacillus, and Eisenbergiella). Metabolomic analysis identified 48 differential metabolites, of which Erosnin and Tyrosyl-Tryptophan were identified as core biomarkers. Erosnin and tyrosyl-tryptophan are potential biomarkers to evaluate the effects of EMIE. This shows that EMIE may regulate the cecum microbiota through Butyricicoccus, with changes in the relative abundance of the genera Eisenbergiella and Un. Peptostreptococcaceae affecting the serum metabolite levels of the host. EMIE is an excellent health product, and dietary isopentenyl flavonols, as bioactive components, can improve health by altering the microbiota structure and the plasma metabolite profiles. This study provides the scientific basis for the future application of EM in diets.

Multi-Omics Profiling Reveals Se Deficiency-Induced Redox Imbalance, Metabolic Reprogramming, and Inflammation in Pig Muscle.

BACKGROUND: Nutritional muscle dystrophy is associated with selenium (Se) deficiency; however, the underlying mechanism remains unclear. OBJECTIVES: This study aimed to understand the crosstalk among redox status, energy metabolism, and inflammation in nutritional muscle dystrophy induced by dietary Se deficiency. METHODS: Eighteen castrated male pigs (Yorkshire, 45 d old) were fed Se-deficient (Se-D; 0.007 mg Se/kg) or Se-adequate (Se-A; in the form of selenomethionine, 0.3 mg Se/kg) diets for 16 wk. The muscle Se concentrations; antioxidant capacity; and gene expression, transcriptome, global proteome, metabolome, and lipidome profiles were analyzed. The transcriptome, metabolome, and proteome profiles were analyzed with biostatistics, bioinformatics, and pathway enrichment analysis; other data were analyzed with Student's 2-sided t tests. RESULTS: The muscle Se content in the Se-D group was 96% lower than that in the Se-A group (P < 0.05). The activity of glutathione peroxidase (GPX) and thioredoxin reductase (TXNRD) in the Se-D group was 42%-69% lower than that in the Se-A group (P < 0.05). The mRNA levels of 10 selenoprotein genes were 25%-84% lower than those in the Se-A group (P < 0.05). Multi-omics analyses indicated that the levels of 1378 transcripts, 83 proteins, 22 metabolites, and 55 lipid molecules were significantly altered in response to Se deficiency. Se deficiency-induced redox imbalance led to muscle central carbon and lipid metabolism reprogramming, which enhanced the glycolysis pathway and decreased phospholipid synthesis. Inflammation and apoptosis were observed in response to Se deficiency-induced muscle oxidative stress, which may have been associated with extracellular matrix (ECM) remodeling, suppressed focal adhesion and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling, and activation of the NF-κB signaling pathway. CONCLUSIONS: These results contributed to understanding the crosstalk among redox, energy metabolism, and inflammation in Se deficiency-induced muscle dystrophy in pigs, and may provide intervention targets for muscle disease treatment.

Etanercept treatment of Stevens-Johnson syndrome and toxic epidermal necrolysis.

BACKGROUND: Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) is a severe cutaneous adverse reaction to drugs with considerable morbidity and mortality. Immunomodulators for SJS/TEN including systemic corticosteroids and intravenous immunoglobulin (IVIG) have been widely used in clinical practice. Emerging evidence suggested the therapeutic effects of tumor necrosis factor-α antagonists on SJS/TEN. OBJECTIVE: To compare the efficacy and safety of IVIG and systemic steroids in conjunction with or without etanercept, a tumor necrosis factor-α inhibitor, for patients with SJS/TEN. METHODS: We undertook a retrospective review of 41 patients with SJS/TEN admitted to our institution from 2015 to February 2021. A total of 25 patients with integrated data were involved in this study, of which 14 patients were treated with IVIG and corticosteroids and 11 were in addition given etanercept. The clinical characteristics, duration of hospitalization, exposure time to high-dose steroids, and the total amount of systemic steroids were analyzed. RESULTS: In comparison to conventional therapy, conjunction with etanercept reduced the duration of hospitalization (13.5 vs 19.0 days; P = .01), the exposure time of high-dose steroids (7.1 vs 14.9 days; P = .01), and the overall amount of systemic steroid (925 mg vs 1412.5 mg; P = .03) in patients with SJS/TEN. No pronounced adverse effects were observed within 6 months of follow-up after the treatment. CONCLUSION: The add-in of etanercept at the time of initiating conventional therapy could be a superior option to accelerate disease recovery and reduce the high dose and total amount of systemic steroids without pronounced adverse events in patients with SJS/TEN.

Effects of chlortetracycline on growth performance and intestinal functions in weaned piglets.

AIM: Weaning stress can cause serious damage to piglet's health. Chlortetracycline (CTC) is widely used to ameliorate weaning stress and prevent infectious diseases in weaned piglets. However, antibiotics as growth promoters have to be limited because of increased antimicrobial resistance. In this study, we evaluated the effects of CTC on growth performance and intestinal functions in order to provide evidence for seeking antibiotic substitutes in weaned piglets. METHODS AND RESULTS: A total of 20 weaned piglets were fed a basal diet or a diet supplemented with 75 mg/kg CTC. CTC decreased the crypt depth and increased the ratio of villus height to crypt depth, whilst failing to affect growth performance and serum biochemical parameters and cytokines. 16S rRNA sequencing suggested that CTC supplementation had no effect on the diversity and composition of colonic microbiota. CONCLUSION: We speculated that gut microbiota is no longer sensitive to a low concentration of CTC due to the long-term use and low bioavailability of CTC in weaned piglets.

Asymmetric Construction of an Aryl-Alkene Axis by Palladium-Catalyzed Suzuki-Miyaura Coupling Reaction.

The application of Suzuki-Miyaura coupling reaction to forge the atropisomeric biaryls has seen remarkable progress but exploration of this chemistry to directly forge chiral C(aryl)-C(alkene) axis is underdeveloped. The replacement of arene substrates by alkenes intensifies the challenges in terms of reactivity, configurational atropostability of product and selectivity control. By meticulous ligand design and fine-tuning of reaction parameters, we identified a highly active 3,3'-triphenylsilyl-substituted phosphite ligand to realize arene-alkene Suzuki-Miyaura coupling of hindered aryl halides and vinyl boronates under very mild conditions. The axially chiral acyclic aryl-alkenes were generated in commendable efficiency, enantioselectivity and E/Z selectivity.

Small molecules regulating reactive oxygen species homeostasis for cancer therapy.

Elevated intracellular reactive oxygen species (ROS) and antioxidant defense systems have been recognized as one of the hallmarks of cancer cells. Compared with normal cells, cancer cells exhibit increased ROS to maintain their malignant phenotypes and are more dependent on the "redox adaptation" mechanism. Thus, there are two apparently contradictory but virtually complementary therapeutic strategies for the regulation of ROS to prevent or treat cancer. The first strategy, that is, chemoprevention, is to prevent or reduce intracellular ROS either by suppressing ROS production pathways or by employing antioxidants to enhance ROS clearance, which protects normal cells from malignant transformation and inhibits the early stage of tumorigenesis. The second strategy is the ROS-mediated anticancer therapy, which stimulates intracellular ROS to a toxicity threshold to activate ROS-induced cell death pathways. Therefore, targeting the regulation of intracellular ROS-related pathways by small-molecule candidates is considered to be a promising treatment for tumors. We herein first briefly introduce the source and regulation of ROS, and then focus on small molecules that regulate ROS-related pathways and show efficacy in cancer therapy from the perspective of pharmacophores. Finally, we discuss several challenges in developing cancer therapeutic agents based on ROS regulation and propose the direction of future development.

Biologically active indolizidine alkaloids.

Indolizidine alkaloids are chemical constituents isolated from various marine and terrestrial plants and animals, including but not limited to trees, fungi, ants, and frogs, with a myriad of important biological activities. In this review, we discuss the biological activity and pharmacological effects of indolizidine alkaloids and offer new avenues toward the discovery of new and better drugs based on these naturally occurring compounds.

Chiral Phosphoric Acid-Catalyzed Remote Control of Axial Chirality at Boron-Carbon Bond.

The previously elusive catalytic enantioselective construction of axially chiral B-aryl-1,2-azaborines with a C-B stereogenic axis has been realized through a chiral phosphoric acid-catalyzed desymmetrization strategy reported herein. The electrophilic aromatic substitution reaction of 3,5-disubsituted phenols with diazodicarboxamides could afford these axially chiral structures in good efficiency with excellent enantiocontrol. The efficient long-range stereochemical control is achieved by multiple well-defined H-bonding interactions between chiral phosphoric acid and both substrates. Meanwhile, the reaction duration could be markedly shortened with weakly acidic N-H in 1,2-azaborine acting as H-bond donor. The scalability of the reaction and facile cleavage of the N-N bond in the product further demonstrated the practicality of this method.

Fluorescent probes based on nucleophilic aromatic substitution reactions for reactive sulfur and selenium species: Recent progress, applications, and design strategies.

Reactive sulfur species (RSS) and reactive selenium species (RSeS) are important substances for the maintenance of physiological balance. Imbalance of RSS and RSeS is closely related to a series of human diseases, so it is considered to be an important biomarker in early diagnosis, treatment, and stage monitoring. Fast and accurate quantitative analysis of different RSS and RSeS in complex biological systems may promote the development of personalized diagnosis and treatment in the future. One way to explore the physiological function of various types of RSS and RSeS in vivo is to detect them at the molecular level, and one of the most effective methods for this is to use fluorescent probes. Nucleophilic aromatic substitution (SNAr) reactions are commonly exploited as a detection mechanism for RSS and RSeS in fluorescent probes. In this review, we cover recent progress in fluorescent probes for RSS and RSeS based on SNAr reactions, and discuss their response mechanisms, properties, and applications. Benzenesulfonate, phenyl-O ether, phenyl-S ether, phenyl-Se ether, 7-nitro-2,1,3-benzoxadiazole (NBD), benzoate, and selenium-nitrogen bonds are all good detection groups. Moreover, based on an integration of different reports, we propose the design and synthesis of RSS- and RSeS-selective probes based on SNAr reactions, current challenges, and future research directions, considering the selection of active sites, the effect of substituents on the benzene ring, and the introduction of other functional groups.

Metabolic engineering of astaxanthin-rich maize and its use in the production of biofortified eggs.

Production of the high-value carotenoid astaxanthin, which is widely used in food and feed due to its strong antioxidant activity and colour, is less efficient in cereals than in model plants. Here, we report a new strategy for expressing ß-carotene ketolase and hydroxylase genes from algae, yeasts and flowering plants in the whole seed using a seed-specific bidirectional promoter. Engineered maize events were backcrossed to inbred maize lines with yellow endosperm to generate progenies that accumulate astaxanthin from 47.76 to 111.82 mg/kg DW in seeds, and the maximum level is approximately sixfold higher than those in previous reports (16.2-16.8 mg/kg DW) in cereals. A feeding trial with laying hens indicated that they could take up astaxanthin from the maize and accumulate it in egg yolks (12.10-14.15 mg/kg) without affecting egg production and quality, as observed using astaxanthin from Haematococcus pluvialis. Storage stability evaluation analysis showed that the optimal conditions for long-term storage of astaxanthin-rich maize are at 4 °C in the dark. This study shows that co-expressing of functional genes driven by seed-specific bidirectional promoter could dramatically boost astaxanthin biosynthesis in every parts of kernel including embryo, aleurone layer and starch endosperm other than previous reports in the starch endosperm only. And the staple crop maize could serve as a cost-effective plant factory for reliably producing astaxanthin.

Synthesis and biological evaluation of disulfides as anticancer agents with thioredoxin inhibition.

Altered redox homeostasis as a hallmark of cancer cells is exploited by cancer cells for growth and survival. The thioredoxin (Trx), an important regulator in maintaining the intracellular redox homeostasis, is cumulatively recognized as a promising target for the development of anticancer drugs. Herein, we synthesized 72 disulfides and evaluated theirinhibition for Trx and antitumor activity. First, we established an efficient and fast method to screen Trx inhibitors by using the probe NBL-SS that was developed by our group to detect Trx function in living cells. After an initial screening of the Trx inhibitory activity of these compounds, 8 compounds showed significant inhibition activity against Trx. We then evaluated the cytotoxicity of these 8 disulfides, compounds 68 and 69 displayed high cytotoxicity to HeLa cells, but less sensitive to normal cell lines. Next, we performed kinetic studies of both two disulfides, 68 had faster inhibition of Trx than 69. Further studies revealed that 68 led to the accumulation of reactive oxygen species and eventually induced apoptosis of Hela cells via inhibiting Trx. The establishment of a method for screening Trx inhibitors and the discovery of 68 with remarkable Trx inhibition provide support for the development of anticancer candidates with Trx inhibition.