Exploring the Localization of Siderophore-Mediated Cargo Delivery in Gram-Negative Bacteria Using 3-Hydroxypyridin-4(1H)-one-Fluorescein Probes.

The design of siderophore-antibiotic conjugates is a promising strategy to overcome drug resistance in negative bacteria. However, accumulating studies have shown that only those antibiotics acting on the cell wall or cell membrane multiply their antibacterial effects when coupled with siderophores, while antibiotics acting on targets in the cytoplasm of bacteria do not show an obvious enhancement of their antibacterial effects when coupled with siderophores. To explore the causes of this phenomenon, we synthesized several conjugate probes using 3-hydroxypyridin-4(1H)-ones as siderophores and replacing the antibiotic cargo with 5-carboxyfluorescein (5-FAM) or malachite green (MG) cargo. By monitoring changes in the fluorescence intensity of FAM conjugate 20 in bacteria, the translocation of the conjugate across the outer membranes of Gram-negative pathogens was confirmed. Further, the use of the fluorogen activating protein(FAP)/MG system revealed that 3-hydroxypyridin-4(1H)-one-MG conjugate 26 was ultimately distributed mainly in the periplasm rather than being translocated into the cytosol of Escherichia coli and Pseudomonas aeruginosa PAO1. Additional mechanistic studies suggested that the uptake of the conjugate involved the siderophore-dependent iron transport pathway and the 3-hydroxypyridin-4(1H)-ones siderophore receptor-dependent mechanism. Meanwhile, we demonstrated that the conjugation of 3-hydroxypyridin-4(1H)-ones to the fluorescein 5-FAM can reduce the possibility of the conjugates crossing the membrane layers of mammalian Vero cells by passive diffusion, and the advantages of the mono-3-hydroxypyridin-4(1H)-ones as a delivery vehicle in the design of conjugates compared to the tri-3-hydroxypyridin-4(1H)-ones. Overall, this work reveals the localization rules of 3-hydroxypyridin-4(1H)-ones as siderophores to deliver the cargo into Gram-negative bacteria. It provides a theoretical basis for the subsequent design of siderophore-antibiotic conjugates, especially based on 3-hydroxypyridin-4(1H)-ones as siderophores.

Manganese-based nanomaterials in diagnostics and chemodynamic therapy of cancers: new development.

In the realm of cancer treatment, traditional modalities like radiotherapy and chemotherapy have achieved certain advancements but continue to grapple with challenges including harm to healthy tissues, resistance to treatment, and adverse drug reactions. The swift progress in nanotechnology recently has opened avenues for investigating innovative approaches to cancer therapy. Especially, chemodynamic therapy (CDT) utilizing metal nanomaterials stands out as an effective cancer treatment choice owing to its minimal side effects and independence from external energy sources. Transition metals like manganese are capable of exerting anti-tumor effects through a Fenton-like mechanism, with their distinctive magnetic properties playing a crucial role as contrast agents in tumor diagnosis and treatment. Against this backdrop, this review emphasizes the recent five-year advancements in the application of manganese (Mn) metal ions within nanomaterials, particularly highlighting their unique capabilities in catalyzing CDT and enhancing MRI imaging. Initially, we delineate the biomedical properties of manganese, followed by an integrated discussion on the utilization of manganese-based nanomaterials in CDT alongside multimodal therapies, and delve into the application and future outlook of manganese-based nanomaterial-mediated MRI imaging techniques in cancer therapy. By this means, the objective is to furnish novel viewpoints and possibilities for the research and development in future cancer therapies.

Primary bone solitary B-cell lymphoblastic lymphoma aberrant expression Fli-1 and ERG: A case report.

ABSTRACT: Primary non-Hodgkin bone lymphoma is a rare disease, and within this category, B-cell lymphoblastic lymphoma (B-LBL) is an even rare clinical entity that has only been reported in small case series or individual case reports. B-LBL can mimic Ewing's sarcoma both clinically and histologically, leading to misdiagnosis. We present a case of primary B-LBL of the bone in a 7-year-old girl. The tumor cells are uniform and small with a diffuse and infiltrative growth pattern similar to EWS. Immunohistochemical results are positive for CD99, Fli-1, ERG, TDT, PAX5, and CD79α, but negative for leukocyte common antigen, CD3, CD20, and NKX2.2. No other lesions are found on positron emission tomography/computed tomography imaging. Finally, primary solitary bone B-LBL of the right tibia was diagnosed.

Photochemical three-component assembly of tri-substituted oxazoles through a carbenic phosphorus-nitrile hybrid ylide formation/trapping cascade.

Construction of complex molecular skeletons with ubiquitous chemical feedstocks in a single transformation is highly appealing in organic synthesis. We report a novel visible-light-induced three-component reaction for the construction of complex 2,4,5-trisubstituted oxazoles, which are valuable in medicinal chemistry, from simple and readily available iodonium-phosphonium hybrid ylides, carboxylic acids, and nitriles. This reaction features a carbenic phosphorus-nitrile hybrid ylide formation/trapping cascade, in which a photo-generated α-phosphonium carbene acts as a sequence trigger. This catalyst- and additive-free transformation exhibits high efficiency and broad substrate scope for synthesizing diverse oxazoles.

Combinatorial metabolic engineering of Streptomyces sp. CB03234-S for the enhanced production of anthraquinone-fused enediyne tiancimycins.

BACKGROUND: Anthraquinone-fused enediynes (AFEs) are excellent payloads for antibody-drug conjugates (ADCs). The yields of AFEs in the original bacterial hosts are extremely low. Multiple traditional methods had been adopted to enhance the production of the AFEs. Despite these efforts, the production titers of these compounds are still low, presenting a practical challenge for their development. Tiancimycins (TNMs) are a class of AFEs produced by Streptomyces sp. CB03234. One of their salient features is that they exhibit rapid and complete cell killing ability against various cancer cell lines. RESULTS: In this study, a combinatorial metabolic engineering strategy guided by the CB03234-S genome and transcriptome was employed to improve the titers of TNMs. First, re-sequencing of CB03234-S (Ribosome engineered mutant strains) genome revealed the deletion of a 583-kb DNA fragment, accounting for about 7.5% of its genome. Second, by individual or combined inactivation of seven potential precursor competitive biosynthetic gene clusters (BGCs) in CB03234-S, a double-BGC inactivation mutant, S1009, was identified with an improved TNMs titer of 28.2 ± 0.8 mg/L. Third, overexpression of five essential biosynthetic genes, including two post-modification genes, and three self-resistance auxiliary genes, was also conducted, through which we discovered that mutants carrying the core genes, tnmE or tnmE10, exhibited enhanced TNMs production. The average TNMs yield reached 43.5 ± 2.4 mg/L in a 30-L fermenter, representing an approximately 360% increase over CB03234-S and the highest titer among all AFEs to date. Moreover, the resulting mutant produced TNM-W, a unique TNM derivative with a double bond instead of a common ethylene oxide moiety. Preliminary studies suggested that TNM-W was probably converted from TNM-A by both TnmE and TnmE10. CONCLUSIONS: Based on the genome and transcriptome analyses, we adopted a combined metabolic engineering strategy for precursor enrichment and biosynthetic pathway reorganization to construct a high-yield strain of TNMs based on CB03234-S. Our study establishes a solid basis for the clinical development of AFE-based ADCs.

Acid-Triggered Degradation of Three-In-One Ag2S Quantum Dots for In Situ Ratiometric NIR-II Fluorescence Imaging-Guided Ion/Gas Combination Therapy.

Smart theranostic nanoprobes with the integration of multiple therapeutic modalities are preferred for precise diagnosis and efficient therapy of tumors. However, it remains a big challenge to arrange the imaging and two or more kinds of therapeutic agents without weakening the intended performances. In addition, most existing fluorescence (FL) imaging agents suffer from low spatiotemporal resolution due to the short emission wavelength (<900 nm). Here, novel three-in-one Ag2S quantum dot (QD)-based smart theranostic nanoprobes were proposed for in situ ratiometric NIR-II FL imaging-guided ion/gas combination therapy of tumors. Under the acidic tumor microenvironment, three-in-one Ag2S QDs underwent destructive degradation, generating toxic Ag+ and H2S. Meanwhile, their FL emission at 1270 nm was weakened. Upon introduction of a downconversion nanoparticle (DCNP) as the delivery carrier and NIR-II FL reference signal unit, the formed Ag2S QD-based theranostic nanoprobes could achieve precise diagnosis of tumors through ratiometric NIR-II FL signals. Also, the generated Ag+ and H2S enabled specific ion/gas combination therapy toward tumors. By combining the imaging and therapeutic functions, three-in-one Ag2S QDs may open a simple yet reliable avenue to design theranostic nanoprobes.

Chalkophomycin Biosynthesis Revealing Unique Enzyme Architecture for a Hybrid Nonribosomal Peptide Synthetase and Polyketide Synthase.

Chalkophomycin is a novel chalkophore with antibiotic activities isolated from Streptomyces sp. CB00271, while its potential in studying cellular copper homeostasis makes it an important probe and drug lead. The constellation of N-hydroxylpyrrole, 2H-oxazoline, diazeniumdiolate, and methoxypyrrolinone functional groups into one compact molecular architecture capable of coordinating cupric ions draws interest to unprecedented enzymology responsible for chalkophomycin biosynthesis. To elucidate the biosynthetic machinery for chalkophomycin production, the chm biosynthetic gene cluster from S. sp. CB00271 was identified, and its involvement in chalkophomycin biosynthesis was confirmed by gene replacement. The chm cluster was localized to a ~31 kb DNA region, consisting of 19 open reading frames that encode five nonribosomal peptide synthetases (ChmHIJLO), one modular polyketide synthase (ChmP), six tailoring enzymes (ChmFGMNQR), two regulatory proteins (ChmAB), and four resistance proteins (ChmA'CDE). A model for chalkophomycin biosynthesis is proposed based on functional assignments from sequence analysis and structure modelling, and is further supported by analogy to over 100 chm-type gene clusters in public databases. Our studies thus set the stage to fully investigate chalkophomycin biosynthesis and to engineer chalkophomycin analogues through a synthetic biology approach.

A Red-Emission Fluorescent Probe with Large Stokes Shift for Detection of Viscosity in Living Cells and Tumor-Bearing Mice.

Abnormal viscosity is closely related to the occurrence of many diseases, such as cancer. Therefore, real-time detection of changes in viscosity in living cells is of great importance. Fluorescent molecular rotors play a critical role in detecting changes in cellular viscosity. Developing red emission viscosity probes with large Stokes shifts and high sensitivity and specificity remains an urgent and important topic. Herein, a novel viscosity-sensitive fluorescent probe (TCF-VIS1) with a large stokes shift and red emission was prepared based on the 2-dicyanomethylene-3-cyano-4,5,5-trimethyl-2,5-dihydrofuran (TCF) skeleton. Due to intramolecular rotation, the probe itself does not fluorescence at low viscosity. With the increase in viscosity, the rotation of TCF-VIS1 is limited, and its fluorescence is obviously enhanced. The probe has the advantages of simple preparation, large Stokes shift, good sensitivity and selectivity, and low cytotoxicity, which make it successfully used for viscosity detection in living cells. Moreover, TCF-VIS1 showed its potential for cancer diagnosis at the cell level and in tumor-bearing mice by detecting viscosity. Therefore, the probe is expected to enrich strategies for the detection of viscosity in biological systems and offer a potential tool for cancer diagnosis.

Exploring the clinical and cellular mechanisms of LncRNA-KCNQ1OT1/miR-29a-3p/SOCS3 molecular axis in cases of unexplained recurrent spontaneous abortion.

OBJECTIVE: The objective of this study is to explore the functions and mechanisms of the LncRNA-KCNQ1OT1/miR-29a-3p/SOCS3 molecular pathway in the context of unexplained recurrent spontaneous abortion (URSA). METHODS: We conducted qRT-PCR to assess the levels of LncRNA-KCNQ1OT1, miR-29a-3p, and SOCS3 in both abortion tissues from women who experienced URSA and healthy early pregnant women. A dual-luciferase assay was employed to investigate whether miR-29a-3p targets SOCS3. Furthermore, RNA IP and RNA Pull-Down assays were employed to confirm the interaction between KCNQ1OT1 and SOCS3 with miR-29a-3p. RNA FISH was used to determine the cellular localization of KCNQ1OT1. Additionally, trophoblast cells (HTR8/SVneo) were cultured and the CCK-8 assay was utilized to assess cell proliferation, while flow cytometry was employed to analyze cell apoptosis. RESULTS: Compared to abortion tissues obtained from healthy early pregnant individuals, those from women who experienced URSA displayed a notable downregulation of KCNQ1OT1 and SOCS3, accompanied by an upregulation of miR-29a-3p. Suppression of KCNQ1OT1 resulted in the inhibition of cell proliferation and the facilitation of apoptosis in HTR8/SVneo cells. Our findings suggest that KCNQ1OT1 may exert a regulatory influence on SOCS3 through a competitive binding mechanism with miR-29a-3p. Notably, KCNQ1OT1 exhibited expression in both the cytoplasm and nucleus, with a predominant localization in the cytoplasm. Furthermore, we observed a negative regulatory relationship between miR-29a-3p and SOCS3, as the miR-29a-3p mimic group demonstrated significantly reduced cell proliferation and an increased rate of apoptosis when compared to the negative control (NC mimic) group. Additionally, the SOCS3 Vector group exhibited a substantial improvement in proliferation capability and a marked reduction in the apoptosis rate in comparison to the NC Vector group. The miR-29a-3p mimic + SOCS3 Vector group demonstrated a remarkable enhancement in proliferation and a reduction in apoptosis when compared to the miR-29a-3p mimic group. CONCLUSION: The competitive binding of miR-29a-3p to LncRNA-KCNQ1OT1 appears to result in the elevation of SOCS3 expression, consequently fostering the proliferation of trophoblast cells while concomitantly suppressing apoptosis.

[Comparative study on excretion of Shuganning Injection and Scutellariae Radix extract in bile, urine, and feces of rats].

Scutellariae Radix extract is one of the important components in Shuganning Injection. In this study, an ultra-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) method was established for simultaneously determining five components in Shuganning Injection and Scutellariae Radix extract in bile, urine, and feces of rats, so as to reveal the difference in the excretion process of Shuganning Injection and Scutellariae Radix extract in rats and explore the law of the excretion process of the five components in vivo before and after the compatibility of Scutellariae Radix. Rats were injected with Shuganning Injection and Scutellariae Radix extract(4.2 mL·kg~(-1)), respectively, and the excretion of baicalin, baicalein, oroxylin A, oroxylin A-7-O-ß-D-glucuronide, and scutellarin in bile, urine, and feces of rats in 24 h was observed. The results showed that except for baicalin, the other four index components were excreted as prototype components in a high proportion after intravenous injection of Shuganning Injection and Scutellariae Radix extract in rats, respectively. The excretion of each component was relatively high in urine and less in feces and bile. After the compatibility of Scutellariae Radix extract, the accumulative excretion of five index components in rats all decreased. Among them, the cumulative excretion of baicalein in bile, urine, and feces significantly decreased by 26.67%, 48.11%, and 31.01%. The cumulative excretion of baicalin in bile, urine, and feces decreased significantly by 70.69%, 19.43%, and 31.22%. The result showed that the five index components in Scutellariae Radix extract were mainly excreted by the kidneys, and other components in Shuganning Injection delayed the excretion process and prolonged the residence time. This study is of great significance for elucidating the compatibility rationality of Shuganning Injection.

Application of three-dimensional speckle tracking technique in measuring left ventricular myocardial function in patients with diabetes.

BACKGROUND: Diabetic cardiomyopathy is considered as a chronic complication of diabetes mellitus (DM). Therefore, early detection of left ventricular systolic function (LVSF) damage in DM is essential. AIM: To explore the use of the three-dimensional speckle tracking technique (3D-STI) for measuring LVSF in DM patients via meta-analysis. METHODS: The electronic databases were retrieved from the initial accessible time to 29 April 2023. The current study involved 9 studies, including 970 subjects. We carried out this meta-analysis to estimate myocardial function in DM compared with controls according to myocardial strain attained by 3D-STI. RESULTS: Night articles including 970 subjects were included. No significant difference was detected in the left ventricular ejection fraction between the control and the diabetic group (P > 0.05), while differences in global longitudinal strain, global circumferential strain, global radial strain, and global area strain were markedly different between the controls and DM patients (all P < 0.05). CONCLUSION: The 3D-STI could be applied to accurately measure early LVSF damage in patients with DM.

Genome-wide identification of JAZ gene family in sugarcane and function analysis of ScJAZ1/2 in drought stress response and flowering regulation.

The JASMONATE ZIM DOMAIN (JAZ) proteins are a key inhibitors of the jasmonic acid (JA) signaling pathway that play an important role in the regulation of plant growth and development and environmental stress responses. However, there is no systematic identification and functional analysis of JAZ gene family members in sugarcane. In this study, a total of 49 SsJAZ genes were identified from the wild sugarcane species Saccharum spontaneum genome that were unevenly distributed on 13 chromosomes. Phylogenetic analysis showed that all SsJAZ members can be divided into six groups, and most of the SsJAZ genes contained photoreactive and ABA-responsive elements. RNA-seq analysis revealed that SsJAZ1-1/2/3/4 and SsJAZ7-1 were significantly upregulated under drought stress. The transcript level of ScJAZ1 which is the homologous gene of SsJAZ1 in modern sugarcane cultivars was upregulated by JA, PEG, and abscisic acid (ABA). Moreover, ScJAZ1 can interact with three other JAZ proteins to form heterodimers. The spatial and temporal expression analysis showed that SsJAZ2-1/2/3/4 were highly expressed in different tissues and growth stages and during the day-night rhythm between 10:00 and 18:00. Overexpression of ScJAZ2 in Arabidopsis accelerated flowering through activating the expression of AtSOC1, AtFT, and AtLFY. Moreover, the transcription level of ScJAZ2 was about 30-fold in the early-flowering sugarcane variety than that of the non-flowering variety, indicating ScJAZ2 positively regulated flowering. This first systematic analysis of the JAZ gene family and function analysis of ScJAZ1/2 in sugarcane provide key candidate genes and lay the foundation for sugarcane breeding.

Advances in Nanodynamic Therapy for Cancer Treatment.

Nanodynamic therapy (NDT) exerts its anti-tumor effect by activating nanosensitizers to generate large amounts of reactive oxygen species (ROS) in tumor cells. NDT enhances tumor-specific targeting and selectivity by leveraging the tumor microenvironment (TME) and mechanisms that boost anti-tumor immune responses. It also minimizes damage to surrounding healthy tissues and enhances cytotoxicity in tumor cells, showing promise in cancer treatment, with significant potential. This review covers the research progress in five major nanodynamic therapies: photodynamic therapy (PDT), electrodynamic therapy (EDT), sonodynamic therapy (SDT), radiodynamic therapy (RDT), and chemodynamic therapy (CDT), emphasizing the significant role of advanced nanotechnology in the development of NDT for anti-tumor purposes. The mechanisms, effects, and challenges faced by these NDTs are discussed, along with their respective solutions for enhancing anti-tumor efficacy, such as pH response, oxygen delivery, and combined immunotherapy. Finally, this review briefly addresses challenges in the clinical translation of NDT.

Application of exosomes in tumor immunity: recent progresses.

Exosomes are small extracellular vesicles secreted by cells, ranging in size from 30 to 150 nm. They contain proteins, nucleic acids, lipids, and other bioactive molecules, which play a crucial role in intercellular communication and material transfer. In tumor immunity, exosomes present various functions while the following two are of great importance: regulating the immune response and serving as delivery carriers. This review starts with the introduction of the formation, compositions, functions, isolation, characterization, and applications of exosomes, and subsequently discusses the current status of exosomes in tumor immunotherapy, and the recent applications of exosome-based tumor immunity regulation and antitumor drug delivery. Finally, current challenge and future prospects are proposed and hope to demonstrate inspiration for targeted readers in the field.

Spatiotemporal orchestration of macrophage activation trajectories by Vγ4 T cells during skin wound healing.

Dysregulated macrophage polarization from pro-inflammatory M1 to anti-inflammatory M2 phenotypes underlies impaired cutaneous wound healing. This study reveals Vγ4+ γδ T cells spatiotemporally calibrate macrophage trajectories during skin repair via sophisticated interferon-γ (IFN-γ) conditioning across multiple interconnected tissues. Locally within wound beds, infiltrating Vγ4+ γδ T cells directly potentiate M1 activation and suppress M2 polarization thereby prolonging local inflammation. In draining lymph nodes, infiltrated Vγ4+ γδ T cells expand populations of IFN-γ-competent lymphocytes which disseminate systemically and infiltrate into wound tissues, further enforcing M1 macrophages programming. Moreover, Vγ4+γδ T cells flushed into bone marrow stimulate increased IFN-γ production, which elevates the output of pro-inflammatory Ly6C+monocytes. Mobilization of these monocytes continually replenishes the M1 macrophage pool in wounds, preventing phenotypic conversion to M2 activation. Thus, multi-axis coordination of macrophage activation trajectories by trafficking Vγ4+ γδ T cells provides a sophisticated immunological mechanism regulating inflammation timing and resolution during skin repair.

Herb-drug interactions: Quantitative analysis of levofloxacin absorption and transporter expression in the rat intestine following combined treatment with Persicaria capitata (Buch.-Ham. ex D. Don) H. Gross.

Persicaria capitata (Buch.-Ham. ex D. Don) H. Gross, a traditional Chinese medicinal plant, is often used to treat various urologic disorders in China. P. capitata extracts (PCE) have been used in combination with levofloxacin (LVFX) to treat urinary tract infections (UTIs) for a long time. However, little is known about the absorption of LVFX and transporter expression in the intestine after combined treatment with PCE, restricting the development and utilization of PCE. In view of this, a UPLC-MS/MS method was established for the determination of LVFX in intestinal sac fluid samples and in situ intestinal circulation perfusate samples to explore the effect of PCE on the intestinal absorption characteristics of LVFX ex vivo and in vivo. To further evaluate the interaction between LVFX and PCE, western blotting, immunohistochemistry, and RT-qPCR were utilized to determine the expression levels of drug transporters (OATP1A2, P-gp, BCRP, and MRP2) involved in the intestinal absorption of LVFX after combined treatment with PCE. Using the everted intestinal sac model, the absorption rate constant (Ka) and cumulative drug absorption (Q) of LVFX in each intestinal segment were significantly lower in groups treated with PCE than in the control group. Ka at 2 h decreased most in the colon segment (from 0.088 to 0.016 µg/h·cm2), and Q at 2 h decreased most in the duodenum (from 213.29 to 33.92 µg). Using the intestinal circulation perfusion model, the Ka value and percentage absorption rate (A) of LVFX in the small intestine decreased significantly when PCE and LVFX were used in combination. These results showed that PCE had a strong inhibitory effect on the absorption of LVFX in the rat small intestine (ex vivo and in vivo intestinal segments). In addition, PCE increased the protein and mRNA expression levels of efflux transporters (P-gp, BCRP, and MRP2) and decreased the expression of the uptake transporter OATP1A2 significantly. The effects increased as the PCE concentration increased. These findings indicated that PCE changed the absorption characteristics of levofloxacin, possibly by affecting the expression of transporters in the small intestine. In addition to revealing a herb-drug interaction (HDI) between PCE and LVFX, these results provide a basis for further studies of their clinical efficacy and mechanism of action.

Innexin hemichannel activation by Microplitis bicoloratus ecSOD monopolymer reduces ROS.

The extracellular superoxide dismutases (ecSODs) secreted by Microplitis bicoloratus reduce the reactive oxygen species (ROS) stimulated by the Microplitis bicoloratus bracovirus. Here, we demonstrate that the bacterial transferase hexapeptide (hexapep) motif and bacterial-immunoglobulin-like (BIg-like) domain of ecSODs bind to the cell membrane and transiently open hemichannels, facilitating ROS reductions. RNAi-mediated ecSOD silencing in vivo elevated ROS in host hemocytes, impairing parasitoid larva development. In vitro, the ecSOD-monopolymer needed to be membrane bound to open hemichannels. Furthermore, the hexapep motif in the beta-sandwich of ecSOD49 and ecSOD58, and BIg-like domain in the signal peptides of ecSOD67 were required for cell membrane binding. Hexapep motif and BIg-like domain deletions induced ecSODs loss of adhesion and ROS reduction failure. The hexapep motif and BIg-like domain mediated ecSOD binding via upregulating innexins and stabilizing the opened hemichannels. Our findings reveal a mechanism through which ecSOD reduces ROS, which may aid in developing anti-redox therapy.