Asymmetric Synthesis and Biological Evaluation of Platensilin, Platensimycin, Platencin, and Their Analogs via a Bioinspired Skeletal Reconstruction Approach.

Platensilin, platensimycin, and platencin are potent inhibitors of ß-ketoacyl-acyl carrier protein synthase (FabF) in the bacterial and mammalian fatty acid synthesis system, presenting promising drug leads for both antibacterial and antidiabetic therapies. Herein, a bioinspired skeleton reconstruction approach is reported, which enables the unified synthesis of these three natural FabF inhibitors and their skeletally diverse analogs, all stemming from a common ent-pimarane core. The synthesis features a diastereoselective biocatalytic reduction and an intermolecular Diels-Alder reaction to prepare the common ent-pimarane core. From this intermediate, stereoselective Mn-catalyzed hydrogen atom-transfer hydrogenation and subsequent Cu-catalyzed carbenoid C-H insertion afford platensilin. Furthermore, the intramolecular Diels-Alder reaction succeeded by regioselective ring opening of the newly formed cyclopropane enables the construction of the bicyclo[3.2.1]-octane and bicyclo[2.2.2]-octane ring systems of platensimycin and platencin, respectively. This skeletal reconstruction approach of the ent-pimarane core facilitates the preparation of analogs bearing different polycyclic scaffolds. Among these analogs, the previously unexplored cyclopropyl analog 47 exhibits improved antibacterial activity (MIC80 = 0.0625 µg/mL) against S. aureus compared to platensimycin.

ROS-induced oxidative stress is a major contributor to sperm cryoinjury.

STUDY QUESTION: What is the mechanism behind cryoinjury in human sperm, particularly concerning the interplay between reactive oxygen species (ROS) and autophagy, and how does it subsequently affect sperm fate? SUMMARY ANSWER: The freeze-thaw operation induces oxidative stress by generating abundant ROS, which impairs sperm motility and activates autophagy, ultimately guiding the sperm toward programmed cell death such as apoptosis and necrosis, as well as triggering premature capacitation. WHAT IS KNOWN ALREADY: Both ROS-induced oxidative stress and autophagy are thought to exert an influence on the quality of frozen-thawed sperm. STUDY DESIGN, SIZE, DURATION: Overall, 84 semen specimens were collected from young healthy fertile males, with careful quality evaluation. The specimens were split into three groups to investigate the ROS-induced cryoinjury: normal control without any treatment, sperm treated with 0.5 mM hydrogen peroxide (H2O2) for 1 h, and sperm thawed following cryopreservation. Samples from 48 individuals underwent computer-assisted human sperm analysis (CASA) to evaluate sperm quality in response to the treatments. Semen samples from three donors were analyzed for changes in the sperm proteome after H2O2 treatment, and another set of samples from three donors were analyzed for changes following the freeze-thaw process. The other 30 samples were used for fluorescence-staining and western blotting. PARTICIPANTS/MATERIALS, SETTING, METHODS: Sperm motility parameters, including progressive motility (PR %) and total motility (PR + NP %), were evaluated using the CASA system on a minimum of 200 spermatozoa. The proteomic profiles were determined with label-free mass spectrometry (MS/MS) and protein identification was performed via ion search against the NCBI human database. Subsequently, comprehensive bioinformatics was applied to detect significant proteomic changes and functional enrichment. Fluorescence-staining and western blot analyses were also conducted to confirm the proteomic changes on selected key proteins. The ROS level was measured using 2',7'-dichlorodihydrofluorescein diacetate labeling and the abundance of bioactive mitochondria was determined by evaluating the inner mitochondrial membrane potential (MMP) level. Molecular behaviors of sequestosome-1 (p62 or SQSTM1) and microtubule-associated proteins 1A/1B light chain 3 (LC3) were monitored to evaluate the state of apoptosis in human sperm. Fluorescent probes oxazole yellow (YO-PRO-1) and propidium iodide (PI) were utilized to monitor programmed cell death, namely apoptosis and necrosis. Additionally, gradient concentrations of antioxidant coenzyme Q10 (CoQ10) were introduced to suppress ROS impacts on sperm. MAIN RESULTS AND THE ROLE OF CHANCE: The CASA analysis revealed a significant decrease in sperm motility for both the H2O2-treatment and freeze-thaw groups. Fluorescence staining showed that high ROS levels were produced in the treated sperm and the MMPs were largely reduced. The introduction of CoQ10 at concentrations of 20 and 30 µM resulted in a significant rescue of progressive motility (P < 0.05). The result suggested that excessive ROS could be the major cause of sperm motility impairment, likely by damaging mitochondrial energy generation. Autophagy was significantly activated in sperm when they were under oxidative stress, as evidenced by the upregulation of p62 and the increased conversion of LC3 as well as the upregulation of several autophagy-related proteins, such as charged multivesicular body protein 2a, mitochondrial import receptor subunit TOM22 homolog, and WD repeat domain phosphoinositide-interacting protein 2. Additionally, fluorescent staining indicated the occurrence of apoptosis and necrosis in both H2O2-treated sperm and post-thaw sperm. The cell death process can be suppressed when CoQ10 is introduced, which consolidates the view that ROS could be the major contributor to sperm cryoinjury. The freeze-thaw process could also initiate sperm premature capacitation, demonstrated by the prominent increase in tyrosine phosphorylated proteins, verified with anti-phosphotyrosine antibody and immunofluorescence assays. The upregulation of capacitation-related proteins, such as hyaluronidase 3 and Folate receptor alpha, supported this finding. LARGE SCALE DATA: The data underlying this article are available in the article and its online supplementary material. LIMITATIONS, REASONS FOR CAUTION: The semen samples were obtained exclusively from young, healthy, and fertile males with progressive motility exceeding 60%, which might overemphasize the positive effects while possibly neglecting the negative impacts of cryoinjury. Additionally, the H2O2 treatment conditions in this study may not precisely mimic the oxidative stress experienced by sperm after thawing from cryopreservation, potentially resulting in the omission of certain molecular alterations. WIDER IMPLICATIONS OF THE FINDINGS: This study provides substantial proteomic data for a comprehensive and deeper understanding of the impact of cryopreservation on sperm quality. It will facilitate the design of optimal protocols for utilizing cryopreserved sperm to improve applications, such as ART, and help resolve various adverse situations caused by chemotherapy, radiotherapy, and surgery. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by grants from the Major Innovation Project of Research Institute of National Health Commission (#2022GJZD01-3) and the National Key R&D Program of China (#2018YFC1003600). All authors declare no competing interests. TRIAL REGISTRATION NUMBER: N/A.

High-yielding, automated radiosynthesis of [11 C]martinostat using [11 C]methyl triflate.

Histone deacetylases (HDACs) mediate epigenetic mechanisms implicated in a broad range of central nervous system dysfunction, including neurodegenerative diseases and neuropsychiatric disorders. [11 C]Martinostat allows in vivo quantification of class I/IIb HDACs and may be useful for the quantification of drug-occupancy relationship, facilitating drug development for disease modifying therapies. The present study reports a radiosynthesis of [11 C]martinostat using [11 C]methyl triflate in ethanol, as opposed to the originally described synthesis using [11 C]methyl iodide and DMSO. [11 C]Methyl triflate is trapped in a solution of 2 mg of precursor 1 dissolved in anhydrous ethanol (400 µl), reacted at ambient temperature for 5 min and purified by high-performance liquid chromatography; 1.5-1.8 GBq (41-48 mCi; n = 3) of formulated [11 C]martinostat was obtained from solid-phase extraction using a hydrophilic-lipophilic cartridge in a radiochemical yield of 11.4% ± 1.1% (nondecay corrected to trapped [11 C]MeI), with a molar activity of 369 ± 53 GBq/µmol (9.97 ± 1.3 Ci/µmol) at the end of synthesis (40 min) and validated for human use. This methodology was used at our production site to produce [11 C]martinostat in sufficient quantities of activity to scan humans, including losses incurred from decay during pre-release quality control testing.

Highly biocompatible and recyclable biomimetic nanoparticles for antibiotic-resistant bacteria infection.

Increasing number of resistant bacteria have emerged with the overuse of antibiotics, which indicates that the bacterial infection has become a global challenge. Furthermore, the pollution of antibiotics to the environment has become a serious threat to public health. It is known that toxins produced by bacteria are the main cause of bacterial infections. Photothermal therapy is an effective antibacterial approach. However, the photothermal reagents cannot eliminate bacterial toxins, and even some anti-bacterial materials are toxic. Here, we synthesized a biomimetic recycled nanoparticle, red blood cell (RBC) membrane-coated Fe3O4 nanoparticles (RBC@Fe3O4), as an antibacterial agent. The RBC@Fe3O4 nanoparticles act as nano-sponges to trap toxins and then kill them all with a photothermal effect. We can describe this process simply as a battle between two armies. Our strategy is to disarm the "enemy" so that we can easily kill the "enemy" who has no power, which results in enhancing the bactericidal efficacy. The toxin of methicillin-resistant Staphylococcus aureus (MRSA) was absorbed by RBC@Fe3O4in vitro. In addition, in vivo studies proved that the RBC@Fe3O4 nanoparticles confer obvious survival benefits against toxin-induced lethality by absorbing the toxin of MRSA. Furthermore, using a mouse model of MRSA wound infection, the RBC@Fe3O4 nanoparticles with laser irradiation were found to have a superior wound-healing effect. Simultaneously, the RBC@Fe3O4 nanoparticles could be recycled in a simple way without affecting the bactericidal efficacy. The highly biocompatible and recyclable RBC@Fe3O4 biomimetic nanoparticles based on photothermal therapy and bacterial toxin adsorption strategy are promising for treating bacterial infections.

Presence of Tertiary Lymphoid Organ in Nasal Inverted Papilloma Is Correlated with Eosinophil Infiltration and Local Immunoglobulin Production.

INTRODUCTION: Nasal inverted papilloma (NIP) is a benign tumour with multiple inflammatory cell infiltration. Tertiary lymphoid organs (TLOs) support local antibody production and play important roles in airway inflammation. However, the evidence of TLOs and local immunoglobulins in NIP has not been reported yet. We investigated the presence of TLOs and immunoglobulins in NIP tissues and their association with the clinical-pathological characteristics of NIPs. METHODS: We analyzed the occurrence and composition of TLOs and local immunoglobulins by immunohistochemistry and evaluated the lymph organogenesis associated genes and cytokines by quantitative qPCR and Luminex assays, respectively, in papilloma tissues from 84 NIP cases. RESULTS: TLOs were present in 54% (45/84) of the NIP patients but not in control subjects. TLOs were composed of T cells, B cells, follicular dendritic cells, macrophages, and natural killer cells. Compared to NIP tissues without TLOs, tissues with TLOs showed significantly higher eosinophil infiltration levels (3.5-fold), elevation of lymphorganogenic genes (CXCL12, CXCL13, CCL20, CCL21, CD21L, and lymphotoxin alpha and beta), and increased Th17 (IL-21, IL-22, and GM-CSF) and Th2 (IL-5 and IL-13) cytokine production. Moreover, NIP with TLOs demonstrated a higher number of follicular T helper cells and immunoglobulin-producing plasma cells (CD138+ IgA+, CD138+ IgM+, CD138+ IgE+, and CD138+ IgG+) than those without TLOs, and these antibody-producing cells were positively correlated with the eosinophil number. CONCLUSION: The high frequency of TLOs and excess local immunoglobulin production are associated with an eosinophilic and Th2 skew microenvironment in the NIP mucosa, which would contribute to an important immunopathogenic response during NIP pathogenesis.

Synthesis of an MOF-based Hg2+-fluorescent probe via stepwise post-synthetic modification in a single-crystal-to-single-crystal fashion and its application in bioimaging.

Although post-synthetic modification (PSM) has been successfully applied to NMOF decoration, only a handful of PSM-based single-crystal-to-single-crystal (SCSC) examples have been reported, particularly those involving multistep MOF-based SCSC transformations. In this contribution, three new MOFs, namely, UiO-68-NCS, UiO-68-R6G and UiO-68-R6G', were prepared via the single-crystal-to-single-crystal post-synthetic modification approach. For bioimaging, nanosized UiO-68-NCS, UiO-68-R6G, and UiO-68-R6G' were also prepared. Herein, nanosized UiO-68-R6G with a rhodamine-based fluorescence switch was found to be a highly sensitive and selective fluorescent probe for the detection of Hg2+ both in vitro and in vivo.

UiO-68-PT MOF-Based Sensor and Its Mixed Matrix Membrane for Detection of HClO in Water.

As an important type of reactive oxygen species (ROS), hypochloric acid (HClO) is closely linked with our daily life, and its convenient and rapid detection is very significant and imperative. Fluorescent and visual probes are being recognized as powerful and convenient tools for detection of ROS in the environment and living organisms by visualizing and imaging. In this contribution, a new metal-organic framework-based fluorescent probe UiO-68-PT, which was generated from a phenthiazine-decorated benzimidazole bridging dicarboxyl ligand and ZrCl4 under solvothermal conditions via in situ one-pot approach, is reported. The obtained UiO-68-PT features a unique HClO and Vitamin C-triggered reversible redox process, which is accompanied by both visual and fluorescence changes. Therefore, it can be a highly sensitive, specific, and reusable sensor to detect HClO species in water via both visual and fluorogenic observation (turn-on). Furthermore, its mixed membrane material (MMM) was fabricated by the combination of UiO-68-PT and poly(vinyl alcohol), and the obtained hydrophilic MMM can be used as a reversible colorimetric card for visual detection of the HClO in aqueous solution.

Chemotherapy-driven increases in the CDKN1A/PTN/PTPRZ1 axis promote chemoresistance by activating the NF-κB pathway in breast cancer cells.

BACKGROUND: Chemotherapy is the primary established systemic treatment for patients with breast cancer, especially those with the triple-negative subtype. Simultaneously, the resistance of triple-negative breast cancer (TNBC) to chemotherapy remains a major clinical problem. Our previous study demonstrated that the expression levels of PTN and its receptor PTPRZ1 were upregulated in recurrent TNBC tissue after chemotherapy, and this increase was closely related to poor prognosis in those patients. However, the mechanism and function of chemotherapy-driven increases in PTN/PTPRZ1 expression are still unclear. METHODS: We compared the expression of PTN and PTPRZ1 between normal breast and cancer tissues as well as before and after chemotherapy in cancer tissue using the microarray analysis data from the GEPIA database and GEO database. The role of chemotherapy-driven increases in PTN/PTPRZ1 expression was examined with a CCK-8 assay, colony formation efficiency assay and apoptosis analysis with TNBC cells. The potential upstream pathways involved in the chemotherapy-driven increases in PTN/PTPRZ1 expression in TNBC cells were explored using microarray analysis, and the downstream mechanism was dissected with siRNA. RESULTS: We demonstrated that the expression of PTN and PTPRZ1 was upregulated by chemotherapy, and this change in expression decreased chemosensitivity by promoting tumour proliferation and inhibiting apoptosis. CDKN1A was the critical switch that regulated the expression of PTN/PTPRZ1 in TNBC cells receiving chemotherapy. We further demonstrated that the mechanism of chemoresistance by chemotherapy-driven increases in the CDKN1A/PTN/PTPRZ1 axis depended on the NF-κB pathway. CONCLUSIONS: Our studies indicated that chemotherapy-driven increases in the CDKN1A/PTN/PTPRZ1 axis play a critical role in chemoresistance, which suggests a novel strategy to enhance chemosensitivity in breast cancer cells, especially in those of the triple-negative subtype.

UiO-68-ol NMOF-Based Fluorescent Sensor for Selective Detection of HClO and Its Application in Bioimaging.

Fluorescent probes are powerful tools for the investigations of reactive oxygen species (ROS) in living organisms by visualization and imaging. As one of the most important of the natural reactive oxygen species (ROS), hypochlorous acid (HClO) plays a crucial role in various physiological and pathological processes. We report herein a new redox-switchable NMOF of UiO-68-ol via a direct ligand modification approach. The obtained UiO-68-ol NPs, which contains organic-based molecular redox switches, exhibit excellent photophysical properties for biological application and can be highly sensitive and selective fluorescent probes to detect HClO species in living cells.

Development of "[11C]kits" for a fast, efficient and reliable production of carbon-11 labeled radiopharmaceuticals for Positron Emission Tomography.

Translation of carbon-11 labeled PET tracers to clinical settings is currently impeded by the technical difficulties associated with [11C]CO2 conversion into the highly reactive methylating agents [11C]CH3I and [11C]CH3OTf using automated modules relying on stationary valves. Here we describe development of the first in its kind "[11C]kit" for production of carbon-11 radiotracer using disposable manifolds. This method proved to be very reliable and allows for consecutive production of PET tracers with minimal intervals between the syntheses.

[The strategy and process of out-hospital emergency care of acute cardiovascular events].

OBJECTIVE: To study the strategy and process of out-hospital emergency care of acute cardiovascular events. METHODS: One hundred and eighty-three patients in the Second Affiliated Hospital of Baotou Medical College were prospectively studied. The patients were divided into two groups according to the different ways of out-hospital care, one group consisted of patients who received first-aid care after calling "120" (94 cases), another was self-aid group consisting of patients sent to hospital by relatives (89 cases). The proportion of persons with higher than high school education and better knowledge for emergency care of patients with heart disease in first-aid group was higher than self-aid group (50.0% vs. 29.2%, 83.0% vs. 60.7%, both P<0.05). When the patients were brought to the emergency room, they were all treated according to our standard procedure and then registered. All patients were followed up at the end of first and third month after illness. RESULTS: Cardiovascular events were mainly myocardial infarction (61.7%) among 183 patients. There were statistically significant differences between two groups in self-aid response time, first disposal time and out-hospital rescuing time [(32.3+/-5.6) minutes vs. (89.6+/- 8.4) minutes, (47.3+/-7.3) minutes vs. (149.8+/-13.5) minutes, (61.7+/-8.3) minutes vs. [(149.8+/- 13.5) minutes, all P<0.01], but no difference was found in in-hospital rescuing time [(29.9+/-5.3) minutes vs. (31.1+/-4.5) minutes, P>0.05]. Morbidity rate was lower in first-aid group than self-aid group in 1st and 3rd month, respectively (2.1% vs. 9.0%, 4.2% vs. 12.4%, both P<0.05). CONCLUSION: Excellent emergency system and procedure can shorten initial disposal time and out-hospital rescuing time, thus improve patients' prognosis. The education level and health knowledge of patients and their relatives directly affect their mode of arriving hospital and prognosis.