RESUMEN
Most diazotrophs fix nitrogen only under nitrogen-limiting conditions, for example, in the presence of relatively low concentrations of NH4+ (0 to 2 mM). However, Paenibacillus sabinae T27 exhibits an unusual pattern of nitrogen regulation of nitrogen fixation, since although nitrogenase activities are high under nitrogen-limiting conditions (0 to 3 mM NH4+) and are repressed under conditions of nitrogen sufficiency (4 to 30 mM NH4+), nitrogenase activity is reestablished when very high levels of NH4+ (30 to 300 mM) are present in the medium. To further understand this pattern of nitrogen fixation regulation, we carried out transcriptome analyses of P. sabinae T27 in response to increasing ammonium concentrations. As anticipated, the nif genes were highly expressed, either in the absence of fixed nitrogen or in the presence of a high concentration of NH4+ (100 mM), but were subject to negative feedback regulation at an intermediate concentration of NH4+ (10 mM). Among the differentially expressed genes, ald1, encoding alanine dehydrogenase (ADH1), was highly expressed in the presence of a high level of NH4+ (100 mM). Mutation and complementation experiments revealed that ald1 is required for nitrogen fixation at high ammonium concentrations. We demonstrate that alanine, synthesized by ADH1 from pyruvate and NH4+, inhibits GS activity, leading to a low intracellular glutamine concentration that prevents feedback inhibition of GS and mimics nitrogen limitation, enabling activation of nif transcription by the nitrogen-responsive regulator GlnR in the presence of high levels of extracellular ammonium.
Asunto(s)
Alanina-Deshidrogenasa , Compuestos de Amonio , Fijación del Nitrógeno/genética , Alanina/genética , Nitrógeno , Ácido Pirúvico , Nitrogenasa/genéticaRESUMEN
Cyclic dinucleotides (CDNs) are a promising class of immune agonists that trigger the stimulator of interferon genes (STING) to activate both innate and acquired immunity. However, the efficacy of CDNs is limited by drug delivery barriers. Therefore, we developed a combined immunotherapy strategy based on injectable reactive oxygen species (ROS)-responsive hydrogels, which sustainably release 5,6-dimethylxanthenone-4-acetic acid (DMXAA) as known as a STING agonist and indocyanine green (ICG) by utilizing a high level of ROS in the tumor microenvironment (TME). The STING agonist combined with photothermal therapy (PTT) can improve the biological efficacy of DMXAA, transform the immunosuppressive TME into an immunogenic and tumoricidal microenvironment, and completely kill tumor cells. In addition, this bioreactive gel can effectively leverage local ROS to facilitate the release of immunotherapy drugs, thereby enhancing the efficacy of combination therapy, improving the TME, inhibiting tumor growth, inducing memory immunity, and protecting against tumor rechallenge.
Asunto(s)
Quitosano , Neoplasias , Humanos , Inmunoterapia , Proteínas de la Membrana , Neoplasias/tratamiento farmacológico , Terapia Fototérmica , Especies Reactivas de Oxígeno , Microambiente TumoralRESUMEN
Older adults are not actively participating in outdoor physical activities. An understanding of what factors influence older adults' outdoor physical activities is important for informing interventions. This study aims to examine the potential effect of service ontology on the intention of outdoor physical activities in older adults. Face-to-face surveys were conducted with 421 older adults from eight districts in Nanjing, China. One-way analysis of variance and ordinal logistic regression analysis revealed that seven of the 20 factors have a positive effect on intention of outdoor physical activities, including gender, health self-assessment, family structure, accessibility, exercise instructors, emergency service, and staff in outdoor space. To further improve the intention of outdoor physical activities, governments and service designers should focus on providing age-friendly community infrastructures. Moreover, specific attention should be paid toward older females and people with low-income/poor health conditions, and strategies should also be adopted to significantly improve the quantity and instruction efficiency of exercise instructors.
Asunto(s)
Ejercicio Físico , Pobreza , Femenino , Humanos , Anciano , Encuestas y Cuestionarios , Intención , ChinaRESUMEN
Two strains HN-1T and 39 were isolated from rhizospheres of different plants grown in different regions of PR China. The two strains exhibited high nitrogenase activities and possessed almost identical 16S rRNA gene sequences. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between the two strains were 99.9 and 99.8%, respectively, suggesting that they belong to one species. Phylogenetic analysis based on the 16S rRNA gene sequence showed that strains HN-1T and 39 are the members of the genus Paenibacillus and both strains exhibited 99.5% similarity to Paenibacillus stellifer DSM 14472T and the both strains represented a separate lineage from all other Paenibacillus species. However, the ANI of type strain HN-1T with P. stellifer DSM 14472T was 90.69, which was below the recommended threshold value (< 95-96% ANI). The dDDH showed 42.1% relatedness between strain HN-1T and P. stellifer DSM 14472T, which was lower than the recommended threshold value (dDDH < 70%). The strain HN-1T contain anteiso-C15:0 as major fatty acids and MK-7 as predominant isoprenoid quinone. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, four aminophospholipids and an unidentified glycolipid. Unlike the most closely related P. stellifer DSM 14472T, strain HN-1T or 39 was positive for catalase reaction. Distinct phenotypic and genomic characterisations from previously described taxa support the classification of strains HN-1T or 39 as representatives of a novel species of the genus Paenibacillus, for which the name Paenibacillus sinensis is proposed, with type strains HN-1T (=CGMCC 1.18902, JCM 34,620), and reference strain 39 (=CGMCC 1.18879, JCM 34,616), respectively.
Asunto(s)
Paenibacillus , Rizosfera , Composición de Base , ADN Bacteriano/genética , Nitrógeno , Paenibacillus/genética , Filogenia , ARN Ribosómico 16S/genéticaRESUMEN
Topical therapy is a favored route for treating skin cancers, but remain many challenges, such as low delivery efficiency, limited tumor tissue penetration, and unsatisfactory blood circulation. Here, a self-heating microneedle (MN) patch with multilevel structures, including a dissolvable base for rapid drug release, a degradable tip for sustained drug release, and a self-heating substrate is described. The thermally enhanced drug release performance is validated through both in vitro and in vivo experiments. High tumor therapeutic efficacy can be achieved due to the rapid release of 5-fluorouracil, while the sustained release of thymoquinone endows the MN patch with long-term tumor inhibition ability. It is further demonstrated the feasibility of such an MN patch for in vivo topical therapy of cutaneous squamous cell carcinoma with high efficacy, low side effects, and long-term inhibition of recurrence. This self-heating MN patch holds great promise for potential clinical applications, especially for the treatment of skin cancers.
Asunto(s)
Carcinoma de Células Escamosas , Neoplasias Cutáneas , Humanos , Neoplasias Cutáneas/tratamiento farmacológico , Neoplasias Cutáneas/patología , Calefacción , Sistemas de Liberación de Medicamentos , Preparaciones Farmacéuticas , Piel/patologíaRESUMEN
Photodynamic therapy (PDT) continues to encounter multifarious hurdles, stemming from the ineffectual preservation and delivery system of photosensitizers, the dearth of imaging navigation, and the antioxidant/hypoxic tumor microenvironment. Herein, a versatile cryomicroneedle patch (denoted as CMN-CCPH) is developed for traceable PDT. The therapeutic efficacy is further amplified by catalase (CAT)-induced oxygen (O2) generation and Cu2+-mediated glutathione (GSH) depletion. The CMN-CCPH is composed of cryomicroneedle (CMN) as the vehicle and CAT-biomineralized copper phosphate nanoflowers (CCP NFs) loaded with hematoporphyrin monomethyl ether (HMME) as the payload. Importantly, the bioactive function of HMME and CAT can be optimally maintained under the protection of CCPH and CMN for a duration surpassing 60 days, leading to bolstered bioavailability and notable enhancements in PDT efficacy. The in vivo visualization of HMME and oxyhemoglobin saturation (sO2) monitored by fluorescence (FL)/photoacoustic (PA) duplex real-time imaging unveils the noteworthy implications of CMN-delivered CCPH for intratumoral enrichment of HMME and O2 with reduced systemic toxicity. This versatile CMN patch demonstrates distinct effectiveness in neoplasm elimination, underscoring its promising clinical prospects.
RESUMEN
To evaluate the flavor characteristics of Chinese bayberry alcoholic beverages, fermented bayberry wine (FBW) and integrated bayberry wine (IBW) were investigated for their volatile and soluble profiles using HS-SPME GC-MS and UHPLC Q-TOF and were analyzed with multidimensional statistical analysis, including PCA and OPLS-DA. The volatile compounds 1-pentanol, ß-caryophyllene and isopentanol were only detected in IBW. ß-caryophyllene, the key flavor component of bayberry, was found to be the most abundant volatile compound in IBW (25.89%) and was 3.73 times more abundant in IBW than in FBW. The levels of ethyl octanoate, ethyl nonanoate, and ethyl decanoate were also several times higher in IBW than in FBW. These compounds contributed to the strong bayberry aroma and better fruity flavor of IBW. On the other hand, high levels of ethyl acetate and octanoic acid in FBW, representing pineapple/overripe or sweat odor, were key contributors to the fermented flavor of FBW. Soluble sugars, such as sucrose, D-glucose, and D-tagatose, as well as amino acids, such as L-glutamate and L-aspartate, had much higher levels in IBW. The anthocyanin pigment cyanidin 3-glucoside, which generates red color, was also higher in IBW. On the other hand, most of the differentially expressed alcohols, acids, amino acids, purines/pyrimidines and esters were present in higher concentrations in FBW compared to IBW. This demonstrated that IBW has a much sweeter and more savory taste as well as a better color generated by more anthocyanins, while FBW presents a more acidic and drier taste as well as a complex formation of alcohols and esters. The study also prompts the need for further research on the flavor profiles of IBW and its potential application and market value.
RESUMEN
5-Aminolevulinic acid-based photodynamic therapy heavily depends on the biological transformation efficiency of 5-aminolevulinic acid to protoporphyrin IX, while the lack of an effective delivery system and imaging navigation are major hurdles in improving the accumulation of protoporphyrin IX and optimizing therapeutic parameters. Herein, we leverage a synthetic biology approach to construct a transdermal theranostic microneedle patch integrated with 5-aminolevulinic acid and catalase co-loaded tumor acidity-responsive copper-doped calcium phosphate nanoparticles for efficient 5-aminolevulinic acid-based photodynamic therapy by maximizing the enrichment of intratumoral protoporphyrin IX. We show that continuous oxygen generation by catalase in vivo reverses tumor hypoxia, enhances protoporphyrin IX accumulation by blocking protoporphyrin IX efflux (downregulating hypoxia-inducible factor-1α and ferrochelatase) and upregulates protoporphyrin IX biosynthesis (providing exogenous 5-aminolevulinic acid and upregulating ALA-synthetase). In vivo fluorescence/photoacoustic duplex imaging can monitor intratumoral oxygen saturation and protoporphyrin IX metabolic kinetics simultaneously. This approach thus facilitates the optimization of therapeutic parameters for different cancers to realize Ca2+/Cu2+-interferences-enhanced repeatable photodynamic therapy, making this theranostic patch promising for clinical practice.
Asunto(s)
Neoplasias , Fotoquimioterapia , Humanos , Fotoquimioterapia/métodos , Ácido Aminolevulínico/farmacología , Catalasa/metabolismo , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Fármacos Fotosensibilizantes , Ferroquelatasa/metabolismo , Biología Sintética , Cobre/metabolismo , Protoporfirinas/metabolismo , Neoplasias/tratamiento farmacológico , Oxígeno/metabolismo , Ligasas/metabolismo , Línea Celular TumoralRESUMEN
Photodynamic therapy (PDT) has attained extensive attention as a noninvasive tumor treatment modality. However, the hypoxia in solid tumors, skin phototoxicity of "always on" photosensitizers (PSs), and abundant supply of glutathione (GSH) in cancer cells severely hampered the clinical applications of PDT. Herein, a self-oxygenation nanoplatform (denoted as CZCH) with GSH depletion ability was encapsulated into the hyaluronic acid microneedle patch (MN-CZCH) to simultaneously improve the biosafety and therapeutic efficacy of PDT. The Cu2+-doped porous zeolitic imidazolate framework incorporated with catalase (CAT) is capable of efficiently loading PS 2-(1-hexyloxyethyl)-2-divinylpyropheophorbic-a (HPPH). The CZCH intermingled MN patch (MN-CZCH) could effectively penetrate the stratum corneum, topically transport HPPH to the target tumor site, achieve a long tumor retention time, and enhance the efficacy of PDT via the simultaneously synergistic effect of CAT-catalyzed self-supplying O2 and Cu2+-mediated GSH depletion. Using traceable fluorescence (FL) imaging of the released HPPH from CZCH, the FL imaging-guided repeatable PDT can be achieved for enhanced antitumor efficacy. As a result, the MN-CZCH patch exhibited excellent therapeutic efficacy against melanoma with minimal toxicity, which has promising potential for cancer theranostics.
Asunto(s)
Neoplasias , Fotoquimioterapia , Humanos , Fotoquimioterapia/métodos , Fármacos Fotosensibilizantes/uso terapéutico , Catalasa/uso terapéutico , Ácido Hialurónico/uso terapéutico , Glutatión , Neoplasias/tratamiento farmacológico , Línea Celular TumoralRESUMEN
Multimodality imaging-guided therapy can improve the diagnostics and therapeutics efficiency of cancer. Herein, we developed a light-responsive nanotheranostic agent based on the indocyanine green (ICG) conjugated mesoporous silica coated gold nanobipyramid (GNB@SiO2) (denoted as GNB@SiO2-ICG) for simultaneous fluorescence (FL)/photoacoustic (PA) imaging-guided photothermal therapy (PTT). The GNB@SiO2 with excellent photostability was used for PA imaging as well as PTT. The loaded ICG promised FL imaging and PTT. The feasibility of the cancer theranostic capability of GNB@SiO2-ICG was evaluated from cancer cells to mice. Under the guidance of FL/PA imaging, GNB@SiO2-ICG exhibited remarkably enhanced therapeutic efficacy, which could eliminate the tumor tissues completely without tumor recurrence. This well-defined nanotheranostic nanoplatform that intelligently integrates dual-modality imaging and phototherapy provides an efficient nanoplatform for cancer nanotheranostics.