HDAC6-Activatable Multifunctional Near-Infrared Probe for Glioma Cell Detection and Elimination.

Glioblastoma multiforme (GBM) is a highly aggressive primary brain tumor associated with limited treatment options and high drug resistance, presenting significant challenges in the pursuit of effective treatment strategies. Epigenetic modifications have emerged as promising diagnostic biomarkers and therapeutic targets for GBM. For instance, histone deacetylase 6 (HDAC6) has been identified as a potential pharmacological target for GBM. Furthermore, the overexpression of monoamine oxidase A (MAO A) in glioma has been linked to tumor progression, making it an attractive target for therapy. In this study, we successfully engineered HDAC-MB, an activatable multifunctional small-molecule probe with the goal of efficiently detecting and killing glioma cells. HDAC-MB can be selectively activated by HDAC6, leading to the "turn on" of near-infrared fluorescence and effective inhibition of MAO A, along with potent photodynamic therapy (PDT) effects. Consequently, HDAC-MB not only enables the imaging of HDAC6 in live glioma cells but also exhibits the synergistic effect of MAO A inhibition and PDT, effectively inhibiting glioma invasion and inducing cellular apoptosis. The distinctive combination of features displayed by HDAC-MB positions it as a versatile and highly effective tool for the accurate diagnosis and treatment of glioma cells. This opens up opportunities to enhance therapy outcomes and explore future applications in glioma theranostics.

Hollow Cu/CoS2 Nanozyme with Defect-Induced Enzymatic Catalytic Sites and Binding Pockets for Highly Sensitive Fluorescence Detection of Alkaline Phosphatase.

Along with an ever-deepening understanding of the catalytic principle of natural enzymes, the rational design of high-activity biomimetic nanozymes has become a hot topic in current research. Inspired by the active centers of natural enzymes consisting of catalytic sites and binding pockets, a Cu-doped CoS2 hollow nanocube (Cu/CoS2 HNCs) nanozyme integrating substitution defects and vacancies is developed through a defect engineering strategy. It is shown that the vacancies and substitution defects in the developed Cu/CoS2 HNC nanozymes serve as binding pockets and catalytic sites, respectively. The construction of this key active center and the accelerated electron transfer from the Co/Cu redox cycle significantly improve the substrate affinity and catalytic efficiency of the Cu/CoS2 HNCs nanozymes, which results in the excellent catalytic performance of the Cu/CoS2 HNC nanozymes. Using the superior enzymatic activity of Cu/CoS2 HNCs, a fluorescence detection platform for alkaline phosphatase (ALP) is established, which is a wider detection range and lower limit of detection (LOD) than previous work. This work broadens the family of nanozymes and provide a new idea for the development of novel nanozymes with high enzyme activity, as well as a guideline for the construction of highly sensitive fluorescent sensors.

Gonadal transcriptomes reveal sex-biased expression genes associated with sex determination and differentiation in red-tail catfish (Hemibagrus wyckioides).

BACKGROUND: Red-tail catfish (Hemibagrus wyckioides) is an important commercially farmed catfish in southern China. Males of red-tail catfish grow faster than females, suggesting that all-male catfish will produce more significant economic benefits in aquaculture practice. However, little research has been reported on sex determination and gonadal development in red-tail catfish. RESULTS: In this study, we performed the first transcriptomic analysis of male and female gonads at four developmental stages at 10, 18, 30, and 48 days post hatching (dph) using RNA-seq technology. A total of 23,588 genes were screened in 24 sequenced samples, of which 28, 213, 636, and 1381 differentially expressed genes (DEGs) were detected at four developmental stages, respectively. Seven candidate genes of sex determination and differentiation were further identified. Real-time quantitative PCR (RT-qPCR) further confirmed that anti-Mullerian hormone (amh), growth differentiation factor 6a (gdf6a), testis-specific gene antigen 10 (tsga10), and cytochrome P450 family 17 subfamily A (cyp17a) were highly expressed mainly in the male, while cytochrome P450 family 19 subfamily A polypeptide 1b (cyp19a1b), forkhead box L2 (foxl2), and hydroxysteroid 17-beta dehydrogenase 1 (hsd17b1) were highly expressed in the female. The KEGG pathway enrichment data showed that these identified DEGs were mainly involved in steroid hormone biosynthesis and TGF-ß signaling pathways. CONCLUSIONS: Based on RNA-seq data of gonads at the early developmental stages, seven DEGs shared by the four developmental stages were identified, among which amh and gdf6a may be the male-biased expression genes, while foxl2, cyp19a1b and hsd17b1 may be the female-biased expression genes in red-tail catfish. Our study will provide crucial genetic information for the research on sex control in red-tail catfish, as well as for exploring the evolutionary processes of sex determination mechanisms in fish.

Enzyme-Directed and Organelle-Specific Sphere-to-Fiber Nanotransformation Enhances Photodynamic Therapy in Cancer Cells.

Employing responsive nanoplatforms as carriers for photosensitizers represents an effective strategy to overcome the challenges associated with photodynamic therapy (PDT), including poor solubility, low bioavailability, and high systemic toxicity. Drawing inspiration from the morphology transitions in biological systems, a general approach to enhance PDT that utilizes enzyme-responsive nanoplatforms is developed. The transformation of phosphopeptide/photosensitizer co-assembled nanoparticles is first demonstrated into nanofibers when exposed to cytoplasmic enzyme alkaline phosphatase. This transition is primarily driven by alkaline phosphatase-induced changes of the nanoparticles in the hydrophilic and hydrophobic balance, and intermolecular electrostatic interactions within the nanoparticles. The resulting nanofibers exhibit improved ability of generating reactive oxygen species (ROS), intracellular accumulation, and retention in cancer cells. Furthermore, the enzyme-responsive nanoplatform is expanded to selectively target mitochondria by mitochondria-specific enzyme sirtuin 5 (SIRT5). Under the catalysis of SIRT5, the succinylated peptide/photosensitizer co-assembled nanoparticles can be transformed into nanofibers specifically within the mitochondria. The resulting nanofibers exhibit excellent capability of modulating mitochondrial activity, enhanced ROS formation, and significant anticancer efficacy via PDT. Consequently, the enzyme-instructed in situ fibrillar transformation of peptide/photosensitizers co-assembled nanoparticles provides an efficient pathway to address the challenges associated with photosensitizers. It is envisaged that this approach will further expand the toolbox for enzyme-responsive biomaterials for cancer therapy.

Reactivity-Tunable Fluorescent Platform for Selective and Biocompatible Modification of Cysteine or Lysine.

Chemoselective modification of specific residues within a given protein poses a significant challenge, as the microenvironment of amino acid residues in proteins is variable. Developing a universal molecular platform with tunable chemical warheads can provide powerful tools for precisely labeling specific amino acids in proteins. Cysteine and lysine are hot targets for chemoselective modification, but current cysteine/lysine-selective warheads face challenges due to cross-reactivity and unstable reaction products. In this study, a versatile fluorescent platform is developed for highly selective modification of cysteine/lysine under biocompatible conditions. Chloro- or phenoxy-substituted NBSe derivatives effectively labeled cysteine residues in the cellular proteome with high specificity. This finding also led to the development of phenoxy-NBSe phototheragnostic for the diagnosis and activatable photodynamic therapy of GSH-overexpressed cancer cells. Conversely, alkoxy-NBSe derivatives are engineered to selectively react with lysine residues in the cellular environment, exhibiting excellent anti-interfering ability against thiols. Leveraging a proximity-driven approach, alkoxy-NBSe probes are successfully designed to demonstrate their utility in bioimaging of lysine deacetylase activity. This study also achieves integrating a small photosensitizer into lysine residues of proteins in a regioselective manner, achieving photoablation of cancer cells activated by overexpressed proteins.

Identification of SIRT3 as an eraser of H4K16la.

Lysine lactylation (Kla) is a novel histone post-translational modification discovered in late 2019. Later, HDAC1-3, were identified as the robust Kla erasers. While the Sirtuin family proteins showed weak eraser activities toward Kla, as reported. However, the catalytic mechanisms and physiological functions of HDACs and Sirtuins are not identical. In this study, we observed that SIRT3 exhibits a higher eraser activity against the H4K16la site than the other human Sirtuins. Crystal structures revealed the detailed binding mechanisms between lactyl-lysine peptides and SIRT3. Furthermore, a chemical probe, p-H4K16laAlk, was developed to capture potential Kla erasers from cell lysates. SIRT3 was captured by this probe and detected via proteomic analysis. And another chemical probe, p-H4K16la-NBD, was developed to detect the eraser-Kla delactylation processes directly via fluorescence indication. Our findings and chemical probes provide new directions for further investigating Kla and its roles in gene transcription regulation.

Universal Strategy to Develop Fluorogenic Probes for Lysine Deacylase/Demethylase Activity and Application in Discriminating Demethylation States.

Dynamically controlling the post-translational modification of the ε-amino groups of lysine residues is critical for regulating many cellular events. Increasing studies have revealed that many important diseases, including cancer and neurological disorders, are associated with the malfunction of lysine deacylases and demethylases. Developing fluorescent probes that are capable of detecting lysine deacylase and demethylase activity is highly useful for interrogating their roles in epigenetic regulation and diseases. Due to the distinct substrate recognition of these epigenetic eraser enzymes, designing a universal strategy for detecting their activity poses substantial difficulty. Moreover, designing activity-based probes for differentiating their demethylation states is even more challenging and still remains largely unexplored. Herein, we report a universal strategy to construct probes that can detect the enzymatic activity of epigenetic "erasers" through NBD-based long-distance intramolecular reactions. The probes can be easily prepared by installing the O-NBD group at the C-terminal residue of specific peptide substrates by click chemistry. Based on this strategy, detecting the activity of lysine deacetylase, desuccinylase, or demethylase with superior sensitivity and selectivity has been successfully achieved through single-step probe development. Furthermore, the demethylase probe based on this strategy is capable of distinguishing different demethylation states by both absorption and fluorescence lifetime readout. We envision that these newly developed probes will provide powerful tools to facilitate drug discovery in epigenetics in the future.

Barbel regeneration and function divergence in red-tail catfish (Hemibagrus wyckioides) based on the chromosome-level genomes and comparative transcriptomes.

Catfish (Siluriformes) are one of the most diverse vertebrate orders and are characterized by whisker-like barbels, which are important sensory organs in most of teleosts. However, their specific biological functions are still unclear. Red-tail catfish (Hemibagrus wyckioides) is well-known catfish species with four pairs of barbels, of which the maxillary barbels reach two-thirds of the body length. In this study, a 776.58 Mb high-quality chromosome-level genome was assembled into 29 chromosomes. Comparative genome data indicated that the barbeled regeneration gene ccl33 has expanded into 11 tandemly duplicated copies. Transcriptome data revealed the functional differentiation of different barbels and suggested that the maxillary barbel might be necessary for water temperature perception. Taste receptor genes were also characterized in teleosts with different food habits. Selection pressures were revealed to affect the sugar-based solute transport domain of the sweet taste receptor gene t1r2 in carnivorous fishes. In addition, the bitter taste receptor gene t2r200 was found to be lost from the genomes of four catfish species. Therefore, our study provides a genomic foundation for understanding the regeneration and functional differentiation of barbels in red-tail catfish and also reveals novel insights into the feeding evolution of fish species with different feeding habits.

Apple-like Zinc-Oxide Mesocrystals as Robust and Versatile Photocatalysts for Efficient Degradation of Eight Different Organic Dyes.

The discovery of efficient photocatalysts is a promising key approach to solve the environmental crisis caused by hazardous organic dyes. Herein, we have for the first time created ZnO mesocrystals with a novel apple-like morphology. We have developed a one-pot biomineralization route to synthesize ZnO nanostructures at room temperature by using the rod-like protein collagen as the template. The shape of ZnO mesocrystals can be conveniently tuned from fusiform-like and kiwi-like to orange-like, apple-like, and snack-like structures. The apple-like ZnO mesocrystals show a significantly better photodegradation efficiency than the commercial ZnO powder as well as other nanostructured ZnO materials for both rhodamine B (RhB) and methyl orange (MO). Furthermore, the apple-like zinc-oxide mesocrystals can degrade all of the tested eight different types of organic dyes (RhB, rhodamine 6G, methylene blue, Coomassie brilliant blue R250, BPB, MO, Li Chunhong S, and carmine) simply under the exposure of sunlight, demonstrating their superior photodegradation prowess, environmental amiability, and energy-saving features. The novel robust and versatile photocatalyst has greatly advanced our abilities for the elimination of organic dyes. The green, one-pot strategy provides a convenient method for the construction of novel metal-oxide nanostructures with promising applications in environmental protection.

The lifestyle of Tuyuhun royal descendants: Identification and chemical analysis of buried plants in the Chashancun cemetery, northwest China.

The Tuyuhun Kingdom (AD 313-663) was one of the most famous regimes in northwest China during the early medieval period. However, the lifestyle and spiritual pursuit of their descendants who became allied with the Tang Dynasty remain enigmatic. The excavation of the Chashancun cemetery, a Tuyuhun royal descendant (AD 691) cemetery in the Qilian Mountains in northwest China, reveals a large amount of uncharred plant remains. These remains provided a rare opportunity to explore the geographical origin of the buried crops and their social implications. In total, 253,647 crops and 12,071 weeds were identified. Foxtail millet and broomcorn millet represent 61.99 and 30.83% of the total plant remains, with the rest being barley, buckwheat, beans, and hemp. The oxygen isotope and trace elements of the crop and weed remains suggest that broomcorn millet, foxtail millet, barley, buckwheat, and hemp were sourced from different regions. The assemblage of plant remains in the Chashancun cemetery suggests that millet cultivation played an important role in the livelihoods of Tuyuhun descendants, and the location of the elite Tuyuhun cemetery and multisources of different buried crops may reflect their memory of ancestors and homelands. This case study provides a unique perspective to understand the interactions among human subsistence strategy, geopolitical patterns, and local natural environments in northwest China during the late 7th century.

Self-assembled nano-photosensitizer for targeted, activatable, and biosafe cancer phototheranostics.

Cancer treatment currently still faces crucial challenges in therapeutic effectiveness, precision, and complexity. Photodynamic therapy (PDT) as a non-invasive tactic has earned widespread popularity for its excellent therapeutic output, flexibility, and restrained toxicity. Nonetheless, drawbacks, including low efficiency, poor cancer specificity, and limited therapeutic depth, remain considerable during the cancer treatment. Although great effort has been made to improve the performance, the overall efficiency and biosafety are still ambiguous and unable to meet urgent clinical needs. Herein, this study integrates merits from previous PDT strategies and develops a cancer-targeting, activatable, biosafe photosensitizer. Owing to excellent self-assembly ability, this photosensitizer can be conveniently prepared as multifunctional nano-photosensitizers, namely MBNPs, and applied to in vivo cancer phototheranostics in "all-in-one" mode. This study successfully verifies the mechanism of MBNPs, then deploys them to cell-based and in vivo cancer PDT. Based on the unique cancer microenvironment, MBNPs achieve precise distribution, accumulation, and activation towards the tumor, releasing methylene blue as a potent photosensitizer for phototherapy. The PDT outcome demonstrates MBNPs' superior cancer specificity, remarkable PDT efficacy, and negligible toxicity. Meanwhile, in vivo NIR fluorescence and photoacoustic imaging have been utilized to guide the PDT treatment synergistically. Additionally, the biosafety of the MBNPs-based PDT treatment is ensured, thus providing potential for future clinical studies.

Effect of sea surface temperature and precipitation on annual frequency of harmful algal blooms in the East China Sea over the past decades.

Coastal harmful algal blooms (HABs) in China's seas have attracted researchers' attention for decades. Among the four seas of China, the HAB frequency is the highest in the East China Sea (ECS). The impact of climate change and anthropogenic dominant factors on HABs is not well quantified and the response of HABs to the changing climate is also not clear. Here, we compiled a time series of observation-based HAB events since the 1980s and performed a regional assessment to elucidate the dominant drivers of HAB events in the ECS. The results showed that the increase in the frequency of HAB events in the ECS between 2000 and 2003 was associated with increases in dissolved inorganic phosphorus and sea surface temperature anomalies as well as decreasing summer precipitation. The declining annual frequency in HAB events in the ECS after 2003 was associated with the two climatological factors, most notably, precipitation. Under the "business-as-usual" scenario, climate change will increase the annual HAB events in the ECS from the historical frequency (1985-2013) by more than five-fold by the end of 21st century. These findings demonstrated that management strategies based on reducing nutrient loading also need to consider the effects of climate change in the future.

In Situ Imaging of Pathological Collagen by Electrostatic Repulsion-Destabilized Peptide Probes.

The development of robust collagen assays is crucial in the diagnosis and treatment of various pathological conditions. Peptide probes composed of the (Gly-Pro-Hyp)n sequences have received extensive attention for their remarkable collagen-targeting capability, which unfortunately has been severely impaired by their high triple helical stability. Herein, we report an efficient strategy to reduce the triple helical propensity of the (Gly-Pro-Hyp)n sequences by electrostatic repulsion. A series of peptides consisting of the (Gly-Pro-Hyp)7 sequence and a number of charged amino acid Asp have been investigated, indicating that the presence of six additional Asp pronouncedly weakened the triple helical stability of peptide probe FAM-PCTP-D6 under physiological conditions (pH 7.4). FAM-PCTP-D6 could be directly applied without any pretreatment to recognize denatured collagen with high selectivity, whereas another dye-labeled peptide probe ROX-PCTP-D6 specifically targeted pathological collagen in various connective tissues of animal disease models and human patients. The inclusion of extra charged natural amino acids has been demonstrated as a convenient approach to create biocompatible collagen-targeting peptide probes with much weaker triple helical stability. Without the need for preheating treatment, these electrostatic repulsion-driven peptide probes provide a handy tool for histopathology staining, showing promising applications in collagen-involved diseases.

Highly specific recognition of denatured collagen by fluorescent peptide probes with the repetitive Gly-Pro-Pro and Gly-Hyp-Hyp sequences.

Denatured collagen is a key biomarker for various critical diseases such as cancer. Peptide probes with the repetitive (Gly-Pro-Hyp)n sequences have recently been found to selectively target denatured collagen; however, thermal or UV pretreatment is required to drive the peptides into the monomer conformation, which poses a substantial challenge for clinical applications. We herein construct two peptide probes, FAM-GOO and FAM-GPP, consisting of the repetitive (Gly-Hyp-Hyp)8 and (Gly-Pro-Pro)8 sequences, respectively. The CD, fluorescence and colorimetric studies have consistently revealed that FAM-GOO showed strong capability of forming the triple helical structure, while FAM-GPP pronouncedly displayed the single stranded conformation at temperatures as low as 4 °C. The binding experiments have indicated that both peptide probes could recognize denatured collagen with high specificity, and FAM-GPP remarkably did not need the preheating treatment. The tissue staining results have shown that preheated FAM-GOO and unheated FAM-GPP could target denatured collagen in a wide variety of rat frozen and human FFPE tissue sections. Compared with antibodies specific for a certain type of collagen, both FAM-GOO and FAM-GPP act as broad-spectrum probes for the selective detection of denatured collagen of different types and from different species. Importantly, FAM-GPP possessed the unique capability of maintaining the monomer conformation by itself, thus avoiding the potential risks of the thermal or UV pretreatment. This novel peptide probe provides a handy and versatile biosensor for specifically targeting denatured collagen, which has attractive potential in the diagnosis and therapeutics of collagen-involved diseases.

Peptide Probes with Aromatic Residues Tyr and Phe at the X Position Show High Specificity for Targeting Denatured Collagen in Tissues.

The construction of potent peptide probes for selectively detecting denatured collagen is crucial for a variety of widespread diseases. However, all of the denatured collagen-targeting peptide probes found till date primarily utilized the repetitive (Gly-X-Y) n sequences with exclusively imino acids Pro and Hyp in the X and Y positions, which stabilized the triple helical conformation of the peptide probes, resulting in severe obstacles for their clinical applications. A novel series of peptide probes have been constructed by incorporating nonimino acids at the X position of the (GPO)3GXO(GPO)4 sequence, while the X-site residue is varied as Tyr, Phe, Asp, and Ala, respectively. Peptide probes FAM-GYO and FAM-GFO containing aromatic residues Tyr and Phe at the X position showed similarly high binding affinity and tissue-staining efficacy as the well-established peptide probe FAM-GPO, while peptide probes FAM-GDO and FAM-GAO with the corresponding charged residue Asp and the hydrophobic residue Ala indicated much weaker binding affinity and tissue-staining capability. Furthermore, FAM-GYO and FAM-GFO could specifically detect denatured collagen in different types of mouse connective tissues and efficiently stain various human pathological tissues. We have revealed for the first time that the incorporation of nonimino acids, particularly aromatic residues at the X and Y positions of the repetitive (Gly-X-Y) n sequences, may provide a convenient strategy to create novel robust collagen-targeting peptide probes, which have promising diagnostic applications in collagen-involved diseases.