Application of Aptamer-SERS Nanotags for Unveiling the PD-L1 Immunomarker Progression Correlated to the Cell Metabolic Bioprocess.

In recent years, the expression and progression of programmed cell death ligand 1 (PD-L1) as an immunomarker in the context of a cell metabolic environment has gained significant attention in cancer research. However, intercellular bioprocesses that control the dynamics of PD-L1 have been largely unexplored. This study aimed to explore the cell metabolic states and conditions that govern dynamic variations of PD-L1 within the cell metabolic environment using an aptamer-based surface-enhanced Raman scattering (SERS) approach. The aptamer-SERS technique offers a sensitive, rapid, and powerful analytical tool for targeted and nondestructive detection of an immunomarker with high sensitivity and specificity. By combining aptamer-SERS with cell state profiling, we investigated the modulation in PD-L1 expression under different metabolic states, including glucose deprivation, metabolic coenzyme activity, and altered time/concentration-based cytokine availability. The most intriguing features in our findings include the cell-specific responses, cell differentiation by revealing distinct patterns, and dynamics of PD-L1 in different cell lines. Additionally, the time-dependent variations in PD-L1 expression, coupled with the dose-dependent relationship between glucose concentration and PD-L1 levels, underscore the complex interplay between immune checkpoint regulation and cellular metabolism. Therefore, this work demonstrates the advantages of using highly-sensitive and specific aptamer-SERS nanotags for investigating the immune checkpoint dynamics and related metabolic bioprocess.

Tea consumption and risk of bone health: an updated systematic review and meta-analysis.

INTRODUCTION: Current research evaluating the association between tea consumption and bone health still has inconsistent findings. MATERIALS AND METHODS: The electronic databases of Embase, PubMed, Scopus, and Web of Science were systematically searched from inception until December 2022 to identify eligible studies. The calculation of summary relative risks (RRs) and 95% confidence intervals (CIs) was carried out using random-effects models. I2 statistics and Forest plots were used to assess the heterogeneity of RR values across studies. RESULTS: The pooled relative risks for bone health-related outcomes of interest among tea drinkers, compared to non-drinkers, were 0.910 (95% confidence interval 0.845 to 0.980) for fractures, based on 20 studies, 0.332 (0.207-0.457) for BMD (13 studies), 0.800 (0.674-0.950) for osteoporosis (10 studies), and 1.006 (0.876-1.156) for osteopenia (5 studies). Subgroup analysis of locations showed that the pooled relative risks were 0.903 (0.844-0.966) for the hip, 0.735 (0.586-0.922) for the femur, 0.776 (0.610-0.988) for the lumbar, 0.980 (0.942-1.021) for the forearm and wrist, 0.804 (0.567-1.139) for the phalanges, and 0.612 (0.468-0.800) for Ward's triangle. One-stage dose-response analysis revealed that individuals who consumed less than 4.5 cups of tea per day had a lower risk of bone health-related outcomes than those who did not consume tea, with statistically significant results. CONCLUSION: There is an association between tea consumption and a reduced risk of fractures, osteoporosis, hip, femur, and lumbar, as well as increased BMD.

Highly sensitive soft optical fiber tactile sensor.

A soft highly sensitive tactile sensor based on an in-fiber interferometer embedded in polydimethylsiloxane (PDMS) structure is studied. Theoretical simulation obtains that the high order sensing modes and PDMS can improve the sensitivity. Experiments show that different order sensing modes, derived by fast Fourier transform (FFT) and inverse FFT methods, present different sensing performance. Corresponding to high order mode, 1.3593 nm/kPa sensitivity and 37 Pa (0.015 N) detection limit is obtained. Meanwhile, it also shows very good stability, reproducibility, and response time. This study not only demonstrates a tactile sensor with high sensitivity but also provides a novel sensing modes analysis method.

A dynamic fluorescence probed glycolysis suppression process in HeLa cells treated with trichostatin A.

Acetylation can be regulated by histone deacetylases (HDACs) and histone acetyltransferases (HATs), and the imbalance between HDACs and HATs can lead to cancers. Trichostatin A (TSA), as one of the typical HDAC inhibitors (HDACis), may regulate the acetylation level and thus prevent the proliferation of cancer cells, in which the metabolic change of glycolysis is involved. However, the dynamic process of glycolysis has not yet been explored, and the mechanism is still elusive. In this work, we constructed GFP-actin-HeLa cells to observe the dynamic change of glycolysis in situ and found that the GFP fluorescence enhanced significantly after TSA treatment, which was consistent with the change of pH in the cells (pHi) depending on the change of lactate originated from glycolysis. Furthermore, we confirmed that the glycolysis was inhibited after TSA treatment, and this process was associated with HIF-1α and c-Myc regulation. As such, this work not only demonstrates the usefulness of the GFP fluorescent probe for monitoring the metabolic process of glycolysis in situ, but also sheds new light on the mechanism of glycolysis suppression in the cancer cells treated with HDACi.

Development of IL-15/IL-15Rα sushi domain-IgG4 Fc complexes in Pichia pastoris with potent activities and prolonged half-lives.

BACKGROUND: Interleukin-15 (IL-15) is a critical cytokine for the development, proliferation, and function of natural killer (NK) cells, NKT cells, and CD8+ memory T cells and has become one of the most promising protein molecules for the treatment of cancer and viral diseases. However, there are several limitations in applying IL-15 in therapy, such as its low yield in vitro, limited potency, and short half-life in vivo. To date, there are several recombinant IL-15 agonists based on configurational modifications that are being pursued in the treatment of cancer, such as ALT-803, which are mainly produced from mammalian cells. RESULTS: In this study, we designed two different forms of the IL-15 complex, which were formed by the noncovalent assembly of IL-15 with dimeric or monomeric sushi domain of IL-15 receptor α (SuIL-15Rα)-IgG4 Fc fusion protein and designated IL-15/SuIL-15Rα-dFc and IL-15/SuIL-15Rα-mFc, respectively. The two IL-15 complexes were expressed in Pichia pastoris (P. pastoris), and their activities and half-lives were evaluated and compared. Pharmacokinetic analysis showed that IL-15/SuIL-15Rα-dFc had a half-life of 14.26 h while IL-15/SuIL-15Rα-mFc had a half-life of 9.16 h in mice, which were much longer than the 0.7-h half-life of commercial recombinant human IL-15 (rhIL-15). Treatment of mice with intravenous injection of the two IL-15 complexes resulted in significant increases in NK cells, NKT cells, and memory CD8+ T cells, which were not observed after rhIL-15 treatment. Treatment of human peripheral blood mononuclear cells (PBMCs) from healthy donors with the two IL-15 complexes yielded enhanced NK and CD8+ T cell activation and proliferation, which was comparable to the effect of rhIL-15. CONCLUSIONS: These findings indicate that the IL-15/SuIL-15Rα-dFc and IL-15/SuIL-15Rα-mFc produced in P. pastoris exhibit potent activities and prolonged half-lives and may serve as superagonists for immunotherapy in further research and applications.

Identification and characterization of PaGL1-like genes from Platanus acerifolia related to the regulation of trichomes.

KEY MESSAGE: Two PaGL1-like genes were identified in London plane and functional in Arabidopsis, moreover, may play an important role in the regulation of trichome development in London plane. Trichome development is governed by a complex regulatory network. In Arabidopsis, subgroup 15 of the R2R3 MYB transcription factor family, which includes GLABRA1 (GL1), is involved in trichome development. In this study, we isolated and characterized two PaGL1-like genes from London plane (Platanus acerifolia). Sequence alignment and phylogenetic analysis indicated that these PaGL1-like genes are homologous to AtGL1. Quantitative real-time PCR (qRT-PCR) analysis showed that PaGL1-like1 was expressed in all of the tested organs taken from adult London plane trees, including trichomes, petioles after trichome removal, stems after trichome removal, and leaves after trichome removal, and also in the roots, cotyledons, hypocotyls and true leaves of seedlings. By contrast, the PaGL1-like2 was expressed only in the trichomes and leaves after trichome removal from adult trees, and in the cotyledons and true leaves of seedlings. Overexpression of PaGL1-like genes caused trichome abortion when transferred into wild type Arabidopsis and promoted trichome formation in the gl1 mutant. The expression profiles of some trichome-related genes were changed in transgenic Arabidopsis lines, and yeast two-hybrid analysis indicated that PaGL1-like proteins can directly interact with trichome-related bHLH proteins from both P. acerifolia and Arabidopsis. These results suggest that PaGL1-like genes are functional in Arabidopsis and may play an important role in the regulation of trichome development in London plane.

Remodeling Chromatin Induces Z-DNA Conformation Detected through Fourier Transform Infrared Spectroscopy.

The SWI/SNF complex is a highly conserved chromatin remodeling complex and can hydrolyze ATP by its catalytic subunit BRG1 or BRM to reconstruct the chromatin. To investigate whether this ATP-dependent chromatin remodeling could affect the DNA conformation, we therefore regulated (knocked down or overexpressed) BRG1/BRM in the cells and applied Fourier transform infrared (FTIR) spectroscopy to probe DNA conformational changes. As a result, we found that BRG1/BRM was indeed associated with the DNA conformational changes, in which knockdown of BRG1/BRM reduced Z-DNA conformation, while overexpression of BRG1/BRM enhanced Z-DNA conformation. This Z-DNA conformational transformation was also verified using the Z-DNA-binding proteins. Therefore, this work has provided a direct analytical tool to probe Z-DNA transformation upon ATP-dependent chromatin remodeling.

Improved the expression level of active transglutaminase by directional increasing copy of mtg gene in Pichia pastoris.

BACKGROUND: The microbial transglutaminase (MTG) is inactive when only the mature sequence is expressed in Pichia pastoris. Although co-expression of MTG and its N-terminal pro-peptide can obtain the active MTG, the enzyme activity was still low. One of the basic steps for strain improvement is to ensure a sufficient level of transcription of the heterologous gene, based on promoter strength and gene copy number. To date, high-copy-number recombinants of P. pastoris are achievable only by cloning of gene concatemers, so methods for rapid and reliable multicopy strains are therefore desirable. RESULTS: The coexpression strains harboring different copies mtg were obtained successfully by stepwise increasing Zeocin concentration based on the rDNA sequence of P. pastoris. The genome of coexpression strains with the highest enzyme activity was analyzed by real-time fluorescence quantitative PCR, and three copies of mtg gene (mtg-3c) was calculated according to the standard curve of gap and mtg genes (gap is regarded as the single-copy reference gene). The maximum enzyme activity of mtg-3c was up to 1.41 U/mL after being inducted for 72 h in 1 L flask under optimal culture conditions, and two protein bands were observed at the expected molecular weights (40 kDa and 5 kDa) by Western blot. Furthermore, among the strains detected, compared with mtg-2c, mtg-6c or mtg-8c, mtg-3c is the highest expression level and enzyme activity, implying that mtg-3c is the most suitable for co-expression pro-peptide and MTG. CONCLUSIONS: This study provides an effective strategy for improving the expression level of active MTG by directional increasing of mtg copies in P. pastoris.

Single-repeat R3 MYB transcription factors from Platanus acerifolia negatively regulate trichome formation in Arabidopsis.

MAIN CONCLUSION: Four R3 MYB genes were cloned and identified from Platanus acerifolia and analysed according to endogenous gene expression profiles, protein-protein interaction patterns, phenotypic effects and related gene expression profiles in transgenic Arabidopsis, suggesting that London plane R3 MYB genes inhibit trichome formation in Arabidopsis. The CPC-like MYB transcription factors including CAPRICE (CPC), TRIPTYCHON (TRY), ENHANCER OF TRY AND CPC 1, 2 and 3 (ETC1, ETC2 and ETC3), TRICHOMELESS1 (TCL1) and TRICHOMELESS2(TCL2) play important roles in controlling trichome patterning in Arabidopsis. In this study, four sequences homologous with the Arabidopsis CPC family were identified from London plane and named PaTRY, PaCPC-like1, PaCPC-like2 and PaCPC-like3. Over-expression of PaTRY, PaCPC-like1, PaCPC-like2 and PaCPC-like3 in Arabidopsis resulted in glabrous phenotypes. In addition, expression of endogenous GL2, GL1, MYB23, TTG2 and a set of R3 MYB-encoding genes was markedly reduced. Furthermore, the protein products of PaTRY, PaCPC-like1, PaCPC-like2 and PaCPC-like3 were shown to interact with PaGL3 in yeast two-hybrid assays. Together, these results likely suggest that the mechanisms of trichome regulation in London plane have similarities with those in Arabidopsis.

The suppression of innate immune response by human rhinovirus C.

Rhinovirus C (RV-C), a newly identified group of human rhinoviruses (RVs), is associated with exacerbation of severe asthma. The type I interferon (IFN) response induced by this virus and the mechanisms of evasion of IFN-mediated innate immunity for RV-C remain unclear. In this study, we constructed a full-length cDNA clone of RV-C (LZ651) from a clinical sample. IFN-ß mRNA and protein levels were not elevated in differentiated Human bronchial epithelial (HBE) cells at the air-liquid interface infected with RV-C, except in the early stage of infection. The ability to attenuate IFN-ß activation was ascribed to 3Cpro of RV-C, and the 40-His site of 3Cpro played an important role. Furthermore, RIG-I was degraded by 3Cpro in a caspase-dependent manner and 3Cpro cleaved MAVS at 148 Q/A, which inhibited IFN signaling. Taken together, our results demonstrate the mechanism by which RV-C circumvents the production of type I IFN in infected cells.

Elimination of N-glycosylation by site mutation further prolongs the half-life of IFN-α/Fc fusion proteins expressed in Pichia pastoris.

BACKGROUND: Interferon (IFN)-α has been commonly used as an antiviral drug worldwide; however, its short half-life in circulation due to its low molecular weight and sensitivity to proteases impacts its efficacy and patient compliance. RESULTS: In this study, we present an IgG1 Fc fusion strategy to improve the circulation half-life of IFN-α. Three different forms of IgG1 Fc fragments, including the wild type, aglycosylated homodimer and aglycosylated single chain, were each fused with IFN-α and designated as IFN-α/Fc-WT, IFN-α/Fc-MD, and IFN-α/Fc-SC, respectively. The recombinant proteins were expressed in Pichia pastoris and tested using antiviral and pharmacokinetic assays in comparison with the commercial pegylated-IFN-α (PEG-IFN-α). The in vitro study demonstrated that IFN-α/Fc-SC has the highest antiviral activity, while IFN-α/Fc-WT and IFN-α/Fc-MD exhibited antiviral activities comparable to that of PEG-IFN-α. The in vivo pharmacokinetic assay showed that both IFN-α/Fc-WT and IFN-α/Fc-MD have a longer half-life than PEG-IFN-α in SD rats, but IFN-α/Fc-SC has the shortest half-life among them. Importantly, the circulating half-life of 68.3 h for IFN-α/Fc-MD was significantly longer than those of 38.2 h for IFN-α/Fc-WT and 22.2 h for PEG-IFN-α. CONCLUSIONS: The results demonstrate that the elimination of N-glycosylation by mutation of putative N-glycosylation site further prolongs the half-life of the IFN-α/Fc fusion protein and could present an alternative strategy for extending the half-life of low-molecular-weight proteins expressed by P. pastoris for in vivo studies as well as for future clinical applications.

Astaxanthin attenuates UV-irradiation aging process via activating JNK-1/DAF-16 in Caenorhabditis elegans.

Astaxanthin (AST) is a xanthophyll carotenoid with strong oxidation resistance, which can effectively scavenge various free radicals and protect organisms from oxidative damage. AST is also known to have prominent anti-aging effects, but the underlying mechanism of AST in anti-radiation aging is largely unknown. In this work, we applied ultraviolet (UV) irradiation to accelerate the aging of Caenorhabditis elegans (C. elegans) and treated the nematodes with AST to explore whether and how AST could attenuate the radiation-induced aging effect. Our results showed that AST improved the survival rate of C. elegans, reduced the aging biomarkers, and alleviated the mitochondrial dysfunction caused by the irradiation. Based on the transcriptome sequencing analysis, we identified that the key genes regulated by AST were involved in JNK-MAPK and DAF-16 longevity signaling pathways. Furthermore, we employed jnk-1 and daf-16 mutants and verified the role of the JNK-1/DAF-16 signaling pathway in the anti-aging effect. As such, this study has not only demonstrated that AST can resist the aging process caused by UV-irradiation but also revealed the anti-aging mechanism of AST through JNK-1/DAF-16 activation in C. elegans.

Astaxanthin targets IL-6 and alleviates the LPS-induced adverse inflammatory response of macrophages.

Numerous natural compounds are recognized for their anti-inflammatory properties attributed to antioxidant effects and the modulation of key inflammatory factors. Among them, astaxanthin (AST), a potent carotenoid antioxidant, remains relatively underexplored regarding its anti-inflammatory mechanisms and specific molecular targets. In this study, human monocytic leukemia cell-derived macrophages (THP-1) were selected as experimental cells, and lipopolysaccharides (LPS) served as inflammatory stimuli. Upon LPS treatment, the oxidative stress was significantly increased, accompanied by remarkable cellular damage. Moreover, LPSs escalated the expression of inflammation-related molecules. Our results demonstrate that AST intervention could effectively alleviate LPS-induced oxidative stress, facilitate cellular repair, and significantly attenuate inflammation. Further exploration of the anti-inflammatory mechanism revealed AST could substantially inhibit NF-κB translocation and activation, and mitigate inflammatory factor production by hindering NF-κB through the antioxidant mechanism. We further confirmed that AST exhibited protective effects against cell damage and reduced the injury from inflammatory cytokines by activating p53 and inhibiting STAT3. In addition, utilizing network pharmacology and in silico calculations based on molecular docking, molecular dynamics simulation, we identified interleukin-6 (IL-6) as a prominent core target of AST anti-inflammation, which was further validated by the RNA interference experiment. This IL-6 binding capacity actually enabled AST to curb the positive feedback loop of inflammatory factors, averting the onset of possible inflammatory storms. Therefore, this study offers a new possibility for the application and development of astaxanthin as a popular dietary supplement of anti-inflammatory or immunomodulatory function.

Simultaneous removal of norfloxacin and chloramphenicol using cold atmospheric plasma jet (CAPJ): Enhanced performance, synergistic effect, plasma-activated water (PAW) contribution, mechanism and toxicity evaluation.

The extensive abuse and inadvertent discharge of various antibiotics into the environment has become a serious problem for posing a big threat to human health. In order to deal with this problem, we utilized cold atmospheric plasma jet (CAPJ) to treat two different antibiotics, namely, norfloxacin and chloramphenicol, and investigated the efficiencies and corresponding mechanisms for removing the mixed antibiotics. In the application of the CAPJ technique, we made use of not only the direct plasma processing, but also the indirect plasma-activated water (PAW) treatment. The efficiency for mixed antibiotics treatment was considerably enhanced as compared to the efficiency for treatment of single antibiotics. The contributions from the CAPJ-induced reactive oxygen/nitrogen species (RONS) were examined, showing that ·OH and 1O2 played a major role in the degradation of norfloxacin and chloramphenicol in the direct plasma treatment, while 1O2 played a major role in the PAW treatment. The bio-toxicity evaluation was also provided to verify the ecological safety of the CAPJ treatment. As such, this work has not only showed the effectiveness of CAPJ treatment of mixed antibiotics, but also elucidated the mechanisms for the enhanced treatment efficiency, which may provide a new solution for treatment of antibiotics in the environment.

Identification and Functional Analysis of the Promoter of a Leucoanthocyanidin Reductase Gene from Gossypium hirsutum.

Leucoanthocyanidin reductase (LAR) is the critical enzyme in the synthesis pathway of proanthocyanidins, which are the primary pigments in brown cotton fibers. Our previous study has revealed significant differences in the expression levels of GhLAR1 between white and brown cotton fibers at 10 DPA. In this work, the expression pattern of the GhLAR1 gene was further studied, and the promoter of GhLAR1 (1780 bp) was isolated and characterized. Bioinformatic analysis indicated that GhLAR1 promoter contained many known light response elements and several defenses related to transcriptional factor-binding boxes, which may partially explain the response of the GhLAR1 to temperature, NaCl, and PEG treatments. Furthermore, GhLAR1 was preferentially and strongly expressed in fibers and flowers of cotton, and the expression levels in all tested tissues (especially fibers) of brown cotton were significantly higher than those in white cotton. Consistent with the expression analysis, the GhLAR1 promoter mainly drove GUS expression in epidermal trichomes and floral organs.

Potentialities of Ganoderma lucidum extracts as functional ingredients in food formulation.

Owing to the recognized therapeutic characteristics of G. lucidum, it is one of the most extensively researched mushrooms as a chemopreventive agent and as a functional food. It is a known wood-degrading basidiomycete possessing numerous pharmacological functions and is termed a natural pharmacy store due to its rich number of active compounds which have proved to portray numerous therapeutic properties. This current review highlights studies on the potentialities of G. lucidum extracts as functional ingredients on organoleptic and nutritional properties of food products (e.g., dairy, wine, beverage, bakery, meat, and other products). In addition, the study delved into various aspects of encapsulated G. lucidum extracts, their morphological and rheological characteristics, prebiotic and immunomodulatory importance, the effects on apoptosis, autophagy, cancer therapy, inflammatory responses, oxidative stress, antioxidant activities, and safety concerns. These findings have significant implications for the development of new products in the food and pharmaceutical industries. On the other hand, the various active compounds extracted from G. lucidum exhibited no toxic or adverse effects, and the appeal for it as a dietary food, natural remedy, and health-fortifying food is drastically increasing as well as attracting the interest of both the industrial and scientific communities. Furthermore, the formation of functional foods based on G. lucidum appears to have actual promise and exciting prospects in nutrition, food, and pharmaceutical sciences.

Biomechanical study of anterior and posterior pelvic rings using pedicle screw fixation for Tile C1 pelvic fractures: Finite element analysis.

OBJECTIVE: The purpose of this study was to analyse the biomechanical characteristics of pedicle screws with different placement methods and diameters in the treatment of Tile C1 pelvic fractures by finite element simulation technology and to compare them with the plate fixation model to verify the effectiveness of pedicle screw fixation. METHODS: A three-dimensional digital model of a normal pelvis was obtained using computed tomography images. A finite element model of a normal pelvis containing major ligaments was built and validated (Model 1). Based on the verified normal pelvis finite element model, a Tile C1 pelvic fracture model was established (Model 2), and then a plate fixation model (Model 3) and a pedicle screw fixation model with different screw placement methods and diameters were established (Models 4-15). For all pelvic fracture fixation models, a vertical load of 500 N was applied on the upper surface of the sacrum to test the displacement and stress distribution of the pelvis in the standing state with both legs. RESULTS: The finite element simulation results showed the maximum displacement of Model 1 and Models 3-15 to be less than 1 mm. The overall maximum displacement of Models 4-15 was slightly larger than that of Model 3 (the maximum difference was 177.91×10-3 mm), but the maximum displacement of iliac bone and internal fixation in Models 4-15 was smaller than that of Model 3. The overall maximum stress (maximum stress of the ilium) and maximum stress of internal fixation in Models 4-15 were less than those in Model 3. The maximum displacement difference and maximum stress difference at the fracture of the pubic ramus between each fixed model were less than 0.01 mm and 1 MPa, respectively. The greater the diameter and number of pedicle screws were, the smaller the maximum displacement and stress of the pelvic fracture models were.The maximum displacement and stress of the pelvic fracture models of the screws placed on the injured side of the pubic region were smaller than the screws on the healthy side. CONCLUSION: Both the anterior and posterior pelvic rings are fixed with a pedicle screw rod system for treatment of Tile C1 pelvic fractures, which can obtain sufficient biomechanical stability and can be used as a suitable alternative to other implants.The greater the diameter and number of pedicle screws were, the greater the pelvic stability was, and the greater was the stability of the screws placed on the injured side of the pubic region than the screws on the healthy side.

Study of the synergistic effect of singlet oxygen with other plasma-generated ROS in fungi inactivation during water disinfection.

Cold atmospheric plasma (CAP) possesses the ability of high-efficiency disinfection. It is reported that mixtures of reactive oxygen species (ROS) including ·OH, 1O2, O2- and H2O2 generated from CAP have better antimicrobial ability than mimicked solution of mixture of single ROS type, but the reason is not clear. In this study, CAP was applied to treat yeasts in water in order to investigate the fungal inactivation efficiency and mechanism. The results showed that plasma treatment for 5 min could result in >2-log reduction of yeast cells, and application of varied ROS scavengers could significantly increase the yeast survival rate, indicating that ·OH and 1O2 played the pivotal role in yeast inactivation. Moreover, the synergistic effect of 1O2 with other plasma-generated ROS was revealed. 1O2 could diffuse into cells and induce the depolarization of mitochondrial membrane potential (MMP), and different levels of MMP depolarization determined different cell death modes. Mild damage of mitochondria during short-term plasma treatment could lead to apoptosis. For long-term plasma treatment, the cell membrane could be severely damaged by the plasma-generated ·OH, so a large amount of 1O2 could induce more depolarization of MMP, leading to increase of intracellular O2- and Fe2+ which subsequently caused cell inactivation. 1O2 could also induce protein aggregation and increase of RIP1/RIP3 necrosome, leading to necroptosis. With participation of 1O2, endogenous ·OH could also be generated via Fenton and Haber-Weiss reactions during plasma treatment, which potentiated necroptosis. Adding l-His could mitigate membrane damage, inhibit the drop of MMP and the formation of necrosome, and thus prevent the happening of necroptosis. These findings may deepen the understanding of plasma sterilization mechanisms and provide guidance for microbial killing in the environment.

Regulation of alternative splicing of PaFT and PaFDL1, the FT and FD homologs in Platanus acerifolia.

Alternative splicing (AS) selects different alternative splice sites and produces a variety of transcripts with different exon/intron combinations, which may result in multiple protein isoforms. The splicing signals include cis-elements and RNA structures; however, the mechanisms of AS regulation in plants have yet to be elucidated. Previous studies have shown that in Platanus acerifolia, the FLOWERING LOCUS T (FT) homolog PaFT has a unique and complex AS pattern, in which most of the splice forms of PaFT involve the first and/or second intron, and the FD homolog PaFDL1 produces two transcripts via AS, whereas the other FT homolog PaFTL is not regulated by AS. In this study, the regulatory mechanism of the AS of PaFT was demonstrated to be conserved in different plant species. To define the distribution of the AS regulatory signals, the intron-swap, site-directed mutagenesis of alternative splice sites, and deletion experiment were performed. For the PaFT gene, all the signals that regulate the AS of the first intron were located within this intron, while the usage of the first alternative splice site in the second intron was determined by the first intron. Meanwhile, the AS of PaFDL1 might be co-regulated by exons and the first intron. Additionally, the first alternative splice site and adjacent region in PaFT intron 1 might contain cis-elements and/or RNA structures that affect the use of the other sites. This study had provided a deeper insight into the distribution of AS signals in plants, namely the AS signals of different splice sites might exist in the intron where the sites were present, and might also be distributed in exons or other introns.

Green synthesis of broccoli-derived carbon quantum dots as effective photosensitizers for the PDT effect testified in the model of mutant Caenorhabditis elegans.

The clinical application of photodynamic therapy (PDT) is still limited because of the drawbacks of the traditional photosensitizers, such as low singlet oxygen (1O2) quantum yield and the problem of photobleaching. Herein, carbon quantum dots (CQDs) derived from broccoli natural biomass as a carbon source were fabricated via a simple hydrothermal method and showed outstanding PDT ability as an effective photodynamic agent tested in Caenorhabditis elegans (C. elegans) models. The as-prepared broccoli-derived CQDs (BCQDs) showed excellent water solubility and optical properties and could generate singlet oxygen (1O2) effectively under irradiated light with a wavelength of 660 nm. The in vivo experiment revealed that the PDT efficiency of the BCQDs was dependent on the induction of germline apoptosis through the cep-1/p53 pathway. Further investigation confirmed the DNA damage of the worm by the BCQDs after sufficient light irradiation, which was tested by measuring the egl-1-fold induction in hus-1(op244), and cep-1(w40) mutants that have a loss of function in the genes involved in DNA damage response such as hus-1 (DNA checkpoint gene) and cep-1/p53 (tumor suppressor). The lack of germline apoptosis in the loss of function mutants egl-1(n487), hus-1(op244), and cep-1(w40) exposed to light irradiation compared with the control proved the necessity of these genes in DNA damage-induced germline apoptosis. Therefore, this work has not only provided a new photodynamic agent but also introduced C. elegans as an easy and high-throughput model for the rapid evaluation of the efficiency of PDT.