CD47 masks pro-phagocytic ligands in cis on tumor cells to suppress antitumor immunity.

Cancer cells often overexpress CD47, which triggers the inhibitory receptor SIRPα expressed on macrophages, to elude phagocytosis and antitumor immunity. Pharmacological blockade of CD47 or SIRPα is showing promise as anticancer therapy, although CD47 blockade has been associated with hematological toxicities that may reflect its broad expression pattern on normal cells. Here we found that, in addition to triggering SIRPα, CD47 suppressed phagocytosis by a SIRPα-independent mechanism. This mechanism prevented phagocytosis initiated by the pro-phagocytic ligand, SLAMF7, on tumor cells, due to a cis interaction between CD47 and SLAMF7. The CD47-SLAMF7 interaction was disrupted by CD47 blockade and by a first-in-class agonist SLAMF7 antibody, but not by SIRPα blockade, thereby promoting antitumor immunity. Hence, CD47 suppresses phagocytosis not only by engaging SIRPα, but also by masking cell-intrinsic pro-phagocytic ligands on tumor cells and knowledge of this mechanism may influence the decision between CD47 blockade or SIRPα blockade for therapeutic purposes.

cis-B7:CD28 interactions at invaginated synaptic membranes provide CD28 co-stimulation and promote CD8+ T cell function and anti-tumor immunity.

B7 ligands (CD80 and CD86), expressed by professional antigen-presenting cells (APCs), activate the main co-stimulatory receptor CD28 on T cells in trans. However, in peripheral tissues, APCs expressing B7 ligands are relatively scarce. This raises the questions of whether and how CD28 co-stimulation occurs in peripheral tissues. Here, we report that CD8+ T cells displayed B7 ligands that interacted with CD28 in cis at membrane invaginations of the immunological synapse as a result of membrane remodeling driven by phosphoinositide-3-kinase (PI3K) and sorting-nexin-9 (SNX9). cis-B7:CD28 interactions triggered CD28 signaling through protein kinase C theta (PKCθ) and promoted CD8+ T cell survival, migration, and cytokine production. In mouse tumor models, loss of T cell-intrinsic cis-B7:CD28 interactions decreased intratumoral T cells and accelerated tumor growth. Thus, B7 ligands on CD8+ T cells can evoke cell-autonomous CD28 co-stimulation in cis in peripheral tissues, suggesting cis-signaling as a general mechanism for boosting T cell functionality.

PD-L1:CD80 Cis-Heterodimer Triggers the Co-stimulatory Receptor CD28 While Repressing the Inhibitory PD-1 and CTLA-4 Pathways.

Combined immunotherapy targeting the immune checkpoint receptors cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death 1 (PD-1), or CTLA-4 and the PD-1 ligand (PD-L1) exhibits superior anti-tumor responses compared with single-agent therapy. Here, we examined the molecular basis for this synergy. Using reconstitution assays with fluorescence readouts, we found that PD-L1 and the CTLA-4 ligand CD80 heterodimerize in cis but not trans. Quantitative biochemistry and cell biology assays revealed that PD-L1:CD80 cis-heterodimerization inhibited both PD-L1:PD-1 and CD80:CTLA-4 interactions through distinct mechanisms but preserved the ability of CD80 to activate the T cell co-stimulatory receptor CD28. Furthermore, PD-L1 expression on antigen-presenting cells (APCs) prevented CTLA-4-mediated trans-endocytosis of CD80. Atezolizumab (anti-PD-L1), but not anti-PD-1, reduced cell surface expression of CD80 on APCs, and this effect was negated by co-blockade of CTLA-4 with ipilimumab (anti-CTLA-4). Thus, PD-L1 exerts an immunostimulatory effect by repressing the CTLA-4 axis; this has implications to the synergy of anti-PD-L1 and anti-CTLA-4 combination therapy.

In-Depth Mass Spectrometry Analysis Reveals the Plasma Proteomic and N-Glycoproteomic Impact of an Amish-Enriched Cardioprotective Variant in B4GALT1.

B4GALT1 encodes ß-1,4-galactosyltransferase 1, an enzyme that plays a major role in glycan synthesis in the Golgi apparatus by catalyzing the addition of terminal galactose. Studies increasingly suggest that B4GALT1 may be involved in the regulation of lipid metabolism pathways. Recently, we discovered a single-site missense variant Asn352Ser (N352S) in the functional domain of B4GALT1 in an Amish population, which decreases the level of LDL-cholesterol (LDL-c) as well as the protein levels of ApoB, fibrinogen, and IgG in the blood. To systematically evaluate the effects of this missense variant on protein glycosylation, expression, and secretion, we developed a nano-LC-MS/MS-based platform combined with TMT-labeling for in-depth quantitative proteomic and glycoproteomic analyses in the plasma of individuals homozygous for the B4GALT1 missense variant N352S versus non-carriers (n = 5 per genotype). A total of 488 secreted proteins in the plasma were identified and quantified, 34 of which showed significant fold changes in protein levels between N352S homozygotes and non-carriers. We determined N-glycosylation profiles from 370 glycosylation sites in 151 glycoproteins and identified ten proteins most significantly associated with decreased galactosylation and sialyation in B4GALT1 N352S homozygotes. These results further support that B4GALT1 N352S alters the glycosylation profiles of a variety of critical target proteins, thus governing the functions of these proteins in multiple pathways, such as those involved in lipid metabolism, coagulation, and the immune response.

Improving Three-Photon Fluorescence of Near-Infrared Quantum Dots for Deep Brain Imaging by Suppressing Biexciton Decay.

Three-photon fluorescence microscopy (3PFM) is a promising brain research tool with submicrometer spatial resolution and high imaging depth. However, only limited materials have been developed for 3PFM owing to the rigorous requirement of the three-photon fluorescence (3PF) process. Herein, under the guidance of a band gap engineering strategy, CdTe/CdSe/ZnS quantum dots (QDs) emitting in the near-infrared window are designed for constructing 3PF probes. The formation of type II structure significantly increased the three-photon absorption cross section of QDs and caused the delocalization of electron-hole wave functions. The time-resolved transient absorption spectroscopy confirmed that the decay of biexcitons was significantly suppressed due to the appropriate band gap alignment, which further enhanced the 3PF efficiency of QDs. By utilizing QD-based 3PF probes, high-resolution 3PFM imaging of cerebral vasculature was realized excited by a 1600 nm femtosecond laser, indicating the possibility of deep brain imaging with these 3PF probes.

High-Throughput Glycan Profiling of Human Serum IgG Subclasses Using Parallel Reaction Monitoring Peptide Bond Fragmentation of Glycopeptides and Microflow LC-MS.

LC-MS-based N-glycosylation profiling in four human serum IgG subclasses (IgG1, IgG2, IgG3, and IgG4) often requires additional affinity-based enrichment of specific IgG subclasses, owing to the high amino acid sequence similarity of Fc glycopeptides among subclasses. Notably, for IgG4 and the major allotype of IgG3, the glycopeptide precursors share identical retention time and mass and therefore cannot be distinguished based on precursor or glycan fragmentation. Here, we developed a parallel reaction monitoring (PRM)-based method for quantifying Fc glycopeptides through combined transitions generated from both glycosidic and peptide bond fragmentation. The latter enables the subpopulation of IgG3 and IgG4 to be directly distinguished according to mass differences without requiring further enrichment of specific IgG subclasses. In addition, a multinozzle electrospray emitter coupled to a capillary flow liquid chromatograph was used to increase the robustness and detection sensitivity of the method for low-yield peptide backbone fragment ions. The gradient was optimized to decrease the overall run time and make the method compatible with high-throughput analysis. We demonstrated that this method can be used to effectively monitor the relative levels of 13 representative glycoforms, with a good limit of detection for individual IgG subclasses.

Monolithically integrated 940†nm VCSELs on bulk Ge substrates.

This research successfully developed an independent Ge-based VCSEL epitaxy and fabrication technology route, which set the stage for integrating AlGaAs-based semiconductor devices on bulk Ge substrates. This is the second successful Ge-based VCSEL technology reported worldwide and the first Ge-based VCSEL technology with key details disclosed, including Ge substrate specification, transition layer structure and composition, and fabrication process. Compared with the GaAs counterparts, after epitaxy optimization, the Ge-based VCSEL wafer has a 40% lower surface root-mean-square roughness and 72% lower average bow-warp. After device fabrication, the Ge-based VCSEL has a 10% lower threshold current density and 19% higher maximum optical differential efficiency than the GaAs-based VCSEL.

Effects of dietary 5-aminolevulinic acid on growth performance and nonspecific immunity of Litopenaeus vannamei, as determined by transcriptomic analysis.

5-aminolevulinic acid (5-ALA) is an endogenous non-protein amino acid that is frequently used in modern agriculture. This study set out to determine how dietary 5-ALA affected the nonspecific immunity and growth performance of Litopenaeus vannamei. The shrimp were supplemented with dietary 5-ALA at 0 mg/kg, 15 mg/kg, 30 mg/kg, 45 mg/kg, and 60 mg/kg for three months. Transcriptome data of the control group and the group supplemented with 45 mg/kg dietary 5-ALA were obtained using transcriptome sequencing. 592 DEGs were identified, of which 426 were up-regulated and 166 were down-regulated. The pathways and genes associated with growth performance and nonspecific immunity were confirmed using qRT-PCR. The highest survival rate, body length growth rate, and weight gain values were observed in shrimp fed diets containing 45 mg/kg 5-ALA. L. vannamei in this group had a significantly higher total hemocyte count, phagocytosis rate and respiratory burst value than those in the control group. High doses of dietary 5-ALA (45 mg/kg, 60mg/kg) significantly increased the activities of catalase, superoxide dismutase, oxidized glutathione, glutathione-peroxidase, phenoloxidase, lysozyme, acid phosphatase, and alkaline phosphatase. At the transcriptional level, dietary 5-ALA significantly up-regulated the expression levels of antioxidant immune-related genes. The optimal concentration of 5-ALA supplementation was 39.43 mg/kg, as indicated by a broken line regression. Our study suggested that dietary 5-ALA positively impacts the growth and nonspecific immunity of L. vannamei, providing a novel theoretical basis for further research into 5-ALA as a dietary supplement.

[Preparation and characterization of co-loaded indocyanine green and elemene nano-emulsion in situ gel and its effect on proliferation of breast cancer MCF-7 cells].

This study aims to prepare co-loaded indocyanine green(ICG) and elemene(ELE) nano-emulsion(NE) in situ gel(ICG-ELE-NE-gel) and evaluate its physicochemical properties and antitumor activity in vitro. ICG-ELE-NE-gel was prepared by aqueous phase titration and cold solution methods, followed by characterization of the morphology, particle size, corrosion, and photothermal conversion characteristics. The human breast cancer MCF-7 cells were taken as the model, combined with 808 nm laser irradia-tion. Cell inhibition rate test and cell uptake test were performed. ICG-ELE-NE was spherical and uniform in size. The average particle size and Zeta potential were(85.61±0.35) nm and(-21.4±0.6) mV, respectively. The encapsulation efficiency and drug loading rate were 98.51%±0.39% and 10.96%±0.24%, respectively. ICG-ELE-NE-gel had a good photothermal conversion effect and good photothermal stability. The dissolution of ICG-ELE-NE-gel had both temperature and pH-responsive characteristics. Compared with free ELE, ICG-ELE-NE-gel combined with near-infrared light irradiation significantly enhanced the inhibitory effect on MCF-7 cells and could be uptaken in large amounts by MCF-7 cells. ICG-ELE-NE-gel was successfully prepared, and its antitumor activity was enhanced after 808 nm laser irradiation.

Effects of dietary melatonin on growth performance, antioxidant capacity, and nonspecific immunity in crayfish, Cherax destructor.

Melatonin (MT) is an indole hormone widely found in plants and animals. Many studies have shown that MT promotes the growth and immunity of mammals, fish, and crabs. However, the effect on commercial crayfish has not been demonstrated. The purpose of this study was to evaluate the effects of dietary MT on growth performance and innate immunity of Cherax destructor from three aspects of individual level, biochemical level, and molecular level after 8 weeks of culture. In this study, we found that MT supplementation increased weight gain rate, specific growth rate, and digestive enzyme activity in C. destructor compared to the control group. Dietary MT not only promoted the activity of T-AOC, SOD, and GR, increased the content of GSH, and decreased the content of MDA in the hepatopancreas, but also increased the content of hemocyanin and copper ions and AKP activity in hemolymph. Gene expression results showed that MT supplementation at appropriate doses increased the expression of cell cycle-regulated genes (CDK, CKI, IGF, and HGF) and non-specific immune genes (TRXR, HSP60, and HSP70). In conclusion, our study showed that adding MT to the diet improved growth performance, enhanced the antioxidant capacity of hepatopancreas, and immune parameters of hemolymph in C. destructor. In addition, our results showed that the optimal dietary supplementation dose of MT in C. destructor is 75-81 mg/kg.

Genome-wide identification and analysis of the MAPKK gene family in Chinese mitten crab (Eriocheir sinensis) and its response to bacterial challenge.

Protein kinases of the MAPK cascade family (MAPKKK-MAPKK-MAPK) play an important role in the growth and development of organisms and their response to environmental stress. The MAPKK gene families in the Chinese mitten crab Eriocheir sinensis have never been systematically analyzed. We identified four MAPKK family genes, EsMEK, EsMAPKK4, EsMAPKK6, and EsMAPKK7, in E. sinensis and analyzed their molecular features and expression patterns. All four MAPKK genes are composed of multiple exons and introns, all have a conserved domain, and all have 10 conserved motifs (except EsMEK and EsMAPKK7 which are missing motif 10). The four MAPKK genes are on four different chromosomes and have no gene duplications, and the results of phylogenetic tree analysis indicate that the ESMAPKK gene family is highly conserved evolutionarily. The EsMAPKK genes were widely expressed in all the examined tissues with higher expression in hemocytes, hepatopancreas, and gills. Notably, EsMAPKK6 was also highly expressed in the ovary. Vibrio parahaemolyticus infection significantly increased the mRNA levels of the EsMAPKK genes in hemocytes. Further disruption of the EsMAPKK gene family expression affects the expression levels of multiple antimicrobial peptides in hemocytes. Our experimental results provide a starting point for a more in-depth study of the innate immunity functional roles of members of the MAPKK gene families in E. sinensis.

Effects of dietary soluble ß-1,3-glucan on the growth performance, antioxidant status, and immune response of the river prawn (Macrobrachium nipponense).

The effects of dietary ß-1,3-glucan on the growth performance, body composition, hepatopancreas tissue structure, antioxidant activities, and immune response of the river prawn (Macrobrachium nipponense) were investigated. In total, 900 juvenile prawns were fed one of five diets with different contents of ß-1,3-glucan (0%, 0.1%, 0.2%, and 1.0%) or 0.2% curdlan for 6 weeks. The growth rate, weight gain rate, specific growth rate, specific weight gain rate, condition factor, and hepatosomatic index of juvenile prawns fed 0.2% ß-1,3-glucan were significantly higher than those fed 0% ß-1,3-glucan and 0.2% curdlan (p < 0.05). The whole-body crude lipid content of prawns supplemented with curdlan and ß-1,3-glucan was significantly higher than that of the control group (p < 0.05). The antioxidant and immune enzyme activities of superoxide dismutase (SOD), total antioxidant capacity (T-AOC), catalase (CAT), lysozyme (LZM), phenoloxidase (PO), acid phosphatase (ACP), and alkaline phosphatase (AKP) in the hepatopancreas of juvenile prawns fed 0.2% ß-1,3-glucan were significantly higher than those of the control and 0.2% curdlan groups (p < 0.05), and tended to increase and then decrease with increasing dietary ß-1,3-glucan. The highest malondialdehyde (MDA) content was observed in juvenile prawns without ß-1,3-glucan supplementation. The results of real-time quantitative PCR indicated that dietary ß-1,3-glucan promoted expression of antioxidant and immune-related genes. Binomial fit analysis of weight gain rate and specific weight gain rate showed that the optimum ß-1,3-glucan requirement of juvenile prawns was 0.550%-0.553%. We found that suitable dietary ß-1,3-glucan improved juvenile prawns growth performance, antioxidant capacity, and non-specific immunity, which provide reference for shrimp healthy culture.

Dietary melatonin positively impacts the immune system of crayfish, Cherax destructor, as revealed by comparative proteomics analysis.

Melatonin, an indoleamine with various biological activities, is being used increasingly in the aquaculture industry for its broad immune effects. Cherax destructor is an emerging economically cultured crayfish that faces many problems in the breeding process. Previous work found that dietary melatonin has positive effects on the growth and immunity of C. destructor, but the specific mechanism involved remained unclear. In this study, proteomics was used to determine the mechanism of action of melatonin in C. destructor. Results showed that dietary melatonin resulted in decreased levels of hydrogen peroxide, alanine aminotransferase, and aspartate aminotransferase, but increased levels of glutathione peroxidase, acid phosphatase, and glutathione S-transferases. In total, 608 proteins were differentially expressed (418 upregulated and 190 downregulated), and were enriched in three main categories: innate immunity (B cell receptor signaling pathway and natural killer cell-mediated cytotoxicity), glucose metabolism (pentose phosphate pathway, pentose and glucuronate interconversions, and propionate metabolism), and amino acid metabolism (valine, leucine, and isoleucine degradation, and cysteine and methionine metabolism). In addition, dietary melatonin was also involved in the regulation of the mTOR signaling pathway, and upregulated the expression of genes encoding key factors, such as Ras-related GTP-binding protein A/B, eukaryotic initiation factor 4E, eukaryotic initiation factor 4E-binding protein, and p70 ribosomal S6 kinase. Overall, this study demonstrates the role of melatonin in the physiological regulation of C. destructor, laying the foundation for the development of melatonin as a feed additive in the aquaculture of this species.

Effects of ß-1,3-glucan on growth, immune responses, and intestinal microflora of the river prawn (Macrobrachium nipponense) and its resistance against Vibrio parahaemolyticus.

In this study, we investigated the impact of ß-1,3-glucan on the immune responses and gut microbiota of the river prawn (Macrobrachium nipponense) in the presence of Vibrio parahaemolyticus stress. Shrimps were fed one of the following diets: control (G1), 0.2% curdlan (G2), 0.1% ß-1,3-glucan (G3), 0.2% ß-1,3-glucan (G4), or 1.0% ß-1,3-glucan (G5) for 6 weeks and then challenged with V. parahaemolyticus for 96 h. Under Vibrio stress, shrimps in G4 exhibited the highest length gain rate, weight gain rate, and survival rate. They also showed increased intestinal muscle thickness and villus thickness compared to the control and 0.2% curdlan groups. The apoptosis rate was lower in G4 than in the control group, and the digestive enzyme activities (pepsin, trypsin, amylase, and lipase), immune enzyme activities (acid phosphatase, alkaline phosphatase, lysozyme, and phenoxidase), and energy metabolism (triglyceride, cholesterol, glycogen, and lactate dehydrogenase) were enhanced. Expression levels of growth-related genes (ecdysone receptor, calmodulin-dependent protein kinase I, chitin synthase, and retinoid X receptor) and immune-related genes (toll-like receptor 3, myeloid differentiation primary response 88, mitogen-activated protein kinase 7, and mitogen-activated protein kinase 14) were higher in G4 than in the control. Microbiota analysis indicated higher bacterial abundance in shrimps fed ß-1,3-glucan, as evidenced by Sob, Chao1, and ACE indices. Moreover, 0.2% ß-1,3-glucan increased the relative abundances of Bacteroidota and Firmicutes while reducing those of Corynebacteriales and Lactobacillales. In summary, ß-1,3-glucan enhances immune enzyme activities, alters immune-related gene expression, and impacts gut microbial diversity in shrimp. These findings provide valuable insights into the mechanisms underlying ß-1,3 glucan's immune-enhancing effects.

Stabilizing Cobalt-free Li-rich Layered Oxide Cathodes through Oxygen Lattice Regulation by Two-phase Ru Doping.

The application of Li-rich layered oxides is hindered by their dramatic capacity and voltage decay on cycling. This work comprehensively studies the mechanistic behaviour of cobalt-free Li1.2 Ni0.2 Mn0.6 O2 and demonstrates the positive impact of two-phase Ru doping. A mechanistic transition from the monoclinic to the hexagonal behaviour is found for the structural evolution of Li1.2 Ni0.2 Mn0.6 O2, and the improvement mechanism of Ru doping is understood using the combination of in operando and post-mortem synchrotron analyses. The two-phase Ru doping improves the structural reversibility in the first cycle and restrains structural degradation during cycling by stabilizing oxygen (O2- ) redox and reducing Mn reduction, thus enabling high structural stability, an extraordinarily stable voltage (decay rate <0.45 mV per cycle), and a high capacity-retention rate during long-term cycling. The understanding of the structure-function relationship of Li1.2 Ni0.2 Mn0.6 O2 sheds light on the selective doping strategy and rational materials design for better-performance Li-rich layered oxides.

Xenon Ion Implantation Induced Surface Compressive Stress for Preventing Dendrite Penetration in Solid-State Electrolytes.

Solid-state electrolytes (SSEs) have been thrust into the limelight for the revival of energy-dense lithium metal batteries, but still face the challenge of failure caused by the dendrite penetration. Mounting evidence indicates that dendrite penetration is related to the mechanical failure in SSEs, which calls for mechanical engineering to tackle this problem. This work reports a proof of concept that ion implantation induced surface compressive stress enables resistance in the dendrite penetration. A deterministic sequential multiple ion energies implantation is used to generate compressive stress, with implanted Xe ions distributed in a range of 160-600 Å from the surface. The symmetric lithium cells show that pellets with an implantation dose of 1013 Xe cm-2 exhibit stable stripping/plating cycles and extended lifespan, while a lower dose of 1012 Xe cm-2 cannot create sufficient stress to prevent dendrite penetration, and an excessive dose of 1014 Xe cm-2 leads to structural destruction and a decrease in stress. This improved performance is attributed to the induced surface compressive stress balanced over crystal grains, which is confirmed by grazing incidence diffraction techniques. The author's efforts demonstrate the usefulness of surface compressive stress to suppress dendrite penetration, offering more insight into rational stress-strain engineering as opposed to empirical optimization.

Emerging Bioelectronic Strategies for Cardiovascular Tissue Engineering and Implantation.

Heart diseases are currently the leading cause of death worldwide. The ability to create cardiovascular tissue has numerous applications in understanding tissue development, disease progression, pharmacological testing, bio-actuators, and transplantation; yet current cardiovascular tissue engineering (CTE) methods are limited. However, there have been emerging developments in the bioelectronics field, with the creation of biomimetic devices that can intimately interact with cardiac cells, provide monitoring capabilities, and regulate tissue formation. Combining bioelectronics with cardiac tissue engineering can overcome current limitations and produce physiologically relevant tissue that can be used in various areas of cardiovascular research and medicine. This review highlights the recent advances in cardiovascular-based bioelectronics. First, cardiac tissue engineering and the potential of bioelectronic therapies for cardiovascular diseases are discussed. Second, advantageous bioelectronic materials for CTE and implantation and their properties are reviewed. Third, several representative cardiovascular tissue-bioelectronic interface models and the beneficial functions that bioelectronics can demonstrate in in vitro and in vivo applications are explored. Finally, the prospects and remaining challenges for clinical application are discussed.

Inhibiting nonhomologous end-joining repair would promote the antitumor activity of gemcitabine in nonsmall cell lung cancer cell lines.

Nonsmall cell lung cancer (NSCLC) is a major type of lung cancer. In current study, we aim to evaluate whether the combination of Ku70/80 heterodimer protein inhibitor STL127705 and gemcitabine would be more favorable approach for the treatment of NSCLC compared with monotreatment with gemcitabine. Clongenic survival assay was used to determine the survival and sensitivity to irradiation. H1299 was stained with fluorescein isothiocyanate-Annexin V, and cell apoptosis was measured by flow cytometry. H1299 cells were transfected with nonhomologous end-joining (NHEJ) repair reporter, and stable cell line was selected by puromycin. NHEJ activity was determined based on the intensity of green fluorescent protein. DNA double-strand breaks (DSBs) were determined by the fluorescence intensity of γH2AX using flow cytometry. The mRNA expressions of Ku70 and Ku80 were determined using quantitative real-time PCR. Combination of STL127705 enhanced sensitivity of NSCLC cell lines to irradiation when compared with treatment with gemcitabine alone. However, small cell lung cancer cell line was not affected. H1299 cells treated with STL127705 in combination with gemcitabine showed a significantly increased apoptosis compared with H1299 cells treated with gemcitabine alone. Moreover, STL127705 treatment dramatically reduced NHEJ activity in H1299 cells when compared with gemcitabine single treatment. Increased DSBs were consistently observed in H1299 when treated with the combination of STL127705 and gemcitabine. However, the mRNA levels of Ku70 and Ku80 were upregulated by the combination treatment. It demonstrated that STL127705 enhanced antitumor activity of gemcitabine. Mechanistically, treatment with STL127705 enhanced DNA damage via inhibiting NHEJ pathway, blocking DNA-PK, and forming Ku70/80 heterodimer, eventually leading to tumor cells apoptosis.

Comparison of immune defense and antioxidant capacity between broodstock and hybrid offspring of juvenile shrimp (Macrobrachium nipponense): Response to acute ammonia stress.

Ammonia is a major environmental pollutant in the aquatic system that poses a great threat to the health of shrimp. Macrobrachium nipponense, as one of the large-yield farmed shrimp, is facing germplasm degradation. Genetic improvement through hybridization is one of the effective methods to solve this problem. However, there are few studies on the effects of ammonia nitrogen on the germplasm resources of M. nipponense. In this study, the broodstock populations (Dianshan, DS) and hybrid offspring (DS ♀ × CD [Changjiang, CJ ♂ × Dongting, DT ♀], SCD) were exposed to 0, 5, or 20 mg/L of ammonia for 96 h. The survival rate of the SCD group was greater than the DS group, although there were no significant differences in weight gain rate and length gain rate (p > 0.05). The number of positive cells and apoptosis rates in the DS group were significantly greater than in the SCD group after ammonia exposure (p < 0.05). As the ammonia concentration increased, the antioxidant enzyme activities in the SCD group were significantly higher than DS group, while the hepatotoxicity enzyme activities in the SCD group were significantly lower than DS group (p < 0.05). The trends in the expression of antioxidant- and immune-related genes were generally consistent with the activities of antioxidant enzymes. Our study found that the hybrid population had stronger stress resistance than their parent populations at the same ammonia concentration. This study confirms our speculation that hybrid population has a greater advantage in antioxidant immunity, which also provides reference for the follow-up study of chronic ammonia toxicity.

Comparison of lipid metabolism between broodstock and hybrid offspring in the hepatopancreas of juvenile shrimp (Macrobrachium nipponense): Response to chronic ammonia stress.

Ammonia nitrogen is a major pollutant that causes great physiological harm to crustaceans in culture. In this study, we conducted a 28 day chronic ammonia nitrogen stress experiment with broodstock populations (Dianshan, DS) and hybrid offspring populations (DS ♀ × CD (Changjiang ♂ × Dongting ♀), SCD) exposed to 0, 1 and 10 mg/L of ammonia concentrations. A 28 day feeding trial and chronic ammonia nitrogen stress were used to investigate the effects on the growth performance, histological structure and lipid metabolism of juvenile shrimp, Macrobrachium nipponense. Our results indicated that survival rates in the SCD groups were significantly higher than those in the DS groups, whereas weight and length gain rates were not significantly different between the groups (p > 0.05). Histological structure results showed that the number of vacuoles in the DS group was significantly higher than that in the SCD group and hepatopancreas cell structures were disrupted in the ammonia treatment groups. The results of oil red staining showed that the number of lipid droplets increased significantly with the increase in ammonia concentration. As the ammonia concentration increased, fatty acid contents, lipid enzyme activities and lipid metabolism-related gene expression all tended to rise. In conclusion, ammonia nitrogen exposure caused damage to the hepatopancreas structure of juvenile shrimp and disturbed the lipid metabolism of the hepatopancreas. In addition, the SCD population had stronger stress resistance than the DS population when subjected to the same concentration of ammonia nitrogen stress.