Selective autophagy receptor p62 promotes antibacterial and antiviral immunity in common carp (Cyprinus carpio).

Sequestosome 1 (SQSTM1/p62) is a selective autophagy adapter protein that participates in antiviral and bacterial immune responses and plays an important regulatory role in clearing the proteins to be degraded and maintaining intracellular protein homeostasis. In this study, two p62 genes were cloned from common carp (Cyprinus carpio), namely Ccp62-1 and Ccp62-2, and conducted bioinformatics analysis on them. The results showed that Ccp62s had the same structural domain (Phox and Bem1 domain, ZZ-type zinc finger domain, and ubiquitin-associated domain) as p62 from other species. Ccp62s were widely expressed in various tissues of fish, and highly expressed in immune organs such as gills, spleen, head kidney, etc. Subcellular localization study showed that they were mainly distributed in punctate aggregates in the cytoplasm. After stimulation with Aeromonas hydrophila and spring viraemia of carp virus (SVCV), the expression level of Ccp62s was generally up-regulated. Overexpression of Ccp62s in EPC cells could inhibit SVCV replication. Upon A. hydrophila challenge, the bacterial load in Ccp62s-overexpressing group was significantly reduced, the expression levels of pro-inflammatory cytokines and interferon factors were increased, and the survival rate of the fish was improved. These results indicated that Ccp62s were involved in the immune response of common carp to bacterial and viral infections.

The molecular characterization of Rab11 and its immune roles in red swamp crayfish (Procambarus clarkii).

The Rab proteins primarily regulate vesicular transport between membrane-bound organelles and are important for innate immune. However, there is currently a lack of studies on crustaceans regarding Rab proteins, particularly core Rabs. We identified a Rab11 gene from Procambarus clarkii (PcRab11) and evaluated its potential involvement in immune response. The results showed PcRab11 was 1789 bp long, with an open reading frame of 645 bp encoding 211 amino acids and an estimated molecular weight of 23.8 kDa. Sequence analysis revealed its remarkable evolutionary conservation. The PcRab11 was widely expressed in various tissues, with highest levels in hepatopancreas, and localized within the cell cytoplasm. Upon infection with white spot syndrome virus (WSSV) or Aeromonas veronii, the expression of PcRab11 in immune organs was significantly induced. Furthermore, silencing PcRab11 reduced phagocytosis-related genes expression and haemocytes' phagocytic activity to FITC-labeled A. veronii, as well as decreased mortality and death time in WSSV or A. veronii infected P. clarkii. Additionally, the potential protein interaction between PcRab11 and 14-3-3ε was identified in haemocytes. Overall, our findings provided evidence for the involvement of Rab11 in P. clarkii's immune response, establishing a foundation to explore the immune role of core Rab proteins in crustaceans' innate immune system.

A comparative study on the dose-effect of low-dose radiation based on microdosimetric analysis and single-cell sequencing technology.

The biological mechanisms triggered by low-dose exposure still need to be explored in depth. In this study, the potential mechanisms of low-dose radiation when irradiating the BEAS-2B cell lines with a Cs-137 gamma-ray source were investigated through simulations and experiments. Monolayer cell population models were constructed for simulating and analyzing distributions of nucleus-specific energy within cell populations combined with the Monte Carlo method and microdosimetric analysis. Furthermore, the 10 × Genomics single-cell sequencing technology was employed to capture the heterogeneity of individual cell responses to low-dose radiation in the same irradiated sample. The numerical uncertainties can be found both in the specific energy distribution in microdosimetry and in differential gene expressions in radiation cytogenetics. Subsequently, the distribution of nucleus-specific energy was compared with the distribution of differential gene expressions to guide the selection of differential genes bioinformatics analysis. Dose inhomogeneity is pronounced at low doses, where an increase in dose corresponds to a decrease in the dispersion of cellular-specific energy distribution. Multiple screening of differential genes by microdosimetric features and statistical analysis indicate a number of potential pathways induced by low-dose exposure. It also provides a novel perspective on the selection of sensitive biomarkers that respond to low-dose radiation.

Adhesion between EVs and tumor cells facilitated EV-encapsulated doxorubicin delivery via ICAM1.

Doxorubicin (Dox) is an anti-tumor drug with a broad spectrum, whereas the cardiotoxicity limits its further application. In clinical settings, liposome delivery vehicles are used to reduce Dox cardiotoxicity. Here, we substitute extracellular vesicles (EVs) for liposomes and deeply investigate the mechanism for EV-encapsulated Dox delivery. The results demonstrate that EVs dramatically increase import efficiency and anti-tumor effects of Dox in vitro and in vivo, and the efficiency increase benefits from its unique entry pattern. Dox-loading EVs repeat a "kiss-and-run" motion before EVs internalization. Once EVs touch the cell membrane, Dox disassociates from EVs and directly enters the cytoplasm, leading to higher and faster Dox import than single Dox. This unique entry pattern makes the adhesion between EVs and cell membrane rather than the total amount of EV internalization the key factor for regulating the Dox import. Furthermore, we recognize ICAM1 as the molecule mediating the adhesion between EVs and cell membranes. Interestingly, EV-encapsulated Dox can induce ICAM1 expression by irritating IFN-γ and TNF-α secretion in TME, thereby increasing tumor targeting of Dox-loading EVs. Altogether, EVs and EV-encapsulated Dox synergize via ICAM1, which collectively enhances the curative effects for tumor treatment.

Rabeprazole mitigates obesity-induced chronic inflammation and insulin resistance associated with increased M2-type macrophage polarization.

Macrophage polarization is closely associated with obesity-induced chronic inflammation and insulin resistance. Proton pump inhibitor Rabeprazole has long been used to treat gastritis and gastric ulcers. However, whether Rabeprazole plays a role in macrophage polarization during obesity is unknown. Here, we show that Rabeprazole suppresses M1-type macrophage-mediated inflammation, leads to increased M2-type macrophages and alters the polarization status from M1 to M2 in vitro. Mechanistically, Rabe-regulated macrophage polarization is associated with inhibition of NF-κB and activation of STAT6 signaling pathways. Furthermore, Rabeprazole induces M2-type adipose tissue macrophages and alleviates chronic inflammation, improving glucose tolerance and insulin sensitivity in high-fat diet-fed mice. In addition, Rabeprazole increases CD206+ M2-type liver macrophages and relieves liver inflammation, alleviating liver injury and lipid accumulation. Thus, our findings show that Rabeprazole effectively regulates macrophage polarization and controls obesity-associated chronic inflammation and insulin resistance, thus providing a potential therapeutic strategy against obesity-associated metabolic diseases.

Proton pump inhibitors enhance macropinocytosis-mediated extracellular vesicle endocytosis by inducing membrane v-ATPase assembly.

Besides participating in diverse pathological and physiological processes, extracellular vesicles (EVs) are also excellent drug-delivery vehicles. However, clinical drugs modulating EV levels are still lacking. Here, we show that proton pump inhibitors (PPIs) reduce EVs by enhancing macropinocytosis-mediated EV uptake. PPIs accelerate intestinal cell endocytosis of autocrine immunosuppressive EVs through macropinocytosis, thereby aggravating inflammatory bowel disease. PPI-induced macropinocytosis facilitates the clearance of immunosuppressive EVs from tumour cells, improving antitumor immunity. PPI-induced macropinocytosis also increases doxorubicin and antisense oligonucleotides of microRNA-155 delivery efficiency by EVs, leading to enhanced therapeutic effects of drug-loaded EVs on tumours and acute liver failure. Mechanistically, PPIs reduce cytosolic pH, promote ATP6V1A (v-ATPase subunit) disassembly from the vacuolar membrane and enhance the assembly of plasma membrane v-ATPases, thereby inducing macropinocytosis. Altogether, our results reveal a mechanism for macropinocytic regulation and PPIs as potential modulators of EV levels, thus regulating their functions.

Development and characterization of 40 InDel markers from the major histocompatibility complex genes of largemouth bass (Micropterus salmoides).

BACKGROUND: The genetic improvement in growth and food habit domestication of largemouth bass (Micropterus salmoides) have made breakthroughs in past decades, while the relevant work on disease resistance were rarely carried out. Major histocompatibility complex (MHC) genes, which are well known as their numbers and high polymorphisms, have been used as candidate genes to mine disease-resistant-related molecular markers in many species. METHODS AND RESULTS: In present study, we developed and characterized 40 polymorphic and biallelic InDel markers from the major histocompatibility complex genes of largemouth bass. The minor allele frequency, observed heterozygosity, expected heterozygosity and polymorphic information content of these markers ranged from 0.0556 to 0.5000, 0.1111 to 0.6389, 0.1064 to 0.5070, and 0.0994 to 0.3750, respectively. Three loci deviated significantly from Hardy-Weinberg equilibrium, while linkage disequilibrium existed at none of these loci. CONCLUSION: These InDel markers might provide references for the further correlation analysis and molecular assisted selection of disease resistance in largemouth bass.

The role of polyethylenimine-functionalized gold nanoclusters carrying plasmid CMTM5 in impeding the malignant progression of prostate cancer cells by promoting EGFR endocytosis.

In this research, polyethylenimine-functionalized gold nanoclusters (PEI-AuNCs) were synthesized for the delivery of plasmid CMTM5 (pCMTM5) to prostate cancer (PCa) cells, with the objective of elucidating the mechanism underlying its anticancer efficacy. The PEI-AuNCs loaded with pCMTM5 (PEI-AuNCs@pCMTM5) tumor-targeting drug delivery system was established. Subsequently, both the obtained PEI-AuNCs and PEI-AuNCs@pCMTM5 underwent characterization through a transmission electron microscope (TEM) and dynamic light scattering (DLS). Employing RT-qPCR, western blot, flow cytometry, immunofluorescence, and co-immunoprecipitation (co-IP) assays, the consequences of CMTM5 overexpression on the expression of EGFR were investigated. Moreover, the influence of PEI-AuNCs@pCMTM5 on PC-3 cells was assessed through CCK-8, wound healing assay, and Transwell experiments. As a result, the PEI-AuNCs and PEI-AuNCs@pCMTM5 were presented as uniformly dispersed spherical with stable particle sizes and positive charges, showcasing favorable dispersion within the solution. In comparison to Lip2000, the PEI-AuNCs demonstrated superior transfection efficiency and lower cellular toxicity. Following the overexpression of CMTM5, the proliferative capacity of PC-3 cells was markedly suppressed, while both migratory and invasive abilities exhibited noteworthy reduction, with the efficacy of PEI-AuNCs@pCMTM5 consistently outperforming that of free pCMTM5. Subsequent mechanistic investigations unveiled that CMTM5 does not directly inhibit the synthesis of EGFR or facilitate its degradation, but rather influences the endocytic process of EGFR. In conclusion, the PEI-AuNCs nano-delivery system exhibits good biocompatibility and efficaciously conveys pCMTM5 to PCa cells. Crucially, pCMTM5 does not directly interact with EGFR, and CMTM5 governs the malignant progression of PC3 cells by promoting EGFR endocytosis.

Characteristics of CD4-1 gene and its immune responses against Aeromonas veronii infection by activating NF-κB signaling in Qihe crucian carp Carassius auratus.

CD4-1 found in bony fish contains four extracellular immunoglobulin (Ig)-like domains similar to that of mammalian CD4, which is crucial for the activation of CD4+ helper T-cell. However, there is limited knowledge regarding the molecular markers, immune functions and regulation mechanism of CD4-1 in teleosts due to their vast diversity. In this study, we cloned and characterized two isoforms of Qihe crucian carp CD4-1, designated as CaCD4-1.1 and CaCD4-1.2. We further explored their expression responses upon stimulation with Aeromonas veronii, and the regulation of their immune responses against A. veronii by NF-κB. The ORF of CaCD4-1.1 and CaCD4-1.2 cDNA encoded 477 and 466 amino acids, respectively. Both proteins contained seven conserved cysteine residues in the extracellular domain, and a CCC motif in their cytoplasm, respectively. However, CaCD4-1.1 exhibited a relatively limited similarity with CaCD4-1.2 in the ectodomain. The quantitative real-time polymerase chain reaction (qRT-PCR) analysis revealed that the mRNA expression of CaCD4-1.1 and CaCD4-1.2 exhibited differential constitutive expression across all examined tissues. Furthermore, the expression level of CD4-1.2 was higher than that of CD4-1.1 in the gills, head kidney, and spleen of Qihe crucian carp subjected to A. veronii challenge, while it was lower in the trunk kidney. Inhibition of NF-κB activity resulted in a decrease in the expression levels of CD4-1.1 and CD4-1.2 mRNA in the gill, while inducing an increase in expression levels in the spleen, in accordance with the observed ultrastructural changes in both organs. Interestingly, the impact of NF-κB on the mRNA expression level of CD4-1.1 appears to be stronger than that of CD4-1.2. Our results suggest that CaCD4-1.1 and CaCD4-1.2 could be expressed on T cells and antigen-sampling cells that exhibit similar characteristics to mammalian M cells, respectively, and differentially regulated by NF-κB in adaptive immune responses against bacterial infection. This research contributes to a better understanding of the crucial role of CD4-1 in the immune response of Qihe crucian carp and provide novel insights for the prevention and treatment of fish diseases in aquaculture.

Role of HIF in fish inflammation.

The hypoxia-inducing factor (HIF) is a central transcription factor in cellular oxygen sensing and regulation. It is common that the inflammation always appears in many diseases, like infectious diseases in fishes, and the inflammation is often accompanied by hypoxia, as a hallmark of inflammation. Besides coordinating cellular responses to low oxygen, HIF-mediated hypoxia signaling pathway is also crucial for immune responses such as the regulations of innate immune cell phenotype and function, as well as metabolic reprogramming under the inflammation. However, the understanding of the molecular mechanisms by which HIFs regulate the inflammatory response in fish is still very limited. Here, we review the characteristics of HIF as well as its roles in innate immune cells and the infections caused by bacteria and viruses. The regulatory effects of HIF on the metabolic reprogramming of innate immune cells are also discussed and the future research directions are outlooked. This paper will serve as a reference for elucidating the molecular mechanism of HIF regulating inflammation and identifying treatment strategies to target HIF for fish disease.

The role of CcPTGS2a in immune response against Aeromonas hydrophila infection in common carp (Cyprinus carpio).

Prostaglandin-endoperoxide synthase 2 (PTGS2), a crucial enzyme in prostaglandin synthesis, catalyzes the conversion of arachidonic acid to prostaglandins and plays a significant role in the inflammatory response. This investigation aimed to determine the regulatory role of PTGS2a in the innate immune response to bacterial infection in fish. To achieve this objective, the CcPTGS2a gene was identified and characterized in common carp (Cyprinus carpio), and its function in immune defense was investigated. According to the sequence and structural analysis results, CcPTGS2a had an open reading frame of 1806 bp that encoded 602 amino acids. It was estimated that the protein's theoretical molecular weight was 69.0 kDa, and its isoelectric point was 8.10. The structure of CcPTGS2a was observed to be conserved, with an epidermal growth factor domain and a peroxidase domain present. Moreover, the amino acid sequence of CcPTGS2a exhibited significant homology with the amino acid sequences of several fish species. CcPTGS2a mRNA was detected in the healthy tissues of common carp, with higher expression in the head kidney, spleen, gills, and liver. Following the challenges with Aeromonas hydrophila and lipopolysaccharide, CcPTGS2a mRNA showed unique geographic and temporal expression patterns, with significant increases detected in the head kidney, gills, spleen, and liver. Additionally, the recombinant CcPTGS2a protein exhibited detectable bacterial binding to various bacteria. As determined by subcellular localization analysis, CcPTGS2a was predominantly localized in the nucleus and cytoplasm. Furthermore, it was discovered that the overexpression of CcPTGS2a stimulated the up-regulation of ferroptosis-related genes and inflammatory cytokine mRNA expression in fish and EPC (Epithelioma papulosum cyprinid) cells while concurrently reducing the bacterial load of A. hydrophila. In contrast, the interference of CcPTGS2a decreased the mRNA expression of ferroptosis-related genes and inflammatory cytokines in fish and EPC cells and increased the bacterial load of A. hydrophila. Notably, A. hydrophila stimulation resulted in the up-regulation of CcPTGS2a protein expression in EPC cells. These results suggested that CcPTGS2a was involved in the immune response to bacterial infections in common carp.

Functional roles of CcGSDMEa-like in common carp (Cyprinus carpio) after Aeromonas hydrophila infection.

GSDMs could punch holes in cell membrane and participate in the immune response to bacterial infections. In current study, the molecular and structural characteristics of CcGSDMEa-like were analyzed, and the role of CcGSDMEa-like in the inflammatory response against Aeromonas hydrophila was studied. The results showed that the CcGSDMEa-like shared the conserved structural characteristics with GSDMEs of other teleosts. The CcGSDMEa-like mRNA and protein expression levels were significantly affected by A. hydrophila challenge. When the CcGSDMEa-like was overexpressed, the expression of CcIL-1ß were significantly increased in fish and EPC cells, and bacterial contents were significantly decreased in fish tissues. While, when the CcGSDMEa-like was knocked down, the expression and secretion of CcIL-1ß were significantly decreased in vivo and in vitro, and the bacterial contents were increased in vivo after A. hydrophila infection 12 h and 24 h. In brief, CcGSDMEa-like could regulate the content of bacteria in fish through mediating the expression and secretion of CcIL-1ß. Bactericidal assay and cytotoxicity assay showed that CcGSDMEa-like had no bactericidal activity to Escherichia coli, and did not disrupt cytomembrane integrity of HEK293T cells. This study suggested that CcGSDMEa-like could play roles in the antibacterial and inflammatory processes in fish.

Correlation analysis of structural and functional changes in the carotid artery in patients with H-type hypertension using ultrasound radiofrequency.

OBJECTIVES: To perform a correlation analysis on the structural and functional changes of the carotid artery in patients with H-type hypertension. METHODS: Outpatients and inpatients with hypertension in our hospital between 2017 and 2018 were selected and divided into the H-type hypertension group (primary hypertension + plasma homocysteine ≥ 10 umol/l) (n = 30) and the simple hypertension group (primary hypertension + plasma Hcy < 10 umol/l) (n = 30) based on the plasma homocysteine (Hcy), and 30 healthy people were included in the control group. Thickness and stiffness parameters of the intima of the carotid artery (compliance coefficient [CC], stiffness index [ß], and pulse wave velocity [PWV]) were measured for all study participants using ultrasound radiofrequency signal-based quality intima-media thickness (QIMT) and quantitative arterial stiffness (QAS) for contrast analysis. RESULTS: Indexes such as QIMT, ß, and PWV of the carotid artery were significantly higher, and the CC was significantly lower in the H-type hypertension group and simple hypertension group than the control group (p < .05), and the difference was statistically significant; these indexes were significantly higher in the H-type hypertension group than in the simple hypertension group, and the CC was significantly lower than in the control group (p < .05), and the difference was statistically significant. CONCLUSIONS: Hypertension can accelerate structural and functional changes of the carotid artery intima, with these changes being more significant in H-type hypertension. The ultrasound radiofrequency technique can be used to quantitatively evaluate the structure and function of the carotid artery in patients with H-type hypertension.

Research progress of pattern recognition receptors in red swamp crayfish (Procambarus clarkii).

Though Procambarus clarkii (red swamp crayfish) is a lower invertebrate, it has nonetheless developed a complex innate immune system. The crayfish farming industry has suffered considerable economic losses in recent years as a consequence of bacterial and viral diseases. Hence, perhaps the most effective ways to prevent microbial infections in P. clarkii are to examine and elucidate its innate immunity. The first step in the immune response is to recognize pathogen-associated molecular patterns (PAMPs) through pattern recognition receptors (PRRs). PRRs are expressed mainly on immune cell surfaces and recognize at least one PAMP. Thence, downstream immune responses are activated and pathogens are phagocytosed. To date, the PRRs identified in P. clarkii include Toll-like receptors (TLRs), lectins, fibrinogen-related proteins (FREPs), and ß-1,3-glucan-binding proteins (BGRPs). The present review addresses recent progress in research on PRRs and aims to provide guidance for improving immunity and preventing and treating infectious diseases in P. clarkii.

A Review on Edible Fungi-Derived Bioactive Peptides: Preparation, Purification and Bioactivities.

Edible fungi bioactive peptides (BAPs) are extracted from fruiting bodies and the mycelium of edible fungus. They have various physiological functions such as antioxidant activity, antihypertensive activity, and antibacterial activity. In this paper, the preparation and purification methods of edible fungus BAPs were reviewed, their common biological activities and structure-activity relationships were analyzed, and their application prospects were discussed.

Two CcCCL19bs orchestrate an antibacterial immune response in Yellow River carp (Cyprinus carpio haematopterus).

Chemokines are a group of chemotactic cytokines with an essential role in homeostasis as well as immunity via specific G protein-coupled receptors and atypical receptors. In our study, two Yellow River carp (Cyprinus carpio haematopterus) CCL19b genes (CcCCL19bs), tentatively named CcCCL19b_a and CcCCL19b_b, were cloned. The open reading frames (ORFs) of CcCCL19b_a and CcCCL19b_b were both 333 bp that encoded a 12 kDa protein with 110 amino acid residues. CcCCL19bs contained a signal peptide and a SCY domain with four typical conserved cysteine residues. The two CcCCL19b proteins shared high similarities with each other in both secondary and three-dimensional structure. Phylogenetic analysis showed that CcCCL19bs and other CCL19bs from tetraploid cyprinid fish were clustered into one clade. CcCCL19bs were highly expressed in gill and intestine in healthy fish, and a significant up-regulation of gene expression after Aeromonas hydrophila infection and poly(I:C) stimulation was observed in gill, liver, and head kidney. Furthermore, chemotaxis and antibacterial activity of CcCCL19bs were studied. The results indicated that recombinant CcCCL19b_a and CcCCL19b_b protein (rCcCCL19b_a and rCcCCL19b_b) exhibited significant attraction to primary head kidney leukocytes (HKLs). Meanwhile, both of rCcCCL19bs could promote the proliferation of HKLs, and significantly up-regulate the expressions of IL-1ß, CCR7, and IL-6, and down-regulate the expression of IL-10 in primary HKLs. In vitro, rCcCCL19bs could bind and aggregate A. hydrophila and Staphylococcus aureus. The rCcCCL19bs exhibited significant antibacterial activity against A. hydrophila, but not S. aureus. Moreover, they inhibited the growth of A. hydrophila and S. aureus. In vivo, overexpression of CcCCL19bs contributed to the bacterial clearance. These studies suggested that CcCCL19bs orchestrate an antibacterial immune response.

Adipose tissue­derived extracellular vesicles: Systemic messengers in health and disease (Review).

Adipose tissue (AT) is a complicated metabolic organ consisting of a heterogeneous population of cells that exert wide­ranging effects on the regulation of systemic metabolism and in maintaining metabolic homeostasis. Various obesity­related complications are associated with the development of dysfunctional AT. As an essential transmitter of intercellular information, extracellular vesicles (EVs) have recently been recognized as crucial in regulating multiple physiological functions. AT­derived extracellular vesicles (ADEVs) have been shown to facilitate cellular communication both inside and between ATs and other peripheral organs. Here, the role of EVs released from ATs in the homeostasis of metabolic and cardiovascular diseases, cancer, and neurological disorders by delivering lipids, proteins, and nucleic acids between different cells is summarized. Furthermore, the differences in the sources of ADEVs, such as adipocytes, AT macrophages, AT­derived stem cells, and AT­derived mesenchymal stem cells, are also discussed. This review may provide valuable information for the potential application of ADEVs in metabolic syndrome, cardiovascular diseases, cancer, and neurological disorders.

Microdosimetric assessment about proton spread-out Bragg peak at different depths based on the normal human mesh-type cell population model.

Objective.In clinical proton therapy, the spread-out Bragg peak (SOBP) is commonly used to fit the target shape. Dose depositions at microscopic sites vary, even with a consistent absorbed dose (D) in SOBP. In the present study, monolayer mesh-type cell population models were developed for microdosimetric assessment at different SOBP depths.Approach.Normal human bronchial epithelial (BEAS-2B) and hepatocytes (L-O2) mesh-type cell models were constructed based on fluorescence tomography images of normal human cells. Particle transport simulation in cell populations was performed coupled with Monte Carlo software PHITS. The relationship between microdosimetry and macrodosimetry of SOBP at different depths was described by analyzing the microdosimetric indicators such as specific energyz,specific energy distributionfz,D,and relative standard deviationσz/z¯within cells. Additionally, the microdosimetric distributions characteristics and their contributing factors were also discussed.Main results.The microscopic dose distribution is strongly influenced by cellular size, shape, and material. The mean specific energyz¯of nucleus and cytoplasm in the cell population is greater than the overall absorbed dose of the cell population model (Dp), with a maximumz¯/Dpof 1.1. The cellular dose distribution is different between the BEAS-2B mesh-type model and its concentric ellipsoid geometry-type model, which difference inz¯is about 10.3% for the nucleus and about 7.5% for the cytoplasm with the SOBP depth of 15 cm. WhenD= 2 Gy, the maximumzof L-O2 nucleus reaches 2.8 Gy andσz/z¯is 5.1% at the mid-depth SOBP (16-18 cm); while the maximumzof the BEAS-2B nucleus reaches 2.2 Gy with only 2.7% ofσz/z¯.Significance.The significant variation of microdosimetric distributions of SOBP different depths indicates the necessity to use mesh-type cell population models, which have the potential to be compared with biological results and build the bio-physical model.

Multiple Mesh-type Real Human Cell Models for Dosimetric Application Coupled with Monte Carlo Simulations.

The mesh-type models are superior to voxel models in cellular dose assessment coupled with Monte Carlo codes. The aim of this study was to expand the micron-scale mesh-type models based on the fluorescence tomography of real human cells, and to investigate the feasibility of these models in the application of various irradiation scenarios and Monte Carlo codes. Six different human cell lines, including pulmonary epithelial BEAS-2B, embryonic kidney 293T, hepatocyte L-02, B-lymphoblastoid HMy2.CIR, Gastric mucosal GES-1, and intestine epithelial FHs74Int, were adopted for single mesh-type models reconstruction and optimization based on laser confocal tomography images. Mesh-type models were transformed into the format of polygon mesh and tetrahedral mesh for the GATE and PHITS Monte Carlo codes, respectively. The effect of model reduction was analyzed by dose assessment and geometry consideration. The cytoplasm and nucleus doses were obtained by designating monoenergetic electrons and protons as external irradiation, and S values with different "target-source" combinations were calculated by assigning radioisotopes as internal exposure. Four kinds of Monte Carlo codes were employed, i.e., GATE with "Livermore," "Standard" and "Standard and Geant4-DNA mixed" models for electrons and protons, as well as PHITS with "EGS" mode for electrons and radioisotopes. Multiple mesh-type real human cellular models can be applied to Monte Carlo codes directly without voxelization when combined with certain necessary surface reduction. Relative deviations between different cell types were observed among various irradiation scenarios. The relative deviation of nucleus S value reaches up to 85.65% between L-02 and GES-1 cells by 3H for the "nucleus-nucleus" combination, while that of 293T and FHs74Int nucleus dose for external beams at a 5.12 cm depth of water is 106.99%. Nucleus with smaller volume is far more affected by physical codes. There is a considerable deviation for dose within BEAS-2B at the nanoscale. The multiple mesh-type real cell models were more versatile than voxel models and mathematical models. The present study provided several models which can easily be extended to other cell types and irradiation scenarios for RBE estimations and biological effect predictions, including radiation biological experiments, radiotherapy and radiation protection.

Activation Mechanism of CcGSDMEb-1/2 and Regulation for Bacterial Clearance in Common Carp (Cyprinus carpio).

Gasdermin E (GSDME), to date, is considered the only direct executor of the pyroptosis process in teleost and plays an important role in innate immunity. In common carp (Cyprinus carpio), there contains two pairs of GSDME (GSDMEa/a-like and GSDMEb-1/2), and the pyroptotic function and regulation mechanism of GSDME still remain unclear. In this study, we identified two GSDMEb genes of common carp (CcGSDMEb-1/2), which contain a conserved N-terminal pore-forming domain, C-terminal autoinhibitory domain, and a flexible and pliable hinge region. We investigated the function and mechanism of CcGSDMEb-1/2 in association with inflammatory and apoptotic caspases in Epithelioma papulosum cyprinid cells and discovered that only CcCaspase-1b could cleave CcGSDMEb-1/2 through recognizing the sites 244FEVD247 and 244FEAD247 in the linker region, respectively. CcGSDMEb-1/2 exerted toxicity to human embryonic kidney 293T cells and bactericidal activity through its N-terminal domain. Interestingly, after i.p. infection by Aeromonas hydrophila, we found that CcGSDMEb-1/2 were upregulated in immune organs (head kidney and spleen) at the early stage of infection, but downregulated in mucosal immune tissues (gill and skin). After CcGSDMEb-1/2 were knocked down and overexpressed in vivo and in vitro, respectively, we found that CcGSDMEb-1/2 could govern the secretion of CcIL-1ß and regulate the bacterial clearance after A. hydrophila challenge. Taken together, in this study, it was demonstrated that the cleavage mode of CcGSDMEb-1/2 in common carp was obviously different from that in other species and played an important role in CcIL-1ß secretion and bacterial clearance.