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Ferroptosis, as one of cell death modalities, is driven by iron‐dependent phospholipid peroxidation and regulated by various cellular metabolic pathways, including iron, amino acid and lipid metabolism, as well as disease‐related signalling pathways. Cell survival or death is a critical issue in the inflammatory response. On the one hand, ferroptosis is more immunogenic than apoptosis, and ruptured ferroptotic cells release damage‐associated molecular patterns (DAMPs), which can trigger an inflammatory response. On the other hand, various pathogenic bacteria may cause peroxidation of polyunsaturated fatty acids (PUFAs) on the cell membrane, leading to ferroptosis. In fish, the key genes and signalling pathways related to ferroptosis are conserved, but there are still differences among fish species. In recent years, frequent occurrences of fish diseases have posed a considerable challenge to the large‐scale aquaculture. The specific precursors for ferroptotic cell death were iron‐dependent oxidative stress and lipid peroxidation, which always occur in fish inflammation. This review summarizes recent studies on ferroptosis in fish inflammation, that is, iron‐dependent programmed cell death, to address ferroptosis, inflammation and correlations between them in fish. This review may contribute to a better understanding of the underlying mechanisms of ferroptosis and inflammation in fish and provides suggestions for sustainable development and large‐scale aquaculture farming. [ABSTRACT FROM AUTHOR]

Host innate immunity modulated by metabolites is a powerful strategy that can be used to defend against microbial infections. However, the mechanisms underlying the metabolic processes in controlling bacterial infections remain unexplored. Here, a GC‐MS based metabolomics approach was adopted to investigate the metabolic characteristics between the surviving and dying Cyprinus carpio upon Aeromonas hydrophila infection. Aspartate was identified as an essential biomarker whose abundance significantly decreased in the dying group while increasing in the surviving group when compared to the control. Exogenous aspartate increased fish survival rate in a dose‐dependent manner. Concurrently, we also found that aspartate regulated the expressions of inflammatory and anti‐inflammatory factors, and alleviated oxidative damage based on the evaluations of the activities of antioxidant enzymes and histopathology. Interestingly, the results revealed that exogenous aspartate promoted arginine and proline metabolism and arginine biosynthesis, but attenuated the TCA cycle, thereby enhancing the disease resistance against A. hydrophila. We further demonstrated that aspartate induced iNOS expression and NO production, and L‐NAME treatment inhibited iNOS expression and blocked NO production, which significantly increased the cumulative mortality of infecting A. hydrophila. These findings indicated that exogenous aspartate could reprogram C. carpio metabolome and improve the host's ability to fight against A. hydrophila infection by inducing of NO release, and demonstrated the metabolite‐mediated immunomodulatory as a therapeutic intervention for A. hydrophila infection. [ABSTRACT FROM AUTHOR]

Superoxide dismutases (SODs), as the prime antioxidant enzymes, present the first line of defense against oxidative stress caused by excessive reactive oxygen species (ROS) in organism. In the study, two distinct members of SOD family were cloned and analyzed in Qihe crucian carp Carassius auratus (designated as CaCu/ZnSOD and CaMnSOD , respectively). The full-length cDNA of CaCu/ZnSOD is 759 bp, containing a 5' -untranslated region (UTR) of 39 bp, a ORF (including stop codon, TAG) of 465 bp and a 3′-UTR of 255 bp. The ORF of CaCu/ZnSOD encodes a protein of 154 amino acids (aa), in which, two Cu/ZnSOD signature ( 45 GFHVHAFGDNT 55 and 139 GNAGGRLACGVI 150 ) and four conserved amino acids for Cu/Zn 2+ -binding sites (H64, H72, H81 and D84) were observed. The full-length CaMnSOD cDNA (960 bp) consists of a 5′-UTR of 114 bp, a ORF of 675 bp and a 3′-UTR of 231 bp, the ORF of CaMnSOD encodes a 224 aa protein with a 26 aa mitochondrial-targeting sequence (MTS) in the N-terminus, and four conserved amino acids for manganese binding (H52, H100, D185 and H189) were observed. Multiple alignment and the structural analysis revealed two Cu/ZnSOD signature motifs and a MnSOD signature motif as well as the invariant binding sites for Cu 2+ /Zn 2+ in CaCu/ZnSOD and Mn 2+ in CaMnSOD. The phylogenetic analysis indicated that CaCu/ZnSOD was homologous to cytosolic Cu/ZnSODs, and CaMnSOD was high similarity with mitochondrial MnSODs from other fish. The tissue distribution analysis demonstrated that CaCu/ZnSOD and CaMnSOD were highly expressed in liver, heart and muscle. The dynamic expressions of CaCu/ZnSOD and CaMnSOD were observed after the challenges with Aeromonas hydrophila or LPS, which generally increased in liver, gill, kidney and spleen, while, the mRNA expressions were down-regulated at some time points in head kidney. The enzyme activities increased after A. hydrophila or LPS challenge, compared to the control. In this study, the molecular structures and functional motifs of CaCu/ZnSOD and CaMnSOD were determined, and it is crucial for us to understand the biological functions of SODs. The highest level in liver showed that the function of liver to remove ROS is much more important. The obvious responses of mRNA expression levels and enzyme activities to pathogens indicate the important roles of CaCu/ZnSOD and CaMnSOD in antioxidant defense in C. auratus . [ABSTRACT FROM AUTHOR]

Antimicrobial peptide is an important component of the host innate immune system and thus serves a crucial function in host defense against microbial invasion. In this study, H2A and derived antimicrobial peptide Ca-L-hipposin were cloned and characterized in Carassius aurutus . The gene H2A full-length cDNA is 908 bp and includes a 5′-terminal untranslated region (UTR) of 55 bp and a 3′-terminal UTR of 466 bp with a canonical polyadenylation signal sequence AATAA, as well as an open reading frame (ORF) of 387 bp encoding a polypeptide of 128 amino acids, with a molecular weight of 13.7 kDa, an isoelectric point of 10.7, and 94% homology with Danio rerio H2A. The secondary structure of H2A includes the α-spiral with 51 amino acids with a composition ratio of 39.8%, as well as a β-corner with 15 amino acids in a composition ratio of 11.7%. The online software ExPaSy predicted that a peptide sequence with 51 amino acids from the 2nd to 52nd amino acids in histone H2A can be produced through hydrolization by protease chymotrypsin, which indicates a difference of only three amino acids, compared with the antimicrobial peptide hipposin in Hippoglossus hippoglossus with a homology of 94%. Ca-L-hipposin includes 51 amino acids with a molecular weight of 5.4 kDa and an isoelectric point of 12.0, the secondary structure of which contains an α-helix of 17 amino acids accounting for 33.3% and a β-corner of 8 amino acids accounting for 15.7%. H2A was extensively expressed in the mRNA levels of various tissues, with higher expression levels in kidney and spleen. After C. aurutus was challenged with Aeromonas hydrophila , the mRNA expression levels of H2A were upregulated in the kidney, spleen, and liver. H2A serves an important function in the defense against the invasion of A. hydrophila . In addition, sequence characteristics reveal that Ca-L-hipposin could be a potential antimicrobial peptide for use in killing pathogenic bacteria in aquaculture. [ABSTRACT FROM AUTHOR]

Abstract: Efficient hybrid solar cells fabricated from TiO2, novel carboxylated polythiophene poly (3-thiophenemalonic acid) P3TMA as sensitizer as well as hole conductor and poly (3-hexylthiophene) (P3HT) as hole transporter was described. UV–Vis absorption and morphology of the active layer were investigated. Device J/V characterizations with different P3HT layer thickness were measured and discussed. Efficiency improvements were observed in thinner P3HT layer thickness and with poly[3,4-(ethylenedioxy)-thiophene]:poly(styrene sulfonate) (PEDOT:PSS) as charge collection layer, and such device showed a short-circuit current density of 1.32mA/cm2, an open-circuit voltage of 0.44V, a fill factor of 0.43, and a energy conversion efficiency of 0.25% at A.M. 1.5 solar illumination (100mW/cm2). [Copyright &y& Elsevier]

Red swamp crayfish Procambarus clarkii is an economically important species that is widely cultivated throughout China. With the application of high-density culture, P. clarkii is usually infected by different pathogens in water. Co-infection with multiple pathogens was common, which has resulted in greater economic loss than single infections. In this study, we investigated a case of co-infected crayfish with bacterial and viral pathogens at a local farm. Firstly, a bacterial strain was isolated from the gills of infected crayfish. According to the results of 16S rRNA sequence and analysis of the Biolog Gen III MicroPlate system, the isolated bacterial strain was finally identified as Aeromonas veronii. The isolated A. veronii exhibited significant virulence to crayfish, with an LD 50 value of 6.04 × 106 CFU/crayfish. As a result, drug sensitivity tests showed that the isolated A. veronii was completely resistant to ampicillin, penicillin, and compound sulfamethoxazole tablets, and highly sensitive to seven kinds of antibiotics. Furthermore, white spot syndrome virus (WSSV) was also detected from the gill tissue of diseased crayfish by polymerase chain reaction. After experimentally co-infected with A. veronii and WSSV, the healthy P. clarkii presented similar clinical and histopathological signs with natural infected P. clarkii. The mortality of the co-infected group was 100%, which was higher than that in the group single infected with A. veronii (70%) or WSSV (83.3%). In summary, a case of co-infection with WSSV and A. veronii from P. clarkii was comprehensively studied in this study. The results will supply an effective diagnosis strategy for the co-infection, and provide therapy reference to prevent and control P. clarkii disease. • A case of co-infection with different pathogens was investigated in P. clarkii. • WSSV and Aeromonas veronii were identified from the gills of P. clarkii , respectively. • The co-infection accelerates the course of disease. • The results will supply diagnosis strategies for co-infection and provide therapy reference to control P. clarkii disease. [ABSTRACT FROM AUTHOR]

We have designed, synthesized, and characterized a library of 38 novel flavonoid compounds linked with amines. Some of these amine-linked flavonoids have potent in vitro activity against parasites that cause cutaneous leishmaniasis, a tropical disease endemic in 80 countries worldwide. The most promising candidate, FM09h , was highly active with IC 50 of 0.3 μM against L. amazonensis , L. tropica and L. braziliensis amastigotes. It was metabolically stable (39% and 66% of FM09h remaining after 30-minute incubation with human and rat liver microsomes respectively). In L. amazonensis LV78 cutaneous leishmaniasis mouse model, intralesional injection of FM09h (10 mg/kg, once every 4 days for 8 times) demonstrated promising effect in reducing the footpad lesion thickness by 72%, displaying an efficacy comparable to SSG (63%)., (Copyright © 2021 American Society for Microbiology.)

An unequal loss of peripheral vision may happen with high sustaining multi-axis acceleration, leading to a great potential flight safety hazard. In the present research, finite element method was used to study the mechanism of unequal loss of peripheral vision. Firstly, a 3D geometric model of skull was developed based on the adult computer tomography (CT) images. The model of double eyes was created by mirroring with the previous right eye model. Then, the double-eye model was matched to the skull model, and fat was filled between eyeballs and skull. Acceleration loads of head-to-foot (G z ), right-to-left (G y ), chest-to-back (G x ) and multi-axis directions were applied to the current model to simulate dynamic response of retina by explicit dynamics solution. The results showed that the relative strain of double eyes was 25.7% under multi-axis acceleration load. Moreover, the strain distributions showed a significant difference among acceleration loaded in different directions. It indicated that a finite element model of double eyes was an effective means to study the mechanism of an unequal loss of peripheral vision at sustaining high multi-axis acceleration.