An analysis combining proteomics and transcriptomics revealed a regulation target of sea cucumber autolysis.

Sea cucumber is a valuable seafood product and autolysis is the main concern for the aquaculture industry. This study employed proteomics and transcriptomics to investigate the autolysis mechanism of sea cucumbers. The fresh sea cucumber was exposed to UV light to induce autolysis. The body wall samples were cut off to analyze by proteomics and transcriptomics. The angiotensin-converting enzyme (ACE) inhibitor of teprotide and the activator of imatinib were gastric gavage to live sea cucumbers, respectively, to identify the regulation target. Autolysis occurrence was evaluated by appearance, soluble peptide, and hydroxyproline content. Four gene-protein pairs were ACE, AJAP10923, Heme-binding protein 2-like, and Ficolin-2-like. Only the ACE protein and gene changed synchronously and a significant down-regulation of ACE occurred in the autolysis sea cucumbers. Teprotide led to a 1.58-fold increase in the TCA-soluble protein content and a 1.57-fold increase in hydroxyproline content. No significant differences were observed between imatinib-treated sea cucumbers and fresh ones regarding TCA-soluble protein content or hydroxyproline levels (P > 0.05). ACE inhibitor accelerated the autolysis of sea cucumber, but ACE activator inhibited the autolysis. Therefore, ACE can serve as a regulatory target for autolysis in sea cucumbers.

Sea Cucumber Polysaccharide from Stichopus japonicu and Its Photocatalytic Degradation Product Alleviate Acute Alcoholic Liver Injury in Mice.

To prevent alcoholic liver disease, the addition of bioactive substances to the alcoholic drink Baijiu has been considered a feasible option. In the present study, the hepatoprotective effects of a sea cucumber sulfated polysaccharide (SCSP) isolated from Stichopus japonicu were investigated. Moreover, in order to enhance its solubility in an alcohol solution, it was depolymerized using a photocatalytic reaction, and the photocatalytic degradation products (dSCSPs) with an average molecular weight of less than 2 kDa were studied and compared with SCSP. They were characterized by a series of chemical and spectroscopy methods and the oligosaccharide fragments in the dSCSP were further identified by HPLC-MSn analysis. Then, the in vivo experiment showed that the addition of SCSP or dSCSP to Baijiu could alleviate alcoholic liver injury in mice. Further analysis also revealed their protective effect in reducing oxidative stress damage and their regulation of the metabolism of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) in the liver. Of note, dSCSP was more effective at reducing the level of malondialdehyde in the liver. These findings indicate that the addition of sea cucumber polysaccharide or its low-molecular-weight derivative in Baijiu has the potential to alleviate alcoholic liver injury.

The protective effect of Enteromorpha prolifera polysaccharide on alcoholic liver injury in C57BL/6 mice.

An alcohol-induced liver injury model was induced in C57BL/6 mice to assess the protective efficacy of Enteromorpha prolifera polysaccharides (EP) against liver damage. Histological alterations in the liver were examined following hematoxylin-eosin (H&E) staining. Biochemical assay kits and ELISA kits were employed to analyze serum and liver biochemical parameters, as well as the activity of antioxidant enzymes and alcohol metabolism-related enzymes. The presence of oxidative stress-related proteins in the liver was detected using western blotting. Liquid chromatography and mass spectrometry were used to profile serum metabolites in mice. The findings demonstrated that EP-H (100 mg/Kg) reduced serum ALT and AST activity by 2.31-fold and 2.32-fold, respectively, when compared to the alcohol-induced liver injury group. H&E staining revealed a significant attenuation of microvesicular steatosis and ballooning pathology in the EP-H group compared to the model group. EP administration was found to enhance alcohol metabolism by regulating metabolite-related enzymes (ADH and ALDH) and decreasing CYP2E1 expression. EP also modulated the Nrf2/HO-1 signaling pathway to bolster hepatic antioxidant capacity. Furthermore, EP restored the levels of lipid metabolites (Glycine, Butanoyl-CoA, and Acetyl-CoA) to normalcy. In summary, EP confers protection to the liver through the regulation of antioxidant activity and lipid metabolites in the murine liver.

Degradation Product of Sea Cucumber Polysaccharide by Dielectric Barrier Discharge Enhanced the Migration of Macrophage In Vitro.

This study investigated the effect of dielectric barrier discharge (DBD) on sea cucumber polysaccharide (SP-2) and evaluated its anti-inflammatory properties. The SP-2 was depolymerized by applying an input voltage of 60~90 V for 3~9 min. The features of the products were examined using high-performance gel permeation chromatography, HPLC-PAD-MS, and the Fourier transform infrared (FTIR) spectrum. The anti-inflammatory properties of the product were investigated by measuring nitric oxide (NO) release, ROS accumulation, and cell migration using RAW264.7 cells (LPS-induced or not-induced). The results showed SP-2 depolymerized into homogeneous and controllable-size oligosaccharide products. The depolymerized ratio can reach 80%. The results of the measurement of reducing sugars indicate that SP-2 was cleaved from within the sugar chain. The SP-2 was deduced to have a monosaccharide sequence of GlcN-Man-Man-Man-Man-Man based on the digested fragment information. The depolymerization product restrained the release of NO and the accumulation of ROS. By testing the RAW264.7 cell scratch assay, it was found that it enhances the migration of immune cells. DBD degradation of SP-2 leads to homogeneous and controllable-size oligosaccharide products, and this technique can be used for polysaccharide structure analysis. The depolymerized product of SP-2 has an anti-inflammatory capability in vitro.

Aflatoxin B1-induced early developmental hepatotoxicity in larvae zebrafish.

Aflatoxin B1 (AFB1) is a ubiquitous mycotoxin that causes oxidative damage in various organs. At present, the research studies on AFB1 are primarily focused on its effects on the terrestrial environment and animals. However, its toxicity mechanism in aquatic environments and aquatic animals has not been largely explored. Thus, in this study, zebrafish was used as a model to study the toxicity mechanism of AFB1 on the liver of developing larvae. The results showed that AFB1 exposure inhibited liver development and promoted fat accumulation in the liver. Transcriptome sequencing analysis showed that AFB1 affected liver redox metabolism and oxidoreductase activity. KEGG analysis showed that AFB1 inhibited the expression of gsto1, gpx4a, mgst3a, and idh1 in the glutathione metabolizing enzyme gene pathway, resulting in hepatic oxidative stress. At the same time, AFB1 also inhibited the expression of acox1, acsl1b, pparα, fabp2, and cpt1 genes in peroxidase and PPAR metabolic pathways, inducing hepatic steatosis and lipid droplet accumulation. Antioxidant N-Acetyl-l-cysteine (NAC) preconditioning up-regulated gsto1, gpx4a and idh1 genes, and improved the AFB1-induced lipid droplet accumulation in the liver. In summary, AFB1 induced hepatic oxidative stress and steatosis, resulting in abnormal liver fat metabolism and accumulation of cellular lipid droplets. NAC could be used as a potential preventative drug to improve AFB1-induced fat accumulation.

The effect of blood flow restriction training combined with electrical muscle stimulation on neuromuscular adaptation: a randomized controlled trial.

Objective: Low-intensity resistance training (≤25% 1RM) combined with blood flow restriction training (BFRT) is beneficial to increasing muscle mass and muscle strength, but it cannot produce increased muscle activation and neuromuscular adaptation, as traditional high-intensity strength training does. The purpose of this study is to investigate the effects of independently applying BFRT and electrical muscle stimulation (EMS), as well as combining the two methods, on muscle function. Methods: Forty healthy participants with irregular exercise experiences were randomly assigned to four groups: BFRT-alone group (BFRT, n = 10), EMS-alone group (EMS, n = 10), BFRT combined with EMS group (CMB, n = 10), and the control group (CTR, n = 10). All participants received low-intensity squat training at a load of 25% 1RM 5 times/week for 6 weeks. Cross-sectional area (CSA) and electromyographic root mean square (RMS) in the rectus femoris, as well as peak torque (PT) of the knee extensor, were measured before and following a 6-week intervention. Results: Following the 6-week intervention, the increases in muscle activation in the CMB group were statistically higher than those in the BFRT group (p < 0.001), but not different from those in the EMS group (p = 0.986). Conclusion: These data suggest that the combination of BFRT and EMS for low-intensity squat training improved the muscle strength of the lower limbs by promoting muscle hypertrophy and improving muscle activation, likely because such a combination compensates for the limitations and deficiencies of the two intervention methods when applied alone.

Structural characterization of a fucoidan from Ascophyllum nodosum and comparison of its protective effect against cellular oxidative stress with its analogues.

In the present study, a fucoidan fraction (ANP-3) was isolated from Ascophyllum nodosum, and the combined application of desulfation, methylation, HPGPC, HPLC-MSn, FT-IR, GC-MS, NMR, and Congo red test elucidated ANP-3 (124.5 kDa) as a triple-helical sulfated polysaccharide constituted by →2)-α-Fucp3S-(1→, →3)-α-Fucp2S4S-(1→, →3,6)-ß-Galp4S-(1→, →3,6)-ß-Manp4S-(1→, →3,6)-ß-Galp4S-(1→，→6)-ß-Manp-(1→, →3)-ß-Galp-(1→, α-Fucp-(1→, and α-GlcAp-(1→ residues. To better understand the relationship between the fucoidan structure of A. nodosum and protective effects against oxidative stress, two fractions ANP-6 and ANP-7 were used as contrast. ANP-6 (63.2 kDa) exhibited no protective effect against H2O2-induced oxidative stress. However, ANP-3 and ANP-7 with the same molecular weight of 124.5 kDa could protect against oxidative stress by down-regulating reactive oxygen species (ROS) and malondialdehyde (MDA) levels and up-regulating total antioxidant capability (T-AOC), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) activities. Then metabolites analysis indicated that arginine biosynthesis and phenylalanine, tyrosine, and tryptophan biosynthesis metabolic pathways and metabolic biomarkers such as betaine were involved in the effects of ANP-3 and ANP-7. The better protective effect of ANP-7 compared to that of ANP-3 could be attributed to its relatively higher molecular weight, sulfate substitution and →6)-ß-Galp-(1→ content, and lower uronic acid content.

Active Obstacle Avoidance Trajectory Planning for Vehicles Based on Obstacle Potential Field and MPC in V2P Scenario.

V2P (vehicle-to-pedestrian) communication can improve road traffic efficiency, solve traffic congestion, and improve traffic safety. It is an important direction for the development of smart transportation in the future. Existing V2P communication systems are limited to the early warning of vehicles and pedestrians, and do not plan the trajectory of vehicles to achieve active collision avoidance. In order to reduce the adverse effects on vehicle comfort and economy caused by switching the "stop-go" state, this paper uses a PF (particle filter) to preprocess GPS (Global Positioning System) data to solve the problem of poor positioning accuracy. An obstacle avoidance trajectory-planning algorithm that meets the needs of vehicle path planning is proposed, which considers the constraints of the road environment and pedestrian travel. The algorithm improves the obstacle repulsion model of the artificial potential field method, and combines it with the A* algorithm and model predictive control. At the same time, it controls the input and output based on the artificial potential field method and vehicle motion constraints, so as to obtain the planned trajectory of the vehicle's active obstacle avoidance. The test results show that the vehicle trajectory planned by the algorithm is relatively smooth, and the acceleration and steering angle change ranges are small. Based on ensuring safety, stability, and comfort in vehicle driving, this trajectory can effectively prevent collisions between vehicles and pedestrians and improve traffic efficiency.

Characterization and Gel Properties of Low-Molecular-Weight Carrageenans Prepared by Photocatalytic Degradation.

Low-molecular-weight carrageenan has attracted great interest because it shows advantages in solubility, absorption efficiency, and bioavailability compared to original carrageenan. However more environment-friendly and efficient methods to prepare low-molecular-weight carrageenan are still in great need. In the present study, a photocatalytic degradation method with only TiO2 has been developed and it could decrease the average molecular weight of κ-carrageenan to 4 kDa within 6 h. The comparison of the chemical compositions of the degradation products with those of carrageenan by FT-IR, NMR, etc., indicates no obvious removement of sulfate group, which is essential for bioactivities. Then 20 carrageenan oligosaccharides in the degradation products were identified by HPLC-MSn, and 75% of them possessed AnGal or its decarbonylated derivative at their reducing end, indicating that photocatalysis is preferential to break the glycosidic bond of AnGal. Moreover, the analysis results rheology and Cryo-SEM demonstrated that the gel property decreased gradually. Therefore, the present study demonstrated that the photocatalytic method with TiO2 as the only catalyst has the potential to prepare low-molecular-weight carrageenan with high sulfation degree and low viscosity, and it also proposed the degradation rules after characterizing the degradation products. Thus, the present study provides an effective green method for the degradation of carrageenan.

Inhibitory effects of fucoidan from Laminaria japonica against some pathogenic bacteria and SARS-CoV-2 depend on its large molecular weight.

Fucoidan is a highly sulfated polysaccharide with a wide range of bioactivities, including anti-pathogenic activity. However, the relationship between structure and activity of fucoidan in inhibiting pathogen infections remains unclear. Here, different-molecular-weight fucoidans were prepared by photocatalytic degradation followed by membrane ultrafiltration, and their chemical structures and anti-pathogenic microbiota activity were compared. Results showed that photocatalytic degradation could effectively degrade fucoidan while its structure block and sulfate groups were not destroyed obviously. Fucoidan (90.8 kDa) of 5 mg/mL could inhibit the growth of S. aureus, S. typhimurium and E. coli, but its degradation products, Dfuc1 (19.2 kDa) and Dfuc2 (5.5 kDa), demonstrated lower inhibitory effect. In addition, compared to Dfuc1 and Dfuc2, fucoidan showed stronger capability to prevent the adhesion of S. aureus, L. monocytogenes, V. parahaemolyticus and S. typhimurium to HT-29 cells. Moreover, the inhibitory effect against SARS-CoV-2 and the binding activity to S protein were also positively correlated to molecular weight. These results indicate that natural fucoidan with higher molecular weight are more effective to inhibit these pathogenic bacteria and SARS-CoV-2, providing a better understanding of the relationship between structure and activity of fucoidan against pathogenic microbiota.

Cardiotoxicity of (-)-borneol, (+)-borneol, and isoborneol in zebrafish embryos is associated with Na+ /K+ -ATPase and Ca2+ -ATPase inhibition.

Borneol is an example of traditional Chinese medicine widely used in Asia. There are different isomers of chiral borneol in the market, but its toxicity and effects need further study. In this study, we used zebrafish embryos to examine the effects of exposure to three isomers of borneol [(-)-borneol, (+)-borneol, and isoborneol] on heart development and the association with Na+ /K+ -ATPase from 4 h post-fertilization (4 hpf). The results showed that the three isomers of borneol increased mortality and decreased hatching rate when the zebrafish embryo developed to 72 hpf. All three isomers of borneol (0.01-1.0 mM) significantly reduced heart rate from 48 to 120 hpf and reduced the expression of genes related to Ca2+ -ATPase (cacna1ab and cacna1da) and Na+ /K+ -ATPase (atp1b2b, atp1a3b, and atp1a2). At the same time, the three isomers of borneol significantly reduced the activities of Ca2+ -ATPase and Na+ /K+ -ATPase at 0.1 to 1.0 mM. (+)-Borneol caused the most significant reduction (p < 0.05), followed by isoborneol and (-)-borneol. Na+ /K+ -ATPase was mainly expressed in otic vesicles and protonephridium. All three isomers of borneol reduced Na+ /K+ -ATPase mRNA expression, but isoborneol was the most significant (p < 0.01). Our results indicated that (+)-borneol was the least toxic of the three isomers while the isoborneol showed the most substantial toxic effect, closely related to effects on Na+ /K+ -ATPase.

Effects of Storage Method on the Quality of Processed Sea Cucumbers (Apostichopus japonicus).

This research aimed to establish an effective storage method to maintain the quality of processed sea cucumbers. In this study, sea cucumbers were stored by various methods including the storage of live sea cucumbers (seawater treatment, oxygen treatment, and ascorbic acid treatment) and the storage of dead sea cucumbers (frozen treatment). The sea cucumber quality was monitored after storage and boiling. The weightlessness rate and WHC of the frozen group increased to 86.96% ± 0.83% and 93.29% ± 0.32%, respectively. Frozen sea cucumbers shrunk with the meat's textural properties deteriorated. During the live sea cucumber storage, the tissue protein degraded from day 3 to day 7 which led to the promotion of TVB-N. Among these, the oxygen group showed the smallest TVB-N increase from day 0 (3.78 ± 0.60 mg 100 g-1) to day 7 (10.40 ± 0.12 mg 100 g-1). The oxygen group exhibited the most moderate change in weightlessness rate (4.24% ± 0.45%) and the most moderate texture parameters decline, such as the hardness of 32.52%, chewiness of 78.98 ± 5.10 N, and adhesion of 0.84 ± 0.00. The oxygen method showed the best condition of sea cucumber after 5 days of storage.

A Sulfated Abalone Polysaccharide Inhibited SARS-CoV-2 Infection of Vero E6 Cells In Vitro.

Sulfate polysaccharides, such as heparin sulfate, have been found to have inhibitory activity against SARS-CoV-2. An abalone polysaccharide, AGSP, was deeply sulfate modified using the chlorosulfonic acid/pyridine method, yielding S-AGSP. AGSP and S-AGSP inhibitions of SARS-CoV-2 infection of Vero E6 cells were tested in vitro. The interference of AGSP or S-AGSP on the binding interaction between the SARS-CoV-2 spike protein and angiotensin-converting enzyme was tested using a biolayer interferometry assay. Results showed that S-AGSP, above a concentration of 1.87 µg/mL, significantly inhibited SARS-CoV-2 infection of Vero E6 cells. Compared with AGSP, S-AGSP obviously weakened the affinity between the SARS-CoV-2 spike protein and ACE2. The polysaccharide's sulfate content played a vital role in influencing the binding affinity of spike protein to ACE2. Therefore, S-AGSP has potential as a COVID-19 competitive inhibitor as well as a candidate to be repurposed as a prophylactic COVID-19 therapeutic.

Oral administration of sea cucumber (Stichopus japonicus) protein exerts wound healing effects via the PI3K/AKT/mTOR signaling pathway.

This study aimed to investigate the effect of the oral administration of sea cucumber protein (SCP) on wound healing. SCP was isolated and purified from the body wall of Stichopus japonicus. A mouse skin incision model was operated on to evaluate the wound repair effect of SCP. The histological changes in the skin at the wound sites of BALB/c mice were observed by staining with haematoxylin and eosin (H&E) and Masson's trichrome. The enzyme-linked immunosorbent assay (ELISA) was used to analyze the expression of inflammatory cytokines in BALB/c mice. The boost cell migration ability was detected by a scratch assay after HaCaT cells were cultured with digested SCP (dSCP). Western blotting and RT-PCR assays were performed to determine the mechanism of SCP promoting wound healing. As a result, the wound healing rate in the SCP high dose group was 1.3-fold, compared to that in the blank group on day 14. Also, increased epidermal thickness and 1.79-fold collagen deposition contrasted with the blank group. Additionally, SCP could up-regulate the levels of pro-inflammatory factors (IL-1ß, IL-6, TNF-α) from day 3 to 7 firstly and decreased from day 7 to 14. IL-8 expression continuously decreased while the level of anti-inflammatory factor (IL-10) increased during the healing stage. Furthermore, the cell closure area reached 67% after being treated with 50 µg mL-1 of dSCP for 48 h. Cell proliferation was associated with the dSCP-activated PI3K/AKT/mTOR pathway. Taken together, SCP can be orally used as an effective agent for wound repair.

Detection and Molecular Characterization of Porcine Parvovirus 7 in Eastern Inner Mongolia Autonomous Region, China.

Porcine parvoviruses (PPV) and porcine circoviruses type 2 (PCV2) are widespread in the pig population. Recently, it was suggested that PPV7 may stimulate PCV2 and PCV3 replication. The present study aimed to make detection and molecular characterization of PPV7 for the first time in eastern Inner Mongolia Autonomous Region, China. Twenty-seven of ninety-four samples (28.72%) and five in eight pig farms were PPV7 positive. Further detection showed that the co-infection rate of PPV7 and PCV2 was 20.21% (19/94), and 9.59% (9/94) for PPV7 and PCV3. In addition, the positive rate of PPV7 in PCV2 positive samples was higher than that in PCV2 negative samples, supporting that PCV2 could act as a co-factor for PPV7 infection. In total, four PPV7 strains were sequenced and designated as NM-14, NM-19, NM-4, and NM-40. The amplified genome sequence of NM-14 and NM-40 were 3,999nt in length, while NM-19 and NM-4 were 3,996nt with a three nucleotides deletion at 3,097-3,099, resulting in an amino acid deletion in the Cap protein. Phylogenetic analysis based on the capsid amino acid (aa) sequences showed that 52 PPV7 strains were divided into two clades, and the four PPV7 strains in this study were all clustered in clade 1. The genome and capsid amino acid sequence of the four PPV7 strains identified in this study shared 80.0-96.9% and 85.9-100% similarity with that of 48 PPV7 reference strains selected in NCBI. Simplot analysis revealed that NM-19 and NM-4 strains were probably produced by recombination of two PPV7 strains from China. The amino acid sequence alignment analysis of capsid revealed that the four PPV7 strains detected in Inner Mongolia had multiple amino acid mutations in the 6 B cell linear epitopes compared with the reference strains, suggesting that the four PPV7 strains may have different characteristics in receptor binding and immunogenicity. In summary, this paper reported the PPV7 infection and molecular characterization in the eastern of Inner Mongolia Autonomous Region for the first time, which is helpful to understand the molecular epidemic characteristics of PPV7.

Pseudoephedrine hydrochloride causes hyperactivity in zebrafish via modulation of the serotonin pathway.

This study aimed to explore behavioral changes of embryonic and larval zebrafish caused by pseudoephedrine hydrochloride (PSE) and its underlying mechanism. Zebrafish embryos were exposed to 0.5 µM, 2 µM, and 8 µM PSE at 4 h post-fertilization (4 hpf) or 22-23 hpf. Mortality, hatching rate, coiling frequency, heart rate, behavior changes, and related gene expression were observed at different developmental stages. PSE below 8 µM did not affect zebrafish mortality, hatching rate, and heart rate compared with the control group. For embryos, PSE caused an increase at 16-32 hpf in zebrafish coiling frequency which could be rescued by serotonin antagonist WAY100635. Similarly, PSE caused an increase in the swimming distance of zebrafish larvae at 120 hpf. PSE also elevated the expression of serotonin (5-HT)-related genes 5-htr1ab and tph2 and dopamine-related gene dbh. Behavioral changes in zebrafish embryos and larvae caused by PSE may be closely associated with increased expression of 5-HT and dopamine-related genes. This may be reflected that the behavioral changes in zebrafish are a possible PSE monitoring indicator.

Inhibitory Effects of Mongolian Medicine Yihe-Tang on Continuous Darkness Induced Liver Steatosis in Zebrafish.

The constant dark induction (DD) causes lipid degeneration and nonalcoholic fatty liver disease (NAFLD) in zebrafish, which might be closely related to the imbalance of gut microbiota and require in-depth study. In this study, a total of 144 zebrafish were divided into four groups, including the control group, Yihe-Tang group, constant dark group, and constant dark + Yihe-Tang group, and were treated with constant darkness (except control and Yihe-Tang groups) for 21 days. The bodyweights of zebrafish were recorded after 8 d, 15 d, and 22 d. The sequencing analysis of gut microbiota, detection of liver histopathological changes, and comparison of lipid metabolism-related gene expression levels were performed on the 22nd day of the experiment. The results showed that the Yihe-Tang could inhibit the constant dark-induced increase in zebrafish weight and liver steatosis. As compared to the control group, the dark treatment could alter the composition of gut microbiota in zebrafish, increase the relative abundance of harmful bacteria, and decrease the Cetobacterium and Bacteroides to Firmicutes ratio in the intestines. The abundance of Proteobacteria in the constant dark + Yihe-Tang group was close to that in the control group and that of Fusobacteria and Cetobacterium increased, especially the Cetobacterium, which increased significantly. The constant dark treatment caused an abnormal expression of liver lipid-related genes, inhibited lipid metabolism, and promoted fat accumulation. However, the Yihe-Tang could restore these changes to the level of the control group. This study indicated that Yihe-Tang could restore the constant dark-induced liver lipid degeneration. We hypothesized that Cetobacterium could significantly inhibit steatosis.

Protective effect of curcumin on zebrafish liver under ethanol-induced oxidative stress.

Oxidative stress has an important role in determining severe damage to the liver, including steatosis. Curcumin (CUR) is a natural polyphenol compound with antioxidant potential but its mechanism is still unclear. In this study, 2% ethanol (ETH) was used to establish a liver injury model in Tg (fabp10: Ps Red) transgenic zebrafish with the fluorescent liver. Ethanol-treated zebrafish had an increased vacuole rate at 144 h post-fertilization (hpf), thus confirming the effectiveness of the proposed model in inducing liver damage. However, when ethanol was submitted to co-exposure with curcumin, fluorescence area and signal intensity, as well as vacuole rate, were similar to the levels found in the control group. RNA-seq results showed that ethanol and CUR affected the regulation of catalytic activity and phenylalanine metabolism, biosynthesis of amino acids, and arginine and proline metabolism signaling pathways. QRT-PCR analysis also showed that treatment with CUR led to the downregulation of genes involved in the Nrf2-Keap1 signaling pathway and altered the expression pattern of genes related to glutathione metabolism (gsr, gpx1a, gstp1, gsto1, and idh1a). CUR also induced an increase in GSH content and recovered decreased GSH caused by ethanol exposure. The findings discussed herein indicate that CUR can promote glutathione synthesis, which aided in the recovery from ethanol-induced liver damage in zebrafish larvae.

Prophenoloxidase-positive tubes derived from the hindguts may be the doorkeeper to detoxify the waste metabolites collected by Malpighian tubules in Lepidoptera insects.

Prophenoloxidase (PPO), an important immunity protein in insects, is mainly produced by hemocytes and released into the hemolymph upon cell lysis. In addition, PPO can also be produced by epidermal cells in the foregut to detoxify the toxic plant secondary metabolites and in the hindgut to kill pathogens through PPO-induced melanization. Previously, we noticed a pair of tubes extended from the larval hindgut became melanized upon staining in dopamine dissolved in 30% ethanol. However, the structure and function of these tubes are largely unknown. In this study, we performed staining of the tubes and the neighboring Malpighian tubule for further confirmation. Eventually, we detected PPO inside epidermal cells of the tubes, and called them as PPO-positive tubes. We observed that the PPO-positive tubes are physically derived from the hindgut but strongly adhere to the Malpighian tubule. Inside the PPO-positive tubes, there is an acellular peritrophic membrane to protect the epidermal cells. Furthermore, the PPO-positive tubes act like a doorkeeper to firstly detoxify the metabolite wastes collected by the Malpighian tubule from the hemolymph.