Influence of Herba Houttuyniae added to fodder on the morphological structure of the intestinal tract, the digestive enzymes, the intestinal flora, and immune function of koi carp (Cyprinus carpio) infected with Aeromonas veronii.

This study investigated whether adding Herba Houttuyniae to feed can improve intestinal function and prevent diseases for koi carp (Cyprinus carpio) infected with Aeromonas veronii. There was a total of 168 koi carp with an average body length of (9.43 ± 0.99) cm and an average body weight of (26.00 ± 11.40) g. The K group was the control group fed with basal feed, while the C group was fed with feed with a H. houttuyniae content of six per thousand. After 14 days of feeding, the fish were fasted for a day and then intraperitoneally injected with A. veronii for artificial infection, injection dose is 0.2 mL, and the concentration is 1 × 107 CFU/mL. Samples were collected from the two groups on days 0, 1, 2, and 4. The fold height, intestinal villus width, and muscle layer thickness in the gut of the koi carp were measured. In addition, on day 4, the activities of trypsin, α-amylase, and lipase in the gut were determined, and the intestinal flora of the carp in both groups was tested. The results showed that on the second and fourth days of sampling, the fold height and muscle layer thickness in the C group were significantly higher than those in the K group (P < 0.05). The villus width in the C group was slightly higher than that in the K group, but the difference was not significant (P > 0.05). Microscopic observation revealed that the intestinal structure of the carp in the C4 (day 4 in C group) group was more intact than that in the K4 (day 4 in K group) group. Moreover, the activities of trypsin, α-amylase, and lipase in the foregut and midgut in the C4 group were higher than those in the K4 group (P < 0.05). The activities of trypsin and α-amylase in the hindgut in the C4 group were higher than those in the K4 group (P < 0.05). Furthermore, beneficial bacteria, especially those in the genus Cetobacterium, were more abundant in the intestinal tract of the carp in the C4 group compared to the K group. In addition, comparisons and tests of IL-4 and IL-10 in the intestines of the fish in both groups demonstrated that the H. houttuyniae added to feed enhanced the immune function of the fish intestines after bacterial attack. In conclusion, for koi carp infected with A.veronii, adding H. houttuyniae to their feed not only improves the activity of digestive enzymes and the morphological structure of the intestine but also optimizes the beneficial intestinal microbiota, thereby protecting the intestinal tract.

Analysis of changes in nutrient salts and other water quality indexes in the pond water for largemouth bass (micropterus salmoides) farming.

To explore the changes in nitrite nitrogen, ammoniacal nitrogen, nitrate nitrogen, phosphates, pH, dissolved oxygen, salinity, and water temperature over time and the correlations and mutual influences between these indexes in the traditional farming of largemouth bass, this study selected three ponds in Lizigu Farm in Baodi District of Tianjin, China as research objects. From May to October 2021, nutrient salts and other water quality indexes in the ponds were measured, and water samples were collected at different depths for repetition, Water is collected from the ponds using Plexiglas samplers and sent back to the lab for determination of water quality indexes using our national laboratory standards. According to the analysis of the measurement results, in traditional farming, nitrite nitrogen, ammoniacal nitrogen, nitrate nitrogen, phosphates, pH, dissolved oxygen, salinity, and water temperature in the ponds for largemouth bass all change significantly over time, with different changing trends and certain correlations with each other. In particular, nutrient salts indexes in ponds are influenced by other water quality indexes, human activities, and phytoplankton. During the breeding process, strengthening the dynamic monitoring of nutrient salts and other water quality indexes in the ponds and adjusting the nitrogen, phosphorus, and ammonia levels in the ponds artificially play an important role in preventing eutrophication in the water and promoting the green and sustainable production of pond ecosystems, in particular, allowing better quality growth of the largemouth bass, as well as ensuring the production and economic efficiency. This study provides a theoretical basis and data support for further optimization of traditional pond aquaculture in similar regions, in order to provide aquatic products with better quality and achieve higher economic benefits.

Metabolic Intervention Liposome Boosted Lung Cancer Radio-Immunotherapy via Hypoxia Amelioration and PD-L1 Restraint.

At present, radiotherapy (RT) still acquires limited success in clinical due to the lessened DNA damage under hypoxia and acquired immune tolerance owing to the amplified programmed death ligand-1 (PD-L1) expression. Incredibly, intracellular PD-L1 expression depression is proven to better sensitize RT by inhibiting DNA damage repair. However, the disability of the clinically used antibodies in disrupting the extracellular PD-L1function still limits the effectiveness of radio-immunotherapy. Therefore, better PD-L1 regulation strategies are still urgently needed to better sensitize radio-immunotherapy. Hence, for this purpose, TPP-LND is synthesized by linking mitochondrial-targeted triphenylphosphine cations (TPP+ ) to the antineoplastic agent lonidamine (LND), which significantly reduces the dose needed for LND to induce effective oxidative phosphorylation inhibition (2 vs 300 µM). Then, TPP-LND is wrapped with liposomes to form TPP-LND@Lip nanoparticles. By doing this, TPP-LND@Lip nanoparticles can sensitize RT by reversing the hypoxic microenvironment of tumors to generate more DNA damage and reducing the expression of PD-L1 via enhancing the adenosine 5'-monophosphate-activated protein kinase activation. As expected, these well-designed economical TPP-LND@Lip nanoparticles are more effective than conventional anti-PD-L1 antibodies to some extent.

Transcriptome profiles revealed high- and low-salinity water altered gill homeostasis in half-smooth tongue sole (Cynoglossus semilaevis).

Salinity is an important environmental factor that affects fish growth, development, and reproduction. As euryhaline fish, half-smooth tongue sole (Cynoglossus semilaevis) are a suitable species for deciphering the salinity adaptation mechanism of fish; however, the molecular mechanisms underlying low- and high-salinity responses remain unclear. In this study, RNA-seq was applied to characterize the genes and regulatory pathways involved in C. semilaevis gill responses to high- (32 ppt), low- (8 ppt), and control-salinity (24 ppt) water. Gills were rich in mitochondria-rich cells (MRCs) in high salinity. Compared with control, 2137 and 218 differentially expressed genes (DEGs) were identified in low and high salinity, respectively. The enriched functions of most DEGs were metabolism, ion transport, regulation of cell cycle, and immune response. The DEGs involved in oxidative phosphorylation, citrate cycle, and fatty acid metabolism were down-regulated in low salinity. For ion transport, high and low salinity significantly altered the expressions of prlr, ca12, and cftr. In cell cycle arrest and cellular repair, gadd45b, igfbp5, and igfbp2 were significantly upregulated in high and low salinity. For immune response, il10, il34, il12b, and crp increased in high and low salinity. Our findings suggested that alterations in material and energy metabolism, ions transport, cell cycle arrest, cellular repair, and immune response, are required to maintain C. semilaevis gill homeostasis under high and low salinity. This study provides insight into the divergence of C. semilaevis osmoregulation mechanisms acclimating to high and low salinity, which will serve as reference for the healthy culture of C. semilaevis.

Simultaneous removal of phosphorous and nitrogen by ammonium assimilation and aerobic denitrification of novel phosphate-accumulating organism Pseudomonas chloritidismutans K14.

Pseudomonas chloritidismutans K14, a novel phosphate-accumulating organism with the capacity to perform ammonium assimilation, aerobic denitrification, and phosphorus removal, was isolated from aquaculture sediments. It produced no hemolysin, and showed susceptibility to most antibiotics. Optimum conditions were achieved with sodium pyruvate as a carbon source, a C/N ratio of 10, pH of 7.5, temperature of 27 °C, P/N ratio of 0.26, and shaking at 140 rpm. Under optimum conditions, the highest removal efficiencies of ammonium, nitrite, and nitrate were 99.82%, 99.11%, and 99.78%, respectively; the corresponding removal rates were 6.27, 4.51, and 4.99 mg/L/h. The strain removed over 98% of phosphorus, and over 87% of chemical oxygen demand. The highest biomass nitrogen during ammonium assimilation was 99.18 mg/L; no gaseous nitrogen was produced. The genes involved in nitrogen and phosphorus removal were amplified by PCR. This study demonstrated the potential application prospects of strain K14 for nitrogen and phosphorus removal.

Isolation and genomic characterization of a pathogenic Providencia rettgeri strain G0519 in turtle Trachemys scripta.

Providencia rettgeri infection has occurred occasionally in aquaculture, but is rare in turtles. Here, a pathogenic P. rettgeri strain G0519 was isolated from a diseased slider turtle (Trachemys scripta) in China, and qPCR assay was established for the RTX toxin (rtxD) gene. Histopathological examination showed that many inflammatory cells were infiltrated into heart, liver and intestine, as well as the necrosis of liver, kidney and spleen. The genome consisted of one circular chromosome (4.493 Mb) and one plasmid (18.8 kb), and predicted to contain 4170 and 19 protein-coding genes, respectively. Multiple pathogenic and virulence factors (e.g., fimbria, adhesion, invasion, toxin, hemolysin, chemotaxis, secretion system), multidrug-resistant genes (e.g., ampC, per-1, oxa-1, sul1, tetR) and a novel genomic resistance island PRI519 were identified. Comparative genome analysis revealed the closest relationship was with P. rettgeri, and with P. heimbachae closer than with other Providencia spp. To our knowledge, this was first report on genomic characterization of multidrug-resistant pathogenic P. rettgeri in cultured turtles.

Transcriptome profiles in the spleen of African catfish (Clarias gariepinus) challenged with Aeromonas veronii.

The African catfish, Clarias gariepinus, an important cultured freshwater species in many countries, possess the characteristic of high disease resistance. However, little genomic information for this character of the fish is available up to now. To address the shortfall and to better understand C. gariepinus immune response to pathogen infection at molecular level, C. gariepinus were challenged with potent A. veronii and the high-throughput RNA sequencing (RNA-seq) technology were employed to produce transcriptomes from spleen. In total, an average of 46,073,372 clean reads obtained were de novo assembled into 156,955 unigenes with an average length of 1082 bp. All of unigenes were annotated to seven public databases. Three comparisons were separately conducted between the infected groups at 3 h, 24 h, 48 h post-challenge and control group. A total of 2482 differentially expressed unigenes (DEGs) were identified. Among these, 114 immune-related DEGs were captured, including 88, 42, and 31 genes at 3 h, 24 h and 48 h after infection respectively, for analysis of expression pattern and enrichment. The 114 DEGs displayed four expression patterns by cluster analysis and they were significantly enriched in 38 pathways (q < 0.01) related to the immune or disease, five of which were NF-kappa B, TNF, NLR, TLR and RLR pathways. Finally, the expression levels of twelve selected immune-related DEGs involved in above five pathways were scrutinized. Seven of which were up-regulated at 3 h after infection, afterward, their expression dropped to control level. In summary, this study provides valuable transcriptome resource for understanding the defense mechanisms of C. gariepinus in resistance to pathogens from the gene expression viewpoint, which also open up the possibility to study the immune complexity and to better comprehend the interrelationships between some immune pathways in C. gariepinus.