Search

Grass carp (Ctenopharyngodon idella) is the most widely produced freshwater aquaculture product worldwide. However, its susceptibility to microbial infections during its cultivation restricts its development. The complement system plays an important role in immune defence. To investigate the transcription of the complement factor C5 and production of its cleavage product C5a in grass carp infected with grass carp reovirus (GCRV), the full-length C5 gene sequence was cloned and sequenced using the rapid amplification of cDNA ends method, and C5 transcription and C5a production in different grass carp tissues at different GCRV infection stages were determined by RT-qPCR and western blotting, respectively. Our results showed that the full-length cDNA of the C5 gene was 5365-bp long, encoding 1687 amino acids. Signal peptide prediction showed that C5 had a secretory signal peptide. After artificial infection with GCRV, C5 transcription in grass carp liver increased significantly before the appearance of symptoms. C5a generation in the liver increased significantly from the onset of disease symptoms, and continued to increase until recovery. GCRV induced C5 cleavage in grass carp, with C5a production.

Objective Thyroid hormone autoantibody (THAb) is a common antibody in autoimmune disease and can interfere with the detection of thyroid hormone (TH). There was no research reporting the prevalence of THAb in Chinese and the rate of THAb interfering with TH detection. Methods We collected 114 patients with autoimmune thyroid disease (AITD) (Hashimoto's thyroiditis, 57 cases; Graves’ disease, 57 cases), 106 patients with nonthyroid autoimmune diseases (NTAID), and 120 healthy subjects. According to the presence or absence of thyroid antibodies, patients with NTAID were divided into two groups: NTAID‐AITD and NTAID groups. Radioimmunoprecipitation technique was used to detect THAb in all subjects. TH was detected on Abbot and Roche platforms in patients with positive THAb. Results The prevalence of THAb was 22.8% in Hashimoto's thyroiditis and 45.6% in Graves’ disease. The prevalence of THAb in AITD group was lower than that in NTAID or NTAID‐AITD groups (34.2% vs. 61.5%, p = 0.014; 34.2% vs. 71.3%, p, We firstly investigated THAb in Chinese patients, and we found the prevalence of THAb in AITD patients was lower than that in NTAID patients. Although THAb has a high frequency in various autoimmune diseases, the rate of THAb interfering with thyroid hormone detection was only 9.18%.

Fish gut microbiota were potentially influenced by habitat changes. However, the fish gut has been shown to have a filtering effect on habitat microorganisms. Here, we hypothesized that the filtering of fish gut microbiota could counteract the effect of dam construction on the gut microbiota composition. To test this hypothesis, we collected water and Rhinogobio cylindricus individuals from four sampling sites located upstream of the Three Gorges Dam (TGD) and analyzed the microbiota composition in the water samples (n = 48) and R. cylindricus gut samples (n = 89) by high-throughput sequencing of the 16S rRNA gene. A total of 6,772,720 (49,435.91 ± 3762.80) high-quality sequences were obtained from 137 samples. The microbiota in the water environment was significantly more diverse than that in the gut of R. cylindricus. The β-diversity of microbiota in the water was significantly lower than that in the gut of R. cylindricus. The water microbiota composition varied greatly according to the distribution of the sampling sites upstream of the TGD, but the gut microbiota of R. cylindricus did not show the same pattern. Rather, the gut microbiota of R. cylindricus were not significantly affected by the TGD. This consistency in the internal tract of R. cylindricus is presumedly a result of a filtering effect on the water microorganisms. Our study furthers our understanding of the stabilization mechanism of the gut microbiota composition of fish and the impact of dams on river ecosystems.

Background: Although functional bacteria are widely used in aquaculture water treatment, whether they affect the indigenous microbiota and whether the impact is persistent remain unclear. Therefore, we aimed to explore the denitrification effect of Pseudomonas furukawaii ZS1 isolated from a grass carp culture pond in nitrogen-rich aquaculture water, and determine whether its effect on the microbiota structure of the aquaculture water was persistent. Methods: Three each of treatment and control groups were set up, and P. furukawaii ZS1 was added to the treatment group. The concentrations of ammonia nitrogen, nitrite, and nitrate, and the pH of each sample were measured for eight consecutive days. Changes of microbiota composition in the water were analysed via high-throughput sequencing. Results: Ammonia, nitrite, and nitrate concentrations were substantially lower in the treatment group than in the control group. There were significant differences in the microbiota structure between treatment and control groups, especially on days 2–7 after adding P. furukawaii ZS1. Furthermore, significantly enriched bacterial genera in the treatment group were initially higher in number than inhibited genera, but subsequently reverted to being lower in number. Conclusions: These results provide theoretical guidance for the effective use of P. furukawaii ZS1 to control aquaculture water.

Background The gut microbiota is closely correlated with host health and is strongly influenced by food composition. Chinese herbs are usually used as natural feed additives in livestock production. Therefore, the present study assessed the influence of diet supplementation with green tea and mulberry leaf powders on the chicken gut microbiota. The gut microbiota compositions were determined using 16S rDNA sequencing. Results Enhanced relative abundances of Bacteroides, Prevotella, and Megamonas were found in the chicken gut when mulberry leaf powder was added to diet. Conversely, a higher abundance of potentially pathogenic Gallibacterium was found in the chicken gut when the diet was supplemented with green tea powder. These results indicated that green tea powder and mulberry leaf powder can greatly affect the gut microbiota of chickens by changing their compositions. Conclusions It is imperative to examine and evaluate the effects of Chinese herbs on animal health before they are introduced as feed additives in animal production.

Purpose: Immunoassay is susceptible to interference by other substances in the serum. The main substances interfering with thyroid function testing include heterophilic antibody, biotin, thyroid hormone autoantibody, and Macro-TSH. We reported a patient with fraudulently elevated FT4 and TSH and described various common experimental methods used to explore the existence of substances interfering with thyroid function testing.Methods and Results: FT4 and TSH were significantly lower when measured on the Architect platform (FT4: 7.09 pmol/L, TSH: 58.94 µIU/ml). Polyethylene glycol precipitation showed lower FT4 and TSH, suggesting the presence of a high molecular weight interfering substance. Heterophile blocking tube study showed heterophilic antibody interfered with TSH detection. 125I-hTSH binding study and radioimmunoprecipitation assay indicated that the patient didn’t contain anti-TSH autoantibody. The new generation of Elecsys immunoassay kit indicated that biotin interfered with TSH detection. Radioimmunoprecipitation assay showed that all four kinds of thyroid hormone autoantibodies were positive. After reviewing 24 literatures, we provided the diagnostic strategy for investigation of interferences with thyroid function immunoassays.Conclusion: We reported a case with falsely elevated TSH due to the combined action of heterophilic antibody and biotin and fraudulently elevated FT4 caused by thyroid hormone autoantibody. When there is a discrepancy between thyroid function and clinical manifestation, the presence of immunoassay interference with one or more indicators needs to be considered.

Both hepatocellular carcinoma (HCC) and metabolic syndrome are closely associated with the composition of the gut microbiota (GM). Although it has been proposed that elements of the GM can be used as biomarkers for the early diagnosis of HCC, whether metabolic syndrome results in a misrepresentation of the results of the early diagnosis of HCC using GM remains unclear. We compared the differences in the faecal microbiota of 10 patients with primary HCC, six patients with type 2 diabetes mellitus (T2DM), seven patients with arterial hypertension, six patients with both HCC and T2DM, and 10 patients with both HCC and arterial hypertension, as well as 10 healthy subjects, using high-throughput sequencing of 16S rRNA gene amplicons. Our results revealed a significant difference in the GM between subjects with and without HCC. The 49 bacterial genera out of the 494 detected genera were significantly different between the groups. These results show that changes in the GM can be used to distinguish between subjects with and without HCC, and can resist interference of T2DM and arterial hypertension with the GM. The results of the present study provide an important basis for the clinical auxiliary diagnosis of HCC by detecting the GM.

Background: Avian leukosis virus (ALV) is a major cause of disease in poultry. Probiotics play a critical role in maintaining animal health. Studies have indicated that viral infection can alter the composition of the chicken gut microbiota. We hypothesized that ALV-J infection alters the probiotics composition in the chicken fecal bacterial microbiome. We performed high-throughput 16S rRNA gene sequencing and evaluated the gut microbiota profiles using feces from ALV-J-infected and healthy chickens.Results: The relative abundance at the phylum and species levels was calculated. The phylum Proteobacteria was more abundant in ALV-J-infected chickens than in healthy chickens. Additionally, the abundance of the opportunistic pathogen Propionibacterium acnes was significantly increased in ALV-J-infected chickens. Interestingly, ALV-J infection tended to be significantly decreased by the probiotics Lactobacillus helveticus and Lactobacillus reuteriConclusions: The study indicates that ALV-J infection significantly altered the gut microbiota distribution in chickens. Additionally, ALV-J infection significantly influenced the abundance of L. helveticus and L. reuteri in the chicken gut.

Background Due to intensive sluice construction and other human disturbances, lakeshore vegetation has been destroyed and ecosystems greatly changed. Rhizospheric microbiota constitute a key part of a functioning rhizosphere ecosystem. Maintaining rhizosphere microbial diversity is a central, critical issue for sustaining these rhizospheric microbiota functions and associated ecosystem services. However, the community composition and abiotic factors influencing rhizospheric microbiota in lakeshore remain largely understudied. Methods The spatiotemporal composition of lakeshore rhizospheric microbiota and the factors shaping them were seasonally investigated in three subtropical floodplain lakes (Lake Chaohu, Lake Wuchang, and Lake Dahuchi) along the Yangtze River in China through 16S rRNA amplicon high-throughput sequencing. Results Our results showed that four archaeal and 21 bacterial phyla (97.04 ± 0.25% of total sequences) dominated the rhizospheric microbiota communities of three lakeshore areas. Moreover, we uncovered significant differences among rhizospheric microbiota among the lakes, seasons, and average submerged depths. The Acidobacteria, Actinobacteria, Bacteroidetes, Bathyarchaeota, Gemmatimonadetes, and Proteobacteria differed significantly among the three lakes, with more than half of these dominant phyla showing significant changes in abundance between seasons, while the DHVEG-6, Ignavibacteriae, Nitrospirae, Spirochaetes, and Zixibacteria varied considerably across the average submerged depths (n = 58 sites in total). Canonical correspondence analyses revealed that the fluctuation range of water level and pH were the most important factors influencing the microbial communities and their dominant microbiota, followed by total nitrogen, moisture, and total phosphorus in soil. These results suggest a suite of hydrological and soil physiochemical variables together governed the differential structuring of rhizospheric microbiota composition among different lakes, seasons, and sampling sites. This work thus provides valuable ecological information to better manage rhizospheric microbiota and protect the vegetation of subtropical lakeshore areas.

Background: Avian leukosis virus (ALV) is one of the major causes of disease in poultry. Probiotics play a critical role in animal health maintenance. Studies have indicated that viral infection can alter the composition of chicken gut flora. We hypothesized that the ALV-J infection could alter Probiotics composition in chicken fecal bacterial microbiome. To test is, we performed high-throughput 16S rRNA gene sequencing and evaluated gut flora profiles from the feces of ALV-J infected and healthy chickens. Results: Relative abundance at the phylum and species levels was calculated. The phylum Proteobacteria was expressed in higher abundance in ALV-J infected chickens than in healthy chickens. Additionally, the abundance of the opportunistic pathogen, Propionibacterium acnes, significantly increased in ALV-J infected chickens. Interestingly, ALV-J infection tended to be significantly decreased by the probiotics Lactobacillus helveticus and Lactobacillus reuteri. Conclusions: The study indicated ALV-J infection significantly altered the gut microbiota distribution in chickens. It also showed that ALV-J infection significantly influenced composition of the probiotics including Lactobacillus helveticus and Lactobacillus reuteri in chicken gut, which implied that to relieve avian leucosis subgroup J, microbiota-targeted therapies such as probiotic supplements are required.

Background: Avian leukosis virus (ALV) is one of the major causes of disease in poultry. Probiotics play a critical role in animal health maintenance. Studies have indicated that viral infection can alter the composition of chicken gut flora. We hypothesized that the ALV-J infection could alter Probiotics composition in chicken fecal bacterial microbiome. To test is, we performed high-throughput 16S rRNA gene sequencing and evaluated gut flora profiles from the feces of ALV-J infected and healthy chickens. Results: Relative abundance at the phylum and species levels was calculated. The phylum Proteobacteria was expressed in higher abundance in ALV-J infected chickens than in healthy chickens. Additionally, the abundance of the opportunistic pathogen, Propionibacterium acnes, significantly increased in ALV-J infected chickens. Interestingly, ALV-J infection tended to be significantly decreased by the probiotics Lactobacillus helveticus and Lactobacillus reuteri. Conclusions: The study indicated ALV-J infection significantly altered the gut microbiota distribution in chickens. It also showed that ALV-J infection significantly influenced composition of the probiotics including Lactobacillus helveticus and Lactobacillus reuteri in chicken gut, which implied that to relieve avian leucosis subgroup J, microbiota-targeted therapies such as probiotic supplements are required.

Pathogen infection poses a serious threat to the survival and commercial quality of cultured Paa spinosa, which provide protection as a substitute for wild P. spinosa. The gut microbiota plays vital roles in host health and immunity. To provide guidance for preventing intestinal diseases of artificial P. spinosa culture, we compared gut microbiota compositions of wild and cultured P. spinosa using high-throughput sequencing. A total of 11,526 operational taxonomic units (OTUs) were identified from 14,043 sequences from each sample. Cetobacterium, PW3 Bacteroides and some unidentified species from Bacteroidales, Rikenellaceae and Clostridiales were significantly increased in the gut microbiota from cultured P. spinosa, whereas Faecalibacterium and unidentified bacteria from Ruminococcaceae were significantly decreased in the gut microbiota from cultured P. spinosa. According to the gut microbiota composition, we hypothesized that the cultured P. spinosa in Jing'an would exhibit a higher risk of pathogenic infection than those in Cili. These results provided a method to forecast the pathogenic infection risk of cultured P. spinosa, which could guide the artificial culture of and prevent diseases in P. spinosa through gut microbiota.

The Toll signaling pathway is highly conserved from insects to mammals. Drosophila is a model species that is commonly used to study innate immunity. Although many studies have assessed protein-coding genes that regulate the Toll pathway, it is unclear whether long noncoding RNAs (lncRNAs) play regulatory roles in the Toll pathway. Here, we evaluated the expression of the lncRNA CR46018 in Drosophila. Our results showed that this lncRNA was significantly overexpressed after infection of Drosophila with Micrococcus luteus. A CR46018-overexpressing Drosophila strain was then constructed; we expected that CR46018 overexpression would enhance the expression of various antimicrobial peptides downstream of the Toll pathway, regardless of infection with M. luteus. RNA-seq analysis of CR46018-overexpressing Drosophila after infection with M. luteus showed that upregulated genes were mainly enriched in Toll and Imd signaling pathways. Moreover, bioinformatics predictions and RNA-immunoprecipitation experiments showed that CR46018 interacted with the transcription factors Dif and Dorsal to enhance the Toll pathway. During gram-positive bacterial infection, flies overexpressing CR46018 showed favorable survival compared with flies in the control group. Overall, our current work not only reveals a new immune regulatory factor, lncRNA-CR46018, and explores its potential regulatory model, but also provides a new perspective for the effect of immune disorders on the survival of Drosophila melanogaster.

To understand how a bacteria-free fish gut ecosystem develops microbiota as the fish ages, we performed a 1-year study on the gut microbiota of hatchling gibel carp (Carassius auratus gibelio). Our results indicate that the gut microbial diversity increases significantly as the fish develop. The gut microbial community composition showed significant shifts corresponding to host age and appeared to shift at two time points despite consistent diet and environmental conditions, suggesting that some features of the gut microbial community may be determined by the host's development. Dietary and environmental changes also seem to cause significant shifts in the fish gut microbial community. This study revealed that the gut microbiota of gibel carp assemble into distinct communities at different times during the host's development and that this process is less affected by the surrounding environment than by the host diet and development. Community phylogenetic analyses based on the net relatedness index further showed that environmental filtering (host selection) deterministically governs the gut microbial community composition. More importantly, the influence of host-associated deterministic filtering tends to weaken significantly over the course of the host's development. However, further studies are needed to assess whether this host development-dependent shift in gut microbiota will still exist under different rearing strategies.

Obesity and the related liver diseases are prevalent around the world. Although probiotics have been shown to prevent obesity through multiple ways, only few researches investigated the lipid-lowering effects of probiotic Bacillus. Moreover, the limited results consistently suggested that Bacillus regulated genes related to lipogenesis and oxidation, but no further exploration was made. Our previous study revealed that Bacillus amyloliquefaciens SC06 has a potent antioxidant capacity in vitro. The aim of this study is to investigate the effects of SC06 on obesity and the associated liver injury of high-fat diet (HFD)-fed-mice and its underlying mechanism. By feeding normal chow (NC), NC+SC06, HFD, and HFD+SC06 to mice, we found that SC06 improved body weight gain, hepatic steatosis, and glucose metabolism of HFD-mice. Furthermore, SC06 also increased the antioxidant capacity of mice through Nrf2/Keap1 signaling pathway. High-throughput sequencing of 16S rRNA gene showed that HFD changed the gut microbiota dramatically, while HFD+SC06 decreased the ratio of Firmicutes/Bacteroidetes and increased TM7 abundance. More differences were also found in lower taxa. Altogether, SC06 is a potential probiotic that decreases HFD-related lipid accumulation and liver injury via regulating the antioxidant capacity and host gut microbiota.

The mechanisms of cell turnover including cell proliferation and cell differentiation were complex. Planarians possess amazing regeneration ability and undergo cell turnover throughout life. We identified a homologous gene of ERas by RNAi in Dugesia japonica. Knocking-down DjERas resulted in regeneration and homeostasis defects. Furthermore, we found that the expression of neoblasts and late progeny marker gene decreased in DjERas RNAi planarians. Our studies indicated that down-regulation of DjERas inhibited the proliferation and differentiation of stem cells through the conserved signaling pathway, resulted in the inability of the planarian to regenerate and maintain homeostasis. Our results suggest that DjERas plays a crucial role in the process of cell turnover.

Gut microbiota dysbiosis is closely associated with primary hepatocellular carcinoma (HCC). Recent studies have evaluated the early diagnosis of primary HCC through analysis of gut microbiota dysbiosis. However, the relationship between the degree of dysbiosis and the prognosis of primary HCC remains unclear. Because primary HCC is accompanied by dysbiosis and dysbiosis usually increases the circulatory concentrations of endotoxin and other harmful bacterial substances, which further increases liver damage, we hypothesized that level of dysbiosis associated with primary HCC increases with the stage of cancer progression. To test this hypothesis, we introduced a more integrated index referred to as the degree of dysbiosis (Ddys); and we investigated Ddys of the gut microbiota with the development of primary HCC through high-throughput sequencing of 16S rRNA gene amplicons. Our results showed that compared with healthy individuals, patients with primary HCC showed increased pro-inflammatory bacteria in their fecal microbiota. The Ddys increased significantly in patients with primary HCC compared with that in healthy controls. Moreover, there was a tendency for the Ddys to increase with the development of primary HCC, although no significant difference was detected between different stages of primary HCC. Our findings provide important insights into the use of gut microbiota analysis during the treatment of primary HCC.

Gut microbiota typically occupy habitats with definable limits/borders that are comparable to oceanic islands. The gut therefore can be regarded as an 'island' for the assembly of microbial communities within the 'sea' of surrounding environments. This study aims to reveal the ecological mechanisms that govern microbiota in the fish gut 'island' ecosystem. Taxonomic compositions, phylogenetic diversity, and community turnover across host development were analyzed via the high-throughput sequencing of 16S rRNA gene amplicons. The results indicate that the Shannon diversity of gut microbiota in the three examined freshwater fish species all significantly decreased with host development, and the dominant bacterial taxa also changed significantly during host development. Null model and phylogenetic-based mean nearest taxon distance (MNTD) analyses suggest that host gut environmental filtering led to the assembly of microbial communities in the fish gut 'island'. However, the phylogenetic clustering of local communities and deterministic processes that governed community turnover became less distinct as the fish developed. The observed mechanisms that shaped fish gut microbiota seemed to be mainly shaped by the gut environment and by some other selective changes accompanying the host development process. These findings greatly enhance our understanding of stage-specific community assembly patterns in the fish gut ecosystem.

Proteinuria is involved in the development of tubular lesions and in the progressive loss of renal function in chronic kidney diseases via uncertain mechanisms. Growing evidence suggests a pathogenic role of mitochondrial dysfunction in chronic kidney diseases. Therefore, the present study aimed to define the roles of mitochondria in proteinuria-induced renal tubular injury and their underlying mechanisms. Using the albumin-overload mouse model, we observed severe tubular structure damage and striking tubular cell apoptosis. Furthermore, tubular epithelial cells displayed a loss of E-cadherin expression and gained expression of α-smooth muscle actin and vimentin, indicating a cellular phenotypic alteration. Strikingly, these albumin overload-induced abnormalities were robustly blocked by a mitochondrial SOD2 mimic, Mn(III) tetrakis (4-benzoic acid)porphyrin chloride (MnTBAP). In agreement with these results, we observed a marked change in mitochondrial morphology accompanied by mitochondrial cytochrome c release and a copy number reduction of mitochondrial DNA. These alterations were largely reversed by MnTBAP, suggesting a key role for mitochondria-derived oxidative stress in mediating the albumin effect on mitochondrial dysfunction and subsequent tubular injury. Moreover, the NOD-like receptor family, pyrin domain-containing 3 (NLRP3)/caspase-1/cytokine cascade was activated in the kidney by albumin overload and was entirely abolished by MnTBAP. In albumin-treated mouse proximal tubular cells, albumin directly induced ROS production, mitochondrial dysfunction, NLRP3/caspase-1/cytokine cascade activation, cell apoptosis, and cellular phenotypic transition. Similar to our in vivo results, treatment with either MnTBAP or cyclosporin A, a mitochondrial permeability transition pore inhibitor, remarkably attenuated these abnormalities in cells. Taken together, these novel findings demonstrate a potential role for the mitochondrial dysfunction/NLRP3 inflammasome axis in the pathogenesis of proteinuria-induced renal tubular injury.

Planarians are an ideal model organism for regeneration research due to their amazing ability to regenerate. DNA replication is crucial for genome stability. Replication factor C (RFC), which is a replication factor C-like complex and plays an important role during DNA replication in eukaryotes, has been reported as a wound response factor during planarian regeneration. However, how RFC controls regeneration in planarians by regulating DNA replication remains to be explained. Here, we used a two-dimensional electrophoresis (2-DE) proteomic approach to identify differentially expressed proteins in intact and regenerated planarians. Approximately 132 protein spots showed differences between intact and regenerative tissues. We selected 21 significantly expressed protein spots and processed them using TOF MS analysis. Finally, we cloned three of these candidate genes (Djhsp70, Djrfc2, Djfaim), focusing on the function of Djrfc2 during regeneration. We found that the distribution of Djrfc2 tends toward the wound site. RNA interference (RNAi) of Djrfc2 increases the number of dividing cells and the expression level of planarian neoblast marker genes, which may result in hyper-proliferation. Our studies use an available approach to directly study the regeneration dynamic at the protein level and provide further evidence to support a function of Djrfc2 in planarian regeneration.

Uncovering which environmental factors govern community diversity patterns and how ecological processes drive community turnover are key questions related to understand the community assembly. However, the ecological mechanisms regulating long-term variations of bacterioplankton communities in lake ecosystems remain poorly understood. Here we present nearly a decade-long study of bacterioplankton communities from the eutrophic Lake Donghu (Wuhan, China) using 16S rRNA gene amplicon sequencing with MiSeq platform. We found strong repeatable seasonal diversity patterns in terms of both common (detected in more than 50% samples) and dominant (relative abundance >1%) bacterial taxa turnover. Moreover, community composition tracked the seasonal temperature gradient, indicating that temperature is a key environmental factor controlling observed diversity patterns. Total phosphorus also contributed significantly to the seasonal shifts in bacterioplankton composition. However, any spatial pattern of bacterioplankton communities across the main lake areas within season was overwhelmed by their temporal variabilities. Phylogenetic analysis further indicated that 75%-82% of community turnover was governed by homogeneous selection due to consistent environmental conditions within seasons, suggesting that the microbial communities in Lake Donghu are mainly controlled by niche-based processes. Therefore, dominant niches available within seasons might be occupied by similar combinations of bacterial taxa with modest dispersal rates throughout different lake areas.

Proteinuria serves as a direct causative factor of renal tubular cell injury and is highly associated with the progression of chronic kidney disease via uncertain mechanisms. Recently, evidence demonstrated that both NLRP3 inflammasome and mitochondria are involved in the chronic kidney disease progression. The present study was undertaken to examine the role of NLRP3 inflammasome/mitochondria axis in albumin-induced renal tubular injury. In patients with proteinuria, NLRP3 was significantly up-regulated in tubular epithelial cells and was positively correlated with the severity of proteinuria. In agreement with these results, albumin remarkably activated NLRP3 inflammasome in both in vitro renal tubular cells and in vivo kidneys in parallel with significant epithelial cell phenotypic alteration and cell apoptosis. Genetic disruption of NLRP3 inflammasome remarkably attenuated albumin-induced cell apoptosis and phenotypic changes under both in vitro and in vivo conditions. In addition, albumin treatment resulted in a significant mitochondrial abnormality as evidenced by the impaired function and morphology, which was markedly reversed by invalidation of NLRP3/caspase-1 signaling pathway. Interestingly, protection of mitochondria function by Mn(III)tetrakis (4-benzoic acid) porphyrin (MnTBAP) or cyclosporin A (CsA) robustly attenuated albumin-induced injury in mouse proximal tubular cells. Collectively, these findings demonstrated a pathogenic role of NLRP3 inflammasome/caspase-1/mitochondria axis in mediating albumin-induced renal tubular injury. The discovery of this novel axis provides some potential targets for the treatment of proteinuria-associated renal injury.

Gut microbiota have attracted extensive attention recently because of their important role in host metabolism, immunity and health maintenance. The present study focused on factors affecting the gut microbiome of grass carp (Ctenopharyngodon idella) and further explored the potential effect of the gut microbiome on metabolism. Totally, 43.39 Gb of screened metagenomic sequences obtained from 24 gut samples were fully analysed. We detected 1228 phylotypes (116 Archaea and 1112 Bacteria), most of which belonged to the phyla Firmicutes, Proteobacteria and Fusobacteria. Totally, 41335 of the detected open reading frames (ORFs) were matched to Kyoto Encyclopedia of Genes and Genomes pathways, and carbohydrate and amino acid metabolism was the main matched pathway deduced from the annotated ORFs. Redundancy analysis based on the phylogenetic composition and gene composition of the gut microbiome indicated that gut fullness and feeding (i.e. ryegrass vs. commercial feed, and pond-cultured vs. wild) were significantly related to the gut microbiome. Moreover, many biosynthesis and metabolism pathways of carbohydrates, amino acids and lipids were significantly enhanced by the gut microbiome in ryegrass-fed grass carp. These findings suggest that the metabolic role played by the gut microbiome in grass carp can be affected by feeding. These findings contribute to the field of fish gut microbial ecology and also provide a basis for follow-up functional studies.

The spatial distribution pattern of organisms is a basic issue in understanding the mechanisms of community assembly. Although the spatial distributions of animals and plants have been well studied, those of microorganisms are still being debated. In this study, we used a fish gut microecosystem to detect the spatial pattern of microbes, because it can provide a relatively unified and stable environment. Results suggest that the turnover of intestinal bacterial assemblages showed a weak but highly significant negative correlation between similarity and distances in the microbial community, in respect of both grass carp intestinal loci distances and the geographical distance between fish sampling sites. Our results also suggest that intestinal bacterial assemblages responded to differences within the external environment and within different parts of the fish themselves. These results show that some, or possibly all, microbes are restricted in their distribution and that environmental factors are also important influences on the structure of intestinal bacterial assemblages. The fish gut microecosystem is useful in promoting study of the spatial distribution patterns of microorganisms.

The intestinal bacteria of vertebrates form a close relationship with their host. External and internal conditions of the host, including its habitat, affect the intestinal bacterial community. Similarly, the intestinal bacterial community can, in turn, influence the host, particularly with respect to disease resistance. We compared the intestinal bacterial communities of grass carp that were collected from farm-ponds or a lake. We conducted denaturing gradient gel electrophoresis of amplified 16S rRNA genes, from which 66 different operational taxonomic units were identified. Using both the unweighted pair-group method with arithmetic means clustering and principal component analysis ordination, we found that the intestinal bacterial communities from the two groups of pond fish were clustered together and inset into the clusters of wild fish, except for DF-7, and there was no significant correlation between genetic diversity of grass carp and their intestinal bacterial communities (Mantel one-tailed test, R=0.157, P=0.175). Cetobacterium appeared more frequently in the intestine of grass carp collected from pond. A more thorough understanding of the role played by intestinal microbiota on fish health would be of considerable benefit to the aquaculture industry.

Metagenomic studies have dramatically expanded our knowledge of the microbial world. Furthermore, the amount of sample for sequencing has significantly increased with the development of high-throughput sequencing technologies. However, fully capturing all DNA sequences carried by every microorganism in the environment is still impossible. Therefore, estimating a reasonable and practical amount for sequencing to achieve the objectives is particularly necessary. In the present study, we introduce a novel method for estimating the required minimum amount for metagenomic sequencing for a given goal. We also calculated the genomic proportion of each operational taxonomic unit and the detection efficiency of a specific gene (we have used SSU rRNA gene as an example) based on a given amount for random metagenomic sequencing. The reasonable and practical estimated amount for sequencing in metagenomic studies will provide good reference information when applying high-throughput sequencing for a given goal.

It is important to assess the effect on zooplankton when perform the environmental protection or restoration technology, especially removing algal blooms, because algae were the major primary producer in algal lakes. The influence on zooplankton community after half a year of algal blooms removed by chitosan-modified soils in Taihu Lake was assessed and the rationality of carrying out the process semiannually was evaluated in the present study. Morphological composition and genetic diversity of zooplankton community were investigated by microscope checkup and polymerase chain reaction-denatured gradient gel electrophoresis (PCR-DGGE). A total of 44 zooplankton taxa (23 protozoa, 17 rotifers, 3 copepoda and 1 cladocera) were detected by microscope checkup, and a total of 91 bands (28 bands amplified by primers F1427-GC and R1616, 63 bands amplified by primers Fung-GC and NS1) were detected by PCR-DGGE. The results of cluster analysis or detrended correspondence analysis indicated that there was no considerable difference in morphological composition of zooplankton and DGGE profiles between experimental and control sites, and DGGE profiles could represent the biologic diversity. The study showed that zooplankton community could recover original condition after half year of algal blooms removed by chitosan-modified soils and it was acceptable to apply this process semiannually. In addition, the results revealed that PCR-DGGE could be applied to investigate the impacts of the environmental protection or restoration engineering on zooplankton community diversity.