Saline and alkaline stresses alter soil properties and composition and structure of gene-based nitrifier and denitrifier communities in a calcareous desert soil.

BACKGROUND: Saline and alkaline stresses damages the health of soil systems. Meanwhile, little is known about how saline or alkaline stress affects soil nitrifier and denitrifier communities. Therefore, we compared the responses of gene-based nitrifier and denitrifier communities to chloride (CS), sulfate (SS), and alkaline (AS) stresses with those in a no-stress control (CK) in pots with a calcareous desert soil. RESULTS: Compared with CK, saline and alkaline stress decreased potential nitrification rate (PNR) and NO3-N; increased pH, salinity, water content, and NH4-N; and decreased copy numbers of amoA-AOA and amoA-AOB genes but increased those of denitrifier nirS and nosZ genes. Copies of nirK increased in SS and AS but decreased in CS. There were more copies of amoA-AOB than of amoA-AOA and of nirS than of nirK or nosZ. Compared with CK, SS and AS decreased operational taxonomic units (OTUs) of amoA-AOB but increased those of nirS and nosZ, whereas CS decreased nirK OTUs but increased those of nosZ. The numbers of OTUs and amoA-AOB genes were greater than those of amoA-AOA. There were positive linear relations between PNR and amoA-AOA and amoA-AOB copies. Compared with CK, the Chao 1 index of amoA-AOA and amoA-AOB decreased in AS, that of nirK increased in CS and SS, but that of nirS and nosZ increased in all treatments. The Shannon index of amoA-AOB decreased but that of nirS increased in CS and SS, whereas the index of nirK decreased in all treatments. Saline and alkaline stress greatly affected the structure of nitrifier and denitrifier communities and decreased potential biomarkers of nirS-type; however, AS increased those of nirK- and nosZ-type, and SS decreased those of nosZ-type. Soil water content, pH, and salinity were important in shaping amoA-AOA and denitrifier communities, whereas soil water and pH were important to amoA-AOB communities. CONCLUSION: These results indicate that the nitrifier and denitrifier communities respond to saline and alkaline stresses conditions. Communities of amoA-AOA and amoA-AOB contribute to nitrification in alluvial gray desert soil, and those of nirS are more important in denitrification than those of nirK or nosZ.

[Effect of vasoactive intestinal peptide on defecation and VIP-cAMP-PKA-AQP3 signaling pathway in rats with constipation].

OBJECTIVE: To observe the effect of vasoactive intestinal peptide (VIP) on the metabolism of intestinal fluid and cyclic AMP protein kinase A signaling pathway (cAMP-PKA) and water channel protein 3 (AQP3) in rats with constipation, and to explore the mechanism of VIP in the treatment of constipation.
 Methods: A total of 45 healthy adult rats were randomly divided into a control group, a model group, a model +VIP group. After 4 weeks of VIP treatment, the first black stool time were examined with the ink gastric method; the water content in feces was calculated; the morphological changes in colonic tissues were observed by HE staining. The expression of VIP and AQP3 protein levels in colon tissues were detected by Western blot; and the cAMP, PKA, AQP3 mRNA expression levels were detected by quantitative real time polymerase chain reaction (qPCR). 
 Results: Compared with the control group, the first black stool time was prolonged, the water content of fecal decreased significantly (both P<0.01); part of the colon mucosa epithelial cells were destructed; the goblet cell volume decreased and quantity was reduced; the contents of AQP3 and VIP in colon tissues were significantly decreased, and the cAMP, PKA and AQP3 mRNA levels were decreased in the model group (all P<0.05). Compared with the model group, the first black stool time in the model +VIP group was shortened, the fecal water content increased significantly (both P<0.05); the mucosal epithelium integrity improved, the number of goblet cells increased; the content of AQP3 and VIP in colon tissues was increased, and the cAMP, PKA, and AQP3 mRNA levels were elevated (all P<0.05).
 Conclusion: Intravenous injection of VIP can regulate intestinal fluid metabolism and improve the symptoms of constipation in rats, which might be related to the regulation of VIP-cAMP-PKA-AQP3 signaling pathway.

A rhoptry protein, localizing in the bulb region of rhoptries, could induce protective immunity against Eimeria tenella infection.

Background: Rhoptry organelle proteins (ROPs) secreted by apicomplexan parasites play important roles during parasites invasion and survival in host cells, and are potential vaccine candidates against apicomplexan diseases. Eimeria tenella (E. tenella) is one of the most noteworthy apicomplexan species, which causes hemorrhagic pathologies. Although dozens of putative E. tenella ROP sequences are annotated, most ROP proteins are not well studied. Methods: In this study, an E. tenella ROP21 gene was identified and the recombinant EtROP21 protein (rEtROP21) was expressed in Escherichia coli. The developmental expression levels, localization, and protective efficacy against E. tenella infection in chickens were studied. Results: An EtROP21 gene fragment with an open reading frame (ORF) of 981 bp was obtained from the Beijing strain of E. tenella. The rEtROP21 has a molecular weight of approximately 50 kDa and was recognized by rEtROP21-immunized mouse serum. Two specific protein bands, about 43 KDa and 95 KDa in size, were detected in the whole sporozoite proteins using the rEtROP21-immunized chicken serum. RT-qPCR analysis of the E. tenella ROP21 gene (EtROP21) revealed that its mRNA levels were higher in merozoites and sporozoites than in sporulated and unsporulated oocysts. Immunofluorescence and immunoelectron analyses showed that the EtROP21 protein predominantly localizes in the bulb region of rhoptries distributed at anterior, posterior, and perinuclear regions of E. tenella sporozoites. Immunization and challenge experiments revealed that immunizing chickens with rEtROP21 significantly increased their average body weight gain while decreasing mean lesion score and oocyst output (P <0.05). When compared with the challenged control group, the rEtROP21-immunized group was associated with a significantly higher relative weight gain (90.2%) and a greater reduction in oocyst output (67%) (P <0.05). The anticoccidial index of the rEtROP21-immunized group was 163.2. Chicken serum ELISA revealed that the levels of the specific anti- rEtROP21 antibody, IFN-γ, and IL-4 were significantly higher in the rEtROP21-immunized group than in the challenged control group (P <0.05). Conclusion: These results indicate that rEtROP21 can induce a high level of specific immune response and it is a potential candidate for the development of vaccines against E. tenella infection in chickens.

[Effects of Cotton Stalk Returning on Soil Enzyme Activity and Bacterial Community Structure Diversity in Cotton Field with Long-term Saline Water Irrigation].

Long-term saline water irrigation will increase soil salinity, adversely affect soil physical and chemical properties, and change the diversity of soil bacteria. Straw returning can improve the soil microenvironment and subsequently affect soil enzyme activity and bacterial community structure diversity. This experiment used two types of irrigation water salinity:fresh water (FW, 0.35 dS·m-1) and saline water (SW, 8.04 dS·m-1). Under each irrigation water salinity, the amount of cotton straw applied was 0 and 6000 kg·hm-2 (represented by FWST and SWST, respectively). The results showed that:compared with those under fresh water irrigation, saline water irrigation significantly increased the soil salt, bulk density, total carbon, and available phosphorus but significantly decreased available potassium content. Under saline water irrigation, straw returning significantly increased the soil total carbon, total nitrogen, available potassium, and available phosphorus but reduced soil bulk density. Compared with those under fresh water irrigation, soil sucrase, alkaline phosphatase, and catalase activities under saline water irrigation decreased by 57.24%, 35.15%, and 3.91%, respectively, whereas urease activity increased by 26.73%. However, straw returning significantly increased sucrase, alkaline phosphatase, and catalase activities but decreased urease activity. Saline water irrigation decreased the relative abundance of Acidobacteriota, Actinobacteriota, Bacteroidota, Verrucomicrobiota, and Firmicutes and increased the abundance of Gemmatimonadota and Myxococcota. Under saline water irrigation, straw returning significantly increased the relative abundance of Actinobacteriota, Bacteroidetes, Firmicutes, Crenarchaeota, Sphingomonas, Dongia, and Steroidobacter. NMDS results also showed that saline water irrigation and straw returning changed the bacterial community structure. In conclusion, straw returning can improve soil nutrient content, reduce soil bulk density and salinity, and then change soil enzyme activity and bacterial community structure diversity. The change in soil bacterial community composition was mainly affected by soil salinity and bulk density. Therefore, straw returning can improve soil fertility and help maintain the health of soil ecosystem. This study revealed a relationship between soil enzyme activities and bacterial communities, which provides a theoretical basis and mechanism for applying cotton stalk to regulate the soil enzyme and micro-ecological environment.

An Investigation of the Relationship between Cyniclomyces guttulatus and Rabbit Diarrhoea.

Cyniclomyces guttulatus is usually recognised as an inhabitant of the gastrointestinal (GI) tract in rabbits. However, large numbers of C. guttulatus are often detected in the faeces of diarrhoeic rabbits. The relationship of C. guttulatus with rabbit diarrhoea needs to be clearly identified. In this study, a C. guttulatus Zhejiang strain was isolated from a New Zealand White rabbit with severe diarrhoea and then inoculated into SPF New Zealand white rabbits alone or co-inoculated with Eimeriaintestinalis, another kind of pathogen in rabbits. Our results showed that the optimal culture medium pH and temperature for this yeast were pH 4.5 and 40-42 °C, respectively. The sequence lengths of the 18S and 26S ribosomal DNA fragments were 1559 bp and 632 bp, respectively, and showed 99.8% homology with the 18S ribosomal sequence of the NRRL Y-17561 isolate from dogs and 100% homology with the 26S ribosomal sequence of DPA-CGR1 and CGDPA-GP1 isolates from rabbits and guinea pigs, respectively. In animal experiments, the C. guttulatus Zhejiang strain was not pathogenic to healthy rabbits, even when 1 × 108 vegetative cells were used per rabbit. Surprisingly, rabbits inoculated with yeast showed a slightly better body weight gain and higher food intake. However, SPF rabbits co-inoculated with C. guttulatus and E. intestinalis developed more severe coccidiosis than rabbits inoculated with C. guttulatus or E. intestinalis alone. In addition, we surveyed the prevalence of C. guttulatus in rabbits and found that the positive rate was 83% in Zhejiang Province. In summary, the results indicated that C. guttulatus alone is not pathogenic to healthy rabbits, although might be an opportunistic pathogen when the digestive tract is damaged by other pathogens, such as coccidia.

trans-Cinnamaldehyde Reverses Depressive-Like Behaviors in Chronic Unpredictable Mild Stress Rats by Inhibiting NF-κB/NLRP3 Inflammasome Pathway.

trans-Cinnamaldehyde (TCA) is the main active component extracted from Cinnamomum cassia (C. cassia), which has many pharmacological effects, such as anti-inflammation, lowering blood glucose, and improving nerve function. However, there is no report of TCA in the treatment of depression. The purpose of this study was to investigate the antidepressant-like effect of TCA and the mechanism of NF kappa B (NF-κB) pathway and NLRP3 inflammasome inhibition by TCA. We divided 40 rats into the control group, CUMS group, FLU group, and the TCA group. The activation of the NF-κB pathway and NLRP3 inflammasome in prefrontal cortex and hippocampus of rats in each group was observed. After the treatments with FLU and TCA, the sucrose consumptions in rats increased significantly and the immobility time in forced swimming was decreased significantly compared to the CUMS group. The expression of TLR4, NF-κB-1, p-p65, TNF-α, NLRP3, ASC, caspase-1, IL-1ß, and IL-18 proteins in prefrontal cortex and hippocampus was decreased, and the expression of IL-1ß, IL-18, and TNF-α in serum was downregulated compared to the CUMS group. Similar to FLU, TCA reverses the depression-like behaviors in rats, which indicates that TCA has a significant antidepressant-like effect. The mechanism of the antidepressant property of TCA might be that it inhibits the activation of the NF-κB pathway and NLRP3 inflammasome in the prefrontal cortex and hippocampus of CUMS rats.

Interaction between heat shock protein 72 and alpha-fetoprotein in human hepatocellular carcinomas.

BACKGROUND: AFP in adult serum often signals pathological conditions, particularly the presence of hepatocellular carcinoma (HCC) and germ cell tumors containing yolk sac cell elements. Heat shock protein 72 (HSP72) as a molecular chaperone has been confirmed to overexpress in epithelial carcinoma cells. There may be a possible correlation between the expression of HSP72 and AFP during the growth and differentiation of hepatocellular carcinoma cells. We investigated the interaction between heat shock protein 72 (HSP72) and alpha-fetoprotein (AFP) in human hepatocellular carcinomas. METHODS: The expression and localization of HSP72 and AFP in human hepatocellular carcinomas were determined by immunohistochemistry and confocal laser microscopy. The interaction between HSP72 and AFP in hepatocellular carcinoma cells was analyzed by immunoprecipitation and Western immunoblots. RESULTS: Hepatocellular carcinoma synchronously co-expressed higher level of HSP72 and AFP than in adjacent normal liver tissues. HSP72 were stained in cell nuclei and cytoplasm respectively, while AFP stained in cell plasma. Based on Western blotting methods, AFP was detected in the immunoprecipitate of anti-HSP72 monoclonal antibody (mAb), while HSP72 existed in the immunoprecipitate of anti-AFP mAb. CONCLUSIONS: HSP72 and AFP expression are higher in hepatocellular carcinoma tissues. HSP72 was associated with alpha-fetoprotein in human hepatocellular carcinoma cells. The interaction between HSP72 and AFP in human hepatocellular carcinoma cells can be a new route for studying the pathogenesis and immunotherapy of hepatocellular carcinoma.

Complex formation between heat shock protein 72 and hepatitis B virus X protein in hepatocellular carcinoma tissues.

Hepatitis B virus (HBV) infection is a major factor contributing to the development of hepatocellular carcinoma (HCC) in the world. Hepatitis B virus X protein (HBx) has been verified to play an important role in hepatocarcinogenesis. Heat shock protein 72 (HSP72) as a molecular chaperone has been confirmed to overexpress in epithelial carcinoma cells. There may be a possible association between the expression of HSP72 and HBx during the growth and progression of hepatocellular carcinoma cells. The aim of the study was to investigate the relationship between heat shock protein 72 and HBx in human hepatocellular carcinomas. The localization of HSP72 and HBx in human hepatocellular carcinomas was determined by immunohistochemistry and confocal laser microscopy. The interaction between HSP72 and HBx in liver cancer cells was analyzed by immunoprecipitation and Western blot. Our results revealed that hepatocellular carcinoma synchronously co-expressed higher level of HSP72 and HBx than that in the adjacent tissues to hepatocellular carcinoma. HSP72 and HBx were mainly immunolocalized in the cytoplasm. On the basis of immunoprecipitation and Western blot, we found that HSP72 formed complex with HBx in human hepatocellular carcinoma cells. The association between HSP72 and HBx in human hepatocellular carcinoma cells may contribute to study the pathogenesis and immunotherapy of hepatocellular carcinoma.

[Cold hardiness of Pinus ponderosa, P. banksian and P. tabulaeformis].

By the method of artificial freezing, this paper made a comparative study on the cold hardiness of Pinus ponderosa, P. banksiana and P. tabulaeformis, with their inherent mechanisms approached. The results showed that the cold hardiness of these three species was in the sequence of P. banksiana > P. tabulaeformis > P. ponderosa. P. banksiana had high bound water/free water ratio (7.0) and ABA content (164.3 microg x g(-1) FW) but low K+ (2450 microg x g(-1) DW) and soluble sugar (12.0%) , P. tabulaeformis had higher contents of ABA (95.8 microg x g(-1) FW), K+ (4538 microg x g(-1) DW) and soluble sugar (18.68%) but low bound water/free water ratio (2.58), while P. ponderosa had high soluble sugar content (18.05%) but low bound water/free water ratio (2.18) and K+ (2275 microg x g(-1) DW) and ABA (63.3 microg x g(-1) FW) contents. These differences might be the reasons resulting in the different cold hardiness of these three species. Low chlorophyll content and high carotenoid/chlorophyll ratio might also contribute to the cold hardiness of P. banksiana. Therefore, though the test species are all of cold hardiness, their inherent mechanisms may be different.