Management Letter, Year Ended June 30, 1999

The intestinal microbiome is essential in humans to maintain physiological balance and nutrition metabolism. Laparoscopic cholecystectomy due to gallstone disease and cholecystitis can cause intestinal microbial dysbiosis, and following bile acid metabolism dysfunction, positions the patient at high risk of colorectal cancer. However, little is known regarding intestinal microbiota characteristics in post-cholecystectomy patients. Here, we compared the microbial composition of cholecystectomy patients with that of a healthy population. We determined that cholecystectomy eliminated aging-associated fecal commensal microbiota and further identified several bile acid metabolism-related bacteria as contributors of colorectal cancer incidence via elevation of secondary bile acids.Significance statementWe identified aging-associated fecal microbiota in a healthy population, which was lost in cholecystectomy patients. Absent intestinal bacteria, such as Bacteroides, were negatively related to secondary bile acids and may be a leading cause of colorectal cancer incidence in cholecystectomy patients. Our study provides novel insight into the connection between cholecystectomy-altered gut microbiota and colorectal carcinoma, which is of value for colorectal cancer diagnosis and management

Anti-hepatotoxic and anti-oxidant effects of extracts from Piper nigrum L. root

The aim of this study was to investigate the effect of Piper nigrum L. root extracts on carbon tetrachloride (CCl4)-induced rat liver injury. Among the three different extracts (water, ethanol and chloroform extract), ethanol extract exhibits the highest hepatoprotective activity (p < 0.05). When using the ethanol extract at a dose of 120 mg/ kg to treat the CCl4-intoxicated rat, the activities of alanine transaminase (ALT) and aspartate transanimase (AST) in rat serum decreased to 65.7 and 84.5%, respectively. At the same time, the lipid peroxidation (MDA) decreased to 52.3% and glutathione (GSH) increased to 55.8% in the rats liver homogenate, as compared with those of the CCl4 positive control rats. The hepatoprotective effect of ethanol extract was also supported by the histopathological observations. Moreover, the ethanol extract was studied for its in vitro antioxidant activity using the methods of ferric thiocyanate (FTC) and thiobarbituric acid (TBA). The findings indicate that the ethanol extract of P. nigrum L. root is an efficient hepatoprotective and antioxidant agent against CCl4-induced liver injury.Keywords: Piper nigrum L. root, ethanol extract, carbon tetrachloride (CCl4), hepatoprotective, antioxidan

Rice lipid transfer protein, OsLTPL23, controls seed germination by regulating starch-sugar conversion and ABA homeostasis

Seed germination is vital for ensuring the continuity of life in spermatophyte. High-quality seed germination usually represents good seedling establishment and plant production. Here, we identified OsLTPL23, a putative rice non-specific lipid transport protein, as an important regulator responsible for seed germination. Subcellular localization analysis confirmed that OsLTPL23 is present in the plasma membrane and nucleus. The knockout mutants of OsLTPL23 were generated by CRISPR/Cas9-mediated genome editing, and osltpl23 lines significantly germinated slower and lower than the Nipponbare (NIP). Starch and soluble sugar contents measurement showed that OsLTPL23 may have alpha-amylase inhibitor activity, and high soluble sugar content may be a causal agent for the delayed seed germination of osltpl23 mutants. Transcript profiles in the germinating seeds exhibited that the abscisic acid (ABA)-responsive genes, OsABI3 and OsABI5, and biosynthesis genes, OsNCED1, OsNCED2, OsNCED3 and OsNCED4, are obviously upregulated in the osltpl23 mutants compared to NIP plants, conversely, ABA metabolism genes OsABA8ox1, OsABA8ox2 and OsABA8ox3 are stepwise decreased. Further investigations found that osltpl23 mutants displays weakened early seedling growth, with elevated gene expresssion of ABA catabolism genes and repressive transcription response of defence-related genes OsWRKY45, OsEiN3, OsPR1a, OsPR1b and OsNPR1. Integrated analysis indicated that OsLTPL23 may exert an favorable effect on rice seed germination and early seedling growth via modulating endogenous ABA homeostasis. Collectively, our study provides important insights into the roles of OsLTPL23-mediated carbohydrate conversion and endogenous ABA pathway on seed germination and early seedling growth, which contributes to high-vigor seed production in rice breeding

Transient receptor potential channel 1 deficiency impairs host defense and proinflammatory responses to bacterial infection by regulating protein kinase Cα signaling

Transient receptor potential channel 1 (TRPC1) is a nonselective cation channel that is required for Ca2+ homeostasis necessary for cellular functions. However, whether TRPC1 is involved in infectious disease remains unknown. Here, we report a novel function for TRPC1 in host defense against Gram-negative bacteria. TRPC1-/- mice exhibited decreased survival, severe lung injury, and systemic bacterial dissemination upon infection. Furthermore, silencing of TRPC1 showed decreased Ca2+ entry, reduced proinflammatory cytokines, and lowered bacterial clearance. Importantly, TRPC1 functioned as an endogenous Ca2+ entry channel critical for proinflammatory cytokine production in both alveolar macrophages and epithelial cells. We further identified that bacterium-mediated activation of TRPC1 was dependent on Toll-like receptor 4 (TLR4), which induced endoplasmic reticulum (ER) store depletion. After activation of phospholipase Cγ (PLC-γ), TRPC1 mediated Ca2+ entry and triggered protein kinase Cα (PKC-α) activity to facilitate nuclear translocation of NF-kB/Jun N-terminal protein kinase (JNK) and augment the proinflammatory response, leading to tissue damage and eventually mortality. These findings reveal that TRPC1 is required for host defense against bacterial infections through the TLR4-TRPC1-PKCγ signaling circuit.Fil: Zhou, Xikun. University Of North Dakota; Estados Unidos. West China Hospital Of Sichuan University; ChinaFil: Ye, Yan. University Of North Dakota; Estados UnidosFil: Sun, Yuyang. University Of North Dakota; Estados UnidosFil: Li, Xuefeng. West China Hospital Of Sichuan University; China. University Of North Dakota; Estados UnidosFil: Wang, Wenxue. University Of North Dakota; Estados UnidosFil: Privratsky, Breanna. University Of North Dakota; Estados UnidosFil: Tan, Shirui. University Of North Dakota; Estados UnidosFil: Zhou, Zongguang. West China Hospital Of Sichuan University; ChinaFil: Huang, Canhua. West China Hospital Of Sichuan University; ChinaFil: Wei, Yu-Quan. West China Hospital Of Sichuan University; ChinaFil: Birnbaumer, Lutz. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. National Institute Of Environmental Health Sciences; Estados UnidosFil: Singh, Brij B.. University Of North Dakota; Estados UnidosFil: Wu, Min. University Of North Dakota; Estados Unido

in KKAy mice

and mechanisms of resveratrol on the amelioration of oxidative stress and hepatic steatosi

Generalist taxa shape fungal community structure in cropping ecosystems

Fungi regulate nutrient cycling, decomposition, symbiosis, and pathogenicity in cropland soils. However, the relative importance of generalist and specialist taxa in structuring soil fungal community remains largely unresolved. We hypothesized that generalist fungi, which are adaptable to various environmental conditions, could potentially dominate the community and become the basis for fungal coexisting networks in cropping systems. In this study, we identified the generalist and habitat specialist fungi in cropland soils across a 2,200 kms environmental gradient, including three bioclimatic regions (subtropical, warm temperate, and temperate). A few fungal taxa in our database were classified as generalist taxa (~1%). These generalists accounted for >35% of the relative abundance of all fungal populations, and most of them are Ascomycota and potentially pathotrophic. Compared to the specialist taxa (5–17% of all phylotypes in three regions), generalists had a higher degree of connectivity and were often identified as hub within the network. Structural equation modeling provided further evidence that after accounting for spatial and climatic/ edaphic factors, generalists had larger contributions to the fungal coexistence pattern than habitat specialists. Taken together, our study provided evidence that generalist taxa are crucial components for fungal community structure. The knowledge of generalists can provide important implication for understanding the ecological preference of fungal groups in cropland systems

Characterization of Fungal nirK-Containing Communities and N2O Emission From Fungal Denitrification in Arable Soils

Fungal denitrifiers play important roles in soil nitrogen cycling, but we have very limited knowledge about their distribution and functions in ecosystems. In this study, three types of arable soils were collected across different climate zones in China, including quaternary red clay soils, alluvial soils, and black soils. The composition and abundance of fungal nirK-containing denitrifiers was determined by MiSeq high-throughput sequencing and qPCR, respectively. Furthermore, a substrate-induced inhibition approach was used to explore N2O emissions from fungal denitrification. The results showed that the arable soils contained a wide range of nirK-containing fungal denitrifiers, with four orders and eight genera. Additionally, approximately 57.30% of operational taxonomic unit (OTUs) belonged to unclassified nirK-containing fungi. Hypocreales was the most predominant order, with approximately 40.51% of the total number of OTUs, followed by Sordariales, Eurotiales, and Mucorales. It was further indicated that 53% of fungal nirK OTUs were shared by the three types of soils (common), and this group of fungi comprised about 98% of the total relative abundance of the nirK-containing population, indicating that the distribution of fungal nirK-containing denitrifiers was quite homogenous among the soil types. These common OTUs were determined by multiple soil characteristics, while the composition of unique OTUs was manipulated by the specific properties of each soil type. Furthermore, fungal N2O emissions were significantly and positively correlated with fungal nirK abundance in the soils, whereas it was not clearly related to fungal nirK compositions. In conclusion, although the arable soils hosted diverse nirK-containing fungal denitrifiers, fungal nirK compositions were highly homogenous among the soil types, which could be a consequence of enduring agricultural practices. The abundance of fungal nirK-containing denitrifiers, rather than their composition, may play more significant roles in relation to N2O emission from fungal denitrification

Effects of bisphenol A exposure at different circadian time on hepatic lipid metabolism in mice

BackgroundLipid metabolism in liver shows circadian-dependent profiles. The hepatotoxicity of environmental chemicals is dependent on circadian time. ObjectiveTo observe the effects of bisphenol A (BPA) exposure at different zeitgeber time (ZT) on hepatic and blood lipid metabolism and decipher the underlying mechanisms related to circadian rhythm in mice. MethodsThirty-five female C57BL/6J mice were sacrificed every 4 h in a light-dark cycle (12 h/12 h). The liver tissues were collected to describe the circadian profiles of hepatic Rev-erba, Bmal1, Clock, Srebp1c, and Chrebp mRNA expression levels within 24 h. Thirty female mice were divided into 6 groups by the timing (ZT3 represents the 3 h after light on, ZT15 represents the 3 h after light off) and dose (50 or 500 μg·kg−1·d−1) of BPA exposure to observe hepatotoxicity. Mice were gavaged with designed doses of BPA once per day for 4 weeks. Mice were maintained with ad libitum access to food and water and measured body weight weekly. After the experiment, mice were euthanatized and liver tissues were separated to determine the biochemical indicators of lipid metabolism and lipid metabolism- and circadian-related gene mRNA expressions. ResultsHepatic Rev-erba, Bmal1, Clock, Srebp1c, and Chrebp mRNA expression levels were rhythmic during a 24 h period in mice. At ZT3 and ZT15, BPA did not alter body weight, plasma glucose, plasma total cholesterol, plasma low density lipoprotein cholesterol, and plasma triglycerides (P>0.05). The plasma high density lipoprotein cholesterol decreased in the 50 μg·kg−1·d−1 BPA group at ZT3 by 14.56% compared with the control group (P<0.05). The liver triglycerides increased in the 50 μg·kg−1·d−1 BPA group at ZT15 by 115.20% compared with the control group (P<0.05). BPA decreased Srebp1c mRNA expression level when dosing at ZT3 and increased Chrebp, Srebp1c, and Acc1 mRNA expression levels when dosing at ZT15 compared with the control group (P<0.05). BPA increased Bmal1 mRNA expression level and decreased Rev-erbα mRNA expression level at ZT3 exposure and decreased Bmal1 and increased Rev-erbα mRNA expression level at ZT15 exposure (P<0.05). ConclusionBPA exposure at light or dark period has different effects on hepatic lipid metabolism in mice. Hepatic lipid deposit appears when BPA is dosed at dark period. Rev-erbα-Bmal1 regulation circuits and the subsequent upregulation of Srebp1c and Chrebp and the target gene Acc1 may be involved