Disease-induced changes in bacterial and fungal communities from plant below- and aboveground compartments.

The plant microbes are an integral part of the host and play fundamental roles in plant growth and health. There is evidence indicating that plants have the ability to attract beneficial microorganisms through their roots in order to defend against pathogens. However, the mechanisms of plant microbial community assembly from below- to aboveground compartments under pathogen infection remain unclear. In this study, we investigated the bacterial and fungal communities in bulk soil, rhizosphere soil, root, stem, and leaf of both healthy and infected (Potato virus Y disease, PVY) plants. The results indicated that bacterial and fungal communities showed different recruitment strategies in plant organs. The number and abundance of shared bacterial ASVs between bulk and rhizosphere soils decreased with ascending migration from below- to aboveground compartments, while the number and abundance of fungal ASVs showed no obvious changes. Field type, plant compartments, and PVY infection all affected the diversity and structures of microbial community, with stronger effects observed in the bacterial community than the fungal community. Furthermore, PVY infection, rhizosphere soil pH, and water content (WC) contributed more to the assembly of the bacterial community than the fungal community. The analysis of microbial networks revealed that the bacterial communities were more sensitive to PVY infection than the fungal communities, as evidenced by the lower network stability of the bacterial community, which was characterized by a higher proportion of positive edges. PVY infection further increased the bacterial network stability and decreased the fungal network stability. These findings advance our understanding of how microbes respond to pathogen infections and provide a rationale and theoretical basis for biocontrol technology in promoting sustainable agriculture. KEY POINTS: • Different recruitment strategies between plant bacterial and fungal communities. • Bacterial community was more sensitive to PVY infection than fungal community. • pH and WC drove the microbial community assembly under PVY infection.

Rhizosphere microbial community enrichment processes in healthy and diseased plants: implications of soil properties on biomarkers.

Plant health states may influence the distribution of rhizosphere microorganisms, which regulate plant growth and development. In this study, the response of rhizosphere bacteria and fungi of healthy and diseased plants compared to bulk microbes was analyzed using high-throughput sequencing. Plant adaptation strategies of plants under potato virus Y (PVY) infection have been studied from a microbial perspective. The diversity and community structure of bacteria and fungi varied between bulk and rhizosphere soils, but not between healthy and diseased rhizosphere soils. A LEfSe analysis revealed the significant differences between different treatments on bacterial and fungal community compositions and identified Roseiflexaceae, Sphingomonas, and Sphingobium as the bacterial biomarkers of bulk (BCK), healthy rhizosphere (BHS), and diseased rhizosphere (BIS) soils, respectively; Rhodotorula and Ascomycota_unidentified_1_1 were identified as the fungal biomarkers of bulk (FCK) and healthy rhizosphere (FHS) soils. Bacterial networks were found to be more complex and compact than fungal networks and revealed the roles of biomarkers as network keystone taxa. PVY infection further increased the connectedness among microbial taxa to improve rhizosphere microbial community stability and resistance to environmental stress. Additionally, water content (WC) played an apparent influence on bacterial community structure and diversity, and pH showed significant effects on fungal community diversity. WC and pH greatly affected the biomarkers of bacterial rhizosphere communities, whereas the biomarkers of bulk bacterial communities were significantly affected by soil nutrients, especially for Sphingobium. Overall, the rhizosphere microbial community enrichment processes were different between healthy and diseased plants by changing the community compositions and identifying different biomarkers. These findings provide insight into the assemblage of rhizosphere microbial communities and soil physicochemical properties, which contributes to a deeper understanding of the establishment of an artificial core root microbiota to facilitate plant growth and bolstering resistance mechanisms. This knowledge contributes to a deeper understanding of the establishment of an artificial core root microbiota, thereby facilitating plant growth and bolstering resistance mechanisms.

Herb pair of Rhubarb-Astragalus mitigates renal interstitial fibrosis through downregulation of autophagy via p38-MAPK/TGF-ß1 and p38-MAPK/smad2/3 pathways.

BACKGROUND: Chronic kidney disease (CKD) has a high incidence and poor prognosis; however, no effective treatment is currently available. Our previous study found that the improvement effect of the herb pair of Rhubarb-Astragalus on CKD is likely related to the inhibition of the TGF-ß1/p38-MAPK pathway. In the present study, a p38-MAPK inhibitor was used to further investigate the inhibitory effect of Rhubarb-Astragalus on the TGF-ß1/p38-MAPK pathway and its relationship with autophagy. METHODS: A rat model of unilateral ureteral obstruction (UUO) was established, and a subgroup of rats was administered Rhubarb-Astragalus. Renal function and renal interstitial fibrosis (RIF) were assessed 21 d after UUO induction. In vitro, HK-2 cells were treated with TGF-ß1 and a subset of cells were treated with Rhubarb-Astragalus or p38-MAPK inhibitor. Western blotting, immunohistochemistry, and qRT-PCR analyses were used to detect the relevant protein and mRNA levels. Transmission electron microscopy was used to observe autophagosomes. RESULTS: Rhubarb-Astragalus treatment markedly decreased the elevated levels of blood urea nitrogen, serum creatinine, and urinary N-acetyl-ß-D-glucosaminidase; attenuated renal damage and RIF induced by UUO; and reduced the number of autophagosomes and lysosomes in UUO-induced renal tissues. Additionally, Rhubarb-Astragalus reduced the protein and mRNA levels of α-SMA, collagen I, LC3, Atg3, TGF-ß1, p38-MAPK, smad2/3, and TAK1 in renal tissues of UUO rats. Rhubarb-Astragalus also reduced protein and mRNA levels of these indicators in vitro. Importantly, the effect of the p38-MAPK inhibitor was similar to that of Rhubarb-Astragalus. CONCLUSIONS: Rhubarb-Astragalus improves CKD possibly by downregulating autophagy via the p38-MAPK/TGF-ß1 and p38-MAPK/smad2/3 pathways.

Enhancing nitrogen removal efficiency and anammox metabolism in microbial electrolysis cell coupled anammox through different voltage application.

The slow growth and difficulty in cultivating anammox bacteria limit the rapid start-up of anammox process and effective microbial enrichment. In this study, microbial electrolysis cell (MEC) was coupled with anammox to investigate the effects of different applying voltage methods on substrate removal efficiency and rates, microbial community structure, anammox metabolism and metabolic pathways. The results showed that applying voltage not only improved NH4+-N removal efficiency and removal rates, but also promoted electron transfer efficiency, key enzyme activity and extracellular polymeric substances (EPS) secretion in the systems. Step-up voltage was more conducive to the growth of Candidatus_Kuenenia in the cathode, which promoted the rapid start-up of anammox and treating wastewater with low ammonia concentration. The main metabolic pathway in step-up voltage operation was hydrazine to nitrogen, while in constant voltage operation was hydroxylamine oxidation pathway. These findings provided a new insight into the enhancement and operation of anammox system.

Ginkgo biloba extract attenuates cisplatin-induced renal interstitial fibrosis by inhibiting the activation of renal fibroblasts through down-regulating the HIF-1α/STAT3/IL-6 pathway in renal tubular epithelial cells.

BACKGROUND: Activation of renal fibroblasts into myofibroblasts plays an important role in promoting renal interstitial fibrosis (RIF). Ginkgo biloba extract (EGb) can alleviate RIF induced by cisplatin (CDDP). PURPOSE: To elucidate the effect of EGb treatment on cisplatin-induced RIF and reveal its potential mechanism. METHODS: The two main active components in EGb were determined by high-performance liquid chromatography (HPLC) analysis. Rats were induced by CDDP and then treated with EGb, 2ME2 (HIF-1α inhibitor) or amifostine. After HK-2 cells and HIF-1α siRNA HK-2 cells were treated with CDDP, EGb or amifostine, the conditioned medium from each group was cultured with NRK-49F cells. The renal function of rats was detected. The renal damage and fibrosis were evaluated by H&E and Masson trichrome staining. The IL-6 content in the cell medium was detected by ELISA. The expression levels of indicators related to renal fibrosis and signaling pathway were examined by western blotting and qRT-PCR. RESULTS: HPLC analysis showed that the contents of quercetin and kaempferol in EGb were 36.0 µg/ml and 45.7 µg/ml, respectively. In vivo, EGb and 2ME2 alleviated renal damage and fibrosis, as well as significantly decreased the levels of α-SMA, HIF-1α, STAT3 and IL-6 in rat tissues induced by CDDP. In vitro, the levels of HIF-1α, STAT3 and IL-6 were significantly increased in HK-2 cells and HIF-1α siRNA HK-2 cells induced by CDDP. Notably, HIF-1α siRNA significantly decreased the levels of HIF-1α, STAT3 and IL-6 in HK-2 cells, as well as the IL-6 level in medium from HK-2 cells. Additionally, the α-SMA level in NRK-49F cells was significantly increased after being cultured with conditioned medium from HK-2 cells or HIF-1α siRNA HK-2 cells exposed to CDDP. Furthermore, exogenous IL-6 increased the α-SMA level in NRK-49F cells. Importantly, the expression levels of the above-mentioned indicators were significantly decreased after the HK-2 cells and HIF-1α siRNA HK-2 cells were treated with EGb. CONCLUSION: This study revealed that EGb improves CDDP-induced RIF, and the mechanism may be related to its inhibition of the renal fibroblast activation by down-regulating the HIF-1α/STAT3/IL-6 pathway in renal tubular epithelial cells.

Supporting routine cognitive reactivity assessment during the perinatal period: psychometric testing of the Chinese version of the Leiden Index of Depression Sensitivity.

BACKGROUND: It is critical to find optimal forms to identify perinatal depression (PND) and its vulnerable factors and make them more applicable to depression screening. This study aims to evaluate the reliability and validity of the Chinese version of the Leiden Index of Depression Sensitivity (LEIDS-RR-CV) among perinatal women in China and determine the cut-off values for screening for high-risk depression. METHODS: Women in their third trimester of pregnancy and six weeks postpartum completed the LEIDS-RR-CV and a diagnostic reference standard online. We assessed the LEIDS-RR-CV using classical test theory (CTT) and item response theory (IRT). We also assessed the test performance for cut-off scores using receiver operator characteristic analysis to further screen for high-risk depression at each time point. RESULTS: In total, 396 (third trimester) and 321 (six weeks postpartum) women participated. Cronbach's alpha, two-week test-retest reliability, and marginal reliability for the scale were all greater than 0.8. It showed a five-factor model; the cut-off values were 58 (third trimester) and 60 (six weeks postpartum). The areas under the curve were acceptable (≥ 0.7), and the LEIDS-RR-CV was positively correlated with the total Edinburgh Postnatal Depression Scale (EPDS) score (r = 0.52 and 0.56, p = 0.00), indicating its predictive validity. An IRT analysis further confirmed its discriminative validity. CONCLUSIONS: The LEIDS-RR-CV was found to be reliable, valid, and can be used to quantify cognitive reactivity among perinatal Chinese women and for screening for high-risk depression during this period.

Ginkgo biloba leaf extract mitigates cisplatin-induced chronic renal interstitial fibrosis by inhibiting the epithelial-mesenchymal transition of renal tubular epithelial cells mediated by the Smad3/TGF-ß1 and Smad3/p38 MAPK pathways.

BACKGROUND: Our previous study indicated that Ginkgo biloba leaf extract (EGb) could protect against cisplatin-induced acute kidney injury in rabbits. The present study aimed to determine the effects and potential molecular mechanisms of EGb on chronic renal interstitial fibrosis induced by cisplatin using in vivo and in vitro models. METHODS: Rats received a single dose of cisplatin on Day 1, and a subset of rats was intraperitoneally injected with EGb daily between Days 22-40. In vitro, HK-2 cells were treated with cisplatin, and a subset of cells was cultivated with EGb or SIS3 (Smad3 inhibitor) for 48 h. Renal function of rats was assessed by detecting the levels of serum creatinine (Scr), blood urea nitrogen (BUN) and urinary N-acetyl-ß-D-glucosaminidase (NAG). Hematoxylin and eosin staining and Masson's trichrome staining were used to evaluate the damage and fibrosis of renal tissue. Western blotting, immunohistochemistry and immunofluorescence were used to detect the protein levels of fibrosis-associated proteins and signaling pathway-related proteins. RT-qPCR analysis was used to examine the mRNA levels of related indicators. RESULTS: EGb significantly decreased the increased levels of Scr, BUN and urinary NAG and attenuated renal damage and the relative area of renal interstitial fibrosis induced by cisplatin. Additionally, EGb decreased the protein levels of α-SMA, Col I, TGF-ß1, smad2/3, phosphorylated (p)-smad2/3, p38 MAPK, and p-p38 MAPK; the ratio of p-p38 MAPK/p38 MAPK; and the mRNA level of p38 MAPK in renal tissues induced by cisplatin. In agreement with in vivo studies, EGb significantly reduced the increased protein levels of these indicators. Additionally, EGb significantly reduced the increased protein levels of vimentin, TIMP-1, and CTGF, as well as the mRNA levels of α-SMA, vimentin, and TGF-ß1, while it significantly increased the reduced E-cadherin protein level and the MMP-1/TIMP-1 ratio in HK-2 cells induced by cisplatin. It's worth noting that the effects of SIS3 in changing the above indicators were similar to those of EGb. CONCLUSION: Our study demonstrated that EGb improved cisplatin-induced chronic renal interstitial fibrosis, and its mechanisms were associated with inhibiting the epithelial-mesenchymal transition of renal tubular epithelial cells via the Smad3/TGF-ß1 and Smad3/p38 MAPK pathways.

Panax notoginseng saponins reduces the cisplatin-induced acute renal injury by increasing HIF-1α/BNIP3 to inhibit mitochondrial apoptosis pathway.

Cisplatin (CDDP) may induce apoptosis of renal tubular epithelial cells (RTEC) and cause CDDP-induced acute kidney injury (CAKI) during cancer treatment, but yet lack of preventive measures and effective treatment. As a new Chinese herbal preparation, Panax notoginseng saponins (PNS) has been found to mitigate CDDP-induced CAKI through elevating the expression of HIF-1α in the rat model, according to the data from our previous works. However, the underlying link between HIF-1α and apoptosis has not been well elucidated. The current study as a follow-up work, was aimed to reveal if PNS improves CAKI through HIF-1α-dependent apoptosis. A stably HIF-1α-knockdown human proximal tubular epithelial cell (HK-2) line was established by transfecting a HIF-1α-siRNA into HK-2 cells. Cell viability, mitochondrial function, cell apoptosis ratio and the expression of apoptosis-associated proteins (Cyt C, Bcl2, Bax, caspases 3) were determined. In order to elucidate the underlying mechanism, the expression of HIF-1α and BNIP3 were assessed. Our results showed that treatment of PNS rescued the cell viability of CDDP-injured HK-2 or HIF-1α-knockdown HK-2 cells, and increased the expression levels of ATP and MMP in HK-2 or HIF-1α-knockdown HK-2 cells which were reduced by CDDP. Moreover, PNS treatment decreased the CDDP or CDDP plus HIF-1α-knockdown-induced elevation of apoptosis and apoptosis-associated protein expressions. These findings demonstrate that PNS reduces CAKI through increasing HIF-1α to inhibit mitochondrial apoptosis pathway. Hence, we suggest PNS as a protective and therapeutic new drug for CDDP treatment of cancers, which might have significant meaning of further research and application potential.

Drug-containing serum of rhubarb-astragalus capsule inhibits the epithelial-mesenchymal transformation of HK-2 by downregulating TGF-ß1/p38MAPK/Smad2/3 pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Rheum palmatum L; Astragalus membranaceus (Fisch.), is referred to as 'Dahuang, Huangqi' in China. As an important medicinal plant, the rhizome of rhubarb and astragalus is traditionally used in the treatment of kidney diseases associated with renal failure, inflammation and tumors. AIM OF THE STUDY: This study aimed to investigate the effect of a drug-containing serum of rhubarb-astragalus capsules (composed of rhubarb and astragalus) and to elucidate its mechanism in the epithelial-mesenchymal transformation of renal tubular epithelial cells. MATERIALS AND METHODS: Epithelial-mesenchymal transformation (EMT) of HK-2 cells was induced by TGF-ß1, and rhubarb-astragalus and losartan drug-containing serum from rats, as well as SB203580 (a specific inhibitor of p38 MAPK), were used. High-performance liquid chromatography analysis was performed to determine the main components of the drug-containing serum of rhubarb-astragalus from rats. Western blotting and immunofluorescence analysis were used to determine the levels of protein expression, and real-time quantitative PCR analysis was used to detect the levels of gene expression. RESULTS: The drug-containing serum of rhubarb-astragalus contained emodin (0.36 µg/ml) and danthraquinone (0.96 µg/ml). Rhubarb-astragalus significantly decreased the protein expression levels of α-SMA, FN, vimentin and N-cadherin in HK-2 cells that were increased by TGF-ß1, while it significantly increased the E-cadherin protein expression level that was decreased by TGF-ß1. Rhubarb-astragalus also significantly decreased the protein expression levels of TGF-ß1 and p38 MAPK and the mRNA expression levels of α-SMA, vimentin, TGF-ß1, p38 MAPK, Smad2 and Smad3 in HK-2 cells that were increased by TGF-ß1. It is worth noting that SB203580 (a p38 MAPK inhibitor) had similar effects as rhubarb-astragalus in this study. CONCLUSION: The drug-containing serum of rhubarb-astragalus can inhibit EMT in HK-2 cells by downregulating the TGF-ß1/p38 MAPK/Smad2/3 pathway.

One-step electroreduction preparation of multilayered reduced graphene oxide/gold-palladium nanohybrid as a proficient electrocatalyst for development of sensitive hydrazine sensor.

A facile and green method for preparation of gold/palladium (Au/Pd) bimetallic nanoparticles interleaved reduced graphene oxide (rGO) composite was presented. One-step electroreduction of Au/Pd precursors and graphene oxide synergistically produced a multilayered and well-structured nanohybrid on glassy carbon electrode, which was explored as a highly efficient electrocatalyst. This operation is easy and controllable, as compared with time-consuming and procedure-tedious hydrothermal synthesis. The morphology and chemical constituents were meticulously characterized. The remarkable electrocatalytic performance of the prepared nanohybrid was demonstrated by detection of a high-risk carcinogen pollutant, hydrazine. By optimizing the preparation condition and investigating the electrochemical behavior, we achieved the sensitive analysis of hydrazine with ultralow oxidation overpotential. Amperometry was employed for constructing the quantitative calibration curve; the steady-state current originating from hydrazine oxidation was proportional to the analytical concentration ranging from 0.1 µM to 200 µM, with the detection limit of 16 nM. Moreover, the nanohybrid displayed considerable anti-interfering ability with respect to hydrazine detection, as a variety of potentially coexisting substances produced negligible electrochemical response in the given analytical condition. Advantages including easy-to-preparation, high sensitivity and favorable selectivity, as well as broad linear response make the present method feasible for monitoring of hydrazine in water environment.

Electrostatically mediated layer-by-layer assembly of nitrogen-doped graphene/PDDA/gold nanoparticle composites for electrochemical detection of uric acid.

A layer-by-layer self-assembled nitrogen-doped graphene/PDDA/gold nanoparticle (NDG/PDDA/GNP) composite was described. Citrate-stabilizing gold nanoparticle colloids (GNPs) were electrostatically adsorbed onto NDG nanosheets using a cationic polyelectrolyte, polydiallyldimethylammonium (PDDA), as the linker, thereby creating a high-performance electrochemical interface. The morphology and chemical composition were characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, ultraviolet-visible spectroscopy, infrared spectroscopy, and Raman spectroscopy. Analytical application was manifested by electrochemical sensing of uric acid (UA), a biomarker involved with a variety of clinical diseases. The prepared nanocomposite exhibited noticeable electroactivity to uric acid oxidation and can give effective peak separation with ascorbic acid and dopamine. Additionally, the nanocomposite practically averted from other potentially interferents including glucose, urea, and serotonin, thus allowing selective voltammetric detection of UA in the biological matrix. Under the optimal condition, peak currents measured by differential pulse voltammetry were proportional to UA concentrations in the range of 0.5~100 µM (R2 = 0.998), with the detection limit of 53 nM. The NDG/PDDA/GNP nanocomposite as presented herein holds potential for aiding the diagnosis of UA-associated diseases and should be a new opportunity for biochemical analysis and biosensing applications. Graphical abstract.

In-situ facile preparation of highly efficient copper/nickel bimetallic nanocatalyst on chemically grafted carbon nanotubes for nonenzymatic sensing of glucose.

Measuring glucose in a convenient and economical manner is crucial for diabetes diagnostics and surveillance. Ongoing efforts are devoted to nonenzymatic sensors using functional nanomaterials. Drawbacks due to costly and cumbersome process, however, hamper the practicality. Here, we report the facile preparation of Cu/Ni bimetallic nanocatalyst toward glucose electrooxidation. Carboxylated multi-walled carbon nanotubes were chemically grafted onto indium tin oxide glass via silanization reaction and amide coupling reaction, providing distinct nucleation sites for Cu/Ni bimetallic electrocatalyst prepared by in-situ succinct electrodeposition, which synthetically created a three-dimensional electron transfer network. The surface morphology and chemical constituents were characterized by scanning electron microscopy, transmission electron microscopy, X-ray energy dispersive spectroscopy, X-ray photoelectron spectroscopy, infrared spectroscopy and atomic force microscopy. The prepared electrocatalyst displayed ultrahigh electrochemical activity; the catalytic current density for glucose oxidation was found to be over 6.7 mA mM-1 cm-2. The linear response spanned three orders of magnitude of glucose concentration ranging from 1 µM to 1 mM. Analytical parameters such as accuracy, reproducibility, specificity and stability have also been validated. Importantly, we reveal that Ni plays a dominant role over Cu in electrocatalytic oxidation of glucose, thus bettering our understanding and strategy for nonenzymatic glucose sensor design. Advantages of the glucose sensor presented include easy bulk preparation, low cost, and ready-to-use.