Inhibition of M. tuberculosis and human ATP synthase by BDQ and TBAJ-587.

Bedaquiline (BDQ), a first-in-class diarylquinoline anti-tuberculosis drug, and its analogue, TBAJ-587, prevent the growth and proliferation of Mycobacterium tuberculosis by inhibiting ATP synthase1,2. However, BDQ also inhibits human ATP synthase3. At present, how these compounds interact with either M. tuberculosis ATP synthase or human ATP synthase is unclear. Here we present cryogenic electron microscopy structures of M. tuberculosis ATP synthase with and without BDQ and TBAJ-587 bound, and human ATP synthase bound to BDQ. The two inhibitors interact with subunit a and the c-ring at the leading site, c-only sites and lagging site in M. tuberculosis ATP synthase, showing that BDQ and TBAJ-587 have similar modes of action. The quinolinyl and dimethylamino units of the compounds make extensive contacts with the protein. The structure of human ATP synthase in complex with BDQ reveals that the BDQ-binding site is similar to that observed for the leading site in M. tuberculosis ATP synthase, and that the quinolinyl unit also interacts extensively with the human enzyme. This study will improve researchers' understanding of the similarities and differences between human ATP synthase and M. tuberculosis ATP synthase in terms of the mode of BDQ binding, and will allow the rational design of novel diarylquinolines as anti-tuberculosis drugs.

Work-family conflict among primary health workers during the COVID-19 pandemic: Its mediating role in the relationship between workload and job burnout.

AIMS AND OBJECTIVES: This study explores the situation of workload, work-family conflict and job burnout among primary health workers in China in the context of COVID-19 and identifies the mediating effect of work-family conflict between workload and job burnout. BACKGROUND: Since the breakout of the COVID-19 pandemic, primary health workers have been working on the frontline of the epidemic and may experience increasing workload, work-family conflict and job burnout. It is important to focus on the issue of how to alleviate job burnout of primary health workers. DESIGN: A cross-sectional study (STROBE) was used. METHODS: Data were collected from 785 primary health workers in China. Multiple regression analysis was used to examine the mediating effect of work-family conflict between workload and job burnout. RESULTS: 18.7%, 10.4% and 39.5% of respondents had high job burnout in the dimensions of emotional exhaustion, depersonalization and personal accomplishment, respectively. 34.6% of the respondents had high or very high workload, and 12.8% of the respondents had high or very high work-family conflict. Results of multiple regression analysis indicated that work-family conflict mediated the relationship between workload and job burnout. Workload (ß = .163, CI = .207-.549) and work-family conflict (ß = .211, CI = .311-.640) positively influenced job burnout, and workload (ß = .428, CI = .375-.508) positively influenced work-family conflict. CONCLUSION: The study indicated that primary health workers experienced a high level of job burnout, especially in the personal accomplishment dimension. Furthermore, this study verified the mediating effect of work-family conflict between workload and job burnout. RELEVANCE TO CLINICAL PRACTICE: Some interventions for alleviating workload, work-family conflict and job burnout should be taken, including workplace assistance programmes, family-friendly policies and a well-integrated healthcare system. NO PATIENT OR PUBLIC CONTRIBUTION: This study does not involve patient or public contribution in any part. IMPACT STATEMENT: Nurses and other primary health workers are health gatekeepers of residents and play a vital role in the healthcare system. Due to the breakout of COVID-19, they have taken more work and are more vulnerable to work overload, work-family conflict and the consequent job burnout. Some interventions should be taken to effectively alleviate their job burnout and improve their health and performance.

Using sodium alginate aided bio-treatment for improving the uniformity of precipitates on recycled aggregates.

The recycled concrete aggregates have high porosity and water absorption, which hinders their utilization in concrete production. Microbial-induced calcium carbonate precipitation was regarded as a very promising method for strengthening recycled aggregates. However, the uneven distribution of CaCO3 on surface of aggregates encountered in the current bio-deposition treatment weakened the efficiency, especially in the aspect of the decrease of water absorption. Therefore, this study innovatively applied a sodium alginate aided bio-deposition treatment to improve the uniform distribution of biogenic CaCO3. The principle was that sodium alginate was used to uniformly "fix" the bio-agents (urea or bacterial cells) on the surface of recycled aggregates, which was supposed to promote the uniform in-situ precipitation of CaCO3 on the surface of aggregates, and hence effectively blocking surface pores, and reducing the water absorption of the aggregates. Two concentrations of sodium alginate (0.2w% and 0.5w%) and four sodium alginate aided bio-deposition treatments were studied. It was found that CaCO3 (a mass increase of 4.05%) was formed on the aggregates after the suitable sodium alginate aided bio-deposition treatment. The participation of sodium alginate made CaCO3 uniformly deposited on full surface of the aggregates, resulting in a significant decrease (42.10%) of water absorption. The biogenic CaCO3 showed limited mass loss under ultrasonic attack, indicated a strong cohesion and bonding strength with aggregates. The results demonstrated that sodium alginate-aided bio-deposition treatment can enhance the efficiency, which was beneficial to improve the quality of recycled aggregates and their utilization of recycled aggregates in concrete production. KEY POINTS: • The SA-aided bio-treatment promoted the distribution uniformity of CaCO3 on aggregates. • The water absorption of aggregates decreased by 42.10%. • The formed CaCO3 showed excellent cohesion and adhesion.

Optimization of deposition process for a productive and cohesive bio-CaCO3 to repair concrete existing cracks.

Microbial-induced carbonate precipitation (MICP) is being investigated to repair concrete cracks because of its good durability and compatibility with cementitious matrix. However, during the in-situ application, the repairing often lasts weeks, even months. And the strength regain is quite low. The repairing time is largely determined by the CaCO3 yield, and the strength regain after the repair is closely related to the cohesion and bonding strength of CaCO3 itself. Thus, the purpose of this paper is to obtain an efficient precipitation of bio-CaCO3 with both high yield and good cohesion to improve the in-situ repairing efficiency. Firstly, the most influential factors on urease activity were screened and the precipitation kinetics were detailly investigated. The results show that the CaCO3 with the largest yield and cohesion was obtained when the bacterial concentration was 107 cells/mL and the concentration of urea and calcium was both 0.5 M at 20 °C. This weight loss of bio-CaCO3 was 9.24% under ultrasonic attack. Secondly, two models were established to quantify or semi-quantify the relationship between the most influential factors and the yield and cohesion of precipitates, respectively. The results showed the order of contribution for bio-CaCO3 precipitation was calcium ions concentration > bacterial concentration > urea concentration > temperature > initial pH. According to these models, the required yield and cohesion of CaCO3 by engineering could be obtained by adjusting affecting factors. Models were proposed for guiding the application of MICP in practical engineering. KEY POINTS: • Screened the most affecting factors on urease activity and investigated the precipitation kinetics. • Obtained optimal conditions of bio-CaCO. • Established two models in order to give some guidance for practical civil engineering.

Instrumental support primarily provided by adult children and trajectories of depressive symptoms among older adults with disabilities in rural China.

OBJECTIVES: This study aimed to examine the trajectories of depressive symptoms over a 5-year period in a sample of community-dwelling older adults with disabilities in rural China, and the association between duration of instrumental support primarily provided by adult children and the trajectories of depressive symptoms. METHODS: Data were drawn from three waves of the China Health and Retirement Longitudinal Study (2011-2015). The sample included 1,466 older adults living in rural areas aged 60 and over who had at least one child in all three waves. Duration of instrumental support provided by adult children was measured by the number of waves that older adults received instrumental support primarily from any adult children in the data collection. Growth mixture modelling was used to identify the trajectory classes of depressive symptoms among these older adults, and logistic regression was used to examine the association between duration of instrumental support primarily provided by adult children and the trajectory classes of depressive symptoms. RESULTS: This study identified two distinct trajectories of depressive symptoms among the respondents: high but decreasing levels of symptoms and persistently low levels of symptoms. Respondents who received a longer duration of instrumental support primarily from adult children were more likely to have high but decreasing symptoms after controlling for other covariates. CONCLUSION: The findings have important implications for promoting the mental health of older adults with disabilities in rural China. There are still very limited long-term care services and programs are available for older adults, particularly in rural China. It is critical to develop these services at both community and institutional levels to meet the care needs of older adults and their families.

Decreased Sirt3 contributes to cyclic production of reactive oxygen species and islet ß-cell apoptosis in high glucose conditions.

BACKGROUND: Reactive oxygen species (ROS) plays a vital role in the apoptosis of islet ß-cells in type 2 diabetes mellitus (T2DM). Sirt3 (Sirtuin 3, a deacetylase) and FoxO1 (a transcription factor) might be involved in ROS production. This study was to investigate mechanism of ROS production and ß-cell apoptosis in T2DM. METHODS: Oxidative stress and apoptosis in islets of db/db mice and high glucose cultured ß-cells were observed by terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) assay and western blotting. Then, H2O2 was used to ascertain the effect of ROS on the expression of Sirt3. Meanwhile, FoxO1, antioxidant enzymes - catalase (CAT) and manganese superoxide dismutase (MnSOD) and ß-cell apoptosis were also determined by western blotting. Finally, Sirt3 was knocked down to evaluate the effect on oxidative stress and apoptosis of ß-cells. RESULTS: Under high glucose environment, enhanced ROS made a decrease of Sirt3 expression, which increased acetylation of FoxO1, thus reduced the expression of its target proteins -MnSOD and CAT, and further significantly increased ROS levels. Increased ROS finally led to the apoptosis of ß-cells. CONCLUSION: Down-regulation of Sirt3 plays an important role in the cyclic production of ROS and ß-cell apoptosis. Targeting Sirt3 may be favorable for the treatment of T2DM.

Effect of a multi-dimensional case management model on anti-retroviral therapy-related outcomes among people living with human immunodeficiency virus in Beijing, China.

BACKGROUND: This paper introduces a comprehensive case management model uniting doctors, nurses, and non-governmental organizations (NGOs) in order to shorten the time from HIV diagnosis to initiation of antiviral therapy, improve patients' adherence, and ameliorate antiretroviral treatment (ART)-related outcomes. METHODS: All newly diagnosed human immunodeficiency virus (HIV) cases at Beijing YouAn Hospital from January 2012 to December 2013 were selected as the control group, while all newly diagnosed HIV-infected patients from January 2015 to December 2016 were selected as the intervention group, receiving the comprehensive case management model. RESULTS: 4906 patients were enrolled, of which 1549 were in the control group and 3357 in the intervention group. The median time from confirming HIV infection to ART initiation in the intervention group was 35 (18-133) days, much shorter than the control group (56 (26-253) days, P < 0.001). Participants in the intervention group had better ART adherence compared to those in the control group (intervention: 95.3%; control: 89.2%; p < 0.001). During the 2 years' follow-up, those receiving case management were at decreased odds of experiencing virological failure (OR: 0.27, 95%CI: 0.17-0.42, P < 0.001). Observed mortality was 0.4 deaths per 100 patient-years of follow-up for patients in the control group compared with 0.2 deaths per 100 patient-years of follow-up in the intervention group. CONCLUSIONS: People living with HIV engaged in the comprehensive case management model were more likely to initiate ART sooner and maintained better treatment compliance and improved clinical outcomes compared to those who received routine care. A comprehensive case management program could be implemented in hospitals across China in order to reduce the HIV disease burden in the country.

The Diagnostic Accuracy of Magnetic Resonance Imaging in Restaging of Rectal Cancer After Preoperative Chemoradiotherapy: A Meta-Analysis and Systematic Review.

OBJECTIVE: To evaluate the overall diagnostic value of magnetic resonance imaging (MRI) in restaging of rectal cancer after preoperative chemoradiotherapy based on qualified studies. METHODS: PubMed, Cochrane, and EMBASE database were searched by the index words to identify the qualified studies, and relevant literature sources were also searched. The latest research was done in April 2019. Heterogeneity of the included studies was tested, which was used to select proper effect model to calculate pooled weighted sensitivity, specificity, and diagnostic odds ratio (DOR). Summary receiver operating characteristic (SROC) analyses were also performed. RESULT: Nineteen studies with 1262 patients were involved in the meta-analysis exploring the diagnostic accuracy of MRI for rectal cancer. The diagnostic accuracy of MRI in T3-T4 rectal cancer was as follows: sensitivity, 81% (95% confidence interval [CI], 67%-90%); specificity, 67% (95% CI, 51%-80%); positive likelihood ratio, 2.48 (95% CI, 1.57-3.91); negative likelihood ratio, 0.28 (95% CI, 0.15-0.52); global DOR, 6.86 (95% CI, 3.07-15.30); the area under the SROC was high (0.81; 95% CI, 0.78-0.84). The diagnostic accuracy of MRI in lymphatic metastasis of rectal cancer was as follows: sensitivity, 77% (95% CI, 65%-86%); specificity, 77% (95% CI, 63%-87%); positive likelihood ratio, 3.40 (95% CI, 2.07-5.59); negative likelihood ratio, 0.30 (95% CI, 0.20-0.45); DOR, 10.81 (95% CI, 4.99-23.39); area under the SROC was high (0.84; 95% CI, 0.80-0.87). CONCLUSIONS: This study provides a systematic review and meta-analysis of diagnostic accuracy studies of MRI for rectal cancer. The results indicate that MRI is a highly accurate diagnostic tool for rectal cancer T3-T4 staging and N staging but sensitivity and specificity are not high.

Computational discovery and characterization of new B2O phases.

We present computational discoveries of new structural phases of the B2O compound exhibiting novel bonding networks and electronic states at ambient and elevated pressures. Our advanced crystal structure searches in conjunction with density functional theory calculations have identified an orthorhombic phase of B2O that is energetically stable at ambient pressure and contains an intriguing bonding network of icosahedral B12 clusters bridged by oxygen atoms. As pressure increases above 1.9 GPa, a structural transformation takes the orthorhombic B2O into a pseudo-layered trigonal phase. We have performed extensive studies to investigate the evolution of chemical bonds and electronic states associated with the B12 icosahedral unit in the orthorhombic phase and the covalent B-O bonds in the trigonal phase. We have also examined the nature of the charge carriers and their coupling to the lattice vibrations in the newly identified B2O crystals. Interestingly, our results indicate that both B2O phases become superconducting at low temperatures, with transition temperatures of 6.4 K and 5.9 K, respectively, in the ambient and high-pressure phase. The present findings establish new B2O phases and characterize their structural and electronic properties, which offer insights and guidance for exploration toward further fundamental understanding and potential synthesis and application.

Complementing urea hydrolysis and nitrate reduction for improved microbially induced calcium carbonate precipitation.

Microbial-induced CaCO3 precipitation has been widely applied in bacterial-based self-healing concrete. However, the limited biogenetic CaCO3 production by bacteria after they were introduced into the incompatible concrete matrix is a major challenge of this technology. In the present study, the potential of combining two metabolic pathways, urea hydrolysis and nitrate reduction, simultaneously in one bacteria strain for improving the bacterial CaCO3 yield has been investigated. One bacterial strain, Ralstonia eutropha H16, which has the highest Ca2+ tolerance and is capable of performing both urea hydrolysis and nitrate reduction in combined media was selected among three bacterial candidates based on the enzymatic examinations. Results showed that H16 does not need oxygen for urea hydrolysis and urease activity was determined primarily by cell concentration. However, the additional urea in the combined medium slowed down the nitrate reduction rate to 7 days until full NO3- decomposition. Moreover, the nitrate reduction of H16 was significantly restricted by an increased Ca2+ ion concentration in the media. Nevertheless, the overall CaCO3 precipitation yield can be improved by 20 to 30% after optimization through the combination of two metabolic pathways. The highest total CaCO3 precipitation yield achieved in an orthogonal experiment was 14 g/L. It can be concluded that Ralstonia eutropha H16 is a suitable bacterium for simultaneous activation of urea hydrolysis and nitrate reduction for improving the CaCO3 precipitation and it can be studied later, on activation of multiple metabolic pathways in bacteria-based self-healing concrete.

Pressure-induced phase transition, metallization and superconductivity in ZrS2.

Zirconium disulfide (ZrS2) is an exemplary case among layered materials that exhibit unusual electronic and vibrational properties, with applications in potential photovoltaic and single-layer transistor materials. Here, we examine the effect of pressure on the structural stability, phonon dispersion, electronic properties and electron-phonon coupling of ZrS2 using first-principles calculations. Our results unravel that ZrS2 undergoes several pressure-induced phase transformations from the ambient-pressure P3[combining macron]m1 structure to a monoclinic P21/m structure at 2.0 GPa, to an orthorhombic Immm structure at 5.6 GPa, and to a tetragonal I4/mmm structure at 25.0 GPa. The electronic band calculations indicate that the layered P3[combining macron]m1 and P21/m structures are narrow-gap semiconductors. The gaps of the above two phases, which are normal semiconductors, decrease with pressure. Our results show that ZrS2 reaches the metallic state by a P21/m → Immm phase transition and keeps its metallic state in the I4/mmm phase. A pressure-driven evolution of the topological Fermi surface has been uncovered. The electron-phonon coupling results identify superconducting states in both metallic Immm and I4/mmm structures. Our research shows that pressure is efficient in the modulation of the bonding states, crystal structures and electronic properties of ZrS2, which will stimulate further high-pressure structural and conductive measurements.

Bacillus sphaericus LMG 22257 is physiologically suitable for self-healing concrete.

The suitability of using a spore-forming ureolytic strain, Bacillus sphaericus, was evaluated for self-healing of concrete cracks. The main focus was on alkaline tolerance, calcium tolerance, oxygen dependence, and low-temperature adaptability. Experimental results show that B. sphaericus had a good tolerance. It can grow and germinate in a broad range of alkaline pH. The optimal pH range is 7 âˆ¼ 9. High alkaline conditions (pH 10 âˆ¼ 11) slow down but not stop the growth and germination. Oxygen was strictly needed during bacterial growth and germination, but not an essential factor during bacterial urea decomposition. B. sphaericus also had a good Ca tolerance, especially at a high bacterial concentration of 108 cells/mL; no significant influence was observed on bacterial ureolytic activity of the presence of 0.9M Ca2+. Furthermore, at a low temperature (10 °C), bacterial spores germinated and revived ureolytic activity with some retardation. However, this retardation can be counteracted by using a higher bacterial concentration and by supplementing yeast extract. It can be concluded that B. sphaericus is a suitable bacterium for application in bacteria-based self-healing concrete.

Globally stable structures of LixZn (x = 1-4) compounds at high pressures.

Pressure can change the properties of atoms and bonding patterns, leading to the synthesis of novel compounds with interesting properties. The intermetallic lithium-zinc (Li-Zn) compounds have attracted increasing attention because of their fascinating mechanical properties and widespread applications in rechargeable Li-ion batteries. Using the effective CALYPSO searching method in combination with first-principles calculations, we theoretically investigated the LixZn (x = 1-4) compounds at pressures of 0 to 100 GPa. We found several stable structures with a variety of stoichiometries and the phase diagram on the Li-rich side under high pressure. The electronic structures of these compounds reveal transferred charges from lithium to zinc mainly fill Zn 4p states and compounds with negatively charged Zn atoms are dramatic. We also calculated the elastic constants to discuss their mechanical properties. Our results enrich the crystal structures of the Li-Zn system and provide a further understanding of structural features and their properties.

Application of microorganisms in concrete: a promising sustainable strategy to improve concrete durability.

The beneficial effect of microbially induced carbonate precipitation on building materials has been gradually disclosed in the last decade. After the first applications of on historical stones, promising results were obtained with the respect of improved durability. An extensive study then followed on the application of this environmentally friendly and compatible material on a currently widely used construction material, concrete. This review is focused on the discussion of the impact of the two main applications, bacterial surface treatment and bacteria based crack repair, on concrete durability. Special attention was paid to the choice of suitable bacteria and the metabolic pathway aiming at their functionality in concrete environment. Interactions between bacterial cells and cementitious matrix were also elaborated. Furthermore, recommendations to improve the effectiveness of bacterial treatment are provided. Limitations of current studies, updated applications and future application perspectives are shortly outlined.

Duplication and Remolding of tRNA Genes in the Mitochondrial Genome of Reduvius tenebrosus (Hemiptera: Reduviidae).

Most assassin bugs are predators that act as important natural enemies of insect pests. Mitochondrial (mt) genomes of these insects are double-strand circular DNAs that encode 37 genes. In the present study, we explore the duplication and rearrangement of tRNA genes in the mt genome of Reduvius tenebrosus, the first mt genome from the subfamily Reduviinae. The gene order rearranges from CR (control region)-trnI-trnQ-trnM-ND2 to CR-trnQ-trnI2-trnI1-trnM-ND2. We identified 23 tRNA genes, including 22 tRNAs commonly found in insects and an additional trnI (trnI2), which has high sequence similarity to trnM. We found several pseudo genes, such as pseudo-trnI, pseudo-CR, and pseudo-ND2, in the hotspot region of gene rearrangement (between the control region and ND2). These features provided evidence that this novel gene order could be explained by the tandem duplication/random loss (TDRL) model. The tRNA duplication/anticodon mutation mechanism further explains the presence of trnI2, which is remolded from a duplicated trnM in the TDRL process (through an anticodon mutation of CAT to GAT). Our study also raises new questions as to whether the two events proceed simultaneously and if the remolded tRNA gene is fully functional. Significantly, the duplicated tRNA gene in the mitochondrial genome has evolved independently at least two times within assassin bugs.

A purple acid phosphatase plays a role in nodule formation and nitrogen fixation in Astragalus sinicus.

The AsPPD1 gene from Astragalus sinicus encodes a purple acid phosphatase. To address the functions of AsPPD1 in legume-rhizobium symbiosis, its expression patterns, enzyme activity, subcellular localization, and phenotypes associated with its over-expression and RNA interference (RNAi) were investigated. The expression of AsPPD1 was up-regulated in roots and nodules after inoculation with rhizobia. Phosphate starvation reduced the levels of AsPPD1 transcripts in roots while increased those levels in nodules. We confirmed the acid phosphatase and phosphodiesterase activities of recombinant AsPPD1 purified from Pichia pastoris, and demonstrated its ability to hydrolyze ADP and ATP in vitro. Subcellular localization showed that AsPPD1 located on the plasma membranes in hairy roots and on the symbiosomes membranes in root nodules. Over-expression of AsPPD1 in hairy roots inhibited nodulation, while its silencing resulted in nodules early senescence and significantly decreased nitrogenase activity. Furthermore, HPLC measurement showed that AsPPD1 overexpression affects the ADP levels in the infected roots and nodules, AsPPD1 silencing affects the ratio of ATP/ADP and the energy charge in nodules, and quantitative observation demonstrated the changes of AsPPD1 transcripts level affected nodule primordia formation. Taken together, it is speculated that AsPPD1 contributes to symbiotic ADP levels and energy charge control, and this is required for effective nodule organogenesis and nitrogen fixation.

A nodule-specific lipid transfer protein AsE246 participates in transport of plant-synthesized lipids to symbiosome membrane and is essential for nodule organogenesis in Chinese milk vetch.

Rhizobia in legume root nodules fix nitrogen in symbiosomes, organelle-like structures in which a membrane from the host plant surrounds the symbiotic bacteria. However, the components that transport plant-synthesized lipids to the symbiosome membrane remain unknown. This study identified and functionally characterized the Chinese milk vetch (Astragalus sinicus) lipid transfer protein AsE246, which is specifically expressed in nodules. It was found that AsE246 can bind lipids in vitro. More importantly, AsE246 can bind the plant-synthesized membrane lipid digalactosyldiacylglycerol in vivo. Immunofluorescence and immunoelectron microscopy showed that AsE246 and digalactosyldiacylglycerol localize in the symbiosome membrane and are present in infection threads. Overexpression of AsE246 resulted in increased nodule numbers; knockdown of AsE246 resulted in reduced nodule numbers, decreased lipids contents in nodules, diminished nitrogen fixation activity, and abnormal development of symbiosomes. AsE246 knockdown also resulted in fewer infection threads, nodule primordia, and nodules, while AsE246 overexpression resulted in more infection threads and nodule primordia, suggesting that AsE246 affects nodule organogenesis associated with infection thread formation. Taken together, these results indicate that AsE246 contributes to lipids transport to the symbiosome membrane, and this transport is required for effective legume-rhizobium symbiosis.

Jak2/Stat1 pathway mediated tetrahydrobiopterin up-regulation contributes to nitric oxide overproduction in high-glucose cultured rat mesangial cells.

Nitric oxide (NO) is crucial for the progression of early diabetic nephropathy (DN). It is important to clarify the mechanism for the production of NO in mesangial cells (MCs). In this study, the amounts/activities of related factors such as reactive oxygen species (ROS), NO, 3 isoforms of nitric oxide synthase (NOS), tetrahydrobiopterin (BH4), GTP cyclohydrolase I (GTPCH I), Jak2, and Stat1 were determined using high-glucose cultured rat MCs. The results showed that the production of BH4 under oxidative stress was strongly stimulated by its rate-limiting enzyme GTP cyclohydrolase, which increased the expression and activity of inducible NOS to facilitate NO synthesis. Furthermore, the relative quantities of activated-Jak2 and activated-Stat1 were increased. Therefore, Jak2/Stat1 pathway mediated BH4 up-regulation can contribute to excessive NO in high-glucose cultured MCs. Our results will be helpful for screening new targets to improve the therapy for early DN.

Effects of Free Anthraquinones Extract from the Rhubarb on Cell Proliferation and Accumulation of Extracellular Matrix in High Glucose Cultured-Mesangial Cells.

Diabetic nephropathy (DN) is the leading cause of end-stage failure of the kidney, but the efficacy of currently available strategies for the prevention of DN remains unsatisfactory. In this study, we investigated the effects of free anthraquinones (FARs) extract, which was extracted from the rhubarb and purified by macroporous resin DM130 with gradient mixtures of ethanol/water as the lelution solvents, in high glucose-cultured glomerular mesangial cells (MCs). The cell proliferation was determined by CCK-8 assay, the levels of TGF-ß1, CTGF, ColIV and FN proteins in the supernatant of MCs were measured by ELISA assays, and the mRNA levels of these four genes were detected by RT-PCR. The results showed that the increased proliferation of MCs, the mRNA levels and protein expression of TGF-ß1, CTGF, ColIV and FN induced by high glucose were inhibited after the treatment with the FARs extract. This indicated that FARs extract could inhibit cell proliferation and the expression of main extracellular matrix induced by high glucose in MCs. The FARs extract exhibited potential values for prophylaxis and therapy of DN.

Efficacy of Metarhizium anisopliae isolate MAX-2 from Shangri-la, China under desiccation stress.

BACKGROUND: Metarhizium anisopliae, a soil-borne entomopathogen found worldwide, is an interesting fungus for biological control. However, its efficacy in the fields is significantly affected by environmental conditions, particularly moisture. To overcome the weakness of Metarhizium and determine its isolates with antistress capacity, the efficacies of four M. anisopliae isolates, which were collected from arid regions of Yunnan Province in China during the dry season, were determined at different moisture levels, and the efficacy of the isolate MAX-2 from Shangri-la under desiccation stress was evaluated at low moisture level. RESULTS: M. anisopliae isolates MAX-2, MAC-6, MAL-1, and MAQ-28 showed gradient descent efficacies against sterile Tenebrio molitor larvae, and gradient descent capacities against desiccation with the decrease in moisture levels. The efficacy of MAX-2 showed no significant differences at 35% moisture level than those of the other isolates. However, significant differences were found at 8% to 30% moisture levels. The efficacies of all isolates decreased with the decrease in moisture levels. MAX-2 was relatively less affected by desiccation stress. Its efficacy was almost unaffected by the decrease at moisture levels > 25%, but slowly decreased at moisture levels < 25%. By contrast, the efficacies of other isolates rapidly decreased with the decrease in moisture levels. MAX-2 caused different infection characteristics on T. molitor larvae under desiccation stress and in wet microhabitat. Local black patches were found on the cuticles of the insects, and the cadavers dried without fungal growth under desiccation stress. However, dark black internodes and fungal growth were found after death of the insects in the wet microhabitat. CONCLUSIONS: MAX-2 showed significantly higher efficacy and superior antistress capacity than the other isolates under desiccation stress. The infection of sterile T. molitor larvae at low moisture level constituted a valid laboratory bioassay system in evaluating M. anisopliae efficacy under desiccation stress.