Tangeretin inhibits fungal ferroptosis to suppress rice blast.

Flavonoids are polyphenolic secondary metabolites that function as signaling molecules, allopathic compounds, phytoalexins, detoxifying agents and antimicrobial defensive compounds in plants. Blast caused by the fungus Magnaporthe oryzae is a serious disease affecting rice cultivation. In this study, we revealed that a natural flavonoid, tangeretin, substantially delays the formation of M. oryzae appressoria and blocks the development of blast lesions on rice plants. Our data suggest that tangeretin has antioxidant activity that interferes with conidial cell death/ferroptosis, which is critical for M. oryzae pathogenicity. Tangeretin showed a ferroptosis inhibition efficacy comparable to the well-established liproxstatin-1. Furthermore, overexpression of the NADPH oxidases NOX1 or NOX2 significantly decreased sensitivity toward tangeretin treatment, suggesting Nox-mediated lipid peroxidation as a possible target for tangeretin in regulating redox signaling and ferroptosis in M. oryzae. Our nursery and field tests showed that application of tangeretin can effectively mitigate overall disease symptoms and prevent leaf blast. Our study reveals the plant-derived fungal ferroptosis inhibitor tangeretin as a potential and novel antifungal agrochemical for the sustainable prevention of the devastating blast disease in important cereal crops.

A Bacterial Isolate Capable of Quenching Both Diffusible Signal Factor- and N-Acylhomoserine Lactone-Family Quorum Sensing Signals Shows Much Enhanced Biocontrol Potencies.

N-Acylhomoserine lactone (AHL) and diffusible signal factor (DSF) molecules are two families of widely conserved quorum sensing (QS) signals. Quorum quenching (QQ) via enzymatic inactivation of QS signals is a promising strategy of biocontrol. In the search for biocontrol agent quenching both AHL and DSF signals, it has been recently identified that DSF-quenching biocontrol agent Pseudomonas sp. HS-18 contains at least three genes (aigA, aigB, and aigC) encoding AHL-acylases displaying strong AHL-acylase activities on various AHLs. Among them, AigA and AigC presented broad-spectrum enzyme activity against AHLs, while AigB preferred longer AHLs. Interestingly, transcriptional expression of aigC could be significantly induced by AHL signals. Heterologous expression of aigA-C in Burkholderia cenocepacia and Pseudomonas aeruginosa resulted in drastically decreased AHL accumulation, virulence factor production, biofilm formation, motility, and virulence on plants. Significantly, the two types of QQ mechanisms in HS-18 showed a strong and much desired synergistic effect for enhanced biocontrol potency against AHL- and DSF-dependent pathogens.

[The effects of two health education models on psychological and nutritional profile of patients waiting for kidney transplantation].

OBJECTIVE: To investigate the effects of two health education models on the psychology and nutrition of patients waiting for cadaveric renal transplantation. METHODS: A total of 125 patients waiting for cadaveric renal transplantations were involved in our study. They were diagnosed with chronic renal failure in our hospital during September 1, 2009 to August 30, 2010. The patients were randomly divided into control group (n = 62) and observational group (n = 63). Patients in the control group received traditional health education with routine preoperative education during hospitalization. In the observational group, full-time nurses assessed the nutrition status of each patient and monitored the data. The observational patients were followed up and were given dietary guidance and knowledge of transplantation. Various kinds of education formats were adopted in observational group to provide communication opportunities between patients and surgeons in charge as well as patients who underwent transplantation. Psychological testings of patients in both groups were tested by self-rating anxiety scale (SAS) and self-rating depression scale (SDS) before and after the health education. Triceps skinfold thickness (TSF), mid-arm muscle circumference (MAMC) and biochemistry index were also tested. Psychological and nutritional status of patients in the two groups was compared. RESULTS: There were no significant differences in scores of the SAS, SDS, TSF, Hb, and albumin (Alb) between the two groups (all P > 0.05) before health education. After health education, SAS and SDS in observational group were lower than those in the control group (40.02 ± 9.05 vs 47.05 ± 10.32, 42.70 ± 10.01 vs 50.83 ± 10.12; both P < 0.01). Both TSF and Hb were elevated after education (P < 0.001 or 0.05). Alb was significantly elevated in the observational group [(35.67 ± 6.19) g/L vs (37.48 ± 5.09) g/L, P < 0.01]. CONCLUSION: Comprehensive and various health education methods can significantly alleviate mental stress and improve nutrition of the patients waiting for kidney transplantation, which is helpful for patients facing disease positively and having a better quality of life.

Tacrolimus therapy in adults with steroid- and cyclophosphamide-resistant nephrotic syndrome and normal or mildly reduced GFR.

BACKGROUND: In a proportion of adults with steroid-resistant nephrotic syndrome (SRNS), intravenous cyclophosphamide therapy fails. Tacrolimus may be a promising alternative to cyclophosphamide for such patients. STUDY DESIGN: Prospective observational study. SETTING & PARTICIPANTS: 19 adults with SRNS (6 with minimal change nephropathy, 8 with focal segmental glomerulosclerosis [FSGS], and 5 with mesangioproliferative glomerulonephritis) that did not respond to intravenous cyclophosphamide therapy were studied from January 2003 to September 2006. Oral tacrolimus was administered (target trough levels, 5 to 10 ng/mL) for 24 weeks, then reduced doses were given (target trough level, 3 to 6 ng/mL) for another 24 weeks. FACTORS: Histopathologic types: minimal change nephropathy (n = 6), FSGS (n = 8), and mesangioproliferative glomerulonephritis (n = 5). MEASUREMENTS: outcome variables included complete remission (decrease in daily proteinuria to protein < or = 0.3 g/d), partial remission (decrease in daily proteinuria to protein < 3.5 g/d but > 0.3 g/d), relapse (increase in daily proteinuria to protein > or = 3.5 g/d in patients who had partial or complete remission), change in kidney function, and tacrolimus dosing and serum levels. RESULTS: 17 patients completed at least 24 weeks of tacrolimus therapy. Complete remission was achieved in 11 patients (64.7%), and partial remission was achieved in 3 (17.6%). Complete or partial remission was achieved in 5 of 5 patients with minimal change nephropathy, 4 of 7 patients with FSGS, and 5 of 5 patients with mesangioproliferative glomerulonephritis. Primary resistance to tacrolimus was seen in 3 patients (17.6%), all with FSGS. Mean times to achieve partial and complete remission were 5.6 +/- 1.4 and 8.0 +/- 5.1 weeks, respectively. In patients who achieved complete or partial remission, 35.7% experienced relapse during follow-up (mean, 37.6 +/- 13.4 months). Two patients had doubling of serum creatinine levels, both with FSGS. LIMITATIONS: Observational study. CONCLUSIONS: Tacrolimus rapidly and effectively induced remission of SRNS in Chinese adults with disease refractory to treatment with intravenous cyclophosphamide. Treatment may be less effective in patients with FSGS.