Phytophthora infestans RXLR effector Pi23014 targets host RNA-binding protein NbRBP3a to suppress plant immunity.

Phytophthora infestans is a destructive oomycete that causes the late blight of potato and tomato worldwide. It secretes numerous small proteins called effectors in order to manipulate host cell components and suppress plant immunity. Identifying the targets of these effectors is crucial for understanding P. infestans pathogenesis and host plant immunity. In this study, we show that the virulence RXLR effector Pi23014 of P. infestans targets the host nucleus and chloroplasts. By using a liquid chromatogrpahy-tandem mass spectrometry assay and co-immunoprecipitation assasys, we show that it interacts with NbRBP3a, a putative glycine-rich RNA-binding protein. We confirmed the co-localization of Pi23014 and NbRBP3a within the nucleus, by using bimolecular fluorescence complementation. Reverse transcription-quantitative PCR assays showed that the expression of NbRBP3a was induced in Nicotiana benthamiana during P. infestans infection and the expression of marker genes for multiple defence pathways were significantly down-regulated in NbRBP3-silenced plants compared with GFP-silenced plants. Agrobacterium tumefaciens-mediated transient overexpression of NbRBP3a significantly enhanced plant resistance to P. infestans. Mutations in the N-terminus RNA recognition motif (RRM) of NbRBP3a abolished its interaction with Pi23014 and eliminated its capability to enhance plant resistance to leaf colonization by P. infestans. We further showed that silencing NbRBP3 reduced photosystem II activity, reduced host photosynthetic efficiency, attenuated Pi23014-mediated suppression of cell death triggered by P. infestans pathogen-associated molecular pattern elicitor INF1, and suppressed plant immunity.

Highly sensitive sensing device based on highly luminescent lanthanide nanocluster for biomarker in human urine and serum.

The level of L-kynurenine (L-kyn) can reflect the health state of human body, and the determination of L-kyn can be used for the medical diagnosis of several cancers and neurological diseases. In this work, a series of air-, water-, and thermo-stable dinuclear lanthanide nanoclusters [Ln2(2,5-DFBA)6(phen)2] (Tb 1, Eu 2, Gd 3, 2,5-DFBA = 2,5-difluorobenzoic acid, phen = 1,10-phenanthroline) are obtained by a facial method. 1 and 2 show very high luminescence quantum yields (QYs) of 71.7% and 81.8%, respectively. Interestingly, investigation reveals that 1 is a quick, highly sensitive and selective sensor for L-kyn in real samples of urine and serum. Furthermore, transmission electron microscope (TEM) results reveal that nanocluster 1 is stable in solution and can be uniform distributed on the base, suggesting it can be deposited on various supports to fabricate sensing devices. Thus, 1 is fabricated into a sensitive test paper for the eye-readable detection of L-kyn in real samples of human urine and serum. The limit of detection (LOD) as low as 0.3 µM, which is enough to rapidly determine L-kyn in human body liquor (usually 5 µM in healthy human body).

The Inhibitory Effect of Celangulin V on the ATP Hydrolytic Activity of the Complex of V-ATPase Subunits A and B in the Midgut of Mythimna separata.

Celangulin V (CV) is a compound isolated from Celastrus angulatus Max that has a toxic activity against agricultural insect pests. CV can bind to subunits a, H, and B of the vacuolar ATPase (V-ATPase) in the midgut epithelial cells of insects. However, the mechanism of action of CV is still unclear. In this study, the soluble complex of the V-ATPase A subunit mutant TSCA which avoids the feedback inhibition by the hydrolysate ADP and V-ATPase B subunit were obtained and then purified using affinity chromatography. The H⁺K⁺-ATPase activity of the complex and the inhibitory activity of CV on ATP hydrolysis were determined. The results suggest that CV inhibits the ATP hydrolysis, resulting in an insecticidal effect. Additionally, the homology modeling of the AB complex and molecular docking results indicate that CV can competitively bind to the AB complex at the ATP binding site, which inhibits ATP hydrolysis. These findings suggest that the AB subunits complex is one of the potential targets for CV and is important for understanding the mechanism of interaction between CV and V-ATPase.

Recurrent multiple-organ involvement of disseminated alveolar echinococcosis in 3 patients: Case report.

RATIONALE: Alveolar echinococcosis (AE) is a rare but highly malignant form of echinococcosis caused by Echinococcus multilocularis. There have been very few reports on multiple-organ AE, especially AE in bones. Here we report 3 rare cases of disseminated multiple-organ AE from western China and its neighboring areas. PATIENT CONCERNS: Patient 1 had back and left hip pain, headache, and weakness in left lower limb, often with minor epilepsy and fluctuation of blood pressure. Lower limbs Babinski sign was positive and muscular tension was above normal range. The second patient had pain in lower limbs and chest discomfort without fever, cough, sputum, chest tightness, or hemoptysis. Patient 3 had masses and pain in the back side of his right shoulder. DIAGNOSES: The patients had been treated for AE multiple times and were positive for serum hydatid antigens. They were diagnosed as multiorgan AE involving liver, spinal cord, and many other organs. INTERVENTIONS: The patients had undergone surgeries to decompress the spinal cord, remove lesions from tissues as required, and were put on albendazole for at least 2 years. OUTCOMES: The patients responded well and AE recurrence has not occurred. LESSONS: All 3 cases experienced multiple recurrences of AE due to missed diagnosis, misdiagnosis, or inappropriate treatment, which resulted in metastatic multiorgan AE. These cases demonstrated the need for more policy attention to battle AE endemic in western China.

A preliminary study of neck-stomach syndrome.

AIM: To determine the expression of c-Fos, caspase-3 and interleukin-1beta (IL-1beta) in the cervical cord and stomach of rats with cervical spondylosis, to analyze their relationship, and to offer an explanation of one possible cause for functional dyspepsia (FD) and irritable bowel syndrome (IBS) caused by cervical spondylosis. METHODS: The cervical spondylosis model in rats was established by destroying the stability of cervical posterior column. The cord segments C4-6 and gastric antrum were collected 3 mo and 5 mo after the operation. Rats with the sham operation were used as controls. The expressions of c-Fos, caspase-3 and IL-1beta in the cervical cord and gastric antrum were determined by immunohistochemistry and/or Western blot. RESULTS: Immunohistochemical staining showed a few c-Fos, caspase-3 and IL-1beta-positive cells in the cervical cord and antrum in the control. There was a significant increase in c-Fos, caspase-3 and IL-1beta expression in model groups compared to the control groups at 3 mo and 5 mo after operation. More importantly, there was a significant (P < 0.05) increase in c-Fos, caspase-3 and IL-1beta expression in the model group rats at 3 mo compared to those at 5 mo after the operation (c-Fos: 11.20 +/- 2.26 vs 27.68 +/- 4.36 in the cervical cord, 11.3 +/- 2.3 vs 29.3 +/- 4.6 in the gastric antrum; caspase-3: 33.83 +/- 3.71 vs 36.32 +/- 4.01 in the cervical cord, 13.23 +/- 3.21 vs 26.32 +/- 4.01 in the gastric antrum; IL-1beta: 42.06 +/- 2.95 vs 45.91 +/- 3.98 in the cervical cord, 26.56 +/- 2.65 vs 32.01 +/- 2.98 in the gastric antrum). Western blot analysis showed time-dependent changes of caspase-3 and IL-1beta protein in the cervical cord and gastric antrum of rats with cervical spondylosis; there was no significant expression of caspase-3 and IL-1beta protein in the control group at 3 mo and 5 mo after the sham operation, whereas there was a significant difference in caspase-3 and IL-1beta protein levels between the model group rats followed up for 3 mo and those for 5 mo (P < 0.05). CONCLUSION: There is a significant association of c-Fos, caspase-3 and IL-1beta expressions in the gastric antrum with that in the spinal cord in rats with cervical spondylosis, suggesting that the gastrointestinal function may be affected by cervical spondylosis.