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Previous study showed that the magnesium-protoporphyrin IX chelatase H subunit (CHLH/ABAR) positively regulates abscisic acid (ABA) signaling. Here, we investigated the functions of a CHLH/ABAR interaction protein, the chloroplast co-chaperonin 20 (CPN20) in ABA signaling in Arabidopsis thaliana. We showed that down-expression of the CPN20 gene increases, but overexpression of the CPN20 gene reduces, ABA sensitivity in the major ABA responses including ABA-induced seed germination inhibition, postgermination growth arrest, promotion of stomatal closure and inhibition of stomatal opening. Genetic evidence supports that CPN20 functions downstream or at the same node of CHLH/ABAR, but upstream of the WRKY40 transcription factor. The other CPN20 interaction partners CPN10 and CPN60 are not involved in ABA signaling. Our findings show that CPN20 functions negatively in the ABAR-WRKY40 coupled ABA signaling independently of its co-chaperonin role, and provide a new insight into the role of co-chaperones in the regulation of plant responses to environmental cues.Electronic supplementary materialThe online version of this article (doi:10.1007/s11103-013-0082-8) contains supplementary material, which is available to authorized users.

Protective effect of edaravone on blood-brain barrier (BBB) in experimental cerebral infarction rats was investigated. SD rats were prepared as the permanent middle cerebral artery occlusion model and randomly divided into 4 groups: cerebral infarction model group, edaravone low, medium and high dose groups. Healthy rats only for operation and no filament were selected as the sham operation control group. Rats in the cerebral infarction model group and the control group were given normal saline, and those in the edaravone low, medium and high dose groups were given edaravone 10, 15 and 20 mg/kg, respectively. The survival status, the body weight and neurological function score before and after treatment, the brain water content and the permeability of the blood-brain barrier after treatment were measured. The expression levels of NFE2-related factor 2 (NRF2) and hemeoxygenase 1 (HO-1) in rat brain tissue were detected by western blotting. Levels of peripheral blood malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH) were detected by ELISA. The state of the rats in three edaravone groups was improved compared with that of the cerebral infarction group. Compared with the cerebral infarction model group, the body weight was significantly increased after treatment and the neurological function score, brain tissue water content and BBB permeability were significantly decreased in three edaravone groups (P<0.05). Compared with the model group of cerebral infarction, the expression of NRF-2 and HO-1 in the brain of the three edaravone groups was significantly higher (P<0.05). Compared with the model group of cerebral infarction, the expression of MDA and GSH in the three edaravone groups was significantly decreased, GSH and SOD was increased (P<0.05), in a dose-dependent manner. Edaravone might play a protective role in the BBB by activating the NRF-2/HO-1 signaling pathway.

Parkinson's disease (PD) is a progressive neurodegenerative disorder. A common and disabling disease of the elderly, the standard dopamine replacement therapies do not arrest the ongoing neurodegeneration, thus calling for new treatment strategies. The present study aimed to clarify the functional relevance of the hypoxia inducible factor-1α (HIF-1α)/microRNA-128-3p (miR-128-3p) axis in hippocampal neurodegeneration in a PD mouse model obtained by intraperitoneal injection of MPTP. Targeting relationship between miR-128-3p and Axin1 was verified, so we probed the roles of Hif1a, miR-128-3p, and Axin1 in apoptosis of hippocampal neurons with gain-and loss-of function experiments using flow cytometry and TUNEL staining. We found that Axin1 was upregulated in hippocampal tissues and cells of the MPTP-lesioned mouse model of PD, while Hif1a and miR-128-3p were downregulated. Elevation of HIF-1α/miR-128-3p inhibited apoptosis of hippocampal neurons via Wnt/β-catenin signaling pathway activation due to the suppression of Axin1 in PD. In addition, forced overexpression of Hif1a could ameliorate motor dysfunction and pathological changes in the model. Collectively, activation of the HIF-1α/miR-128-3p axis could repress hippocampal neurodegeneration in MPTP-lesioned mice through an activated Wnt/β-catenin pathway due to Axin1 downregulation.

Geniposide (GEN) is a natural antioxidant and anti-inflammatory product and plays an important role in the treatment of diabetes and diabetic complications. To explore the biological functions and mechanism of GEN in diabetic retinopathy (DR), we constructed the in vitro and in vivo model of DR by using primary cultured mouse retinal Müller cells and C57BL/6 mice, respectively. We found that GEN inhibited ROS accumulation, NF-κB activation, Müller cell activation, and inflammatory cytokine secretion both in vitro and in vivo, which is probably mediated through the Nrf2 pathway. Exendin (9-39) (EX-9), an antagonist of glucagon-like peptide-1 receptor (GLP-1R), abolished the protective effect of GEN on high glucose- (HG-) induced Müller cells. Additionally, GEN decreased hyperglycemia-induced damage to Müller cells and blood-retinal barrier in the retinas of mice with DR. We demonstrated that GEN was capable of protecting Müller cells and mice from HG-induced oxidative stress and inflammation, which is mostly dependent on the Nrf2 signaling pathway through GLP-1R. GEN may be an effective approach for the treatment of DR.

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BackgroundEndophthalmitis, or inflammation of the internal tissues of the eye, may follow trauma and results in loss of vision if not treated promptly. Vitrectomy is used to debride the inflamed vitreous. This retrospective study aimed to compare the outcome from conventional vitrectomy (CV) and endoscope-assisted vitrectomy (EAV) performed for endophthalmitis within five days and 10 days after open ocular trauma.Material/MethodsThe clinical data from 18 patients (18 eyes) with endophthalmitis caused by open ocular trauma were analyzed at a single center. CV or EAV was performed based on the degree of vision and the involvement of the vitreous cavity.ResultsOf the 18 patients with endophthalmitis, seven patients underwent EAV, and 11 patients underwent CV. The number of cases with preoperative corneal laceration, edema, bleeding, and formation of corneal nebular opacity was higher in the EAV group compared to the CV group. Four patients had retinal detachment, of which three patients were treated with EAV. Seventeen patients had their sight restored by a single vitrectomy procedure. In 10 cases, the culture of the vitreous fluid was positive for infection, and eight patients had Gram-positive Staphylococcus epidermidis infection. Follow-up showed that vitrectomy performed within five days (P=0.001) and 10 days (P=0.047) of open ocular trauma resulted in significant improvement of visual acuity.ConclusionsVitrectomy for endophthalmitis due to open ocular trauma performed within five days of injury restored visual acuity. EAV was shown to be an effective alternative to CV.