Identification, Functional Study, and Promoter Analysis of HbMFT1, a Homolog of MFT from Rubber Tree (Hevea brasiliensis).

A homolog of MOTHER OF FT AND TFL1 (MFT) was isolated from Hevea brasiliensis and its biological function was investigated. Protein multiple sequence alignment and phylogenetic analysis revealed that HbMFT1 conserved critical amino acid residues to distinguish MFT, FLOWERING LOCUS T (FT) and TERMINAL FLOWER1 (TFL1)-like proteins and showed a closer genetic relationship to the MFT-like group. The accumulation of HbMFT1 was generally detected in various tissues except pericarps, with the highest expression in embryos and relatively higher expression in roots and stems of seedlings, flowering inflorescences, and male and female flowers. HbMFT1 putative promoter analysis showed that tissue-specific, environmental change responsive and hormone-signaling responsive elements were generally present. HbMFT1 was strongly induced under a short-day condition at 28 °C, with the highest expression after the onset of a day. Overexpression of HbMFT1 inhibited seed germination, seedling growth, and flowering in transgenic Arabidopsis. The qRT-PCR further confirmed that APETALA1 (AP1) and FRUITFULL (FUL) were drastically down-regulated in 35S::HbMFT1 plants. A histochemical ß-glucuronidase (GUS) assay showed that HbMFT1::GUS activity was mainly detected in stamens and mature seeds coinciding with its original expression and notably induced in rosette leaves and seedlings of transgenic Arabidopsis by exogenous abscisic acid (ABA) due to the presence of ABA cis-elements in HbMFT1 promoter. These results suggested that HbMFT1 was mainly involved in maintenance of seed maturation and stamen development, but negatively controlled germination, growth and development of seedlings and flowering. In addition, the HbMFT1 promoter can be utilized in controlling transgene expression in stamens and seeds of rubber tree or other plant species.

Correlation among RKIP expression, NF-κB p65 levels, and T-lymphocyte subsets in gastric cardia adenocarcinoma.

The aim of this study was to characterize variations in Raf kinase inhibitor protein (RKIP) expression and related signaling molecules in gastric cardia adenocarcinoma. Cancerous and precancerous tissues were collected from patients with gastric cardia adenocarcinoma and normal tissue was collected from healthy controls. RKIP expression was detected in these tissues and the serum levels of NF-κB p65 and T-lymphocyte subsets were measured. Positive RKIP expression was higher in gastric cardia adenocarcinoma tissues than in precancerous tissues. The serum level of total NF-κB p65 was higher in patients with gastric cardia adenocarcinoma than in healthy controls. Levels of NF-κB p65 did not correlate with positive and negative expression of RKIP, but were higher in patients with lymph node metastasis than in those without it. The cellular immune function of the gastric cardia adenocarcinoma group was lower than in normal controls, particularly in cases with negative RKIP expression. RKIP is downregulated in gastric cardia adenocarcinoma tissues, which is related to the occurrence, progression, invasion, and metastasis of tumors. The possible mechanism for this may be the inhibition of NF-κB activity and cellular immune function, which allows for the escape of tumor cells from immune surveillance.

Rituximab regulates the expression of the Raf kinase inhibitor protein via NF-κB in renal tissue of rats with diabetic nephropathy.

This study aimed to investigate the expression levels of the Raf kinase inhibitor protein (RKIP) and NF-κB in renal tissues of diabetic nephropathy (DN) rats, and to determine the underlying molecular targets of rituximab (RTX), with the goal of developing new clinical treatment selection for DN. Sprague-Dawley rats were randomly divided into a normal group (N), a DN group (M), and an RTX treatment group (D). Blood glucose and 24-h urine protein levels of rats were determined. The expression levels of RKIP and NF-κB in glomerular tissues were determined by immunohistochemistry staining and Western blotting. Comparisons between the M and N groups revealed that the concentrations of blood glucose and 24-h urine protein were significantly increased by DN (P < 0.01), and the expression levels of RKIP and NF-κB were significantly decreased and increased (P < 0.05), respectively. In the D group, the expression levels of RKIP and NF-κB were, respectively, upregulated and downregulated by RTX, and the concentrations of 24-h urine protein were also decreased by RTX. These results suggest that expression levels of RKIP might be regulated by RTX via NF-κB. This pathway could play an important role in the development and pathogenesis of DN. Therefore, RTX could be selected for clinical treatment of DN.

Proteomic analysis of the mice hippocampus after preconditioning induced by N-methyl-D-aspartate (NMDA).

Preconditioning induced by N-methyl-D-aspartate (NMDA) has been used as a therapeutic tool against later neuronal insults. NMDA preconditioning affords neuroprotection against convulsions and cellular damage induced by the NMDA receptor agonist, quinolinic acid (QA) with time-window dependence. This study aimed to evaluate the molecular alterations promoted by NMDA and to compare these alterations in different periods of time that are related to the presence or lack of neuroprotection. Putative mechanisms related to NMDA preconditioning were evaluated via a proteomic analysis by using a time-window study. After a subconvulsant and protective dose of NMDA administration mice, hippocampi were removed (1, 24 or 72 h) and total protein analyzed by 2DE gels and identified by MALDI-TOF. Differential protein expression among the time induction of NMDA preconditioning was observed. In the hippocampus of protected mice (24 h), four proteins: HSP70(B), aspartyl-tRNA synthetase, phosphatidylethanolamine binding protein and creatine kinase were found to be up-regulated. Two other proteins, HSP70(A) and V-type proton ATPase were found down-regulated. Proteomic analysis showed that the neuroprotection induced by NMDA preconditioning altered signaling pathways, cell energy maintenance and protein synthesis and processing. These events may occur in a sense to attenuate the excitotoxicity process during the activation of neuroprotection promoted by NMDA preconditioning.

Proteomic analysis of low- to high-grade astrocytomas reveals an alteration of the expression level of raf kinase inhibitor protein and nucleophosmin.

Proteomic approaches have been useful for the identification of aberrantly expressed proteins in complex diseases such as cancer. These proteins are not only potential disease biomarkers, but also targets for therapy. The aim of this study was to identify differentially expressed proteins in diffuse astrocytoma grade II, anaplastic astrocytoma grade III and glioblastoma multiforme grade IV in human tumor samples and in non-neoplastic brain tissue as control using 2-DE and MS. Tumor and control brain tissue dissection was guided by histological hematoxylin/eosin tissue sections to provide more than 90% of tumor cells and astrocytes. Six proteins were detected as up-regulated in higher grade astrocytomas and the most important finding was nucleophosmin (NPM) (p<0.05), whereas four proteins were down-regulated, among them raf kinase inhibitor protein (RKIP) (p<0.05). We report here for the first time the alteration of NPM and RKIP expression in brain cancer. Our focus on these proteins was due to the fact that they are involved in the PI3K/AKT/mTOR and RAS/RAF/MAPK pathways, known for their contribution to the development and progression of gliomas. The proteomic data for NPM and RKIP were confirmed by Western blot, quantitative real-time PCR and immunohistochemistry. Due to the participation of NPM and RKIP in uncontrolled proliferation and evasion of apoptosis, these proteins are likely targets for drug development.