24-Methylenecycloartanyl ferulate, a major compound of γ-oryzanol, promotes parvin-beta expression through an interaction with peroxisome proliferator-activated receptor-gamma 2 in human breast cancer cells

Inhibition of the ILK-AKT pathway by upregulation of PARVB contributes to the cochlear cell death in Fascin2 gene knockout mice

The Fscn2 (Fascin2) gene encodes an actin cross-linking protein that is involved in the formation of hair cell stereocilia and retina structure. Mutations in Fscn2 gene have been linked to hearing impairment and retinal degeneration in humans and mice. To understand the function of the Fscn2 gene, we generated the Fscn2 knockout mice, which showed progressive loss of hearing and hair cells. Our goal of the present study was to investigate the mechanism underlying cochlear cell death in the Fscn2 knockout mice. Microarray analysis revealed upregulation of expression of PARVB, a local adhesion protein, in the inner ears of Fscn2 knockout mice at 8 weeks of age. Further studies showed increased levels of PARVB together with cleaved-Caspase9 and decreased levels of ILK, p-ILK, p-AKT, and Bcl-2 in the inner ears of Fscn2 knockout mice of the same age. Knockdown of Fscn2 in HEI-OCI cells led to decreased cell proliferation ability and migration rate, along with increased levels of PARVB and decreased levels of ILK, p-ILK, p-AKT, Bcl-2 and activated Rac1 and Cdc42. Overexpression of Fscn2 or inhibition of Parvb expression in HEI-OC1 cells promoted cell proliferation and migration, with increased levels of ILK, p-ILK, p-AKT, and Bcl-2. Finally, FSCN2 binds with PPAR-γ to reduce its nuclear translocation in HEI-OC1 cells, and inhibition of PPAR-γ by GW9662 decreased the level of PARVB and increased the levels of p-AKT, p-ILK, and Bcl-2. Our results suggest that FSCN2 negatively regulates PARVB expression by inhibiting the entry of PPAR-γ into the cell nucleus, resulting in inhibition of ILK-AKT related pathways and of cochlear cell survival in Fscn2 knockout mice. Our findings provide new insights and ideas for the prevention and treatment of genetic hearing loss.

Eukaryotic initiation factor 5A hypusine as a negative regulator of adenosine 2B receptor (A2bAR) through interaction with stem loop sequences within the A2bAR 3'-untranslated region

PURPOSE

The aim of this study was to investigate whether eIF5A hypusine (eIF5A^Hyp) reduces adenosine 2b receptor (A2bAR) gene expression through interaction with highly structured stem-loop sequences within the A2bAR 3'UTR.

METHODS AND RESULTS

Based on real-time PCR and western blotting, expression of A2bAR mRNA was significantly decreased upon treatment with eIF5A^Hyp in mouse embryonic fibroblasts of eIF5A (eIF5A-MEF) and 3T3-L1 cells. Target Scan software and RNAfold web server predicted two different structures formed by stem-loop sequences with overlapping microRNA 27 seed sequences and mutations. The EMSA results showed significantly impaired formation of the wild type (WT) biotin-labeled A2bAR probe (27 base) containing stem loop sequences-eIF5A^Hyp complex by mutation of stem-loop sequences or by eIF5A non-hypusine (eIF5A^Lys). The luciferase reporter assay showed that GC7-induced eIF5A^Lys accumulation increased the activity of pMIR-A2bAR WT containing the same stem-loop sequence in 3T3-L1 cells, whereas the activity with pMIR-A2bAR Mut was increased compared to WT control without dependence on GC7. Oil Red O staining showed that suppression of A2bAR expression (A2bAR siRNA and eIF5A^Hyp) increased the amount of lipid droplet formation and the mRNA levels of lipid droplet-related genes (C/EBP-β, PPAR-γ, FABP4, SREBP-1, and Perilipin). In contrast, overexpression of A2bAR (A2bAR vector, eIF5A^Lys vector, and GC7) significantly decreased the expression of lipid droplet-associated genes and lipid droplet formation.

CONCLUSIONS

eIF5A^Hyp acts as a negative regulator of A2bAR gene expression through stem loop sequences in A2bAR 3'UTR, allowing differentiation of adipocytes.

Parvin: A hub of intracellular signalling pathways regulating cellular behaviour and disease progression

α-actinin superfamily houses the family of parvins, comprising α, β and γ isoforms in the vertebrates and a single orthologue in the invertebrates. Parvin as an adaptor protein is a member of the ternary IPP-complex including Integrin Linked Kinase (ILK) and particularly-interesting-Cys-His-rich protein (PINCH). Each of the complex proteins showed a conserved lineage and was principally used by the evolutionarily primitive integrin-adhesome machinery to regulate cellular behaviour and signalling pathways. Parvin facilitated integrin mediated integration of the extracellular matrix with cytoskeletal framework culminating in regulation of cellular adhesion and spreading, cytoskeleton reorganisation and cell survival. Studies have established role of parvin in pregnancy, lactation, matrix degradation, blood vessel formation and in several diseases such as cancer, NAFLD and cardiac diseases etc. This review narrates the history of parvin discovery, its elaborate gene structure and conservation across phyla including cellular expression, localisation and interacting partners in vertebrates as well as invertebrates. The review further discusses how parvin acts as an epicentre of signalling pathways, its associated mutants and diseased conditions.

Isolation and structural elucidation of unique γ-oryzanol species in rice bran oil

Even though γ-oryzanol (OZ) such as 24-methylenecycloartanyl ferulate (24MCAFA) is abundant in purified rice bran oil, we realized that the oil contained the prospect of two additional novels of OZ species. To identify this, we isolated and analyzed their chemical structures by using HPLC-UV-MS, NMR, and IR. We revealed for the first time that the oil had also contained cyclobranyl ferulate (CBFA) and cyclosadyl ferulate (CSFA) which are likely to be exist due to the isomerism of 24MCAFA under acid condition. OZ profile including CBFA and CSFA was roughly similar between commercial rice bran oils and processed foods containing the oils, suggesting that people might have often consumed CBFA and CSFA from rice bran oils and/or processed foods. Since different OZ species are known to have different functionality, this study opens the chance to explore more the contribution of CBFA and CSFA for human health and wellness.

Definitive evidence of the presence of 24-methylenecycloartanyl ferulate and 24-methylenecycloartanyl caffeate in barley

γ-Oryzanol (OZ), which has a lot of beneficial effects, is a mixture of ferulic acid esters of triterpene alcohols (i.e., triterpene alcohol type of OZ (TTA-OZ)) and ferulic acid esters of plant sterols (i.e., plant sterol type of OZ (PS-OZ)). Although it has been reported that OZ is found in several kinds of cereal typified by rice, TTA-OZ (e.g., 24-methylenecycloartanyl ferulate (24MCA-FA)) has been believed to be characteristic to rice and has not been found in other cereals. In this study, we isolated a compound considered as a TTA-OZ (i.e., 24MCA-FA) from barley and determined the chemical structure using by HPLC-UV-MS, high-resolution MS, and NMR. Based on these results, we proved for the first time that barley certainly contains 24MCA-FA (i.e., TTA-OZ). During the isolation and purification of 24MCA-FA from barley, we found the prospect that a compound with similar properties to OZ (compound-X) might exist. To confirm this finding, the compound-X was also isolated, determined the chemical structure, and identified as a caffeic acid ester of 24-methylenecycloartanol (24MCA-CA), which has rarely been reported before. We also quantified these compounds in various species of barley cultivars and found for the first time the existence of 24MCA-FA and 24MCA-CA in various barley. Through these findings, it opens the possibility to use barley as a new source of 24MCA-FA and 24MCA-CA.

Cytotoxic Effects of 24-Methylenecyloartanyl Ferulate on A549 Nonsmall Cell Lung Cancer Cells through MYBBP1A Up-Regulation and AKT and Aurora B Kinase Inhibition

Lung cancer is the second most prevalent cancer. Nonsmall cell lung cancer (NSCLC) is the most common type of lung cancer. The low efficacy in current chemotherapies impels us to find new alternatives to prevent or treat NSCLC. Rice bran oil is cytotoxic to A549 cells, a NSCLC cell line. Here, we identified 24-methylenecyloartanyl ferulate (24-mCAF) as the main component responsible for the cytotoxicity in A549 cells. An iTRAQ-based quantitative proteomics analysis revealed that 24-mCAF inhibits cell proliferation and activates cell death and apoptosis. 24-mCAF induces up-regulation of Myb binding protein 1A (MYBBP1A), a tumor suppressor that halts cancer progression. 24-mCAF inhibits the activity of AKT and Aurora B kinase, two Ser/Thr kinases involved in MYBBP1A regulation and that represent important targets in NSCLC. This study provides the first insight of the effect of 24-mCAF, the main component of rice bran oil, on A459 cells at the cellular and molecular levels.

The impact of Rhizopus oryzae cultivation on rice bran: Gamma-oryzanol recovery and its antioxidant properties

This study evaluated the effect of the solid state cultivation (SSC) time of rice bran by Rhizopus oryzae on γ-oryzanol recovery and its antioxidant properties. Gamma-oryzanol was extracted with organic solvents and its extracts were characterized by GC-FID and HPLC-UV. The antioxidant capacity was assessed by DPPH and ABTS⁺ assays, β-carotene/linoleic acid system, and reduction of oxidation in lipid system. The biomass showed the γ-oryzanol recovery increased by 51.5% (20.52mg/g), and 5.7% in polyunsaturated fatty acids. The γ-oryzanol major components changing in their profile. The γ-oryzanol extract from biomass (72h) showed the greatest DPPH inhibition (59.0%), while 90.5% inhibition of oxidation of β-carotene/linoleic acid system, and 30% reduction of the indicators of oxidation in olive oil was observed in the one cultivated at 96h, these behaviors were confirmed by PCA analyses. SSC provides an increase in the γ-oryzanol recovery followed by improving of the functional properties of rice bran.

Ninety-day oral toxicity study of rice-derived γ-oryzanol in Sprague-Dawley rats

A 90-day oral toxicity study of γ-oryzanol, a rice-derived triterpenoid ferulate, was performed by oral gavage administration to male and female Sprague-Dawley rats at doses of 0, 1000, and 2000 mg/kg body weight/day. All rats administered γ-oryzanol survived throughout the study period. Both male and female rats showed no toxicologically significant changes of the general signs, examination findings, body weight, food consumption, functional observational battery results, ophthalmological findings, urinalysis, hematology tests, clinical chemistry tests, organ weights, and necropsy findings. Moreover, there were no histopathological changes related to administration of γ-oryzanol in males and females from the 2000 mg/kg body weight/day group. In conclusion, the no observed adverse effect level (NOAEL) of γ-oryzanol exceeded 2000 mg/kg body weight/day for both male and female rats under the conditions of this study.