MYB2 Is Important for Tapetal PCD and Pollen Development by Directly Activating Protease Expression in Arabidopsis.

Tapetal programmed cell death (PCD) is a complex biological process that plays an important role in pollen formation and reproduction. Here, we identified the MYB2 transcription factor expressed in the tapetum from stage 5 to stage 11 that was essential for tapetal PCD and pollen development in Arabidopsis thaliana. Downregulation of MYB2 retarded tapetal degeneration, produced defective pollen, and decreased pollen vitality. EMSA and transcriptional activation analysis revealed that MYB2 acted as an upstream activator and directly regulated expression of the proteases CEP1 and ßVPE. The expression of these proteases was lower in the buds of the myb2 mutant. Overexpression of either/both CEP1 or/and ßVPE proteases partially recover pollen vitality in the myb2 background. Taken together, our results revealed that MYB2 regulates tapetal PCD and pollen development by directly activating expression of the proteases CEP1 and ßVPE. Thus, a transcription factor/proteases regulatory and activated cascade was established for tapetal PCD during another development in Arabidopsis thaliana. Highlight: MYB2 is involved in tapetal PCD and pollen development by directly regulating expression of the protease CEP1 and ßVPE and establishes a transcription factor/proteases regulatory and activated cascade.

Chronic acarbose treatment alleviates age-related behavioral and biochemical changes in SAMP8 mice.

The administration of maintaining the homeostasis of insulin/insulin-like growth factor 1 (IGF-1) signaling and/or glucose metabolism may reverse brain aging. In the present study, we investigated the effect of acarbose, an inhibitor of α-glucosidase, on age-related behavioral and biochemical changes. The SAMP8 mice were randomly divided into old control group and acarbose-treatment group. The mice in the acarbose group were administered acarbose (20 mg/kg/d, dissolved in drinking water) orally from 3 to 9 months of age when a new group of 3-month-old mice was added as young controls. The results showed that the aged controls exhibited declines in sensorimotor ability, open field anxiety, spatial and non-spatial memory abilities, decreased serum insulin levels, increased IGF-1 receptor and synaptotagmin 1 (Syt1) levels and decreased insulin receptor, brain-derived neurotrophic factor (BDNF) and syntaxin 1 (Stx1) levels in the hippocampal layers. The age-related behavioral deficits correlated with the serological and histochemical data. Chronic acarbose treatment relieved these age-related changes, especially with respect to learning and memory abilities. This protective effect of acarbose on age-related behavioral impairments might be related to changes in the insulin system and the levels of BDNF, IGF-1R, and the pre-synaptic proteins Syt1 and Stx1. In conclusion, long-term treatment with acarbose ameliorated the behavioral deficits and biochemical changes in old SAMP8 mice and promoted successful aging. This study provides insight into the potential of acarbose for the treatment of brain aging.

Cordycepin decreases activity of hippocampal CA1 pyramidal neuron through membrane hyperpolarization.

Cordycepin (3'-deoxyadenosine) is the main functional component of Cordycepins militaris, a renowned traditional Chinese medicine, which has been shown to possess anti-tumor, anti-inflammatory, anti-diabetic and neuro-protective effects. However, the effect of cordycepin on the central nervous system (CNS) remains unclear. In this study, the effects of cordycepin on neuronal activity were investigated on the CA1 pyramidal neurons in rat hippocampal brain slices using a whole-cell patch clamp technique. Our results revealed that cordycepin significantly decreased the frequency of both the spontaneous and evoked action potential (AP) firing. While AP spike width, the amplitude of fast after hyperpolarization (fAHP), and membrane input resistance were not altered by cordycepin, the neuronal membrane potential was hyperpolarized by cordycepin. Collectively, these results demonstrate that cordycepin reduces neuronal activity by inducing membrane hyperpolarization, indicating that cordycepin may be a potential therapeutic strategy for ischemic and other excitotoxic disorders.

[Biotransformation of furannoligularenone by hairy root cultures of Polygonum multiflorum].

OBJECTIVE: To investigate the biotransformation of furannoligularenone by hairy roots of Polygonum multiflorum. METHODS: Furannoligularenone was added to the medium of hairy roots of P. multiflorum after precultured for 9 days, then they were co-cultured. The products were isolated and identified on the basis of their physical chemical properties and spectroscopic data. The T-C curve of biotransformation was investigated with HPLC. RESULTS: The hairy roots of P. multiflorum transformed the substrate to two products, 3-oxo-eremophila-1,7(11)-dien-12,8-olide(II) and 3-oxo-8-hydroxy-eremophila-1,7(11)-dien-12,8-olide(III). After co-cultured for 3 days, the mole conversion ratio of the substrate reached the highest (27.2%). CONCLUSION: It's possible to biotransform furannoligularenone by hairy roots of P. multiflorum.