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Azulene, a simple polar polycyclic aromatic hydrocarbon with connected electron donor and acceptor (DA), ignites the hope of designing second-order nonlinear optical (NLO) molecular materials from pure nonpolar carbon nanomaterials. In this work, a butterfly-shaped nanographene (π-DA-π) was designed by incorporating azulene between two coronenes. One more electron in a N atom or one electron fewer in a B atom with respect to a C atom can polarize charge distribution in carbon nanomaterials, and further doping of B and N in the designed butterfly-shaped nanographene changes the system from π-DA-π to D-π-A, leading to strong NLO responses. For example, the largest static first hyperpolarizability even reaches 173.89×10-30 â esu per heavy atom. The synergetic role of B, N and azulene in the nanographene is scrutinized, and such a doping strategy is found to provide an effective means for the design of carbon-based functional materials. The strong second-order NLO responses of these butterfly-shaped carbon-based nanographenes under external fields, for example, sum frequency generation and difference frequency generation, could inspire future experimental exploration.
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Push-pull π-conjugated molecules are one of the paradigms of second order nonlinear optical (NLO) materials and have been extensively explored. However, high-performance second order NLO materials with an optimum electron donor (D), π-bridge (π) and acceptor (A) under this paradigm are still the most sought-after. In the present work, D-π-A molecules with optimal D, π and A combination for strong second order NLO properties are proposed based on molecular orbital theories. The optimal D-π-A push-pull molecule achieves an unprecedentedly strong NLO response under the D-π-A paradigm, i.e., the static first hyperpolarizability reaches -453.92 × 10-30 esu per heavy atom using azulene as part of the π-bridge and acceptor to synergistically reinforce the strength of the acceptor. The protocols of D-π-A NLO molecule design through frontier molecular orbital matching of D, π and A with optimal combination of electron donating and accepting strengths shed light on future molecular NLO materials exploration. The simulated two-dimensional second order spectra provide useful information (e.g., sum frequency generation) on the applications of those D-π-A push-pull molecules in nonlinear optics.
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The high stability, feasible modification, and good π-conjugation of porphyrin derivatives render these porphyrin-based nanomaterials suitable as potential third order nonlinear optical (NLO) materials. Introducing an azulene in pristine porphyrins can significantly improve the second order NLO properties of the system, and this is studied in the present work using density functional theory based methods and the sum-over-states model. The relative orientation of azulene plays a determinant role in the enhancement of the static first hyperpolarizability (ãß0ã), e.g., the ãß0ã per heavy atom increases from 0.31 × 10-30 esu to 9.78 × 10-30 esu. Further addition of metals (Mg and Zn) in these azulene-fused porphyrin systems leads to an even larger ãß0ã per heavy atom of 41.59 × 10-30 esu, much larger than that of a recently reported porphyrin derivative (26.47 × 10-30 esu). A novel strategy to stabilize the electronic structures as well as maintain good second order NLO responses by introducing appropriate metals into the azulene-fused porphyrins is extendable to other similar systems. Strong sum frequency generation and different frequency generations of those azulene-fused porphyrins in visible and near-infrared regions may inspire experimental exploration and related applications of azulene-based porphyrins particularly in biological nonlinear optics.
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Porfirinas , Azulenos/química , Porfirinas/químicaRESUMO
The recently synthesized triangulenes with non-bonding edge states could have broad potential applications in magnetics, spintronics and electro-optics if they have appropriate electronic structure modulation. In the present work, strategies based on molecular orbital theory through heteroatom doping are proposed to redistribute, reduce or eliminate the spin of triangulenes for novel functional materials design, and the role of B, N, NBN, and BNB in such intended electronic structure manipulation is scrutinized. π-Extended triangulenes with tunable electronic properties could be potential nonlinear optical (NLO) materials with appropriate inhibition of their polyradical nature. The elimination of spin is achieved by B, N, NBN, and BNB doping with the intended geometric arrangement for enhanced polarity. Intended doping of BNB results in an optimal structure with large static first hyperpolarizability (ãß0ã) as well as strong Hyper-Rayleigh scattering (HRS) ßHRS(-2ω; ω, ω) (ω = 1064.0 nm), TG7-BNB-ba with a large ãß0ã (18.85 × 10-30 esu per heavy atom) and ßHRS (1.15 × 10-28 esu per heavy atom) much larger than that of a synthesized triangular molecule (1.12 × 10-30 esu of ãß0ã per heavy atom and 5.04 × 10-30 esu of ßHRS per heavy atom). The strong second order NLO responses in the near-infrared and visible regions, particularly the strong sum frequency generation, make these B or (and) N doped triangulenes promising candidates for the fabrication of novel carbon-based optoelectronic devices and micro-NLO devices.
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Novel carbon based "X-type" graphene nanoribbons (GNRs) with azulenes were designed for applications in nonlinear optics in the present work, and the second order nonlinear optical (NLO) properties of those X-type GNRs were predicted using the sum-over-states (SOS) model. The GNRs with edge states are feasibly polarized. The effects of zigzag edges on the NLO properties of GNRs are scrutinized by passivation, and the electronic structures of GNRs are modulated with heteroatoms at the zigzag edges for improved stability and NLO properties. Those nanomaterials were further functionalized with electron-donating and electron-withdrawing groups (NH2/NO2) to enhance the NLO responses, and the connection of those functional groups at the azulene ends play a determinant role in the enhancement of the NLO properties of those X-type nanoribbons, e.g., the static first hyperpolarizability (ãß0ã) changes from -783.23 × 10-30 esu to -1421.98 × 10-30 esu. The mechanism of such an enhancement has been investigated. Through two-dimensional second order NLO spectra simulations, particularly besides the strong electro-optical Pockels effect and optical rectification responses, strong electronic sum frequency generations and difference frequency generations are observed in those GNRs. The strong second order NLO responses of those GNRs in the visible light region bring about potential applications of these carbon nanomaterials in nonlinear nanophotonic devices and biological nonlinear optics.
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Iron (Fe) deficiency is a world-wide serious agricultural problem. Maize secretes 2'-deoxymugineic acid (DMA) to uptake and utilize Fe from the soil. In order to explore the gene expression patterns of the DMA secretion channel gene YS3, we cloned the 2813 bp YS3 promoter, and constructed the plant expression vector pCAMBIA-YS3GUS. The promoter contains a lot of TATA-boxes and CAAT-boxes, and cis-acting regulatory elements such as the light responsive elements and the hormone responsive elements. Arabidopsis was transformed via Agrobacterium tumefacients-mediated procedures to obtain the pYS3::GUS transgenic plants, which were confirmed by GUS staining. Then, the stained tissue was observed using paraffin section methods and the YS3 promoter activity was also analyzed. We found that the promoter could drive GUS gene expression specifically in the root epidermal cells. Mechanical damage could activate the promoter, and drive the GUS gene expression adjacent to the damage sites. Our results provide a molecular basis to understand the DMA secretion process in maize.
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Ácido Azetidinocarboxílico/análogos & derivados , Genes de Plantas/genética , Proteínas de Plantas/genética , Regiões Promotoras Genéticas/genética , Zea mays/genética , Arabidopsis/genética , Ácido Azetidinocarboxílico/metabolismo , Clonagem Molecular/métodos , Regulação da Expressão Gênica de Plantas/genética , Raízes de Plantas/genética , Plantas Geneticamente Modificadas/genéticaRESUMO
BACKGROUND: Studies of functional modules in a Protein-Protein Interaction (PPI) network contribute greatly to the understanding of biological mechanisms. With the development of computing science, computational approaches have played an important role in detecting functional modules. RESULTS: We present a new approach using multi-agent evolution for detection of functional modules in PPI networks. The proposed approach consists of two stages: the solution construction for agents in a population and the evolutionary process of computational agents in a lattice environment, where each agent corresponds to a candidate solution to the detection problem of functional modules in a PPI network. First, the approach utilizes a connection-based encoding scheme to model an agent, and employs a random-walk behavior merged topological characteristics with functional information to construct a solution. Next, it applies several evolutionary operators, i.e., competition, crossover, and mutation, to realize information exchange among agents as well as solution evolution. Systematic experiments have been conducted on three benchmark testing sets of yeast networks. Experimental results show that the approach is more effective compared to several other existing algorithms. CONCLUSIONS: The algorithm has the characteristics of outstanding recall, F-measure, sensitivity and accuracy while keeping other competitive performances, so it can be applied to the biological study which requires high accuracy.
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Algoritmos , Biologia Computacional/métodos , Evolução Molecular , Mapeamento de Interação de Proteínas/métodos , Proteínas Fúngicas/metabolismo , Humanos , Leveduras/metabolismoRESUMO
Porphyrins are widely used as potential nonlinear optical (NLO) materials because of their highly delocalized π electrons and feasible synthesis and functionalization with broad biological applications. A variety of linear and cyclic porphyrin derivatives have been synthesized, and the correlation between their structures and NLO properties awaits being disclosed. In this work, the electronic structures and third-order NLO properties of linear and cyclic butadiyne-linked zinc porphyrin oligomers have been studied by quantum chemical methods and sum-over-states model. The static second hyperpolarizability (<γ0>) increases exponentially with the number of zinc porphyrin units ([<γ0>n] = 0.67[<γ0>1]n2.63, n = 2 â¼ 6) in linear π-conjugated oligomers, and the <γ0> of the linear hexamer is about 74 times that of the monomer. Such enhancement of <γ0> in linear oligomers originates from closely-lying frontier molecular orbitals available for low energy electron excitations and strong charge transfer-based excitations across porphyrins. The <γ0>s of cyclic porphyrins are lower than that of the linear hexamer, though the interaction between the ring and the ligand enhances the <γ0> of some cyclic zinc porphyrin complexes. The large two-photon absorption cross sections confer on these zinc porphyrin derivatives excellent candidates for two-photon absorption applications.
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Nonlinear optical (NLO) materials play an increasingly important role in optoelectronic devices, biomedicine, micro-nano processing, and other fields. The development of organic materials with strong second or (and) third NLO properties and a high stability is still challenging due to the unknown strategies for obtaining enhanced high order NLO properties. In the present work, π-conjugated systems are constructed by doping boron or (and) nitrogen atoms in the azulene moiety of azulene-based nanographenes (formed with an azulene chain with two bridging HCCHs at the two sides of the connecting CC bonds between azulenes, A1A2A3), and the NLO properties are predicted with time-dependent density functional theory based methods and a sum-over-states model. The doping of heteroatoms induces charge redistribution, tunes the frontier molecular orbital energy gap, changes the composition of some frontier molecular orbitals, and affects the NLO properties of those nanographenes. Among the designed nanographenes, the azulene-based nanographene with two nitrogen atoms at the two ends has the largest static first hyperpolarizability (91.30 × 10-30 esu per heavy atom), and the further introduction of two N atoms at the two ends of the central azulene moiety of this nanographene results in a large static second hyperpolarizability while keeping the large static first hyperpolarizability.
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INTRODUCTION: Aging of hematopoietic stem cells (HSCs) has emerged as an important challenge to human health. Recent advances have raised the prospect of rejuvenating aging HSCs via specific medical interventions, including pharmacological treatments. Nonetheless, efforts to develop such drugs are still in infancy until now. OBJECTIVES: We aimed to screen the prospective agents that can rejuvenate aging HSCs and explore the potential mechanisms. METHODS: We screened a set of natural anti-aging compounds through oral administration to sub-lethally irradiated mice, and identified 2,3,5,4'-tetrahydroxystilbene-2-O-ß-D-glucoside (TSG) as a potent rejuvenating agent for aging HSCs. Then naturally aged mice were used for the follow-up assessment to determine the HSC rejuvenating potential of TSG. Finally, based on the transcriptome and DNA methylation analysis, we validated the role of the AMP-activated protein kinase (AMPK)-ten-eleven-translocation 2 (Tet2) axis (the AMPK-Tet2 axis) as the underlying mechanisms of TSG for ameliorating HSCs aging. RESULTS: TSG treatment not only significantly increased the absolute number of common lymphoid progenitors (CLPs) along with B lymphocytes, but also boosted the HSCs/CLPs repopulation potential of aging mice. Further elaborated mechanism research demonstrated that TSG supplementation restored the stemness of aging HSCs, as well as promoted an epigenetic reprograming that was associated with an improved regenerative capacity and an increased rate of lymphopoiesis. Such effects were diminished when the mice were co-treated with an AMPK inhibitor, or when it was performed in Tet2 knockout mice as well as senescent cells assay. CONCLUSION: TSG is effective in rejuvenating aging HSCs by modulating the AMPK- Tet2 axis and thus represents a potential candidate for developing effective HSC rejuvenating therapies.
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Nanographenes (NGs) have drawn extensive attention as promising candidates for next-generation optoelectronic and nonlinear optical (NLO) materials, owing to its unique optoelectronic properties and high thermal stability. However, the weak polarity or even non-polarity of NGs (resulting in weak even order NLO properties) and the high chemical reactivity of zigzag edged NGs hinder their further applications in nonlinear optics, thus stabilization (lowering the chemical reactivity) and polarizing the charge distribution in NGs are necessary for such applications of NGs. The fusion of heptagon and pentagon endows the azulene with the character of donor-acceptor, and the B=N unit is isoelectronic to C=C unit. The introduction of polar azulene and BN are idea to polarize and stabilize the electronic structure of NGs for NLO applications. In the present review, a survey on the functionalization and applications of NGs in nonlinear optics is conducted. The engineering of the electronic structure of NGs by topological defects, doping and edge modulation is summarized. Finally, a summary of challenges and perspectives for carbon-based NLO nanomaterials is presented.
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Multiple sclerosis (MS) is a systemic inflammatory illness of the central nervous system that involves demyelinating lesions in the myelin-rich white matter and pathology in the grey matter. Despite significant advancements in drug research for MS, the disease's complex pathophysiology makes it difficult to treat the progressive forms of the disease. In this study, we identified a natural flavonoid compound icariin (ICA) as a potent effective agent for MS in ameliorating the deterioration of symptoms including the neurological deficit score and the body weight in a murine experimental autoimmune encephalomyelitis (EAE) model. These improvements were associated with decreased demyelination in the corpus callosum and neuron loss in the hippocampus and cortex confirmed by immunohistochemistry analysis. Meanwhile, it was observed that the activation of microglia in cerebral cortex and hippocampus were inhibited followed by the neuroinflammatory cytokines downregulation such as IL-1ß, IL-6 and TNF-α after ICA treatment, which was probably attributable to the suppression of microglial NLRP3 inflammasome activation. Additionally, molecular docking also revealed the binding force of ICA to NLRP3 inflammasome protein complexes in vitro. Taken together, our findings have demonstrated that ICA, as pleiotropic agent, prevents EAE-induced MS by improving demyelination and neuron loss, which interferes with the neuroinflammation via microglial NLRP3 inflammasome activation.
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Encefalomielite Autoimune Experimental , Esclerose Múltipla , Substância Branca , Camundongos , Animais , Esclerose Múltipla/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Inflamassomos/metabolismo , Simulação de Acoplamento Molecular , Encefalomielite Autoimune Experimental/patologia , Substância Branca/patologia , Microglia/metabolismo , Camundongos Endogâmicos C57BL , Modelos Animais de DoençasRESUMO
Improving autophagy-lysosome fusion has been considered a key method in the treatment of Alzheimer's disease (AD). Cornel iridoid glycoside (CIG) is extracted from Cornus officinalis and has been shown to promote the clearance of tau oligomers via the autophagy pathway. However, the mechanisms of CIG on autophagy deficits are not understood. Here, we found autophagy deficit and tau aggregation in the brains of P301S tau transgenic mice and MAPT cells edited using CRISPR-Cas9 technology. CIG decreased tau aggregation and alleviated autophagic markers involving the JNK/Beclin-1 signaling pathway which demonstrated CIG that might enhance lysosome formation by upregulating ATPase Vps4A expression. Knocking down VPS4A increased autophagosome accumulation and attenuated the effect of CIG on p62. In addition, CIG had no effect on tau oligomers but still inhibited the level of tau monomer in VPS4A knockout cells. The effective component (Sweroside, SWE) of CIG attenuated tau oligomers accumulation and increased Vps4A level but not CHMP2B. SWE could not change the level of tau oligomers in VPS4A knockout cells. In conclusion, CIG suppressed autophagosome accumulation by regulating the ATPase Vps4A/JNK. SWE is a core of active factors of CIG in Vps4A regulation. These findings suggest CIG may be a potential drug in AD treatment.
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Doença de Alzheimer , Autofagossomos , Adenosina Trifosfatases , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Animais , Autofagossomos/metabolismo , Autofagia/genética , Glicosídeos Iridoides/farmacologia , Iridoides/farmacologia , CamundongosRESUMO
Along with the extensive application of radiation in medical, military and other fields, human beings carry a greater risk of exposure to radiation environment that causes a range of physical injure, particularly to the brain in cognition. However, the radiation-associated cognitive disability is poorly understood and there is no effective prevention or long-term treatment. Here, we demonstrate that neurogenesis and neuroinflammation disorder are primarily involved in the pathophysiological basis of irradiation-induced cognitive decline. Furthermore, we discovered that tetrahydroxy stilbene glucoside (TSG), a natural active ingredient from Heshouwu that has been well known for its unique anti-aging effect as the Chinese herb, can be a promising mitigator to improve learning-memory ability by facilitating the neurogenesis in the proliferation and differentiation of the surviving neural progenitor cells via AMPK/Tet2, and attenuating the neuroinflammation in the microglial NLRP3 inflammasomes activation via AMPK in vivo. Additionally, TSG was also revealed to activate AMPK by molecular docking and kinase enzyme system assay in vitro. Taken together, our findings identify TSG, as the AMPK activator, prevents radiation-induced cognitive dysfunction by regulating neurogenesis and neuroinflammation via AMPK/Tet2 in rodents, and represents a very promising candidate for developing drugs that can be used for radiation-associated brain injury.
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Proteínas Quinases Ativadas por AMP , Dioxigenases , Cognição , Proteínas de Ligação a DNA , Dioxigenases/farmacologia , Glucosídeos , Humanos , Simulação de Acoplamento Molecular , Neurogênese , Doenças Neuroinflamatórias , EstilbenosRESUMO
Cognitive impairment is the main clinical manifestation of Alzheimer's disease (AD), and amyloid-ß (Aß) deposition and senile plaques are the characteristic neuropathological hallmarks in AD brains. This study aimed to explore the effect and mechanism of tetrahydroxy stilbene glucoside (TSG) on cognitive function in APP/PS1 mice during long-term administration. Here, we treated APP/PS1 model mice of AD with different doses of TSG (50 mg/kg and 100 mg/kg) for 5 to 17 months by gavage, and we further observed whether TSG could ameliorate the cognitive decline in APP/PS1 mice using behavioral tests, and investigated the possible mechanisms by immunohistochemistry and Western blotting. Our results showed that TSG treatment rescued the spatial and non-spatial learning and memory impairments of APP/PS1 mice at Morris water maze test and novel object recognition test. Furthermore, Aß40/42 deposition in the cortex and hippocampus of APP/PS1 mice treated with TSG was significantly reduced compared to the wild type mice using the immunohistochemical technique. Finally, Western blotting showed that TSG primarily decreased the APP expression to avoid the Aß plaque deposition in the cortex and hippocampus of mice. These results reveal the beneficial effects of TSG in APP/PS1-AD mice, which may be associated with the reduction of Aß deposits in the brain.
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Precursor de Proteína beta-Amiloide/metabolismo , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/patologia , Glucosídeos/uso terapêutico , Presenilina-1/metabolismo , Estilbenos/uso terapêutico , Peptídeos beta-Amiloides/metabolismo , Animais , Disfunção Cognitiva/complicações , Disfunção Cognitiva/fisiopatologia , Glucosídeos/farmacologia , Hipocampo/metabolismo , Hipocampo/patologia , Transtornos da Memória/complicações , Transtornos da Memória/tratamento farmacológico , Transtornos da Memória/fisiopatologia , Camundongos Transgênicos , Fragmentos de Peptídeos/metabolismo , Estilbenos/farmacologiaRESUMO
Schizophrenia is a mental illness characterized by episodes of psychosis, apathy, social withdrawal, and cognitive impairment. White matter lesions and glutamatergic hypofunction are reported to be the key pathogeneses underlying the multiple clinical symptoms of schizophrenia. Cuprizone (CPZ) is a copper chelator that selectively injures oligodendrocytes, and MK-801 is an antagonist of the N-methyl d-aspartate (NMDA) receptor. To better mimic the psychosis and complicated pathogenesis of schizophrenia, a novel possible mouse model was established by the combination of CPZ and MK-801. After exposure to CPZ for 5 weeks, the mice received a daily intraperitoneal injection of MK-801 for 2-weeks. Behavioral changes in the mouse model were evaluated using Y-maze, object recognition, and open field tests. Pathological changes were observed by transmission electron microscopy, oil red O staining, immunohistochemistry, and western blotting. The results showed that the novel mouse model induced by CPZ plus MK-801 exhibited severe spatial and recognition memory deficits, hyperactivity, and anxiety disorder. Moreover, the mice showed obvious demyelination and white matter damage and decreased expression levels of myelin basic protein (MBP) and 2',3'-cyclic nucleotide-3'-phosphodiesterase (CNPase) in the corpus callosum. Furthermore, the phosphorylation levels of Fyn and NMDA receptor 2B in the corpus callosum and NMDA receptor 1 in the cerebral cortex were noticeably decreased. Taken together, the novel mouse model induced by the combination of cuprizone and MK-801 showed comprehensive behavioral and neurobiological changes, which might make it a suitable animal model for schizophrenia.
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Quelantes , Cuprizona , Maleato de Dizocilpina , Esquizofrenia/induzido quimicamente , Psicologia do Esquizofrênico , Animais , Ansiedade/induzido quimicamente , Ansiedade/psicologia , Comportamento Animal , Corpo Caloso/efeitos dos fármacos , Corpo Caloso/metabolismo , Hipercinese/induzido quimicamente , Hipercinese/psicologia , Injeções Intraperitoneais , Masculino , Transtornos da Memória/induzido quimicamente , Transtornos da Memória/psicologia , Camundongos , Camundongos Endogâmicos C57BL , Reconhecimento Psicológico , Esquizofrenia/patologia , Memória Espacial/efeitos dos fármacos , Substância Branca/metabolismo , Substância Branca/patologiaRESUMO
Objective: Alzheimer's disease (AD) is along with cognitive decline due to amyloid-ß (Aß) plaques, tau hyperphosphorylation, and neuron loss. Shenqi Xingnao Granules (SQXN), a traditional Chinese medicine, significantly ameliorated the cognitive function and daily living abilities of patients with AD. However, till date, no study has investigated the mechanism of action of SQXN on AD. The present study aimed to verify the effects of SQXN treatment on cognitive impairments and AD-like pathologies in APP/PS1 mice. Methods: Four-month-old APP/PS1 transgenic (Tg) mice were randomly divided into a model group and SQXN-treated (3.5, 7, 14 g/kg per day) groups. Learning-memory abilities were determined by Morris water maze and object recognition test. All mice were sacrificed and the brain samples were collected after 75 d. The soluble Aß contents were detected by Elisa kit; The levels of expression of NeuN, APP, phosphorylated tau and related protein were measured by Western blotting; The inflammation factors were detected by the proinflammatory panel kit. Results: Four-month-old APP/PS1 mice were administered SQXN by oral gavage for 2.5 months. Using the Morris water maze tests and Novel object recognition, we found that SQXN restored behavioral deficits in the experimental group of Tg mice when compared with the controls. SQXN also inhibited neuronal loss (NeuN marker). SQXN treatment decreased soluble Aß42 through inhibiting the expression of sAPPß and BACE-1 without regulating full-length amyloid precursor protein (FL APP). Insulin degrading enzyme (IDE), the Aß degrading enzyme, were increased by SQXN. In addition, SQXN reduced hyperphosphorylated tau protein levels and prevented excessive activation of p-GSK-3ß in the brain of APP/PS1 mice. Compared with APP/PS1 transgenic negative mice, IFN-γ, IL-1ß, IL-2, IL-4, IL-5, IL-6, IL-12p70, KC/GRO and TNF-α were not obviously changed in the brain of 6.5-month-old APP/PS1 transgenic (Tg) mice. However, SQXN could inhibited the expression of IL-2. Conclusion: These results demonstrate that SQXN ameliorates the cognitive impairments in APP/PS1 mice. The possible mechanisms involve its inhibition of neuronal loss, soluble Aß deposition, tau hyperphosphorylation and inflammation.
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Alzheimer's disease (AD), also defined as a tauopathology, is a common neurodegenerative disease. Hyper-phosphorylation, cleavage or truncation, and aggregation of tau contribute to AD. Thus, targeting the post-translational modifications on tau may be a therapeutic strategy to treat AD. This study understood how cornel iridoid glycoside (CIG) affects tau post-translational modifications and synaptic abnormalities. The 10-month old P301S tau transgenic mice were given CIG at 100 and 200 mg/kg every day orally for 1 month. Hyperphosphorylated and truncated tau, synapse-associated proteins and glutamatergic receptors were all detected using Western blotting. The interactions between Morroniside (MOR) or Loganin (LOG) and tau were detected using Autodock and Surface Plasmon Resonance (SPR). The effects of CIG on the aggregation of tau were investigated using a cell-free system. CIG attenuated tau hyperphosphorylation at Thr205, Ser212, Ser262, Thr231 and Ser235 (AT180), but had no effect on tau truncation in the brains of 10-month old P301S mice. Binding free energies and interactions revealed that MOR and LOG bound with tau. We also found that CIG upregulated synapse-associated proteins such as PSD-95, syntaxin1A and synaptotagmin. In addition, CIG restored N-methyl-D-aspartic acid receptor and glutamate receptor levels. CIG improves post-translational modification of tau as well as synaptic abnormalities. The data presented here reveal that CIG may be used in the treatment of AD.
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Glicosídeos/administração & dosagem , Iridoides/administração & dosagem , Mutação , Tauopatias/tratamento farmacológico , Proteínas tau/química , Proteínas tau/metabolismo , Administração Oral , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Sistema Livre de Células , Modelos Animais de Doenças , Feminino , Glicosídeos/farmacologia , Humanos , Iridoides/farmacologia , Masculino , Camundongos , Camundongos Transgênicos , Modelos Moleculares , Simulação de Acoplamento Molecular , Fenótipo , Ligação Proteica , Receptores de Glutamato/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Tauopatias/genética , Tauopatias/metabolismo , Resultado do Tratamento , Proteínas tau/genéticaRESUMO
Chronic cerebral hypoperfusion is an important risk factor for vascular dementia (VaD) and other brain dysfunctions, for which there are currently no effective medications available. In the present study, we investigated the potential therapeutic effects of cornel iridoid glycoside (CIG) on VaD in rats modeled by permanent bilateral common carotid artery ligation (2-vessel occlusion, 2VO). The object recognition test (ORT) and Morris water maze (MWM) test were conducted to evaluate the learning and memory function. Western blot analysis and immunohistochemical staining were used to detect the expression of related proteins. Results showed that intragastric administration of CIG (30, 60, and 120â¯mg/kg) for 3 months significantly increased the discrimination index in ORT and decreased the escape latency in MWM test, ameliorating the learning and memory deficit in 2VO rats. Further data indicated that CIG increased the expression of neurotrophic factors (NGF and BDNF) and their receptors (TrkA and TrkB), glutamate receptor subunits (NMDAR1 and GluR2) in the cerebral cortex and hippocampus of 2VO rats. In addition, CIG elevated the expression of PI3K subunits p110α and p85, further upregulated the phosphorylation of Akt, GSK3ß-ser9 and CREB in the cerebral cortex and hippocampus at 3 months after 2VO surgery. Collectively, CIG treatment improved learning and memory deficit induced by chronic cerebral hypoperfusion via increasing neurotrophic factors thus protecting glutamate receptors and activating PI3K/Akt/GSK3ß/CREB signaling pathway in rats. These results suggest that CIG may be beneficial to VaD therapy.
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Córtex Cerebral/efeitos dos fármacos , Disfunção Cognitiva/tratamento farmacológico , Cornaceae , Demência Vascular/tratamento farmacológico , Glicosídeos Iridoides/farmacologia , Aprendizagem/efeitos dos fármacos , Fatores de Crescimento Neural/efeitos dos fármacos , Receptores de Glutamato/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Animais , Comportamento Animal/efeitos dos fármacos , Disfunção Cognitiva/etiologia , Demência Vascular/complicações , Modelos Animais de Doenças , Hipocampo/efeitos dos fármacos , Glicosídeos Iridoides/administração & dosagem , Masculino , Ratos , Ratos Sprague-DawleyRESUMO
Alzheimer's disease (AD) is a multifactorial complex disease. The pathogenesis of AD is very complicated, and involves the ß-amyloid (Aß) cascade, tau hyperphosphorylation, neuroinflammation, oxidative stress, mitochondrial dysfunction, reduced levels of neurotrophic factors, and damage and loss of synapses as well as cholinergic neurons. The multi-target characteristics of traditional Chinese medicine (TCM) may be advantageous over single-target drugs in the treatment of complex diseases. These drugs have therefore attracted more attention in the research and development of AD therapies. This review describes advances made in experimental studies of TCM for AD treatment. It discusses research, from our group and other laboratories, on TCM compound drugs (Shenwu capsule) and approximately 10 Chinese medicinal herb extracts (tetrahydroxystilbene glucoside, epimedium flavonoid, icariin, cornel iridoid glycoside, ginsenoside, puerarin, clausenamide, huperzine A, and timosaponins).