Molecular basis for recognition of Gly/N-degrons by CRL2ZYG11B and CRL2ZER1.

N-degron pathways are a set of proteolytic systems that target the N-terminal destabilizing residues of substrates for proteasomal degradation. Recently, the Gly/N-degron pathway has been identified as a new branch of the N-degron pathway. The N-terminal glycine degron (Gly/N-degron) is recognized by ZYG11B and ZER1, the substrate receptors of the Cullin 2-RING E3 ubiquitin ligase (CRL2). Here we present the crystal structures of ZYG11B and ZER1 bound to various Gly/N-degrons. The structures reveal that ZYG11B and ZER1 utilize their armadillo (ARM) repeats forming a deep and narrow cavity to engage mainly the first four residues of Gly/N-degrons. The α-amino group of the Gly/N-degron is accommodated in an acidic pocket by five conserved hydrogen bonds. These structures, together with biochemical studies, decipher the molecular basis for the specific recognition of the Gly/N-degron by ZYG11B and ZER1, providing key information for future structure-based chemical probe design.

C-terminal glutamine acts as a C-degron targeted by E3 ubiquitin ligase TRIM7.

The exposed N-terminal or C-terminal residues of proteins can act, in cognate sequence contexts, as degradation signals (degrons) that are targeted by specific E3 ubiquitin ligases for proteasome-dependent degradation by N-degron or C-degron pathways. Here, we discovered a distinct C-degron pathway, termed the Gln/C-degron pathway, in which the B30.2 domain of E3 ubiquitin ligase TRIM7 (TRIM7B30.2) mediates the recognition of proteins bearing a C-terminal glutamine. By determining crystal structures of TRIM7B30.2 in complexes with various peptides, we show that TRIM7B30.2 forms a positively charged binding pocket to engage the "U"-shaped Gln/C-degron. The four C-terminal residues of a substrate play an important role in C-degron recognition, with C-terminal glutamine as the principal determinant. In vitro biochemical and cellular experiments were used to further analyze the substrate specificity and selective degradation of the Gln/C-degron by TRIM7.

Structural insights into ORF10 recognition by ZYG11B.

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a major threat to human health. As a unique putative protein of SARS-CoV-2, the N-terminus of ORF10 can be recognized by ZYG11B, a substrate receptor of the Cullin 2-RING E3 ubiquitin ligase (CRL2). Here we elucidated recognition mechanism of ORF10 N-terminus by ZYG11B through presenting the crystal structure of ZYG11B bound to ORF10 N-terminal peptide. Our work expands the current understanding of ORF10 interaction with ZYG11B, and may also inspire the development of novel therapies for COVID-19.

Photocatalytic oxidation of trace carbamazepine in aqueous solution by visible-light-driven Znln2S4: Performance and mechanism.

In this work, visible-light-driven Znln2S4 photocatalyst (band gap 1.98 eV, absorption wavelength 300-600 nm) was synthesized by a facile hydrothermal method for photocatalytic degradation of trace pharmaceutical carbamazepine (CBZ) in aqueous solution, and characterized by UV-Vis diffusive reflectance spectroscopy, BET, SEM and XRD, respectively. It demonstrated that a complete degradation of CBZ was achieved with an optimal Znln2S4 dosage of 30 mg/L under a 100 W iodine-gallium lamp irradiation of 20 min, which afforded the reaction rate constant and half-life being respectively 10.44 times higher and 1/8 less than that obtained by a direct photolysis without Znln2S4 photocatalyst. A negligible influence of initial solution pH on photocatalytic degradation of CBZ was confirmed under the given pH range of 5.0-9.0. The degradation efficiency of CBZ was slightly decreased from 91% to 84% after five consecutive cycles. Hydroxy radical (·OH) plays an important role in CBZ degradation accompanying a synergistic effect of photogenerated hole (h+) and O2- active species during reaction. Further, 44 intermediates were detected by LCMS-IT-TOF technique and tentative degrading pathways were proposed on the basis of the experimental results.

Morphological diversity of GABAergic and cholinergic interneurons in the striatal dorsolateral and ventromedial regions of rats.

The striatum plays a fundamental role in sensorimotor and cognitive functions of the body, and different sub-regions control different physiological functions. The striatal interneurons play important roles in the striatal function, yet their specific functions are not clearly elucidated so far. The present study aimed to investigate the morphological properties of the GABAergic interneurons expressing neuropeptide Y (NPY), calretinin (Cr), and parvalbumin (Parv) as well as the cholinergic interneurons expressing choline acetyltransferase (ChAT) in the striatal dorsolateral (DL) and ventromedial (VM) regions of rats using immunohistochemistry and Western blot. The present results showed that the somatic size of Cr+ was the smallest, while ChAT+ was the largest among the four types of interneurons. There was no regional difference in neuronal somatic size of all types of interneurons. Cr+ and Parv+ neurons were differentially distributed in the striatum. Moreover, Parv+ had the longest primary dendrites in the DL region, while NPY+ had the longest ones in the VM region of striatum. But there was regional difference in the length of primary dendrites of Parv. The numbers of primary dendrites of Parv+ were the largest in both DL and VM regions of striatum. Both Cr+ and Parv+ primary dendrites displayed regional difference in the striatum. Western blot further confirmed the regional differences in the protein expression level of Cr and Parv. Hence, the present study indicates that GABAergic and cholinergic interneurons might be involved in different physiological functions based on their morphological and distributional diversity in different regions of the rat striatum.

Ratiometric fluorescent detection of sulfide ions in Radix Codonopsis and living cells based on PVP-supported gold/copper nanoclusters with tunable dual emission.

Herein, a novel fluorometric-sensor with dual-emission system was constructed on the basis of polyvinylpyrrolidone (PVP) and 2-mercaptobenzothiazole (MBT) co-functionalized gold/copper nanoclusters (PVP/MBT-Au@CuNCs) by a facile and eco-friendly one-pot approach. The sensor exhibited ratiometric fluorescence emission (F590 nm/F422 nm) for visual and selective detection of S2- with a sensitive detection limit of 11.9 nM. Besides, fluorescence quenched sensing of S2- was chalked up by a quickly selectivity monitoring time of 30 s, owing to the strongly binding of Cu2S and Au2S by hard-soft-acid-base theory and the destruction of the aggregated structure of PVP/MBT-Au@CuNCs. Furthermore, the platform also provided the portable analysis for visual detection of S2- by capturing the change in fluorescence color with a single dual-emissive ratiometric paper strip. It is worth mentioning that the fluorescent gold-copper nanoclusters showed excellent application activities in the selective detection of S2- in Radix Codonopsis or Tremella samples and recognition of S2- in HeLa cells or macrophages by confocal microscopy fluorescent imaging. Overall, the sensing system paved a new avenue for effectively developing a convenient ratiometric fluorescent sensor platform for evaluating the safety of food with S2- pollution in environment and biological system.

Discovery of novel benzylquinazoline molecules as p97/VCP inhibitors.

Introduction: Protein p97 is an extensively investigated AAA ATPase with various cellular activities, including cell cycle control, ubiquitin-proteasome system, autophagy, and NF-κB activation. Method: In this study, we designed, synthesized and evaluated eight novel DBeQanalogs as potential p97 inhibitors in vivo and in vitro. Results: In the p97 ATPase inhibition assay, compounds 6 and 7 showed higher potency than the known p97 inhibitors, DBeQ and CB-5083. Compounds 4-6 dramatically induced G0/G1 phase arrest in the HCT116 cells, and compound 7 arrested the cells in both G0/G1 and S phases. Western blots showed elevated levels of SQSTM/p62, ATF-4, and NF-κB in HCT116 cells with the treatment of compounds 4-7, confirming their role in inhibiting the p97 signaling pathway in cells. In addition, the IC50 of compounds 4-6 against HCT116, RPMI-8226, and s180 proliferation were 0.24-6.9 µM with comparable potency as DBeQ. However, compounds 4-6 displayed low toxicity against the normal human colon cell line. Thus, compounds 6 and 7 were proved to be potential p97 inhibitors with less cytotoxicity. In vivo studies using the s180 xenograft model have demonstrated that compound 6 inhibited tumor growth, led to a significant reduction of p97 concentration in the serum and tumor, and indicated non-toxicity on the body weight and organ-to-brain weight ratios except for the spleen at the dose of 90 µmol/kg/day for 10 days. Furthermore, the present study indicated that compound 6 may not induce s180 mice myelosuppression often observed in the p97 inhibitors. Conclusion: Compound 6 displayed high binding affinity to p97, great p97 ATPase inhibition, selective cytotoxicity, remarkable anti-tumor effect, and upregulated safety, which improved the clinical potential of p97 inhibitors.

Resource Allocation Equity in the China's Rural Three-Tier Healthcare System.

The rural three-tier healthcare system is an essential part of the Chinese healthcare service system. To ensure rural residents' equal access to such healthcare services, it is necessary to examine the current status of the healthcare system in rural China and formulate corresponding improvement suggestions. This study therefore collects the data from the China Health Statistics Yearbook, the China Health Yearbook and the China Statistical Yearbook between the years 2004 and 2021 to calculate the Gini coefficient (G), health resource density index (HRDI) and Theil index (T) first, and then perform the Mann-Kendall test afterwards to evaluate the equity of healthcare resource allocation comprehensively. This series of analysis helps in drawing the following conclusions: (1) county and county-level city medical and health institutions (CMHIs) show a higher development trend in comparison with township hospitals (THs) and village clinics (VCs); (2) VCs have higher institutional fairness, while for beds and personnel, CMHIs and THs are more fairly positioned; (3) more specifically for CMHIs and THs, personnel allocation is more fair than beds and institution allocations; (4) the density of healthcare resources in the eastern and central regions is higher than that in the western part, while the intra-regional distribution of beds and personnel in the west and central regions is better than that in the eastern region; (5) intra-regional differences are more significant than inter-regional differences and the fairness according to population distribution is higher than that of geographical area allocation. The results of this study provide theoretical basis for further optimizing the allocation of healthcare resources and improving the fairness of healthcare resources allocation from a macro perspective.

Livelihood Capital Effects on Famers' Strategy Choices in Flood-Prone Areas-A Study in Rural China.

The global climate change has resulted in huge flood damages, which seriously hinders the sustainable development of rural economy and society and causes famers' livelihood problems. In flood-prone areas, it is imperative to actively study short and long-term strategies and solve farmers' livelihood problems accordingly. Following the sustainable development analysis framework proposed by the Department for International Development (DFID), this study collects empirical data of 360 rural households in six sample villages in the Jialing River Basin of Sichuan Province, China through a village-to-household field questionnaire and applies the Multinominal Logit Model (MNL) to explore the influence of farmer households' capital on livelihood strategy choice. Research results show that: (1) In human capital category, the education level of the household head has a significant positive impact on the livelihood strategies of farmers' families; (2) In physical capital category, farmer households with larger space have more funds to choose among flood adaptation strategies; (3) In natural capital category, house location and the sale of family property for cash have the greatest negative impact on farmers' livelihood strategies; (4) Rural households with more credit opportunities in financial capital are more willing to obtain emergency relief funds; (5) Farmers' families helped by the village for a long time will probably not choose to move to avoid floods, but are more likely to choose buying flood insurance. This study provides an empirical reference for effective short and long term prevention and mitigation strategies design and application in rural in flood-prone areas.

Nanoparticles of a New Small-Molecule P-Selectin Inhibitor Attenuate Thrombosis, Inflammation, and Tumor Growth in Two Animal Models.

PURPOSE: To assess whether the newly designed small-molecule oral P-selectin inhibitor 3S-1,2,3,4-tetrahydro-ß-carboline-3-methyl aspartyl ester (THCMA) as a nanomedicine enhances antithrombosis, anti-inflammation, and antitumor activity more than the clinical trial drug PSI-697. METHODS: THCMA was designed as an amphiphile containing pharmacophores of PSI-697. Its nanofeatures were explored with TEM, SEM, Tyndall effect, ζ-potential, FT-ICR-MS, and NOESY 2D 1H NMR. The P-selectin inhibitory effect of THCMA was demonstrated with molecular docking, ultraviolet (UV) spectra, and competitive ELISA. In vivo and in vitro assays - anti-arterial thrombosis, anti-venous thrombosis, anti-inflammation, antitumor growth, anti-platelet aggregation, rat-tail bleeding time, anticoagulation index, soluble P-selectin (sP-selectin) expression, and serum TNFα expression - were performed to explore bioactivity and potential mechanisms. Water solubility of THCMA was measured using UV-absorption spectra. RESULTS: THCMA self-assembled into nanorings of approximately 100 nm in diameter. Its water solubility was about 1,030-fold that of PSI-697. THCMA exhibited more potent P-selectin inhibitory effect than PSI-697. The oral efficacy of THCMA was 100-fold that of PSI-697 in inhibiting arterial and venous thrombosis and tenfold in inhibiting inflammation. THCMA inhibited thrombosis at a dose that produces no coagulation disorders and no bleeding risk. THCMA exhibited enhanced antitumor activity over PSI-697 without systemic chemotherapy toxicity. THCMA significantly inhibited platelet aggregation in vitro and downregulated the expression levels of serum sP-selectin and TNFα in vivo. CONCLUSION: A new small-molecule P-selectin inhibitor, THCMA, has been successfully designed as a nanomedicine with largely enhanced oral efficacy compared to the clinical trial drug PSI-697, and thus might be developed for the oral treatment of arterial thrombosis, venous thrombosis, inflammation, and cancer-associated thrombosis.

Synthesis and In Vitro Evaluation of 2-[3-(2-Aminoethyl)-1H-indol-1-yl]-N-benzylquinazolin-4-amine as a Novel p97/VCP Inhibitor Lead Capable of Inducing Apoptosis in Cancer Cells.

P97/VCP, an endoplasmic reticulum associated protein, belongs to AAA ATPase family, ubiquitous ATPases associated with various cellular activities. Recent research has elucidated the roles of p97/VCP and evaluated its potential as a therapeutic target for some kinds of cancer diseases. We screened the small molecule compounds from a previously established library and found promise in the compound 2-[3-(2-aminoethyl)-1H-indol-1-yl]-N-benzylquinazolin-4-amine (FQ393). Data from docking simulation indicates FQ393 acts as an ATP competitor, and ATPase activity assays showed FQ393 was an inhibitor of p97/VCP. Furthermore, in vitro FQ393 is able to promote apoptosis and prohibit proliferation in a variety of cancer cell lines. Using comparative proteomic profiling of HCT-116 cells, we found significantly different canonical KEGG pathways, which revealed that the protein changes in FQ393 groups were associated with p97/VCP or tumor-related pathways. The present data suggests that FQ393 exerts antitumor activity, at least in part through p97/VCP inhibition.

TAT-Modified Gold Nanoparticles Enhance the Antitumor Activity of PAD4 Inhibitors.

PURPOSE: Histone citrullination by peptidylarginine deiminases 4 (PAD4) regulates the gene expression of tumor suppressor. In our previously study, YW3-56 (356) was developed as a potent PAD4 inhibitor for cancer therapy with novel function in the autophagy pathway. To enhance the antitumor activity, the PAD4 inhibitor 356 was modified by the well-established cationic penetrating peptide RKKRRQRRR (peptide TAT) and gold nanoparticles to obtain 356-TAT-AuNPs which could enhance the permeability of chemical drug in solid tumor. METHODS: 356-TAT-AuNPs were prepared, and their morphology were characterized. The antitumor activity of 356-TAT-AuNPs was evaluated in vitro and in vivo. RESULTS: 356-TAT-AuNPs exhibited higher anticancer activity against HCT-116, MCF-7 and A549 cells than 356 and 356-AuNPs. Compared with 356 and 356-AuNPs, 356-TAT-AuNPs entered the cytoplasm and nuclear, exhibited stronger anticancer activity by increasing apoptosis, inducing autophagy and inhibiting of histone H3 citrullination, and in HCT-116 xenograft mouse model, 356-TAT-AuNPs could improve the antitumor activity. CONCLUSION: The modified AuNPs with peptide TAT as drug delivery system are potent in delaying tumor growth and could be a powerful vehicle for profitable anticancer drug development. We believe that peptide TAT modification strategy may provide a simple and valuable method for improving antitumor activity of PAD4 inhibitors for clinical use.

Dimethyl 2,2'-[2,2'-(ethane-1,1-diyl)bis(1H-indole-3,2-diyl)]-diacetate: a small molecule capable of nano-scale assembly, inhibiting venous thrombosis and inducing no bleeding side effect.

BACKGROUND: Due to the discovery that deep venous thrombosis (DVT) inhibitor is of chemotherapeutic importance, the nano-property of dimethyl 2,2'-[2,2'-(ethane-1,1-diyl) bis(1H-indole-3,2-diyl)]-diacetate (DEBIC), a recently reported antitumor agent, is worthy of characterization. MATERIALS AND METHODS: One-pot reaction was used to prepare DEBIC. Electrospray Ionization (+/-)-Fourier Transform-Ion Cyclotron Resonance-Mass Spectrometer (ESI(+/-)-FT-ICR-MS), quadrupole Collision Induced Dissociation (qCID) and nuclear overhauser effect spectroscopy spectra were used to present the assembly of DEBIC. Transmission electron microscopy, scanning electron microscopy, atomic force microscopy and Faraday-Tyndall effect were used to visualize the nano-property of DEBIC. Rat models were used to evaluate DVT inhibition and the bleeding reaction of DEBIC. RESULTS: One-pot reaction can provide DEBIC in acceptable yield and high purity. In water, rat plasma and lyophilized powders of DEBIC existed as particles of small nano-size. In vivo DEBIC inhibited DVT in a dose-dependent manner. The minimal effective dose of DEBIC was 1.7 µmol/kg. Even the dose of 36 µmol/kg/day DEBIC did not induce bleeding side effect in DVT rats like in warfarin (0.82 µmol/kg/day). CONCLUSION: DEBIC is a small molecule capable of nano-scale assembly, inhibiting venous thrombosis and inducing no bleeding side effect.

Docking of THPDTPI: to explore P-selectin as a common target of anti-tumor, anti-thrombotic and anti-inflammatory agent.

The impact of soluble P-selectin on tumor growth, thrombosis and inflammation has been individually documented. Whether the down-regulation of P-selectin expression can simultaneously slow the tumor growth, inhibit the thrombosis and attenuate the inflammatory response remains unknown. In this context, (2'S,5'S)- tetrahydropyrazino[1',2':1,6]-di{2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole}-1',4'-dione (THPDTPI) was designed as an inhibitor of P-selectin. The suitable docking of THPDTPI towards the active site of P-selectin, the significant down-regulation of THPDTPI to P-selectin expression, and the direct action of THPDTPI on P-selectin suggest that P-selectin could be a target of THPDTPI. In vivo THPDTPI possesses the anti-tumor activity, the anti-thrombotic activity and the anti-inflammatory activity. This implies that targeting P-selectin is of essential importance for this triple activity. The minimal effective doses of THPDTPI inhibiting the tumor growth, the rat arterial thrombosis and the mouse ear edema are 0.01 µmol/kg, 0.1 µmol/kg and 0.001 µmol/kg, respectively. Atomic force microscopy images and FT-MS spectra showed that the adhesion of THPDTPI onto the surfaces of the platelets may be the first step of P-selectin targeting. Besides, the dependence of the triple action of THPDTPI inhibiting the tumor growth, the thrombosis and the inflammation on the decrease of the soluble P-selectin led to the correlation of the soluble P-selectin with the serum TNF-α and serum IL-8.

[CoCuMnOx Photocatalyzed Oxidation of Multi-component VOCs and Kinetic Analysis].

Solar energy absorption coating CoCuMnOx was prepared by co-precipitation method and applied to photodegrade multi- component VOCs including toluene, ethyl acetate and acetone under visible light irradiation. The photocatalytic oxidation performance of toluene, ethyl acetate and acetone was analyzed and reaction kinetics of VOCs were investigated synchronously. The research indicated that removal rates of single-component toluene, ethyl acetate and acetone were 57%, 62% and 58% respectively under conditions of 400 mg · m⁻³ initial concentration, 120 mm illumination distance, 1 g/350 cm² dosage of CoCuMnOx and 6 h of irradiation time by 100 W tungsten halogen lamp. Due to the competition among different VOCs, removal efficiencies in three-component mixture were reduced by 5%-26% as compared with single VOC. Degradation processes of single-component VOC and three-component VOCs both fitted pseudo first order reaction kinetics, and kinetic constants of toluene, ethyl acetate and acetone were 0.002, 0.002 8 and 0.002 33 min⁻¹ respectively under single-component condition. Reaction rates of VOCs in three-component mixture were 0.49-0.88 times of single components.

DHDMIQK(KAP): a novel nano-delivery system of dihydroxyl-tetrahydro-isoquinoline-3-carboxylic acid and KPAK towards the thrombus.

Vascular thrombosis is a major risk of the onset of stroke and so novel therapeutic candidates have been attracting interest. In this context, here docking based computer assisted screening and mesoscale simulation were used to design N-[(S)-6,7-dihydroxy-1,1-dimethyl-1,2,3,4-tetrahydroisoquinoline-3-carbonyl]-Lys(Pro-Ala-Lys), DHDMIQK(KAP), for inhibiting P-selectin expression. In vitro, 1 nM of DHDMIQK(KAP) effectively down-regulated P-selectin expression. In water, in rat plasma and in the solid state DHDMIQK(KAP) formed nanoparticles of a size capable of suitable delivery in the blood circulation. FT-MS and NOESY 2D NMR spectra showed DHDMIQK(KAP) formed hexamers, identified the intermolecular interactions of the hexamer, and assigned the hexamer a butterfly like conformation. Transmission electron microscopy, scanning electron microscopy and atomic force microscopy (AFM) imaged DHDMIQK(KAP) forming size-suitable nanoparticles for safe delivery in the blood circulation. In particular, AFM images showed that the nanoparticles effectively adhered onto the surfaces of the platelets. In vivo DHDMIQK(KAP) lysed the thrombus and inhibited thrombosis with a minimal effective dose of 0.01 nmol kg-1. FT-MS spectrum analyses defined a specific distribution of DHDMIQK(KAP) in the thrombus, but not in the blood and vital organs. Therefore, DHDMIQK(KAP) should be a novel nano-delivery system of 6,7-dihydroxyl-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid and KPAK to target the thrombus.

Aqueous extract of Rabdosia rubescens leaves: forming nanoparticles, targeting P-selectin, and inhibiting thrombosis.

The hot water extract of Rabdosia rubescens was traditionally used as an antithrombotic medicine. To explore its antithrombotic utility and mechanism, we carried out a series of in vitro and in vivo assays in this study. In vitro platelet aggregation assay showed that the half maximal inhibitory concentration values of aqueous extract of R. rubescens leaves (AERL) inhibiting platelet aggregation induced by thrombin, arachidonic acid, adenosine diphosphate, and platelet-activating factor ranged from 0.12 mg/mL to 1.43 mg/mL. The minimal effective oral dose of AERL inhibiting the rats from forming thrombus was 25 mg/kg. Both in vitro and in vivo actions were correlated with AERL concentration-dependently inhibiting sP-selectin release. In water, AERL formed nanoparticles, and their size depended on the concentration. Docking the five nucleotides, 21 phenolic acids, and four diterpenoids identified by high-performance liquid chromatography-photodiode array detector/(-)electrospray ionization-tandem mass spectrometry analysis into the active site of P-selectin, rosmarinic acid was predicted to be the antithrombotic ingredient of AERL. In flow cytometry analysis, 1 µM of rosmarinic acid effectively inhibited sP-selectin release in arachidonic acid-activated platelets. In a rat model, 5 mg/kg of oral rosmarinic acid effectively inhibited thrombosis.

Small molecule PZL318: forming fluorescent nanoparticles capable of tracing their interactions with cancer cells and activated platelets, slowing tumor growth and inhibiting thrombosis.

Low selectivity of chemotherapy correlates with poor outcomes of cancer patients. To improve this issue, a novel agent, N-(1-[3-methoxycarbonyl-4-hydroxyphenyl]-ß-carboline-3-carbonyl)-Trp-Lys-OBzl (PZL318), was reported here. The transmission electron microscopy, scanning electron microscopy, and atomic force microscopy images demonstrated that PZL318 can form nanoparticles. Fluorescent and confocal images visualized that PZL318 formed fluorescent nanoparticles capable of targeting cancer cells and tracing their interactions with cancer cells. In vitro, 40 µM of PZL318 inhibited the proliferation of tumorigenic cells, but not nontumorigenic cells. In vivo, 10 nmol/kg of PZL318 slowed the tumor growth of S180 mice and alleviated the thrombosis of ferric chloride-treated ICR mice, while 100 µmol/kg of PZL318 did not injure healthy mice and they exhibited no liver toxicity. By analyzing Fourier transform-mass spectrometry and rotating-frame Overhauser spectroscopy (ROESY) two-dimensional nuclear magnetic resonance spectra, the chemical mechanism of PZL318-forming trimers and nanoparticles was explored. By using mesoscale simulation, a nanoparticle of 3.01 nm in diameter was predicted containing 13 trimers. Scavenging free radicals, downregulating sP-selectin expression and intercalating toward DNA were correlated with the antitumor mechanism of PZL318.

Specific reactions of different striatal neuron types in morphology induced by quinolinic acid in rats.

Huntington's disease (HD) is a neurological degenerative disease and quinolinic acid (QA) has been used to establish HD model in animals through the mechanism of excitotoxicity. Yet the specific pathological changes and the underlying mechanisms are not fully elucidated. We aimed to reveal the specific morphological changes of different striatal neurons in the HD model. Sprague-Dawley (SD) rats were subjected to unilaterally intrastriatal injections of QA to mimic the HD model. Behavioral tests, histochemical and immunhistochemical stainings as well as Western blots were applied in the present study. The results showed that QA-treated rats had obvious motor and cognitive impairments when compared with the control group. Immunohistochemical detection showed a great loss of NeuN+ neurons and Darpp32+ projection neurons in the transition zone in the QA group when compared with the control group. The numbers of parvalbumin (Parv)+ and neuropeptide Y (NPY)+ interneurons were both significantly reduced while those of calretinin (Cr)+ and choline acetyltransferase (ChAT)+ were not changed notably in the transition zone in the QA group when compared to the controls. Parv+, NPY+ and ChAT+ interneurons were not significantly increased in fiber density while Cr+ neurons displayed an obvious increase in fiber density in the transition zone in QA-treated rats. The varicosity densities of Parv+, Cr+ and NPY+ interneurons were all raised in the transition zone after QA treatment. In conclusion, the present study revealed that QA induced obvious behavioral changes as well as a general loss of striatal projection neurons and specific morphological changes in different striatal interneurons, which may help further explain the underlying mechanisms and the specific functions of various striatal neurons in the pathological process of HD.

EPO-dependent activation of PI3K/Akt/FoxO3a signalling mediates neuroprotection in in vitro and in vivo models of Parkinson's disease.

Erythropoietin (EPO) may become a potential therapeutic candidate for the treatment of the neurodegenerative disorder -- Parkinson's disease (PD), since EPO has been found to prevent neuron apoptosis through the activation of cell survival signalling. However, the underlying mechanisms of how EPO exerts its neuroprotective effect are not fully elucidated. Here we investigated the mechanism by which EPO suppressed 6-hydroxydopamine (6-OHDA)-induced neuron death in in vitro and in vivo models of PD. EPO knockdown conferred 6-OHDA-induced cytotoxicity. This effect was reversed by EPO administration. Treatment of PC12 cells with EPO greatly diminished the toxicity induced by 6-OHDA in a dose- and time-dependent manner. EPO effectively reduced apoptosis of striatal neurons and induced a significant improvement on the neurological function score in the rat models of PD. Furthermore, EPO increased the expression of phosphorylated Akt and phosphorylated FoxO3a, and abrogated the 6-OHDA-induced dysregulation of Bcl-2, Bax and Caspase-3 in PC12 cells and in striatal neurons. Meanwhile, the EPO-dependent neuroprotection was notably reversed by pretreatment with LY294002, a specific inhibitor of phosphatidylinositol 3-kinase (PI3K). Our data suggest that PI3K/Akt/FoxO3a signalling pathway may be a possible mechanism involved in the neuroprotective effect of EPO in PD.