Transcriptomic congruence analysis for evaluating model organisms.

Model organisms are instrumental substitutes for human studies to expedite basic, translational, and clinical research. Despite their indispensable role in mechanistic investigation and drug development, molecular congruence of animal models to humans has long been questioned and debated. Little effort has been made for an objective quantification and mechanistic exploration of a model organism's resemblance to humans in terms of molecular response under disease or drug treatment. We hereby propose a framework, namely Congruence Analysis for Model Organisms (CAMO), for transcriptomic response analysis by developing threshold-free differential expression analysis, quantitative concordance/discordance scores incorporating data variabilities, pathway-centric downstream investigation, knowledge retrieval by text mining, and topological gene module detection for hypothesis generation. Instead of a genome-wide vague and dichotomous answer of "poorly" or "greatly" mimicking humans, CAMO assists researchers to numerically quantify congruence, to dissect true cross-species differences from unwanted biological or cohort variabilities, and to visually identify molecular mechanisms and pathway subnetworks that are best or least mimicked by model organisms, which altogether provides foundations for hypothesis generation and subsequent translational decisions.

Overcoming cancer chemotherapy resistance by the induction of ferroptosis.

Development of resistance to chemotherapy in cancer continues to be a major challenge in cancer management. Ferroptosis, a unique type of cell death, is mechanistically and morphologically different from other forms of cell death. Ferroptosis plays a pivotal role in inhibiting tumour growth and has presented new opportunities for treatment of chemotherapy-insensitive tumours in recent years. Emerging studies have suggested that ferroptosis can regulate the therapeutic responses of tumours. Accumulating evidence supports ferroptosis as a potential target for chemotherapy resistance. Pharmacological induction of ferroptosis could reverse drug resistance in tumours. In this review article, we first discuss the key principles of chemotherapeutic resistance in cancer. We then provide a brief overview of the core mechanisms of ferroptosis in cancer chemotherapeutic drug resistance. Finally, we summarise the emerging data that supports the fact that chemotherapy resistance in different types of cancers could be subdued by pharmacologically inducing ferroptosis. This review article suggests that pharmacological induction of ferroptosis by bioactive compounds (ferroptosis inducers) could overcome chemotherapeutic drug resistance. This article also highlights some promising therapeutic avenues that could be used to overcome chemotherapeutic drug resistance in cancer.

High-dimension to high-dimension screening for detecting genome-wide epigenetic and noncoding RNA regulators of gene expression.

MOTIVATION: The advancement of high-throughput technology characterizes a wide variety of epigenetic modifications and noncoding RNAs across the genome involved in disease pathogenesis via regulating gene expression. The high dimensionality of both epigenetic/noncoding RNA and gene expression data make it challenging to identify the important regulators of genes. Conducting univariate test for each possible regulator-gene pair is subject to serious multiple comparison burden, and direct application of regularization methods to select regulator-gene pairs is computationally infeasible. Applying fast screening to reduce dimension first before regularization is more efficient and stable than applying regularization methods alone. RESULTS: We propose a novel screening method based on robust partial correlation to detect epigenetic and noncoding RNA regulators of gene expression over the whole genome, a problem that includes both high-dimensional predictors and high-dimensional responses. Compared to existing screening methods, our method is conceptually innovative that it reduces the dimension of both predictor and response, and screens at both node (regulators or genes) and edge (regulator-gene pairs) levels. We develop data-driven procedures to determine the conditional sets and the optimal screening threshold, and implement a fast iterative algorithm. Simulations and applications to long noncoding RNA and microRNA regulation in Kidney cancer and DNA methylation regulation in Glioblastoma Multiforme illustrate the validity and advantage of our method. AVAILABILITY AND IMPLEMENTATION: The R package, related source codes and real datasets used in this article are provided at https://github.com/kehongjie/rPCor. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Missense mutation of c.635 T > C in CAPN3 impairs muscle injury repair in a Limb-Girdel Muscular Dystropy Model.

Limb-girdle muscular dystrophy recessive 1 (LGMDR1), previously known as LGMD2A, is a specific LGMD caused by a gene mutation encoding the calcium-dependent neutral cysteine protease calpain-3 (CAPN3). In our study, the compound heterozygosity with two missense variants c.635 T > C (p.Leu212Pro) and c.2120A > G (p.Asp707Gly) was identified in patients with LGMDR1. However, the pathogenicity of c.635 T > C has not been investigated. To evaluate the effects of this novel likely pathogenic variant to the motor system, the mouse model with c.635 T > C variant was prepared by CRISPR/Cas9 gene editing technique. The pathological results revealed that a limited number of inflammatory cells infiltrated the endomyocytes of certain c.635 T > C homozygous mice at 10 months of age. Compared with wild-type mice, motor function was not significantly impaired in Capn3 c. 635 T > C homozygous mice. Western blot and immunofluorescence assays further indicated that the expression levels of the Capn3 protein in muscle tissues of homozygous mice were similar to those of wild-type mice. However, the arrangement and ultrastructural alterations of the mitochondria in the muscular tissues of homozygous mice were confirmed by electron microscopy. Subsequently, muscle regeneration of LGMDR1 was simulated using cardiotoxin (CTX) to induce muscle necrosis and regeneration to trigger the injury modification process. The repair of the homozygous mice was significantly worse than that of the control mice at day 15 and day 21 following treatment, the c.635 T > C variant of Capn3 exhibited a significant effect on muscle regeneration of homozygous mice and induced mitochondrial damage. RNA-sequencing results demonstrated that the expression levels of the mitochondrial-related functional genes were significantly downregulated in the mutant mice. Taken together, the results of the present study strongly suggested that the LGMDR1 mouse model with a novel c.635 T > C variant in the Capn3 gene was significantly dysfunctional in muscle injury repair via impairment of the mitochondrial function.

New abietane and tigliane diterpenoids from the roots of Euphorbia fischeriana and their cytotoxic activities.

Three new abietane and two new tigliane diterpenoids were isolated from the roots Euphorbia fischeriana. Their structures were elucidated by spectroscopic methods and quantum chemical calculation. Compounds 4 and 5 exhibited the inhibitory activities against human cancer cells HeLa and HepG2, with IC50 ranging from 3.54 to 11.45 µM.

Assessment of Blood Volume in Liposuction Fluids Using Colorimetry.

OBJECTIVE: The possibility of using a color contrast method to evaluate blood loss during liposuction was assessed. A color chart of blood-lipid content associated with different blood volumes was developed. METHODS: Three color cards with different concentrations of blood were developed based on clinical parameters. The color cards were used to evaluate the volume of blood present in liposuction solutions obtained from 60 clinical liposuction patients. The red blood cell count also was evaluated for each patient. The data obtained using each evaluation method were compared and statistically analyzed to determine the most accurate calculation formula. RESULTS: The red blood cell counts were compared to the color card results. The paired t test results for the calculated values for the 3:1, 2:1, and 1:1 color cards and the red blood cell count values were comparable (44.3 ± 22.1 ml vs. 53.6 ± 25.0 ml, t = 10.5; 45.4 ± 19.0 ml vs. 55.2 ± 20.7 ml, t = 18.1; 41.9 ± 25.6 ml vs. 52.8 ± 28.3 ml, t = 14.0). The P values were < 0.05, and the difference between the two groups was statistically significant. The average standard error of the mean was 0.90, 0.54, and 0.77, respectively. Sixty samples were evaluated in a scatter diagram using the two detection methods. Trend analysis revealed that the two results demonstrated a linear increase (y = 5.6 + 1.1x), R2 = 0.989, indicating that the two inspection methods were highly correlated with only small errors. CONCLUSION: The colorimetric card protocol developed in this study could quickly, accurately, and conveniently calculate blood volumes in liposuction fluids, which has considerable clinical significance. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors http://www.springer.com/00266 .

Dysregulation of iron homeostasis and methamphetamine reward behaviors in Clk1-deficient mice.

Chronic administration of methamphetamine (METH) leads to physical and psychological dependence. It is generally accepted that METH exerts rewarding effects via competitive inhibition of the dopamine transporter (DAT), but the molecular mechanism of METH addiction remains largely unknown. Accumulating evidence shows that mitochondrial function is important in regulation of drug addiction. In this study,  we investigated the role of Clk1, an essential mitochondrial hydroxylase for ubiquinone (UQ), in METH reward effects. We showed that Clk1+/- mutation significantly suppressed METH-induced conditioned place preference (CPP), accompanied by increased expression of DAT in plasma membrane of striatum and hippocampus due to Clk1 deficiency-induced inhibition of DAT degradation without influencing de novo synthesis of DAT. Notably, significantly decreased iron content in striatum and hippocampus was evident in both Clk1+/- mutant mice and PC12 cells with Clk1 knockdown. The decreased iron content was attributed to increased expression of iron exporter ferroportin 1 (FPN1) that was associated with elevated expression of hypoxia-inducible factor-1α (HIF-1α) in response to Clk1 deficiency both in vivo and in vitro. Furthermore, we showed that iron played a critical role in mediating Clk1 deficiency-induced alteration in DAT expression, presumably via upstream HIF-1α. Taken together, these data demonstrated that HIF-1α-mediated changes in iron homostasis are involved in the Clk1 deficiency-altered METH reward behaviors.

Terpenoids from the Liverwort Plagiochila fruticosa and Their Antivirulence Activity against Candida albicans.

Fourteen new terpenoids plagicosins A-N (1-14), including seven sesquiterpenoids (1-7) consisting of six ent-bicyclogermacrenes and one ent-2,3-seco-aromadendrane, as well as seven diterpenoids (8-14) comprising five fusicoccanes, a eunicellane, and a rare gersemiane, were isolated from the Chinese liverwort Plagiochila fruticosa Mitt. The structures of these terpenoids were determined on the basis of comprehensive analysis of MS and NMR spectroscopic data coupled with electronic circular dichroism (ECD) and coupling constant calculations. Plagicosin F (6) displayed potent antivirulence activity through inhibiting the hyphal morphogenesis, adhesion, and biofilm formation of Candida albicans. The genes related to hyphal formation were regulated by 6.

Regulation of microRNAs by rape bee pollen on benign prostate hyperplasia in rats.

The miRNAs are dysregulated in BPH. Rape bee pollen (RBP) is used to improve benign prostatic hyperplasia (BPH). Whether RBP treats BPH by regulating the dysregulated miRNAs remains unclear. Here, we identified miRNAs regulated along with the improvement of BPH by RBP in posterior lobes of prostate in rats. Firstly, to screened miRNAs might relate to improvement of BPH by RBP, we compared differentially expressed miRNAs between BPH model group and RBP group by high-throughput sequencing. As a result, 10 known miRNAs and 17 novel miRNA were up-regulated in RBP group, and 6 known and 13 novel miRNAs were down-regulated. Secondly, among the known miRNAs, we identified those that might relate to BPH by RT-qPCR, while only rno-miR-184 was screened, so we compared it among normal control group, BPH model group and RBP group. The results showed that rno-miR-184 was significantly lower expressed in BPH group, but up-regulated along with the improvement of BPH by RBP. Moreover, expression level of rno-miR-184 was no difference between RBP group and normal control level. Therefore, we considered that RBP might improve BPH through regulating expression of miRNAs like rno-miR-184 in prostate in rats.

SILGGM: An extensive R package for efficient statistical inference in large-scale gene networks.

Gene co-expression network analysis is extremely useful in interpreting a complex biological process. The recent droplet-based single-cell technology is able to generate much larger gene expression data routinely with thousands of samples and tens of thousands of genes. To analyze such a large-scale gene-gene network, remarkable progress has been made in rigorous statistical inference of high-dimensional Gaussian graphical model (GGM). These approaches provide a formal confidence interval or a p-value rather than only a single point estimator for conditional dependence of a gene pair and are more desirable for identifying reliable gene networks. To promote their widespread use, we herein introduce an extensive and efficient R package named SILGGM (Statistical Inference of Large-scale Gaussian Graphical Model) that includes four main approaches in statistical inference of high-dimensional GGM. Unlike the existing tools, SILGGM provides statistically efficient inference on both individual gene pair and whole-scale gene pairs. It has a novel and consistent false discovery rate (FDR) procedure in all four methodologies. Based on the user-friendly design, it provides outputs compatible with multiple platforms for interactive network visualization. Furthermore, comparisons in simulation illustrate that SILGGM can accelerate the existing MATLAB implementation to several orders of magnitudes and further improve the speed of the already very efficient R package FastGGM. Testing results from the simulated data confirm the validity of all the approaches in SILGGM even in a very large-scale setting with the number of variables or genes to a ten thousand level. We have also applied our package to a novel single-cell RNA-seq data set with pan T cells. The results show that the approaches in SILGGM significantly outperform the conventional ones in a biological sense. The package is freely available via CRAN at https://cran.r-project.org/package=SILGGM.

LOX Mutations Predispose to Thoracic Aortic Aneurysms and Dissections.

RATIONALE: Mutations in several genes have been identified that are responsible for 25% of families with familial thoracic aortic aneurysms and dissections. However, the causative gene remains unknown in 75% of families. OBJECTIVES: To identify the causative mutation in families with autosomal dominant inheritance of thoracic aortic aneurysms and dissections. METHODS AND RESULTS: Exome sequencing was used to identify the mutation responsible for a large family with thoracic aortic aneurysms and dissections. A heterozygous rare variant, c.839G>T (p.Ser280Arg), was identified in LOX, encoding a lysyl oxidase, that segregated with disease in the family. Sanger and exome sequencing was used to investigate mutations in LOX in an additional 410 probands from unrelated families. Additional LOX rare variants that segregated with disease in families were identified, including c.125G>A (p.Trp42*), c.604G>T (p.Gly202*), c.743C>T (p.Thr248Ile), c.800A>C (p.Gln267Pro), and c.1044T>A (p.Ser348Arg). The altered amino acids cause haploinsufficiency for LOX or are located at a highly conserved LOX catalytic domain, which is relatively invariant in the population. Expression of the LOX variants p.Ser280Arg and p.Ser348Arg resulted in significantly lower lysyl oxidase activity when compared with the wild-type protein. Individuals with LOX variants had fusiform enlargement of the root and ascending thoracic aorta, leading to ascending aortic dissections. CONCLUSIONS: These data, along with previous studies showing that the deficiency of LOX in mice or inhibition of lysyl oxidases in turkeys and rats causes aortic dissections, support the conclusion that rare genetic variants in LOX predispose to thoracic aortic disease.

Study on the inhibition of Mfn1 by plant-derived miR5338 mediating the treatment of BPH with rape bee pollen.

BACKGROUND: Recent studies have found that plant derived microRNA can cross-kingdom regulate the expression of genes in humans and other mammals, thereby resisting diseases. Can exogenous miRNAs cross the blood-prostate barrier and entry prostate then participate in prostate disease treatment? METHODS: Using HiSeq sequencing and RT-qPCR technology, we detected plant miRNAs that enriched in the prostates of rats among the normal group, BPH model group and rape bee pollen group. To forecast the functions of these miRNAs, the psRobot software and TargetFinder software were used to predict their candidate target genes in rat genome. The qRT-PCR technology was used to validate the expression of candidate target genes. RESULTS: Plant miR5338 was enriched in the posterior lobes of prostate gland of rats fed with rape bee pollen, which was accompanied by the improvement of BPH. Among the predicted target genes of miR5338, Mfn1 was significantly lower in posterior lobes of prostates of rats in the rape bee pollen group than control groups. Further experiments suggested that Mfn1 was highly related to BPH. CONCLUSIONS: These results suggesting that plant-derived miR5338 may involve in treatment of rat BPH through inhibiting Mfn1 in prostate. These results will provide more evidence for plant miRNAs cross-kingdom regulation of animal gene, and will provide preliminary theoretical and experimental basis for development of rape bee pollen into innovative health care product or medicine for the treatment of BPH.

Effect of Different Doses of Radiation on Intestinal Injury in NOD/SCID Mice.

Objective To study the effect of different doses of radiation on intestinal injury,with an attempt to find the optimal radiation dose for establishing intestinal injury models in NOD/SCID mice. Methods Forty healthy male SPF-grade NOD/SCID mice were divided randomly into four groups:blank control group and 4-,5-,6-Gy irradiatio groups,with 10 mice in each group. The irradiation rate was 1 Gy/min. The general conditions,body weight,intestinal bacterial translocation,and histopathologic changes were observed and compared. Results The survival rate was 60%,50%,and 30% in the 4-,5-,and 6-Gy groups 15 days after irradiation,and the intestinal bacterial translocation rate was 20%,50%,and 70%,respectively. The body weights in 5-Gy group (P=0.015) and 6-Gy group (P=0.011) were significantly higher than that in blank control group. The length of small intestinal villi decreased in the 4-Gy group. In the 5-Gy group,the structure of intestinal mucosa villi became wide,flat,and inverted,along with the shedding of epithelial cells,the atrophy of glands,and the damage of recess structures. In the 6-Gy group,the structure of intestinal mucosal villi was damaged,the villi were ruptured and smashed,and the recess structures were missing;meanwhile,there was a large amount of inflammatory cell infiltration between tissues,along with visible spotty bleeding and necrosis. The length of small intestine villi in the blank control group and 4-,5-,and 6-Gy groups were (361.77±22.77),(291.68±32.45),(248.03±51.09),and (195.90±26.39) µm,respectively. In particular,it was significantly shorter in 4-Gy group (P=0.005),5-Gy group (P<0.001),and 6-Gy (P<0.001) than in the blank control group,was significantly shorter in the 5-Gy group (P=0.041) and 6-Gy group (P=0.001) than in the 4-Gy group,and significantly shorter in 6-Gy group than in the 5-Gy group (P=0.020). Conclusion 5-Gy irradiation in mice models can decrease body weight,cause the damage of intestinal mucosa and the shedding of inflammatory cells,with stable survival rate and bacterial translocation rate.

Exosomal MicroRNA MiR-1246 Promotes Cell Proliferation, Invasion and Drug Resistance by Targeting CCNG2 in Breast Cancer.

BACKGROUND/AIMS: Treatment of breast cancer remains a clinical challenge. This study aims to validate exosomal microRNA-1246 (miR-1246) as a serum biomarker for breast cancer and understand the underlying mechanism in breast cancer progression. METHODS: The expression levels of endogenous and exosomal miRNAs were examined by real time PCR, and the expression level of the target protein was detected by western blot. Scanning electron and confocal microscopy were used to characterize exosomes and to study their uptake and transfer. Luciferase reporter plasmids and its mutant were used to confirm direct targeting. Furthermore, the functional significance of exosomal miR-1246 was estimated by invasion assay and cell viability assay. RESULTS: In this study, we demonstrate that exosomes carrying microRNA can be transferred among different cell lines through direct uptake. miR-1246 is highly expressed in metastatic breast cancer MDA-MB-231 cells compared to non-metastatic breast cancer cells or non-malignant breast cells. Moreover, miR-1246 can suppress the expression level of its target gene, Cyclin-G2 (CCNG2), indicating its functional significance. Finally, treatment with exosomes derived from MDA-MB-231 cells could enhance the viability, migration and chemotherapy resistance of non-malignant HMLE cells. CONCLUSIONS: Together, our results support an important role of exosomes and exosomal miRNAs in regulating breast tumor progression, which highlights their potential for applications in miRNA-based therapeutics.

Extracellular vesicles: An overview of biogenesis, function, and role in breast cancer.

Extracellular vesicles have emerged as important mediators of intercellular communication and play an active role in cancer, including breast cancer. Despite limited studies, initial observations suggest that these vesicles are important in breast physiology and pathophysiology. We here, in brief, describe their potential use as future biomarkers and therapeutic agents in breast cancer. Extracellular vesicles in blood and breast fluid may have a great potential to detect and predict the presence of breast cancer, and extracellular vesicles modulation may emerge as a therapeutic approach in cancer therapy.

Effects of Surface Charges on the Bactericide Activity of CdTe/ZnS Quantum Dots: A Cell Membrane Disruption Perspective.

The inhibitory effects of CdTe/ZnS quantum dots (QDs) modified with 3-mercaptopropionic acid (negatively charged) or cysteamine (positively charged) on the metabolic activity of Escherichia coli were investigated using biological microcalorimetry. Results show that the inhibitory ratio of positive QDs is higher than that of negative QDs. Transmission electron microscopy images indicate that QDs are prone to be adsorbed on the surface of E. coli. This condition disturbs the membrane structure and function of E. coli. Fluorescence anisotropy results demonstrate that positive QDs show a significant increase in the membrane fluidity of E. coli and dipalmitoylphosphatidylcholine (DPPC) model membrane. Furthermore, fluorescence anisotropy values of DPPC membrane in the gel phase decreased upon the addition of positive QDs. By contrast, anisotropy values in the liquid-crystalline phase are almost constant. The change in membrane fluidity is associated with the increased permeability of the membrane. Finally, the kinetics of dye leakage from liposomes demonstrate that the surface charge of QDs is crucial to the interaction between QDs and membrane.

FastGGM: An Efficient Algorithm for the Inference of Gaussian Graphical Model in Biological Networks.

Biological networks provide additional information for the analysis of human diseases, beyond the traditional analysis that focuses on single variables. Gaussian graphical model (GGM), a probability model that characterizes the conditional dependence structure of a set of random variables by a graph, has wide applications in the analysis of biological networks, such as inferring interaction or comparing differential networks. However, existing approaches are either not statistically rigorous or are inefficient for high-dimensional data that include tens of thousands of variables for making inference. In this study, we propose an efficient algorithm to implement the estimation of GGM and obtain p-value and confidence interval for each edge in the graph, based on a recent proposal by Ren et al., 2015. Through simulation studies, we demonstrate that the algorithm is faster by several orders of magnitude than the current implemented algorithm for Ren et al. without losing any accuracy. Then, we apply our algorithm to two real data sets: transcriptomic data from a study of childhood asthma and proteomic data from a study of Alzheimer's disease. We estimate the global gene or protein interaction networks for the disease and healthy samples. The resulting networks reveal interesting interactions and the differential networks between cases and controls show functional relevance to the diseases. In conclusion, we provide a computationally fast algorithm to implement a statistically sound procedure for constructing Gaussian graphical model and making inference with high-dimensional biological data. The algorithm has been implemented in an R package named "FastGGM".

Impact of multiple quaternary ammonium salts on dynamic properties of BSA adsorption layer at different pH values.

The interaction mechanism of multiple quaternary ammonium salts (MQAS) with bovine serum albumin (BSA) was examined by the fluorescence quenching method and circular dichroism (CD) spectra. Moreover, the effects of MQAS on the dynamic properties of BSA adsorption layers at different pH values were investigated using dilational interfacial rheology. Results show that the quenching constants increase with an increase in pH values and decrease with an increase in the experiment temperature at pH 5.3. The quenching mechanism is static quenching, and the electrostatic force dominates the interaction between MQAS and BSA at pH 5.3. Due to three positive head groups, MQAS can significantly affect the dynamic interfacial activity of BSA molecules at a relatively low concentration. At pH 4.3, the electrostatic repulsion is unfavorable for the formation of MQAS/BSA complexes. Consequently, MQAS molecules will replace BSA molecules from the interface by competitive adsorption. At the pH value above the isoelectric point of BSA, the electrostatic attraction is better for the formation of MQAS/BSA complexes, which exhibit a rapid adsorption rate and an enhanced interfacial activity. Moreover, the kinetic dependencies of interfacial dilational elasticity for the MQAS/BSA mixtures become nonmonotonous. The appearance of the maximum interfacial elasticity values can be attributed to the formation of tails and loops, which suggests that the addition of MQAS destroys the secondary and tertiary structure of protein in the bulk phase. In addition, the effects of MQAS on the secondary structure of protein were demonstrated by CD spectra.

Dihydromyricetin protects neurons in an MPTP-induced model of Parkinson's disease by suppressing glycogen synthase kinase-3 beta activity.

AIM: It is general believed that mitochondrial dysfunction and oxidative stress play critical roles in the pathology of Parkinson's disease (PD). Dihydromyricetin (DHM), a natural flavonoid extracted from Ampelopsis grossedentata, has recently been found to elicit potent anti-oxidative effects. In the present study, we explored the role of DHM in protecting dopaminergic neurons. METHODS: Male C57BL/6 mice were intraperitoneally injected with 1-methyl4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) for 7 d to induce PD. Additionally, mice were treated with either 5 or 10 mg/kg DHM for a total of 13 d (3 d before the start of MPTP, during MPTP administration (7 d) and 3 d after the end of MPTP). For the saline or DHM alone treatment groups, mice were injected with saline or DHM for 13 d. On d 14, behavioral tests (locomotor activity, the rotarod test and the pole test) were administered. After the behavioral tests, the mice were sacrificed, and brain tissue was collected for immunofluorescence staining and Western blotting. In addition, MES23.5 cells were treated with MPP+ and DHM, and evaluated using cell viability assays, reactive oxygen species (ROS) measurements, apoptosis analysis and Western blotting. RESULTS: DHM significantly attenuated MPTP-induced mouse behavioral impairments and dopaminergic neuron loss. In the MES23.5 cells, DHM attenuated MPP+-induced cell injury and ROS production in a dose-dependent manner. In addition, DHM increased glycogen synthase kinase-3 beta phosphorylation in a dose- and time-dependent manner, which may be associated with DHM-induced dopaminergic neuronal protection. CONCLUSION: The present study demonstrated that DHM is a potent neuroprotective agent for DA neurons by modulating the Akt/GSK-3ß pathway, which suggests that DHM may be a promising therapeutic candidate for PD.