FL-circAS: an integrative resource and analysis for full-length sequences and alternative splicing of circular RNAs with nanopore sequencing.

Circular RNAs (circRNAs) are RNA molecules with a continuous loop structure characterized by back-splice junctions (BSJs). While analyses of short-read RNA sequencing have identified millions of BSJ events, it is inherently challenging to determine exact full-length sequences and alternatively spliced (AS) isoforms of circRNAs. Recent advances in nanopore long-read sequencing with circRNA enrichment bring an unprecedented opportunity for investigating the issues. Here, we developed FL-circAS (https://cosbi.ee.ncku.edu.tw/FL-circAS/), which collected such long-read sequencing data of 20 cell lines/tissues and thereby identified 884 636 BSJs with 1 853 692 full-length circRNA isoforms in human and 115 173 BSJs with 135 617 full-length circRNA isoforms in mouse. FL-circAS also provides multiple circRNA features. For circRNA expression, FL-circAS calculates expression levels for each circRNA isoform, cell line/tissue specificity at both the BSJ and isoform levels, and AS entropy for each BSJ across samples. For circRNA biogenesis, FL-circAS identifies reverse complementary sequences and RNA binding protein (RBP) binding sites residing in flanking sequences of BSJs. For functional patterns, FL-circAS identifies potential microRNA/RBP binding sites and several types of evidence for circRNA translation on each full-length circRNA isoform. FL-circAS provides user-friendly interfaces for browsing, searching, analyzing, and downloading data, serving as the first resource for discovering full-length circRNAs at the isoform level.

Transcriptome-wide analyses of piRNA binding sites suggest distinct mechanisms regulate piRNA binding and silencing in C. elegans.

PIWI-interacting RNAs (piRNAs) protect genome integrity by silencing transposon mRNAs and some endogenous mRNAs in various animals. However, C. elegans piRNAs only trigger gene silencing at select predicted targeting sites, suggesting additional cellular mechanisms regulate piRNA silencing. To gain insight into possible mechanisms, we compared the transcriptome-wide predicted piRNA targeting sites to the in vivo piRNA binding sites. Surprisingly, while sequence-based predicted piRNA targeting sites are enriched in 3' UTRs, we found that C. elegans piRNAs preferentially bind to coding regions (CDS) of target mRNAs, leading to preferential production of secondary silencing small RNAs in the CDS. However, our analyses suggest that this CDS binding preference cannot be explained by the action of antisilencing Argonaute CSR-1. Instead, our analyses imply that CSR-1 protects mRNAs from piRNA silencing through two distinct mechanisms-by inhibiting piRNA binding across the entire CSR-1 targeted transcript, and by inhibiting secondary silencing small RNA production locally at CSR-1 bound sites. Together, our work identifies the CDS as the critical region that is uniquely competent for piRNA binding in C. elegans. We speculate the CDS binding preference may have evolved to allow the piRNA pathway to maintain robust recognition of RNA targets in spite of genetic drift. Together, our analyses revealed that distinct mechanisms are responsible for restricting piRNA binding and silencing to achieve proper transcriptome surveillance.

Investigation of N-Glycan Functions in Receptor for Advanced Glycation End Products V Domain through Chemical Glycoprotein Synthesis.

The receptor for advanced glycation end products (RAGE) plays a crucial role in inflammation-related pathways and various chronic diseases. Despite the recognized significance of N-glycosylation in the ligand-binding V domain (VD) of RAGE, a comprehensive understanding of the site-activity and structure-activity relationships is lacking due to the challenges in obtaining homogeneous glycoprotein samples through biological expression. Here, we combined chemical and chemoenzymatic approaches to synthesize RAGE-VD and its congeners with Asn3-glycosylation by incorporating precise N-glycan structures. Evaluation of these samples revealed that, in comparison to other RAGE-VD forms, α2,6-sialylated N-glycosylation at the Asn3 site results in more potent inhibition of HMGB1-induced nuclear factor-κB (NF-κB) expression in RAGE-overexpressing cells. Hydrogen/deuterium exchange-mass spectrum analysis revealed a sialylated RAGE-VD-induced interaction region within HMGB1. Conversely, Asn3 N-glycosylation in VD has negligible effects on RAGE-VD/S100B interactions. This study established an approach for accessing homogeneously glycosylated RAGE-VD and explored the modulatory effects of N-glycosylation on the interactions between RAGE-VD and its ligand proteins.

Revisiting the roles of glucose transporters in skeletal muscle physiology: is GLUT10 a novel player?

Skeletal muscle is the largest metabolic tissue responsible for systemic glucose handling. Glucose uptake into skeletal tissue is highly dynamic and delicately regulated, in part through the controlled expression and subcellular trafficking of multiple types of glucose transporters. Although the roles of GLUT4 in skeletal muscle metabolism are well established, the physiological significance of other, seemingly redundant, glucose transporters remain incompletely understood. Nonetheless, recent studies have shed light on the roles of several glucose transporters, such as GLUT1 and GLUT10, in skeletal muscle. Mice experiments suggest that GLUT10 could be a novel player in skeletal muscle metabolism in the context of mechanical overload, which is in line with the meta-analytical results of gene expression changes after resistance exercise in humans. Herein we discuss the knowns, unknowns, and implications of these recent findings.

Performance of a photoelectron momentum microscope in direct- and momentum-space imaging with ultraviolet photon sources.

The Photoelectron-Related Image and Nano-Spectroscopy (PRINS) endstation located at the Taiwan Photon Source beamline 27A2 houses a photoelectron momentum microscope capable of performing direct-space imaging, momentum-space imaging and photoemission spectroscopy with position sensitivity. Here, the performance of this microscope is demonstrated using two in-house photon sources - an Hg lamp and He(I) radiation - on a standard checkerboard-patterned specimen and an Au(111) single crystal, respectively. By analyzing the intensity profile of the edge of the Au patterns, the Rashba-splitting of the Au(111) Shockley surface state at 300 K, and the photoelectron intensity across the Fermi edge at 80 K, the spatial, momentum and energy resolution were estimated to be 50 nm, 0.0172 Å-1 and 26 meV, respectively. Additionally, it is shown that the band structures acquired in either constant energy contour mode or momentum-resolved photoemission spectroscopy mode were in close agreement.

Interstitial fibrosis increases the risk of end-stage kidney disease in patients with lupus nephritis.

OBJECTIVE: To evaluate the risk of end-stage kidney disease (ESKD) in LN patients using tubulointerstitial lesion scores. METHODS: Clinical profiles and histopathological presentations of 151 biopsy-proven LN patients were retrospectively examined. Risk factors of ESKD based on characteristics and scoring of their tubulointerstitial lesions [e.g. interstitial inflammation (II), tubular atrophy (TA) and interstitial fibrosis (IF)] were analysed. RESULTS: The mean age of 151 LN patients was 36 years old, and 136 (90.1%) were female. The LN cases examined included: class I/II (n = 3, 2%), class III/IV (n = 119, 78.8%), class V (n = 23, 15.2%) and class VI (n = 6, 4.0%). The mean serum creatinine level was 1.4 mg/dl. Tubulointerstitial lesions were recorded in 120 (79.5%) patients. Prior to receiving renal biopsy, nine (6.0%) patients developed ESKD. During the follow-up period (mean, 58 months), an additional 47 patients (31.1%) progressed to ESKD. Multivariate analyses identified serum creatinine [hazard ratio (HR): 1.7, 95% CI: 1.42-2.03, P < 0.001] and IF (HR: 3.2, 95% CI: 1.58-6.49, P = 0.001) as independent risk factors of ESKD. Kaplan-Meier analysis further confirmed a heightened risk of ESKD associated with IF. CONCLUSION: Tubulointerstitial involvement is commonly observed in the histopathological presentation of LN. However, IF, rather than II or TA, was found to increase the risk of ESKD in our cohort. Therefore, to predict renal outcome in LN patients prior to adjusting immunosuppressive treatment, the degree of IF should be reviewed.

Efficacy and safety of narrowband ultraviolet B versus combined ultraviolet A/narrowband ultraviolet B phototherapy in the treatment of chronic atopic dermatitis: A randomised double-blind study.

Phototherapy is a useful treatment modality for atopic dermatitis (AD). This is a prospective randomised double-blind study comparing the clinical efficacy of combined ultraviolet-A (UVA)/narrowband ultraviolet-B (NBUVB) versus NBUVB phototherapy in the treatment of chronic AD. Patients with moderate-to-severe AD were randomised to receive either UVA/NBUVB or NBUVB phototherapy twice weekly over 12 weeks. At baseline, weeks 6 and 12, Eczema Area And Severity Index (EASI), itch score and adverse effects were assessed. At baseline and week 12, disease-related quality of life was evaluated using the Dermatology Life Quality Index (DLQI). Nine patients were randomised to receive UVA/NBUVB and 10 received NBUVB. At week 12, both groups showed significant improvement in EASI and itch scores (p < 0.05). Significant improvement in DLQI was seen in the UVA/NBUVB arm (p = 0.009) with a trend towards improvement in the NBUVB arm (p = 0.11). The efficacy of both modalities were comparable, as were reported adverse effects aside from skin dryness which was higher in the NBUVB arm (40% vs. 0%, p = 0.033). Combined UVA/NBUVB and NBUVB phototherapy have comparable clinical efficacy and safety in the treatment of chronic AD. NBUVB may induce greater skin dryness.

Catalytic Synthesis of Silanols by Hydroxylation of Hydrosilanes: From Chemoselectivity to Enantioselectivity.

As a crucial class of functional molecules in organosilicon chemistry, silanols are found valuable applications in the fields of modern science and will be a potentially powerful framework for biologically active compounds or functional materials. It has witnessed an increasing demand for non-natural organosilanols, as well as the progress in the synthesis of these structural features. From the classic preparative methods to the catalytic selective oxidation of hydrosilanes, electrochemical hydrolysis of hydrosilanes, and then the construction of the most challenging silicon-stereogenic silanols. This review summarized the progress in the catalyzed synthesis of silanols via hydroxylation of hydrosilanes in the last decade, with a particular emphasis on the latest elegant developments in the desymmetrization strategy for the enantioselective synthesis of silicon-stereogenic silanols from dihydrosilanes.

Intake of Added Sugar from Different Sources and Risk of All-cause Mortality and Cardiovascular Diseases: The Role of Body Mass Index.

BACKGROUND: Recent studies have shown an ascending trend in global added sugar consumption. Evidence for the long-term consequences of added sugar from different sources on all-cause mortality and cardiovascular diseases (CVDs) remains limited. OBJECTIVE: This study aimed to examine the associations between added sugar from various sources and the risk of all-cause mortality and CVDs, and to determine whether genetic predisposition and body mass index (BMI) influence or mediate these associations. METHODS: We included 196,414 UK Biobank participants who completed a 24-hour food survey between 2009 and 2012. Sugar contents were collected from the Composition of Foods Integrated Dataset (CoFID). The National Death Registries and hospital records provided data on death and the disease diagnosis. We employed a polygenic risk score (PRS) to assess the genetic predisposition. Cox proportional hazards regression was used to analyze the associations. RESULTS: Totally, 10,081 deaths, 38,563 hypertension cases, 12,306 ischaemic heart diseases (IHD), and 5,491 cerebrovascular diseases were documented. Compared with the lowest quartile group of added sugar intake, the hazards ratios for all-cause mortality in the highest quartile were 1.21 (95% CI: 1.14, 1.30) for total added sugar, 1.03(95% CI: 0.97, 1.10) for solids, and 1.16(95% CI: 1.10, 1.23) for beverages. For CVDs, significant associations were observed in total added sugar and beverage sources. These associations were not altered by PRS, and individuals at greatest risk showed higher PRS along with excessive added sugar consumption (Ptrend<0.001). BMI was found to mediate the highest proportion of the association between added sugar and hypertension (19.10% for total; 36.95% for beverages). CONCLUSION: Higher intake of added sugar, especially from beverages, is associated with an increased risk of all-cause mortality and CVDs. BMI mediates a proportion of these associations.

Risk Factors and Incidence of Serious Infections in Patients With Systemic Lupus Erythematosus Undergoing Rituximab Therapy.

OBJECTIVE: To evaluate the risk and protective factors of serious infection (SI) in patients with systemic lupus erythematosus (SLE) within 180 days of rituximab (RTX) treatment. METHODS: Patients with SLE treated with RTX were analyzed. SI was defined as any infectious disease requiring hospitalization. The clinical characteristics, laboratory profiles, medications, and incidence rate (IR) are presented. Multivariate Cox proportional hazards models and Kaplan-Meier analysis for risk factors of SI were performed. RESULTS: A total of 174 patients with SLE receiving RTX treatment were enrolled. The overall IR of SIs was 51.0/100 patient-years (PYs). Pneumonia (30.4/100 PYs), followed by soft tissue infections, intra-abdominal infections, and Pneumocystis jiroveci pneumonia (all 6.1/100 PYs) were the leading types of SIs. Twelve patients died during the 180-day follow-up (crude mortality rate: 14.6/100 PYs). Chronic kidney disease (CKD), defined as an estimated glomerular filtration rate < 60 mL/min/1.73 m2 (hazard ratio [HR] 2.88, 95% CI 1.30-6.38), and a background prednisolone (PSL) equivalent dosage ≥ 15 mg/day (HR 3.50, 95% CI 1.57-7.78) were risk factors for SIs among all patients with SLE. Kaplan-Meier analysis confirmed the risk of SI for patients with SLE with CKD and a background PSL equivalent dosage ≥ 15 mg/day (log-rank P = 0.001 and 0.02, respectively). Hydroxychloroquine (HCQ) reduced the risk of SIs in patients with SLE (HR 0.35, 95% CI 0.15-0.82; log-rank P = 0.003). CONCLUSION: SI was prevalent in patients with SLE after RTX treatment. Patients with SLE with CKD and high-dose glucocorticoid use required constant vigilance. HCQ may reduce the risk of SI among patients with SLE administered RTX.

Bacterial persisters are a stochastically formed subpopulation of low-energy cells.

Persisters represent a small subpopulation of non- or slow-growing bacterial cells that are tolerant to killing by antibiotics. Despite their prominent role in the recalcitrance of chronic infections to antibiotic therapy, the mechanism of their formation has remained elusive. We show that sorted cells of Escherichia coli with low levels of energy-generating enzymes are better able to survive antibiotic killing. Using microfluidics time-lapse microscopy and a fluorescent reporter for in vivo ATP measurements, we find that a subpopulation of cells with a low level of ATP survives killing by ampicillin. We propose that these low ATP cells are formed stochastically as a result of fluctuations in the abundance of energy-generating components. These findings point to a general "low energy" mechanism of persister formation.

Guiding the Formation of Metal-Organic Structures of 1,4-Diaminoanthraquinone through Surface-Based Cu Atoms.

The gradual guidance of the formation of metal-organic structures through surface-based Cu atoms for 1,4-diaminoanthraquinones (DAQs) has been studied by scanning tunneling microscopy (STM) at room temperature. On the Ag(110) surface, the transition from a hydrogen-bond network structure to metal-organic coordination structures of DAQs can be induced by introducing foreign copper atoms. Due to the weak interaction between DAQs and Ag(110), thermal treatment easily leads to the desorption of DAQs from the surface. To address this challenge, Cu(111) is selected as the substrate. Under thermal driving and in the presence of copper adatoms, the hydrogen-bond network structure of DAQs on the surface gradually undergoes a transition into a metal-coordinated structure, eventually leading to the formation of metal-organic complexes through amino dehydrogenation. It is demonstrated that the construction of a metal-organic coordination structure on metal surfaces is a result of the competition among factors such as metal atoms, functional groups of molecules, surface chemical activity, and temperature.

Phase Transitions of Naphthalene-2,3-carbonitride Steered by Solvent Effects and Metal Ion Concentration Variation.

The delicate regulation of structural phase transition can provide advanced approaches for fabricating desired and well-organized nanoarchitectures on surfaces. Introduction of metal ions into pure organic systems can facilitate the phase transition from hydrogen-bonded structures to metal-organic structures by coordinating with organic molecules. However, it remains a challenge to attain a phase transition dominated by variable metal coordination configurations through adjustment of the metal ion concentration. Herein, we report the phase transitions of naphthalene-2,3-carbonitride (2,3-DCN) molecules on highly oriented pyrolytic graphite (HOPG) under varying solvents and Cu2+ ion concentrations. By integrating data from scanning tunneling microscopy imaging and density functional theory calculations, it is demonstrated that phase transitions of 2,3-DCN occur through forming diverse coordination configurations where Cu2+ ions can coordinate with 2,3-DCN and 1-nonanoic acid or Cl- ions to form different ligand components with a coordination number of 4 when varying the molar ratios of 2,3-DCN to Cu2+ ion in the 1-nonanoic acid solvent. However, in the case of 1-heptanoic acid as a solvent, the self-assembly structure of 2,3-DCN only changes via the alteration of hydrogen bonding sites and Cu2+ ions do not coordinate with 2,3-DCN molecules. These findings provide valuable insights into the coordination behavior of metal ions in different solvents.

Identifying Human miRNA Target Sites via Learning the Interaction Patterns between miRNA and mRNA Segments.

miRNAs (microRNAs) target specific mRNA (messenger RNA) sites to regulate their translation expression. Although miRNA targeting can rely on seed region base pairing, animal miRNAs, including human miRNAs, typically cooperate with several cofactors, leading to various noncanonical pairing rules. Therefore, identifying the binding sites of animal miRNAs remains challenging. Because experiments for mapping miRNA targets are costly, computational methods are preferred for extracting potential miRNA-mRNA fragment binding pairs first. However, existing prediction tools can have significant false positives due to the prevalent noncanonical miRNA binding behaviors and the information-biased training negative sets that were used while constructing these tools. To overcome these obstacles, we first prepared an information-balanced miRNA binding pair ground-truth data set. A miRNA-mRNA interaction-aware model was then designed to help identify miRNA binding events. On the test set, our model (auROC = 94.4%) outperformed existing models by at least 2.8% in auROC. Furthermore, we showed that this model can suggest potential binding patterns for miRNA-mRNA sequence interacting pairs. Finally, we made the prepared data sets and the designed model available at http://cosbi2.ee.ncku.edu.tw/mirna_binding/download.

High-performance monolayer MoS2nanosheet GAA transistor.

In this article, a 0.7 nm thick monolayer MoS2nanosheet gate-all-around field effect transistors (NS-GAAFETs) with conformal high-κmetal gate deposition are demonstrated. The device with 40 nm channel length exhibits a high on-state current density of ~410µAµm-1with a large on/off ratio of 6 × 108at drain voltage = 1 V. The extracted contact resistance is 0.48 ± 0.1 kΩµm in monolayer MoS2NS-GAAFETs, thereby showing the channel-dominated performance with the channel length scaling from 80 to 40 nm. The successful demonstration of device performance in this work verifies the integration potential of transition metal dichalcogenides for future logic transistor applications.

Brominated Flame Retardant HBCD and Artificial Light at Night Synergically Caused Visual Disorder and Sleep Difficulty in Zebrafish Larvae.

Sleep difficulty is a widespread health concern exacerbated by factors such as light and chemical pollution. Artificial light at night (ALAN) can disrupt natural sleep-wake cycles, whereas chemical pollutants can impair sleep-related processes. The prevalence of ALAN increases the health risk of coexposure, yet it has not gained sufficient attention. Meanwhile, visual inputs are important for sleep regulation, especially the non-image-forming circadian visual system centered around melanopsin. This study evaluated the light perception ability and sleep performance of zebrafish larvae exposed to flame retardant hexabromocyclododecanes (HBCDs) at environmentally relevant concentrations (2.5 and 25 µg/L) and to cotreatment of HBCD and ALAN. HBCD induced a longer sleep latency of 34.59 min under 25 µg/L (p < 0.01) versus control (26.04 min). The situation was intensified by coexposure with low-level ALAN (10 lx) to 48.04 min. Similar synergic effects were observed for upregulations of Xenopus-related melanopsin genes and downregulations of the melatonin synthesis gene aanat2, suggesting a melanopsin-aanat2-sleep retina-brain pathway. Image-forming opsins (opn1sw1 and opn1sw2) were also activated by HBCD to 1.29-1.53-fold (p < 0.05), together with elevated retina glutamate, but without synergic effects. Collectively, we found that HBCD and ALAN coexposure caused synergic effects on the non-image-forming visual system and caused sleep difficulty in zebrafish larvae.

Mixed Metal Components in PM2.5 Contribute to Chemokine Receptor CCR5-Mediated Neuroinflammation and Neuropathological Changes in the Mouse Olfactory Bulb.

Particulate matter, especially PM2.5, can invade the central nervous system (CNS) via the olfactory pathway to induce neurotoxicity. The olfactory bulb (OB) is the key component integrating immunoprotection and olfaction processing and is necessarily involved in the relevant CNS health outcomes. Here we show that a microglial chemokine receptor, CCR5, is the target of environmentally relevant PM2.5 in the OB to trigger neuroinflammation and then neuropathological injuries. Mechanistically, PM2.5-induced CCR5 upregulation results in the pro-inflammatory paradigm of microglial activation, which subsequently activates TLR4-NF-κB neuroinflammation signaling and induces neuropathological changes that are closely related to neurodegenerative disorders (e.g., Aß deposition and disruption of the blood-brain barrier). We specifically highlight that manganese and lead in PM2.5 are the main contributors to CCR5-mediated microglial activation and neuroinflammation in synergy with aluminum. Our results uncover a possible pathway of PM2.5-induced neuroinflammation and identify the principal neurotoxic components, which can provide new insight into efficiently diminishing the adverse health effects of PM2.5.

Exploring the effects of acceptable palliative care models on survival time and healthcare expenditure among patients with cancer: a national longitudinal population-based study.

OBJECTIVE: Hospice care ensures better end-of-life quality by relieving terminal symptoms. Prior research has indicated that hospice care could prolong survival and reduce end-of-life medical expenditures among patients with cancer. However, the dearth of studies on the effects of hospice care type and use sequence on survival time and end-of-life medical expenditures substantiates the need for investigation. DATA SOURCES AND STUDY SETTING: Two million random records were obtained from the National Health Insurance Research Database. STUDY DESIGN: We estimated the effects of the type and sequence of hospice care use on survival time and medical expenditures among advanced cancer patients. This was a cross-sectional study. DATA COLLECTION/EXTRACTION METHODS: Patient data were collected from 2 million random records provided by the National Health Insurance Research Database of Taiwan. We included people with cancer and excluded patients under 20 years of age; 2860 patients remained after matching. PRINCIPAL FINDINGS: The results indicated that the average survival time of patients who received inpatient palliative care (1022 days) was significantly shorter than that of patients who did not receive palliative care (P < 0.001), but the health care expenditure during the entire course of cancer therapy was not the lowest. Interestingly, patients who received inpatient palliative care had the lowest health care expenditure at 1 year or month before the end of life (P < 0.001). CONCLUSION: The type and sequence of palliative care affected the survival time and health care expenditures of cancer patients. Receiving palliative care did not prolong survival but rather reduced health care expenditures. The sequence of receiving palliative care significantly affected health care expenditures.

Photoreceptor laminin drives differentiation of human pluripotent stem cells to photoreceptor progenitors that partially restore retina function.

Blindness caused by advanced stages of inherited retinal diseases and age-related macular degeneration are characterized by photoreceptor loss. Cell therapy involving replacement with functional photoreceptor-like cells generated from human pluripotent stem cells holds great promise. Here, we generated a human recombinant retina-specific laminin isoform, LN523, and demonstrated the role in promoting the differentiation of human embryonic stem cells into photoreceptor progenitors. This chemically defined and xenogen-free method enables reproducible production of photoreceptor progenitors within 32 days. We observed that the transplantation into rd10 mice were able to protect the host photoreceptor outer nuclear layer (ONL) up to 2 weeks post transplantation as measured by full-field electroretinogram. At 4 weeks post transplantation, the engrafted cells were found to survive, mature, and associate with the host's rod bipolar cells. Visual behavioral assessment using the water maze swimming test demonstrated visual improvement in the cell-transplanted rodents. At 20 weeks post transplantation, the maturing engrafted cells were able to replace the loss of host ONL by extensive association with host bipolar cells and synapses. Post-transplanted rabbit model also provided congruent evidence for synaptic connectivity with the degenerated host retina. The results may pave the way for the development of stem cell-based therapeutics for retina degeneration.

Chemical Constituents of the Fruits of Cornus Officinalis and Evaluation of their Neuroprotective Activity.

The phytochemical investigation of the fruits of Cornus officinalis yielded a new phenolic acid derivative, neophenolic acid A (1), and a novel flavonoid glycoside, (2R)-naringenin-7-O-ß-(6''-galloyl-glucopyranoside) (2 a), along with six known flavonoid glycosides (2 b-7). Their structures were determined by 1D, 2D NMR and HRESIMS data. The absolute configuration of 1 was established by ECD analysis. Compounds 1- 7 were evaluated for their neuroprotective activities against corticosterone (CORT)-induced injury in PC-12 cells. Compounds 1, 2 a, 2 b, 5, and 6 exhibited neuroprotective activities against CORT-induced neurotoxicity in PC-12 cells. The underlying mechanism study suggested that compounds 1, 2 a, 2 b, 5, and 6 were able to attenuate CORT-induced apoptosis and damage, increase the levels of MMP and decrease Ca2+ inward flow in PC-12 cells.