Mitofusin 2 Mediates the Protective Effect of NR6A1 Silencing Against Neuronal Injury in Experimental Stroke Models.

An abnormal increase in the expression of nuclear receptor subfamily 6 group A member 1 (NR6A1) in the hippocampus has been reported to result in depressive-like behavior in mice. However, the role of NR6A1 in the progression of neuronal death induced by ischemic stroke remains unknown. In this study, we observed an increase in NR6A1 in neurons in both in vivo and in vitro cerebral ischemic models. We found that knocking down NR6A1 in HT-22 neuronal cells subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) attenuated mitochondrial dysfunction and endoplasmic reticulum (ER) stress. Conversely, NR6A1 overexpression exacerbated neuronal damage following OGD/R. NR6A1 hindered the transcription of mitonfusin 2 (MFN2), leading to a decrease in its expression. In contrast, MFN2 conferred the protective effect of NR6A1 silencing against both mitochondrial dysfunction and ER stress. In addition, NR6A1 silencing also attenuated brain infarction, ER stress, neuronal apoptosis, and loss of MFN2 in mice subjected to middle cerebral artery occlusion/reperfusion. These findings indicate that NR6A1 is a promising target for the treatment of neuronal death following cerebral ischemia. Furthermore, these results confirm the involvement of MFN2 in the effects of NR6A1 silencing. Therefore, targeting NR6A1 has potential as a viable strategy for the treatment of ischemic stroke.

Hybrid teaching after COVID-19: advantages, challenges and optimization strategies.

BACKGROUND: In the post-pandemic era of higher education, hybrid teaching has emerged as a prevalent approach and is anticipated to persist as a defining trend in the future teaching reforms worldwide. However, despite its widespread adoption, certain limitations have become apparent. The objective of this study is to identify the genuine factors that impact students' performance, explore strategies that teachers can employ to enhance their teaching effectiveness and enhance students' academic self-efficacy. METHODS: The study was performed among undergraduate medical students enrolled in Physiology course at Harbin Medical University in 2020 and 2022. Since 2020, influenced by the COVID-19 pandemic, a hybrid teaching method based on an established offline teaching model called BOPPPS was implemented. A questionnaire was performed in both 2020 and 2022 to evaluate students' satisfaction and efficiency of our hybrid teaching. A comparison was also carried out on the final examination scores of students majoring in Pharmacy and Clinical Pharmacy across the years 2020 to 2022. RESULTS: The final examination scores of students in 2022 were significantly lower than those in 2020 and 2021 both in Pharmacy and Clinical Pharmacy majors. There was also a decrease of the score in students of Clinical Pharmacy in 2021 compared to 2020. The questionnaire indicated that over half (52.0%) of the students in 2022 preferred offline teaching method, in contrast to 39.1% in 2020. There were obvious changes in students from 2020 to 2022 about the disadvantages of hybrid teaching, the improvement of students' learning ability and the duration of students' autonomous learning. Through cross statistical analysis, online learning styles, learning ability improvement and students' learning burden have been identified as the primary factors influencing their preference for future teaching method. CONCLUSIONS: Hybrid teaching is still a necessary trend in the future teaching reform base on its multiple advantages. However, in order to improve the teaching outcomes and foster students' participation and learning initiatives, it is imperative to undertake additional reforms in the future teaching process.

Using case-based learning supported by role-playing situational teaching method in endocrine physiology education.

Embedding clinically relevant learning experience in basic science subjects is desired for the preclinical phase of undergraduate medical education. The present study aimed to modify case-based learning (CBL) with a role-playing situational teaching method and assess the student feedback and learning effect. One hundred seventy-six sophomore students majoring in clinical medicine from Harbin Medical University were randomly divided into two groups: the control group (n = 90), who received traditional hybrid teaching, and the experimental group (n = 86), who received the role-playing situational teaching. Students in the experimental group were given a 1-wk preclass preparation to dramatize a hyperthyroidism scenario through online autonomous learning of thyroid physiology and performed the patient's consultation process in class, followed by a student presentation about key points of lecture content and a question-driven discussion. A posttest and questionnaire survey were conducted after class. The test scores of the two groups had no statistical differences, whereas the rate of excellence (high scores) of the experimental group was significantly higher than that of the control group. Furthermore, the record of online self-directed learning engagements was significantly improved in the experimental group. In the questionnaire, >70% of the students showed positive attitudes toward the role-playing situational teaching method and were willing to participate in other chapters of the physiology course. Such results show that CBL supported by a role-playing situational teaching method encourages active learning and improves the application of basic knowledge of physiology, which can be incorporated in the preclinical curricula to bridge the gap between theory and practice.NEW & NOTEWORTHY Formal application through structured role-play is often overlooked in physiology education. In traditional case-based learning (CBL), clinical cases are the subject and unfocused discussion often occurs. The present study aimed to modify CBL with a role-playing situational teaching method and assess the student feedback and learning effect. The results show that the new teaching model encourages active learning and improves the application of basic knowledge of physiology.

Enhancing medical students' science communication skills: from the perspective of new media.

With the development of science over the years, people have increasingly realized the importance of science communication. Unfortunately, very little research has focused on helping medical students develop the capabilities of science communication. To improve medical students' science communication and evaluate the effectiveness of New Media through mobile clients in health science communication, a competition was held among medical undergraduates. Outstanding works were selected for publication on our official health science communication WeChat account. Furthermore, the participants volunteered to complete a questionnaire survey to help us assess students' awareness of science communication. Our analysis revealed that students had a strong willingness to serve society and to participate in science communication work. Students generally agreed that science communication work had excellent effects on professional knowledge and related skills. In addition, the correlation results showed that the greater students' willingness to participate in health science communication was, the greater their sense of gain. New Media effectively expand the influence of students' popular science works. Our findings suggest that competition in science communication has a positive impact on enhancing students' awareness and capabilities in science communication. In addition, New Media are an effective way to improve students' scientific communication efficiency. However, we also noted that students' participation rate and enthusiasm for scientific communication were not high. Further research is needed to determine the reasons for this situation and potential strategies to further improve students' science communication.NEW & NOTEWORTHY The science communication competition had a positive impact on helping medical students develop awareness and capabilities for science communication. In addition, New Media are an effective way to improve students' scientific communication efficiency.

Examining the effects of student-centered flipped classroom in physiology education.

BACKGROUND: The flipped classroom approach has gained increasing popularity in medical education. Physiology is a basic medical course that studies the phenomena and laws of human life activities, and is a crucial link course connecting preclinical courses and clinical courses. However, there is a paucity of data showing the effectiveness of the flipped classroom model for the entirety of physiology course in medical undergraduate students. METHOD: 131 sophomore students with clinical medicine major at Harbin Medical University were recruited and they were randomly allocated into two groups: the control group which was subjected to traditional lecture teaching (n = 69), and the experimental group which was subjected to flipped classroom teaching (n = 62). To assess the effect of flipped teaching, the usual performance and final exam scores were used to evaluate the physiology learning effectiveness of students. The correlation between the usual performance and final exam scores by Pearson method was also conducted in the two teaching groups. After course completion, an anonymous questionnaire survey was conducted among the subjects of flipped classroom group to assess students' opinion regarding the flipped classroom teaching. RESULTS: Our results showed that the usual performance and final exam scores of students in the flipped classroom were both significantly higher than that in the traditional teaching class (P < 0.05). Moreover, our results also showed that the usual performance of students was significantly correlated with the final exam scores in the flipped classroom (r = 0.3945, P < 0.01), but not in the traditional teaching group (r = 0.1522, P = 0.2119). The results of questionnaire survey showed that 77.58% of the students believed flipped classroom teaching improved their knowledge acquisition. 70%~86% of students perceived that flipped classroom enhanced their learning abilities, including self-study ability, collaborative learning and problem-solving skills, and clinical thinking ability. In addition, about 60% of students acknowledged the teaching design and teaching environment, more students' engagement and presentation of group learning in the flipped classroom. CONCLUSION: The flipped classroom teaching significantly improved students' learning effectiveness in physiology course, as indicated by final exam score and usual performance. It also promoted higher-order ability-set acquisition and allowed a rationalized formative evaluation system.

Single-nucleus RNA sequencing unveils critical regulators in various hippocampal neurons for anti-N-methyl-D-aspartate receptor encephalitis.

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a neuropsychiatric disease with variable clinical manifestations caused by NMDAR autoantibody. The underlying molecular underpinnings of this disease are rarely characterized on a genomic scale. Anti-NMDAR encephalitis mainly affects the hippocampus, however, its effect on gene expression in hippocampal neurons is unclear at present. Here, we construct the active and passive immunization mouse models of anti-NMDAR encephalitis, and use single-nucleus RNA sequencing to investigate the diverse expression profile of neuronal populations isolated from different hippocampal regions. Dramatic changes in cell proportions and differentially expressed genes were observed in excitatory neurons of the dentate gyrus (DG) subregion. In addition, we found that ATP metabolism and biosynthetic regulators related genes in excitatory neurons of DG subregion were significantly affected. Kcnq1ot1 in inhibitory neurons and Meg3 in interneurons also changed. Notably, the latter two molecules exhibited opposite changes in different models. Therefore, the above genes were used as potential targets for further research on the pathological process of anti-NMDAR encephalitis. These data involve various hippocampal neurons, which delineate a framework for understanding the hippocampal neuronal circuit and the potential molecular mechanisms of anti-NMDAR encephalitis.

Stabilization of nuclear ß-catenin by inhibiting KDM2A mediates cerebral ischemic tolerance.

Hypoxic postconditioning (HPC) with 8% oxygen increases nuclear accumulation of ß-catenin through activating the classical Wnt pathway, thereby alleviating transient global cerebral ischemia (tGCI)-induced neuronal damage in the hippocampal CA1 subregion of adult rats. However, little is understood about the regulatory mechanism of nuclear ß-catenin in HPC-mediated cerebral ischemic tolerance. Although lysine(K)-specific demethylase 2A (KDM2A) has been known as a crucial regulator of nuclear ß-catenin destabilization, whether it plays an important role through modulating nuclear ß-catenin in cerebral ischemic tolerance induced by HPC remains unknown. In this study, we explored the molecular mechanism of stabilizing nuclear ß-catenin by inhibiting KDM2A-mediated demethylation in the HPC-offered neuroprotection against tGCI. In addition, we confirmed that nuclear methylated-ß-catenin in CA1 decreased and nuclear ß-catenin turnover increased after tGCI, which were reversed by HPC. The administration with methyltransferase inhibitor AdOx abrogated HPC-induced methylation and stabilization of nuclear ß-catenin in CA1, as well as the neuroprotection against tGCI. Notably, HPC downregulated the expression of KDM2A in CA1 and reduced the interaction between KDM2A and ß-catenin in the nucleus after tGCI. The knockdown of KDM2A with small-interfering RNA could upregulate nuclear methylated-ß-catenin and stabilize ß-catenin, thereby increasing survivin in CA1 and improving the cognitive function of rats after tGCI. Opposite results were observed by the administration of KDM2A-carried adenovirus vector. Furthermore, we demonstrated that KDM2A mediates the demethylation of nuclear ß-catenin through jumonji C (JmjC) domain of KDM2A in HEK-293T and SH-SY5Y cells. Our data support that the inhibition of KDM2A-mediated demethylation of nuclear ß-catenin contributes to HPC-induced neuroprotection against tGCI.

IRAK-M suppresses the activation of microglial NLRP3 inflammasome and GSDMD-mediated pyroptosis through inhibiting IRAK1 phosphorylation during experimental autoimmune encephalomyelitis.

The activation of the NOD-like receptor family pyrin domain-containing protein 3 (NLRP3) inflammasome triggers pyroptosis proinflammatory cell death in experimental autoimmune encephalomyelitis (EAE). However, the underlying mechanisms of the inflammatory processes of microglia in EAE remain unclear. Our previous studies suggested that interleukin-1 receptor-associated kinase (IRAK)-M down-regulates the toll-like receptor 4/interleukin-1 receptor signaling pathway. Here, we used IRAK-M knockout (IRAK-M-/-) mice and their microglia to dissect the role of IRAK-M in EAE. We found that deletion of IRAK-M increased the incidence rate and exacerbated the clinical symptoms in EAE mice. We then found that IRAK-M deficiency promoted the activation of microglia, activated NLRP3 inflammasomes, and enhanced GSDMD-mediated pyroptosis in the microglia of EAE. In contrast, over-expression of IRAK-M exerted inhibitory effects on neuroinflammation, NLRP3 activation, and pyroptosis. Moreover, IRAK-M deficiency enhanced the phosphorylation of IRAK1, while IRAK-M over-expression downregulated the level of phosphorylated IRAK1. Finally, we found upregulated binding of IRAK1 and TNF receptor-associated factor 6 (TRAF6) in IRAK-M-/- EAE mice compared to WT mice, which was blocked in AAVIRAK-M EAE mice. Our study reveals a complex signaling network of IRAK-M, which negatively regulates microglial NLRP3 inflammasomes and pyroptosis by inhibiting IRAK1 phosphorylation during EAE. These findings suggest a potential target for the novel therapeutic approaches of multiple sclerosis (MS)/EAE and NLRP3-related inflammatory diseases.

Hypoxic postconditioning restores mitophagy against transient global cerebral ischemia via Parkin-induced posttranslational modification of TBK1.

Hypoxic postconditioning (HPC) has been reported to enhance Parkin-catalyzed mitochondrial ubiquitination to restore mitophagy in hippocampal CA1 against transient global cerebral ischemia (tGCI). However, the molecular mechanism leading ubiquitinated mitochondria to final clearance during HPC-mediated mitophagy after tGCI is unclear. This study aims to investigate whether HPC restores mitophagy after tGCI through Parkin-induced K63-linked poly-ubiquitination (K63-Ub) to activate tumor necrosis factor associated factor family member associated nuclear factor κB activator -binding kinase 1 (TBK1) in CA1 of male rats. We found that HPC maintained TBK1 expression, promoted p62 and TBK1 phosphorylation in mitochondria, and enhanced their recruitments to mitochondria in CA1 after tGCI. However, these effects were partially abolished by TBK1 inhibitor BX795. K63-Ub of mitochondrial TBK1 was disturbed at 26 h of reperfusion after tGCI, which was reversed by HPC. The maintenance of K63-Ub of mitochondrial TBK1 induced by HPC was counteracted under Parkin knockdown with AAV-mediated Prkn small-interfering RNA, accompanied by the suppression on TBK1 activation and the reduction of mitochondrial p62 phosphorylation. This innovative study indicated that HPC maintained K63-Ub of TBK1 in a Parkin-dependent manner to promote TBK1 phosphorylation, and then phosphorylated TBK1 activated p62 to restore mitophagy, thereby alleviating neuronal damage in CA1 after tGCI.

Complete Genome Sequence of Lactobacillus acidophilus LA-10A, a Promising Probiotic Strain Isolated from Fermented Mare's Milk.

This report describes the whole-genome sequence of Lactobacillus acidophilus LA-10A, isolated from fermented mare's milk. This strain has been widely consumed due to its excellent performance in the treatment and prevention of Helicobacter pylori infection. The genome sequence of LA-10A provides further molecular information about its features.

Assessment of the effectiveness of BOPPPS-based hybrid teaching model in physiology education.

BACKGROUND: Online teaching has become increasingly common in higher education of the post-pandemic era. While a traditional face-to-face lecture or offline teaching remains very important and necessary for students to learn the medical knowledge systematically, guided by the BOPPPS teaching model, combination of online and offline learning approaches has become an unavoidable trend for maximizing teaching efficiency. However, in physiological education, the effectiveness of combined online teaching and offline teaching models remains poorly assessed. The present study aims at providing an assessment to the hybrid teaching model. METHODS: The study was performed among undergraduate medical students of Class 2017 ~ 2019 in the Physiology course in Harbin Medical University during 2018-2020. Based on established offline teaching model with BOPPPS components in 2018, we incorporated online teaching contents into it to form a hybrid BOPPPS teaching model (HBOPPPS, in brief), preliminarily in 2019 and completely in 2020. HBOPPPS effectiveness was assessed through comparing the final examination scores of both objective (multi-choice and single answer questions) and subjective (short and long essays) questions between classes taught with different modalities. RESULTS: The final examination score of students in Class 2019 (83.9 ± 0.5) who were taught with the HBOPPPS was significantly higher than that in Class 2017 (81.1 ± 0.6) taught with offline BOPPPS and in Class 2018 (82.0 ± 0.5) taught with immature HBOPPPS. The difference mainly attributed to the increase in average subjective scores (41.6 ± 0.3 in Class 2019, 41.4 ± 0.3 in Class 2018, and 38.2 ± 0.4 in Class 2017). In the questionnaire about the HBOPPPS among students in Class 2019, 86.2% responded positively and 79.4% perceived improvement in their learning ability. In addition, 73.5% of the students appreciated the reproducibility of learning content and 54.2% valued the flexibility of HBOPPPS. Lastly, 61.7% of the students preferred the HBOPPPS relative to BOPPPS in future learning. CONCLUSIONS: HBOPPPS is likely a more effective teaching model and useful for enhancing effectiveness of Physiology teaching. This is attributable to the reproducibility and flexibility as well as the increased learning initiatives.

Estradiol Valerate Enhances Cardiac Function via the Nrf2 Signaling Pathway to Protect Against Oxidative Stress by the Nrf2 Signaling Pathway in an Ovariectomized Rat Model.

BACKGROUND: The increased risk of cardiovascular disease (CVD) in postmenopausal women and ovariectomized patients suggests that estrogen has a protective effect on cardiac function. Oxidative stress is the main cause of CVD, and the cellular defensive Nrf2 antioxidant pathway plays a protective role in various pathologies. However, the regulation of Nrf2 by estrogen has received little attention. OBJECTIVE: The present study aimed to investigate the role of Nrf2 in the effect of estrogen on cardiac function. METHODS: In the present study, female SD rats were divided into three groups as follows: sham operation (SHAM), bilateral ovariectomy (OVX) and bilateral ovariectomy with estradiol valerate (EV) supplementation (OVX+EV). Vaginal smears and E2 concentrations were used to confirm the success of the model. We compared cardiac morphology and function by echocardiography and HE staining. The levels of oxidative stress markers and antioxidant enzymes as well as protein expression of antioxidant genes were evaluated by Western blotting and immunohistochemistry. RESULTS: Our results showed that supplementation with estrogen restored the parameters to some extent. Left ventricular end diastolic diameter at diastolic (LVID;d) and left ventricular volume at diastolic (LV vol;d) increased but MV E wave/A wave (E/A) significantly decreased. The oxidative stress indicators (malondialdehyde) increased, and the antioxidant activity indicators, such as superoxide dismutase (SOD) and catalase (CAT), decreased. Further, the expression of most Nrf2 antioxidant pathway-related proteins in the heart decreased after ovariectomy. CONCLUSION: The present study demonstrated that estrogen may protect cardiac function by regulating antioxidant capacity through the Nrf2 pathway.

Hypoxic postconditioning promotes mitophagy against transient global cerebral ischemia via PINK1/Parkin-induced mitochondrial ubiquitination in adult rats.

Mitophagy alleviates neuronal damage after cerebral ischemia by selectively removing dysfunctional mitochondria. Phosphatase and tensin homolog (PTEN) induced putative kinase 1 (PINK1)/Parkin-mediated mitophagy is the most well-known type of mitophagy. However, little is known about the role of PINK1/Parkin-mediated mitophagy in ischemic tolerance induced by hypoxic postconditioning (HPC) with 8% O2 against transient global cerebral ischemia (tGCI). Hence, we aimed to test the hypothesis that HPC-mediated PINK1/Parkin-induced mitochondrial ubiquitination and promotes mitophagy, thus exerting neuroprotection in the hippocampal CA1 subregion against tGCI. We found that mitochondrial clearance was disturbed at the late phase of reperfusion after tGCI, which was reversed by HPC, as evidenced by the reduction of the translocase of outer mitochondrial membrane 20 homologs (TOMM20), translocase of inner mitochondrial membrane 23 (TIMM23) and heat shock protein 60 (HSP60) in CA1 after HPC. In addition, HPC further increased the ratio of LC3II/I in mitochondrial fraction and promoted the formation of mitophagosomes in CA1 neurons after tGCI. The administration of lysosome inhibitor chloroquine (CQ) intraperitoneally or mitophagy inhibitor (Mdivi-1) intracerebroventricularly abrogated HPC-induced mitochondrial turnover and neuroprotection in CA1 after tGCI. We also found that HPC activated PINK1/Parkin pathway after tGCI, as shown by the augment of mitochondrial PINK1 and Parkin and the promotion of mitochondrial ubiquitination in CA1. In addition, PINK1 or Parkin knockdown with small-interfering RNA (siRNA) suppressed the activation of PINK1/Parkin pathway and hampered mitochondrial clearance and attenuated neuroprotection induced by HPC, whereas PINK1 overexpression promoted PINK1/Parkin-mediated mitophagy and ameliorated neuronal damage in CA1 after tGCI. Taken together, the new finding in this study is that HPC-induced neuroprotection against tGCI through promoting mitophagy mediated by PINK1/Parkin-dependent pathway.

The Synthesis and Functional Study of Multicolor Nitrogen-Doped Carbon Dots for Live Cell Nuclear Imaging.

The nitrogen-doped carbon dots (N-CQDs) were synthesized by citric acid as a raw material and propylene diamine as a passivation agent. Structure, optical properties and biocompatibility of N-CQDs were analyzed. It was found that the N-CQDs possessed concentration-dependent, multicolor photoluminescence and low toxicity. As demonstrated in the imaging of bioluminescence, by adjusting the concentration of N-CQDs, the cell imaging effect can be adjusted. The internalized N-CQDs were concentrated in the nucleus. A novel tool for studying the nuclear changes during the cell cycle was developed.

Hypoxic postconditioning activates the Wnt/ß-catenin pathway and protects against transient global cerebral ischemia through Dkk1 Inhibition and GSK-3ß inactivation.

The Wingless/Int (Wnt)/ß-catenin pathway plays an essential role in cell survival. Although postconditioning with 8% oxygen can alleviate transient global cerebral ischemia (tGCI)-induced neuronal damage in hippocampal CA1 subregion in adult rats as demonstrated by our previous studies, little is understood about the role of Wnt/ß-catenin pathway in hypoxic postconditioning (HPC)-induced neuroprotection. This study tried to investigate the involvement of Wnt/ß-catenin pathway in HPC-induced neuroprotection against tGCI and explore the underlying molecular mechanism thereof. We observed that HPC elevated nuclear ß-catenin level as well as increased Wnt3a and decreased Dickkopf-1 (Dkk1) expression in CA1 after tGCI. Accordingly, HPC enhanced the expression of survivin and reduced the ratio of B-cell lymphoma/lewkmia-2 (Bcl-2)-associated X protein (Bax) to Bcl-2 following reperfusion. Moreover, our study has shown that these effects of HPC were abolished by lentivirus-mediated overexpression of Dkk1, and that the overexpression of Dkk1 completely reversed HPC-induced neuroprotection. Furthermore, HPC suppressed the activity of glycogen synthase kinase-3ß (GSK-3ß) in CA1 after tGCI, and the inhibition of GSK-3ß activity with SB216763 increased the nuclear accumulation of ß-catenin, up-regulated the expression of survivin, and reduced the ratio of Bax to Bcl-2, thus preventing the delayed neuronal death after tGCI. Finally, the administration of LY294002, an inhibitor of PI3K, increased GSK-3ß activity and blocked nuclear ß-catenin accumulation, thereby decreasing survivin expression and elevating the Bax-to-Bcl-2 ratio after HPC. These results suggest that activation of the Wnt/ß-catenin pathway through Dkk1 inhibition and PI3K/protein kinase B pathway-mediated GSK-3ß inactivation contributes to the neuroprotection of HPC against tGCI.-Zhan, L., Liu, D., Wen, H., Hu, J., Pang, T., Sun, W., Xu, E. Hypoxic postconditioning activates the Wnt/ß-catenin pathway and protects against transient global cerebral ischemia through Dkk1 inhibition and GSK-3ß inactivation.

Neuroglobin mediates neuroprotection of hypoxic postconditioning against transient global cerebral ischemia in rats through preserving the activity of Na+/K+ ATPases.

Hypoxic postconditioning (HPC) is an innovative neuroprotective strategy with cytoprotective effects on the hippocampal neurons against transient global cerebral ischemia (tGCI) in adult rats. However, its molecular mechanisms have not yet been adequately elucidated. Neuroglobin (Ngb) is an endogenous neuroprotectant with hypoxia-inducible property, and its role in experimental stroke has been increasingly attractive. Hence, the purpose of this study is to explore the involvement of Ngb in HPC-mediated neuroprotection and to further investigate its underlying molecular mechanism. We found that HPC increased Ngb expression in CA1 subregion after tGCI. Also, the inhibition of Ngb expression with Ngb antisense oligodeoxynucleotide (AS-ODNs) eliminated the neuroprotective effect mediated by HPC, whereas overexpression of Ngb ameliorated neuronal damage in CA1 after tGCI, indicating that HPC conferred neuroprotective effects via upregulation of Ngb. We further showed that HPC increased the membranous level of Na+/K+ ATPases ß1 subunit (Atp1b1) in CA1 after tGCI. Furthermore, we demonstrated that Ngb upregulation in CA1 after HPC maintained the membranous level of Atp1b1 through Ngb-Atp1b1 interaction and reduced the glutathionylation of membranous Atp1b1 via suppression of reactive oxygen species (ROS), ultimately preserving the activity of NKA. Taken together, these data indicate that Ngb is involved in the neuroprotection of HPC against tGCI via maintenance of NKA activity in the hippocampal CA1.

Designing of dual inhibitors for GSK-3ß and CDK5: Virtual screening and in vitro biological activities study.

Alzheimer's disease is a multifactorial neurodegenerative disorder with many drug targets contributing to its etiology. Despite the devastating effects of this disease, therapeutic methods for treating Alzheimer's disease remain limited. The multifactorial nature of Alzheimer's disease strongly supports a multi-target rationale as a drug design strategy. Glycogen synthase kinase-3 beta and cyclin-dependent kinase 5 have been identified as being involved in the pathological hyperphosphorylation of tau proteins, which leads to the formation of neurofibrillary tangles and causes Alzheimer's disease. In this study, using a molecular docking method to screen a virtual library, we discovered molecules that can simultaneously inhibit Glycogen synthase kinase-3 beta and cyclin-dependent kinase 5 as lead compounds for the treatment of Alzheimer's disease. The docking results revealed the key residues in the substrate binding sites of both Glycogen synthase kinase-3 beta and cyclin-dependent kinase 5. A receiver operating characteristic curve indicated that the docking model consistently and selectively scored the majority of active compounds above decoys. The pre-treatment of cells with screened compounds protected them against Aß25-35- induced cell death by up to 80%. Collectively, these findings suggest that some compounds have potential to be promising multifunctional agents for Alzheimer's disease treatment.

Rab7 may be a novel therapeutic target for neurologic diseases as a key regulator in autophagy.

Macroautophagy is an evolutionally conserved membrane trafficking pathway that delivers intracellular materials to lysosomes for degradation and recycling. Rab7, as a member of the Rab GTPase superfamily, has a unique role in the regulation of macroautophagy, especially in modulating autophagy flux. The functional states of Rab7 generally switch between GTP-bound and GDP-bound states under the control of guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs). Activated GTP-Rab7 is capable of regulating autophagosome formation, autophagosome transportation along microtubules, endosome and autophagosome maturation, as well as lysosome biogenesis via interacting with its effector molecules. Rab7-mediated macroautophagy is closely associated with various pathological processes of several neurologic diseases, such as Parkinson's disease, Huntington's disease, Alzheimer's disease, Charcot-Marie-Tooth type 2B disease, and cerebral ischemic diseases. Considering that macroautophagy can be the prime therapeutic target in certain nervous system diseases, in-depth study of Rab7 in the regulation of macroautophagy may be helpful to identify novel strategies for the treatment of autophagy-related neurologic diseases. © 2017 Wiley Periodicals, Inc.

Patuletin induces apoptosis of human breast cancer SK-BR-3 cell line via inhibiting fatty acid synthase gene expression and activity.

Fatty acid synthase (FASN) is a key enzyme involved in fatty acid biosynthesis and serves an important role in breast cancer development. The aim of the present study was to investigate the effects of patuletin on the gene expression and activity of FASN in the human breast cancer SK-BR-3 cell line, and the apoptotic effects of patuletin to breast cancer cells. Quantitative reverse transcription polymerase chain reaction, western blotting and intracellular FASN activity assays were used to evaluate FASN gene expression, protein expression and activity in patuletin-treated SK-BR-3 cells. MTT assays and flow cytometry were used to measure cell growth and cell apoptosis, respectively, following patuletin treatment. As a result, it was demonstrated that patuletin dose-dependently reduces FASN expression and intracellular activity in human breast cancer cells, and induces apoptosis in FASN over-expressing SK-BR-3 cells. Notably, apoptosis is associated with the reduction of intracellular FASN activity. The present study demonstrates that patuletin may be considered as a novel natural inhibitor of FASN, may induce anti-proliferative and pro-apoptotic effects in certain human breast cancer cells and may be useful for preventing and/or treating human breast cancer.

Neuroprotection of hypoxic postconditioning against global cerebral ischemia through influencing posttranslational regulations of heat shock protein 27 in adult rats.

We previously reported that hypoxic postconditioning (HPC) ameliorated hippocampal neuronal death induced by transient global cerebral ischemia (tGCI) in adult rats. However, the mechanism of HPC-induced neuroprotection is still elusive. Notably, heat shock protein 27 (Hsp27) has recently emerged as a potent neuroprotectant in cerebral ischemia. Although its robust protective effect on stroke has been recognized, the mechanism of Hsp27-mediated neuroprotection is largely unknown. Here, we investigated the potential molecular mechanism by which HPC modulates the posttranslational regulations of Hsp27 after tGCI. We found that HPC increased expression of Hsp27 in CA1 subregion after tGCI. Inhibition of Hsp27 expression with lentivirus-mediated short hairpin RNA (shRNA) abolished the neuroprotection induced by HPC in vivo. Furthermore, pretreatment with cycloheximide, a protein synthesis inhibitor, resulted in a significant decrease in the degradation rate of Hsp27 protein in postconditioned rats, suggesting that the increase in the expression of Hsp27 after HPC might result from its decreased degradation. Next, pretreatment with leupeptin, a lysosomal inhibitor, resulted in an accumulation of Hsp27 after tGCI, indicating that autophagic pathway may be responsible for the degradation of Hsp27. We further showed that the formation of LC3-II and autophagosomes increased after tGCI. Meanwhile, the degradation of Hsp27 was suppressed and neuronal damage was reduced when blocking autophagy with 3-Methyladenine, whereas activating autophagy with rapamycin showed an opposite tendency. Lastly, we confirmed that HPC increased the expression of phosphorylated MAPKAP kinase 2 (MK2) and Hsp27 after tGCI. Also, administration of SB203580, a p38 mitogen-activated protein kinase inhibitor, decreased the expressions of phosphorylated MK2 and Hsp27. Our results suggested that inhibition of Hsp27 degradation mediated by down-regulation of autophagy may induce ischemic tolerance after HPC. Additionally, phosphorylation of Hsp27 induced by MK2 might be associated with the neuroprotection of HPC.