Nuclear Receptor Nur77 Facilitates Melanoma Cell Survival under Metabolic Stress by Protecting Fatty Acid Oxidation.

Fatty acid oxidation (FAO) is crucial for cells to overcome metabolic stress by providing ATP and NADPH. However, the mechanism by which FAO is regulated in tumors remains elusive. Here we show that Nur77 is required for the metabolic adaptation of melanoma cells by protecting FAO. Glucose deprivation activates ERK2 to phosphorylate and induce Nur77 translocation to the mitochondria, where Nur77 binds to TPß, a rate-limiting enzyme in FAO. Although TPß activity is normally inhibited by oxidation under glucose deprivation, the Nur77-TPß association results in Nur77 self-sacrifice to protect TPß from oxidation. FAO is therefore able to maintain NADPH and ATP levels and prevent ROS increase and cell death. The Nur77-TPß interaction further promotes melanoma metastasis by facilitating circulating melanoma cell survival. This study demonstrates a novel regulatory function of Nur77 with linkage of the FAO-NADPH-ROS pathway during metabolic stress, suggesting Nur77 as a potential therapeutic target in melanoma.

Communications between macrophages and cardiomyocytes.

The heart is a muscular organ that pumps blood throughout the body and is one of the most vital organs in human body. While cardiomyocytes are essential for maintaining the normal function of the heart, a variety of cardiovascular diseases such as coronary artery occlusion, arrhythmia, and myocarditis can lead to cardiomyocyte death, resulting in deterioration of heart function. The adult mammalian heart is incapable of regenerating sufficient cardiomyocytes following cardiac injuries, eventually leading to heart failure and death. Cardiac macrophages are ubiquitously distributed in the healthy heart and accumulated at the site of injury. Macrophages play essential roles in regulating homeostasis and proliferation of cardiomyocyte, promoting electrical conduction, and removing dead cardiomyocytes and debris through direct and indirect cell-cell crosstalk. In this review, we summarize the latest insights into the role of macrophages in maintaining cardiac homeostasis and the macrophage-cardiomyocyte crosstalk in both healthy and injured scenarios. Video Abstract.

Blocking PPARγ interaction facilitates Nur77 interdiction of fatty acid uptake and suppresses breast cancer progression.

Nuclear receptor Nur77 participates in multiple metabolic regulations and plays paradoxical roles in tumorigeneses. Herein, we demonstrated that the knockout of Nur77 stimulated mammary tumor development in two mouse models, which would be reversed by a specific reexpression of Nur77 in mammary tissues. Mechanistically, Nur77 interacted and recruited corepressors, the SWI/SNF complex, to the promoters of CD36 and FABP4 to suppress their transcriptions, which hampered the fatty acid uptake, leading to the inhibition of cell proliferation. Peroxisome proliferator-activated receptor-γ (PPARγ) played an antagonistic role in this process through binding to Nur77 to facilitate ubiquitin ligase Trim13-mediated ubiquitination and degradation of Nur77. Cocrystallographic and functional analysis revealed that Csn-B, a Nur77-targeting compound, promoted the formation of Nur77 homodimer to prevent PPARγ binding by steric hindrance, thereby strengthening the Nur77's inhibitory role in breast cancer. Therefore, our study reveals a regulatory function of Nur77 in breast cancer via impeding fatty acid uptake.

Thymosin ß4 reverses phenotypic polarization of glial cells and cognitive impairment via negative regulation of NF-κB signaling axis in APP/PS1 mice.

BACKGROUND: Thymosin ß4 (Tß4) is the most abundant member of the ß-thymosins and plays an important role in the control of actin polymerization in eukaryotic cells. While its effects in multiple organs and diseases are being widely investigated, the safety profile has been established in animals and humans, currently, little is known about its influence on Alzheimer's disease (AD) and the possible mechanisms. Thus, we aimed to evaluate the effects and mechanisms of Tß4 on glial polarization and cognitive performance in APP/PS1 transgenic mice. METHODS: Behavior tests were conducted to assess the learning and memory, anxiety and depression in APP/PS1 mice. Thioflavin S staining, Nissl staining, immunohistochemistry/immunofluorescence, ELISA, qRT-PCR, and immunoblotting were performed to explore Aß accumulation, phenotypic polarization of glial cells, neuronal loss and function, and TLR4/NF-κB axis in APP/PS1 mice. RESULTS: We demonstrated that Tß4 protein level elevated in all APP/PS1 mice. Over-expression of Tß4 alone alleviated AD-like phenotypes of APP/PS1 mice, showed less brain Aß accumulation and more Insulin-degrading enzyme (IDE), reversed phenotypic polarization of microglia and astrocyte to a healthy state, improved neuronal function and cognitive behavior performance, and accidentally displayed antidepressant-like effect. Besides, Tß4 could downregulate both TLR4/MyD88/NF-κB p65 and p52-dependent inflammatory pathways in the APP/PS1 mice. While combination drug of TLR4 antagonist TAK242 or NF-κB p65 inhibitor PDTC exerted no further effects. CONCLUSIONS: These results suggest that Tß4 may exert its function by regulating both classical and non-canonical NF-κB signaling and is restoring its function as a potential therapeutic target against AD.

Forced Physical Training Increases Neuronal Proliferation and Maturation with Their Integration into Normal Circuits in Pilocarpine Induced Status Epilepticus Mice.

Increased number of newly-born neurons produced at latent stage after status epilepticus (SE) contribute to aberrant rewiring of hippocampus and are hypothesized to promote epileptogenesis. Although physical training (PT) was reported to cause further increase in neurogenesis after SE, how PT affect their integration pattern is still elusive, whether they integrate into normal circuits or increase aberrant integrations is yet to be determined. To understand this basic mechanism by which PT effects SE and to elaborate the possible role of neuronal integrations in prognosis of SE, we evaluated the effect of 4 weeks of treadmill PT in adult male mice after pilocarpine-induced SE on behavioral and aberrant integrations' parameters. Changes in BDNF gene methylation and its protein level in hippocampus was also measured at latent stage (2-weeks) to explore underlying pathways involved in increasing neurogenesis. Our results demonstrated that although PT increased proliferation and maturation of neurons in dentate gyrus, they showed reduced aberrant integrations into hippocampal circuitry assessed through a decrease in the number of ectopic granular cells, hilar basal dendrites and mossy fiber sprouting as compared to non-exercised SE mice. While SE decreased the percentage methylation of specific CpGs of BDNF gene's promoter, PT did not yield any significant difference in methylation of BDNF CpGs as compared to non-exercised SE mice. In conclusion, PT increases hippocampal neurogenesis through increasing BDNF levels by some pathways other than demethylating BDNF CpGs and causes post SE newly-born neurons to integrate into normal circuits thus resulting in decreased spontaneous recurrent seizures and enhanced spatial memory.

Knockdown of TRIM32 Protects Hippocampal Neurons from Oxygen-Glucose Deprivation-Induced Injury.

Tripartite motif 32 (TRIM32) is a member of TRIM family that plays a potential role in neural regeneration. However, the biological function of TRIM32 in cerebral ischemia reperfusion injury has not been investigated. In the present study, we evaluated the expression level of TRIM32 in hippocampal neurons following oxygen-glucose deprivation/reperfusion (OGD/R). The results showed that TRIM32 expression was significantly elevated in hippocampal neurons subjected to OGD/R as compared to the neurons cultured in the normoxia condition. To further evaluate the role of TRIM32, hippocampal neurons were transfected with TRIM32 small interfering RNA (si-TRIM32) to knock down TRIM32. We found that knockdown of TRIM32 improved cell viability of OGD/R-stimulated hippocampal neurons. Generation of reactive oxygen species was decreased, while contents of superoxide dismutase and glutathione peroxidase were increased after si-TRIM32 transfection. Knockdown of TRIM32 suppressed cell apoptosis, as proved by the increased bcl-2 expression along with decreased bax expression and caspase-3 activity. We also found that TRIM32 knockdown enhanced OGD/R-induced activation of Nrf2 signaling pathway in hippocampal neurons. Furthermore, siRNA-Nrf2 was transfected to knock down Nrf2. SiRNA-Nrf2 transfection reversed the protective effects of TRIM32 knockdown on neurons. These data suggested that knockdown of TRIM32 protected hippocampal neurons from OGD/R-induced oxidative injury through activating Nrf2 signaling pathway.

MicroRNA-770 affects proliferation and cell cycle transition by directly targeting CDK8 in glioma.

BACKGROUND: MicroRNAs play crucial roles in tumorigenesis and tumor progression. miR-770 has been reported to be downregulated in several cancers and affects cancer cell proliferation, apoptosis, metastasis and drug resistance. However, the role and underlying molecular mechanism of miR-770 in human glioma remain unknown and need to be further elucidated. METHODS: The expression of miR-770 in glioma tissues and cell lines was measured by quantitative real-time PCR (qRT-PCR) to explore the association of miR-770 expression with clinicopathological characteristics. The expression of CDK8 was detected by qRT-PCR and Western blotting in glioma tissues. A target prediction program and a dual-luciferase reporter assay were used to confirm that CDK8 is a target gene of miR-770. MTT and cell counting assays were used to assess the effect of miR-770 on glioma cell proliferation. The cell cycle distribution and apoptosis were examined by flow cytometry. CDK8 siRNA and overexpression were used to further confirm the function of the target gene. RESULTS: We demonstrated that miR-770 expression was downregulated in human glioma tissues and cell lines. The overexpression of miR-770 inhibited glioma cell proliferation and cell cycle G1-S transition and induced apoptosis. The inhibition of miR-770 facilitated cell proliferation and G1-S transition and suppressed apoptosis. miR-770 expression was inversely correlated with CDK8 expression in glioma tissues. CDK8 was confirmed to be a direct target of miR-770 by using a luciferase reporter assay. The overexpression of miR-770 decreased CDK8 expression at both the mRNA and protein levels, and the suppression of miR-770 increased CDK8 expression. Importantly, CDK8 silencing recapitulated the cellular and molecular effects observed upon miR-770 overexpression, and CDK8 overexpression eliminated the effects of miR-770 overexpression on glioma cells. Moreover, both exogenous expression of miR-770 and silencing of CDK8 resulted in suppression of the Wnt/ß-catenin signaling pathway. CONCLUSIONS: Our study demonstrates that miR-770 inhibits glioma cell proliferation and G1-S transition and induces apoptosis through suppression of the Wnt/ß-catenin signaling pathway by targeting CDK8. These findings suggest that miR-770 plays a significant role in glioma progression and serves as a potential therapeutic target for glioma.

Activation of Wnt3α/ß-catenin signal pathway attenuates apoptosis of the cerebral microvascular endothelial cells induced by oxygen-glucose deprivation.

Brain microvascular endothelial cells (BMECs) play vital roles in cerebral ischemia, during which many signal pathways mediate BMECs apoptosis. In this study, we explored the potential role of Wnt3α/ß-catenin signal in BMECs apoptosis induced by ischemia. Here, we found that oxygen-glucose deprivation (OGD) could induce apoptosis of BMECs with Wnt3a mRNA expression decrease. Meanwhile, activation Wnt3a/ß-catenin signal with exogenous Wnt3α protein (100 ng/ml) or Lithium Chloride (LiCl, 4 mM) decreased significantly apoptosis of BMECs induced by OGD with increasing expression of Bcl-2 in the whole cell and ß-catenin in the nucleus. But, inhibition Wnt3a/ß-catenin signal with DKK1 (100 ng/ml) or 2.4-diamino quinazoline (DQ, 0.2 µM) increased apoptosis of BMECs with decreasing expression of Bcl-2. These results suggest that activation Wnt3α/ß-catenin signal attenuate apoptosis of BMECs induced by ischemia.

Downregulation of ATP1A1 promotes cancer development in renal cell carcinoma.

BACKGROUND: Aberrant expression of Na+/K+-ATPase α1 subunit (ATP1A1) is widely observed in multiple types of tumors, and its tissue-specific expression relates to cancer development. However, the functions and molecular mechanisms in renal cell carcinoma (RCC) are not fully understood. METHODS: We investigated the ATP1A1 expression changes and possible roles in RCC through a quantitative proteomic approach and an integrative biochemical assessment. We detected ATP1A1 in RCC with LC-MS/MS, and further validated its expression with immunohistochemical analyses of 80 pairs of the RCC tumor and non-tumor tissues samples. The association of ATP1A1 expression with RCC pathology was statistically analyzed. Cell proliferation, migration and apoptosis were measured by CCK-8, boyden chamber assay and flow cytometry, respectively. The production of reactive oxygen species (ROS) was labeled with a single staining using a commercial kit, and was further detected with flow cytometry. RESULTS: The ATP1A1 shows a significantly decreased expression in human RCC tissues than in the adjacent non-tumor tissues. The RCC patients with ATP1A1-positive expression exhibit longer overall survival time than the ATP1A1-negative patients. The exogenous overexpression of ATP1A1 inhibits RCC cell proliferation and cell migration by increasing the production of ROS. In addition, ATP1A1-mediated Raf/MEK/ERK signaling pathway is suppressed in RCC cells, indicating the possible occurrence of induced cell apoptosis. CONCLUSIONS: Our in vitro and in vivo data of ATP1A1 inhibitory roles in RCC progression suggest that ATP1A1 is a potential novel suppressor protein for renal cancer.

[Optimization of trypsin digestion intensity to obtain high-purity in vitro cultured astrocytes].

The aim of the present study was to observe the effect of trypsin digestion on the purity of in vitro cultured astrocytes and optimize the culture methods. The cerebral cortical tissue from newborn Sprague Dawley (SD) rats was isolated and digested with 0.25% trypsin for 20, 30, or 40 min. The obtained single cell suspension was then cultured. Once reaching confluence, the cells were shaken at a constant temperature. Then, each of 20 and 30 min groups was subdivided into two groups, the control group with normal digestion and two-time-digestion group, and the cells were passaged and purified. Through inverted phase contrast microscope and MTT assay, cell growth and proliferation were observed, respectively. Immunofluorescence for glial fibrillary acidic protein (GFAP) was used to observe the morphology of astrocytes and to assess their purity in different stages. Flow cytometric analysis was used to detect the apoptotic rates of purified astrocytes. The results showed that, the cells being digested for 20 min usually reached confluence at 9 d after seeding. When the digestion time was extended to 30 min, the cells grew faster and reached confluence at 7 d after seeding, meanwhile the morphology of astrocytes was normal, GFAP positive rate (70.2 ± 4.0)% being much higher than that of the 20 min group (P < 0.05). Compared with 20 min group, 40 min group showed higher GFAP positive rate, whereas the cell proliferation was slower, and cell injury was more obvious. After shaking at constant temperature, two times of trypsin digestion could decrease the number of contaminated cells after passage. The GFAP positive rates of two-time-digestion groups in passage 1 (P1) were higher than those of corresponding control groups, and the GFAP positive rate of 30 min + two-time-digestion group in P1 reached (98.1 ± 1.7)%, which was equivalent to that of the 20 min + control group in P3. However, the apoptotic rate showed no significant difference between these two groups. Based on above mentioned results, we conclude that 30 min + two-time of trypsin digestion effectively improves the purity of astrocytes and shortens the time of primary culture and purification, suggesting that it is a rapid and effective method to obtain astrocytes with high purity in vitro.

Indoleamine 2,3-Dioxygenase (IDO) Activity: A Perspective Biomarker for Laboratory Determination in Tumor Immunotherapy.

Indoleamine 2,3-dioxygenase 1 (IDO1) is a heme enzyme involved in catalyzing the conversion of tryptophan (Trp) into kynurenine (Kyn) at the first rate-limiting step in the kynurenine pathway of L-tryptophan metabolism. It has been found to be involved in several biological functions such as aging, immune microorganism, neurodegenerative and infectious diseases, and cancer. IDO1 plays an important role in immune tolerance by depleting tryptophan in the tumor microenvironment and inhibiting the proliferation of effector T cells, which makes it an important emerging biomarker for cancer immunotherapy. Therefore, the research and development of IDO1 inhibitors are of great importance for tumor therapy. Of interest, IDO activity assays are of great value in the screening and evaluation of inhibitors. Herein, we mainly review the biological functions of IDO1, immune regulation, key signaling molecules in the response pathway, and the development of IDO1 inhibitors in clinical trials. Furthermore, this review provides a comprehensive overview and, in particular, a discussion of currently available IDO activity assays for use in the evaluation of IDO inhibitors in human blood. We believe that the IDO activity is a promising biomarker for the immune escape and laboratory evaluation of tumor immunotherapy.

Research hotspots and new trends in the impact of resistance training on aging, bibliometric and visual analysis based on CiteSpace and VOSviewer.

Purpose: Resistance training (RT) can intervene in aging, which can effectively improve trainees' life. However, unhealthy living habits such as irregular life, obesity and hyperlipidemia, and chronic diseases lead to a significant decline in the energy level of the population, seriously affecting the health of the population. Our research identifies the research hotspots of RT to intervene in aging from the perspective of bibliometrics, predicts research frontiers and development trends, and provides more perspectives for research on aging populations. Methods: In this study, we used CiteSpace and VOSviewer visualization software to draw the scientific knowledge map of countries/regions, institutions, authors, co-occurrence keywords, and co-cited references of published articles, and explore the Web of Science core collection database all about the RT intervention aging research status, hotspots, frontiers, and development trends of articles on aging. Results: Among the 760 articles that meet the inclusion criteria, the number of articles published and the frequency of citations have increased steadily in the past 5 years. Judging from the countries/regions, institutions, scholars, and journals that published articles, the ones with the largest numbers are the USA, Univ Estadual Londrina, Cyrino ES, and Exp Gerontol. The ones with the highest influence are England, Univ Arkansas Med Sci, Frontera WR, and Biochem Biophys Rep Co. The top five co-occurrence keywords of include exercise, strength, resistance training, skeletal muscle, and muscle strength. The research frontier is physical function. Conclusion: In the field of RT intervention aging research, relevant scholars deserve further in-depth research and exploration. The United States, Brazil, Canada, and other economically developed countries/regions, institutions, and authors have greater influence and productivity. These quantitative research results can provide references for relevant scholars' follow-up research and government departments to formulate and modify health policies or measures.

Therapeutic potency of compound RMY-205 for pulmonary fibrosis induced by SARS-CoV-2 nucleocapsid protein.

Pulmonary fibrosis is a typical sequela of coronavirus disease 2019 (COVID-19), which is linked with a poor prognosis for COVID-19 patients. However, the underlying mechanism of pulmonary fibrosis induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is unclear. Here, we demonstrated that the nucleocapsid (N) protein of SARS-CoV-2 induced pulmonary fibrosis by activating pulmonary fibroblasts. N protein interacted with the transforming growth factor ß receptor I (TßRI), to disrupt the interaction of TßRI-FK506 Binding Protein12 (FKBP12), which led to activation of TßRI to phosphorylate Smad3 and boost expression of pro-fibrotic genes and secretion of cytokines to promote pulmonary fibrosis. Furthermore, we identified a compound, RMY-205, that bound to Smad3 to disrupt TßRI-induced Smad3 activation. The therapeutic potential of RMY-205 was strengthened in mouse models of N protein-induced pulmonary fibrosis. This study highlights a signaling pathway of pulmonary fibrosis induced by N protein and demonstrates a novel therapeutic strategy for treating pulmonary fibrosis by a compound targeting Smad3.

mGluR5 is involved in proliferation of rat neural progenitor cells exposed to hypoxia with activation of mitogen-activated protein kinase signaling pathway.

Hypoxia/ischemia induces proliferation of neural progenitor cells (NPCs) in rodent and human brain; however, the mechanisms remain unknown. We investigated the effects of metabotropic glutamate receptor 5 (mGluR5) on NPC proliferation under hypoxia, the expression of cyclin D1, and the activation of the mitogen-activated protein kinases (MAPKs) signaling pathway in cell culture. The results showed that hypoxia induced mGluR5 expression on NPCs in vitro. Under hypoxia, the mGluR5 agonists DHPG and CHPG significantly increased NPC proliferation in cell activity, diameter of neurospheres, bromodeoxyuridine (BrdU) incorporation and cell division, and expression of cyclin D1, with decreasing cell death. The mGluR5 siRNA and antagonist MPEP decreased the NPC proliferation and expression of cyclin D1, with increasing cell death. Phosphorylated JNK and ERK increased with the proliferation of NPCs after DHPG and CHPG treatment under hypoxia, while p-p38 level decreased. These results demonstrate that the expression of mGluR5 was upregulated during the proliferation of rat NPCs stimulated by hypoxia in vitro. The activation of the ERK and JNK signaling pathway and the expression of cyclin D1 were increased in this process. These finding suggest the involvement of mGluR5 in rat NPC proliferation and provide a target molecule in neural repair after ischemia/hypoxia injury of CNS.

Roles of microRNA on cancer cell metabolism.

Advanced studies of microRNAs (miRNAs) have revealed their manifold biological functions, including control of cell proliferation, cell cycle and cell death. However, it seems that their roles as key regulators of metabolism have drawn more and more attention in the recent years. Cancer cells display increased metabolic autonomy in comparison to non-transformed cells, taking up nutrients and metabolizing them in pathways that support growth and proliferation. MiRNAs regulate cell metabolic processes through complicated mechanisms, including directly targeting key enzymes or transporters of metabolic processes and regulating transcription factors, oncogenes / tumor suppressors as well as multiple oncogenic signaling pathways. MiRNAs like miR-375, miR-143, miR-14 and miR-29b participate in controlling cancer cell metabolism by regulating the expression of genes whose protein products either directly regulate metabolic machinery or indirectly modulate the expression of metabolic enzymes, serving as master regulators, which will hopefully lead to a new therapeutic strategy for malignant cancer. This review focuses on miRNA regulations of cancer cell metabolism,including glucose uptake, glycolysis, tricarboxylic acid cycle and insulin production, lipid metabolism and amino acid biogenesis, as well as several oncogenic signaling pathways. Furthermore, the challenges of miRNA-based strategies for cancer diagnosis, prognosis and therapeutics have been discussed.

Efficient extraction of chitin from crustacean waste via a novel ternary natural deep eutectic solvents.

Extraction of chitin from crustacean waste with acidic natural deep eutectic solvents (NADESs) is usually accompanied by degradation of chitin, which lowers the yield and molecular weight of product. Herein, this study proposed a eco-friendly and feasible route for effectively improving the yield and molecular weight of chitin by introducing N-acetyl-D-glucosamine into ternary NADESs. A high molecular weight chitin with molecular weight of 3.92 × 105 Da, purity of 90.2% and yield of 85.6% was obtained from crab shell. Compared with conventional acid/alkali and binary NADESs method, the maximum yield of chitin extracted by ChCl-G-FA2 was increased by 1.57 times and 1.39 times respectively. Molecular weight of chitin was 3.16 times that of acid/alkali method. Recycling performance evaluation revealed that the purity of chitin could still reach 80.4% after five cycles of NADESs. This study provided a eco-friendly utilization strategy for crustacean waste based on multifunctional NADESs.

Deficiency of endothelial FGFR1 alleviates hyperoxia-induced bronchopulmonary dysplasia in neonatal mice.

Disrupted neonatal lung angiogenesis and alveologenesis often give rise to bronchopulmonary dysplasia (BPD), the most common chronic lung disease in children. Hyperoxia-induced pulmonary vascular and alveolar damage in premature infants is one of the most common and frequent factors contributing to BPD. The purpose of the present study was to explore the key molecules and the underlying mechanisms in hyperoxia-induced lung injury in neonatal mice and to provide a new strategy for the treatment of BPD. In this work, we reported that hyperoxia decreased the proportion of endothelial cells (ECs) in the lungs of neonatal mice. In hyperoxic lung ECs of neonatal mice, we detected upregulated fibroblast growth factor receptor 1 (FGFR1) expression, accompanied by upregulation of the classic downstream signaling pathway of activated FGFR1, including the ERK/MAPK signaling pathway and PI3K-Akt signaling pathway. Specific deletion of Fgfr1 in the ECs of neonatal mice protected the lungs from hyperoxia-induced lung injury, with improved angiogenesis, alveologenesis and respiratory metrics. Intriguingly, the increased Fgfr1 expression was mainly attributed to aerosol capillary endothelial (aCap) cells rather than general capillary endothelial (gCap) cells. Deletion of endothelial Fgfr1 increased the expression of gCap cell markers but decreased the expression of aCap cell markers. Additionally, inhibition of FGFR1 by an FGFR1 inhibitor improved alveologenesis and respiratory metrics. In summary, this study suggests that in neonatal mice, hyperoxia increases the expression of endothelial FGFR1 in lung ECs and that deficiency of endothelial Fgfr1 can ameliorate hyperoxia-induced BPD. These data suggest that FGFR1 may be a potential therapeutic target for BPD, which will provide a new strategy for the prevention and treatment of BPD.

ERK-Smurf1-RhoA signaling is critical for TGFß-drived EMT and tumor metastasis.

Epithelial-mesenchymal transition (EMT) has fundamental roles in various biological processes. However, there are still questions pending in this fast-moving field. Here we report that in TGFß-induced EMT, ERK-mediated Smurf1 phosphorylation is a prerequisite step for RhoA degradation and the consequent mesenchymal state achievement. Upon TGFß treatment, activated ERK phosphorylates Thr223 of Smurf1, a member of HECT family E3 ligase, to promote Smurf1-mediated polyubiquitination and degradation of RhoA, thereby leading to cell skeleton rearrangement and EMT. Blockade of phosphorylation of Smurf1 inhibits TGFß-induced EMT, and accordingly, dramatically blocks lung metastasis of murine breast cancer in mice. Hence, our study reveals an unknown role of ERK in TGFß-induced EMT and points out a potential strategy in therapeutic intervention.

Research progress on biomarkers of pulmonary embolism.

OBJECTIVES: To present a review on the traditional and new biomarkers of pulmonary embolism (PE). DATA SOURCE: A systematic search has been carried out using keywords as PE, biomarker, diagnosis and risk stratification. RESULTS: The results of this work have been structured into three parts: first, conventional biomarkers for vascular, cardiac and inflammation, including static markers and dynamic markers for measuring the time course; next, a review of new biomarkers in recent years, such as RNAs and markers obtained through proteomics and mass spectrometry; finally, use of new detection methods to directly detect the activity of existing markers, such as the determination of coagulation factor II and plasmin activities based on the proteolytic activation of an engineered zymogen. CONCLUSIONS: This work summarized the characteristics of current traditional biomarkers for clinical diagnosis and risk stratification of PE, as well as a series of newly discovered biomarkers obtained through various clinical experimental methods.

The neurotoxic effect of isoflurane on age-defined neurons generated from tertiary dentate matrix in mice.

INTRODUCTION: Recent animal studies showed that isoflurane exposure may lead to the disturbance of hippocampal neurogenesis and later cognitive impairment. However, much less is known about the effect of isoflurane exposure on the neurons generated form tertiary dentate matrix, even though a great increase of granule cell population during the infantile period is principally derived from this area. METHODS: To label the new cells originated from the tertiary dentate matrix, the mice were injected with BrdU on postnatal day 6 (P6). Then, the mice were exposed to isoflurane for 4 hr at 1, 8, 21, and 42 days after BrdU injection, and the brains were collected 24 hr later. The loss of newly generated cells/neurons with different developmental stage was assessed by BrdU, BrdU + DCX, BrdU + NeuN, or BrdU + Prox-1 staining, respectively. RESULTS: We found that the isoflurane exposure significantly decreased the numbers of nascent cells (1 day old) and mature neurons (42 days old), but had no effect on the immature (8 days old) and early mature neurons (8 and 21 days old, respectively). CONCLUSION: The results suggested isoflurane exposure exerts the neurotoxic effects on the tertiary dentate matrix-originated cells with an age-defined pattern in mice, which partly explain the cognitive impairment resulting from isoflurane exposure to the young brain.