Epigenetic mechanisms in depression: Implications for pathogenesis and treatment.

The risk of depression is influenced by both genetic and environmental factors. It has been suggested that epigenetic mechanisms may mediate the risk of depression following exposure to adverse life events. Epigenetics encompasses stable alterations in gene expression that are controlled through transcriptional, post-transcriptional, translational, or post-translational processes, including DNA modifications, chromatin remodeling, histone modifications, RNA modifications, and non-coding RNA (ncRNA) regulation, without any changes in the DNA sequence. In this review, we explore recent research advancements in the realm of epigenetics concerning depression. Furthermore, we evaluate the potential of epigenetic changes as diagnostic and therapeutic biomarkers for depression.

Cell type-specific NRBF2 orchestrates autophagic flux and adult hippocampal neurogenesis in chronic stress-induced depression.

Dysfunctional autophagy and impairment of adult hippocampal neurogenesis (AHN) each contribute to the pathogenesis of major depressive disorder (MDD). However, whether dysfunctional autophagy is linked to aberrant AHN underlying MDD remains unclear. Here we demonstrate that the expression of nuclear receptor binding factor 2 (NRBF2), a component of autophagy-associated PIK3C3/VPS34-containing phosphatidylinositol 3-kinase complex, is attenuated in the dentate gyrus (DG) under chronic stress. NRBF2 deficiency inhibits the activity of the VPS34 complex and impairs autophagic flux in adult neural stem cells (aNSCs). Moreover, loss of NRBF2 disrupts the neurogenesis-related protein network and causes exhaustion of aNSC pool, leading to the depression-like phenotype. Strikingly, overexpressing NRBF2 in aNSCs of the DG is sufficient to rescue impaired AHN and depression-like phenotype of mice. Our findings reveal a significant role of NRBF2-dependent autophagy in preventing chronic stress-induced AHN impairment and suggest the therapeutic potential of targeting NRBF2 in MDD treatment.

PDGF-BB-Dependent Neurogenesis Buffers Depressive-Like Behaviors by Inhibition of GABAergic Projection from Medial Septum to Dentate Gyrus.

Hippocampal circuitry stimulation is sufficient to regulate adult hippocampal neurogenesis and ameliorate depressive-like behavior, but its underlying mechanism remains unclear. Here, it is shown that inhibition of medial septum (MS)-dentate gyrus (DG) circuit reverses the chronic social defeat stress (CSDS)-induced depression-like behavior. Further analysis exhibits that inhibition of gamma-aminobutyric acidergic neurons in MS projecting to the DG (MSGABA+ -DG) increases the expression of platelet-derived growth factor-BB (PDGF-BB) in somatostatin (SOM) positive interneurons of DG, which contributes to the antidepressant-like effects. Overexpression of the PDGF-BB or exogenous administration of PDGF-BB in DG rescues the effect of chronic stress on the inhibition of neural stem cells (NSCs) proliferation and dendritic growth of adult-born hippocampal neurons, as well as on depressive-like behaviors. Conversely, knockdown of PDGF-BB facilitates CSDS-induced deficit of hippocampal neurogenesis and promotes the susceptibility to chronic stress in mice. Finally, conditional knockdown platelet-derived growth factor receptor beta (PDGFRß) in NSCs blocks an increase in NSCs proliferation and the antidepressant effects of PDGF-BB. These results delineate a previously unidentified PDGF-BB/PDGFRß signaling in regulating depressive-like behaviors and identify a novel mechanism by which the MSGABA+ -DG pathway regulates the expression of PDGF-BB in SOM-positive interneurons.

BNIP3L/NIX-mediated mitophagy alleviates passive stress-coping behaviors induced by tumor necrosis factor-α.

Recent studies based on animal models of various neurological disorders have indicated that mitophagy, a selective autophagy that eliminates damaged and superfluous mitochondria through autophagic degradation, may be involved in various neurological diseases. As an important mechanism of cellular stress response, much less is known about the role of mitophagy in stress-related mood disorders. Here, we found that tumor necrosis factor-α (TNF-α), an inflammation cytokine that plays a particular role in stress responses, impaired the mitophagy in the medial prefrontal cortex (mPFC) via triggering degradation of an outer mitochondrial membrane protein, NIP3-like protein X (NIX). The deficits in the NIX-mediated mitophagy by TNF-α led to the accumulation of damaged mitochondria, which triggered synaptic defects and behavioral abnormalities. Genetic ablation of NIX in the excitatory neurons of mPFC caused passive coping behaviors to stress, and overexpression of NIX in the mPFC improved TNF-α-induced synaptic and behavioral abnormalities. Notably, ketamine, a rapid on-set and long-lasting antidepressant, reversed the TNF-α-induced behavioral abnormalities through activation of NIX-mediated mitophagy. Furthermore, the downregulation of NIX level was also observed in the blood of major depressive disorder patients and the mPFC tissue of animal models. Infliximab, a clinically used TNF-α antagonist, alleviated both chronic stress- and inflammation-induced behavioral abnormalities via restoring NIX level. Taken together, these results suggest that NIX-mediated mitophagy links inflammation signaling to passive coping behaviors to stress, which underlies the pathophysiology of stress-related emotional disorders.

Microglia-dependent excessive synaptic pruning leads to cortical underconnectivity and behavioral abnormality following chronic social defeat stress in mice.

Synapse loss in medial prefrontal cortex (mPFC) has been implicated in stress-related mood disorders, such as depression. However, the exact effect of synapse elimination in the depression and how it is triggered are largely unknown. Through repeated longitudinal imaging of mPFC in the living brain, we found both presynaptic and postsynaptic components were declined, together with the impairment of synapse remodeling and cross-synaptic signal transmission in the mPFC during chronic stress. Meanwhile, chronic stress also induced excessive microglia phagocytosis, leading to engulfment of excitatory synapses. Further investigation revealed that the elevated complement C3 during the stress acted as the tag of synapses to be eliminated by microglia. Besides, chronic stress induced a reduction of the connectivity between the mPFC and neighbor regions. C3 knockout mice displayed significant reduction of synaptic pruning and alleviation of disrupted functional connectivity in mPFC, resulting in more resilience to chronic stress. These results indicate that complement-mediated excessive microglia phagocytosis in adulthood induces synaptic dysfunction and cortical hypo-connectivity, leading to stress-related behavioral abnormality.

Long noncoding RNA Gm2694 drives depressive-like behaviors in male mice by interacting with GRP78 to disrupt endoplasmic reticulum homeostasis.

Long noncoding RNAs (lncRNAs) are involved in various biological processes and implicated in the regulation of neuronal activity, but the potential role of lncRNAs in depression remains largely unknown. Here, we identified that lncRNA Gm2694 was increased in the medial prefrontal cortex (mPFC) of male mice subjected to chronic social defeat stress (CSDS). The down-regulation of Gm2694 in the mPFC alleviated CSDS-induced depressive-like behaviors through enhanced excitatory synaptic transmission. Furthermore, we found that Gm2694 preferentially interacted with the carboxyl-terminal domain of 78-kilodalton glucose-regulated protein (GRP78), which abrogated GRP78 function and disrupted endoplasmic reticulum homeostasis, resulting in a reduction of the surface expression of AMPA receptors (AMPARs). Overexpression of GRP78 in the mPFC promoted the surface expression of AMPARs and attenuated the CSDS-induced depressive-like behaviors of mice. Together, our results unraveled a previously unknown role of Gm2694 in regulating endoplasmic reticulum homeostasis and excitatory synaptic transmission in depression.

The Effective Analysis for Blue Honeysuckle Extract in the Treatment of Hepatocellular Carcinoma.

To further determine how BHE affected the growth of HCC cells, the proportion of each cell cycle phase was explored in HCC cells by flow cytometry. Blue honeysuckle (Lonicera caerulea L.) is a species of bush that grows in eastern Russia. Blue honeysuckle extract (BHE) is rich in bioactive phytochemicals which can inhibit the proliferation of tumor cells. The mechanism underlying the anticancer activity of BHE in primary liver cancer is poorly understood. The purpose of this study was to evaluate the growth inhibition mechanism of bioactive substances from blue honeysuckle on hepatocellular carcinoma (HCC) cells and to explore its protein and gene targets. The compounds in BHE were determined by high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS). Cell counting kit-8 (CCK8) assay was used to evaluate the effects of BHE on HCC cell proliferation, and flow cytometry assay (FCA) was used to determine how BHE arrested the proportion of each cell cycle phase in HCC cells. Western blot (WB) was performed to determine the expression of cell cycle-related proteins in HCC cells treated with different concentrations of BHE. The xenograft tumor animal models were established by HCC cell implantation. The results showed that cyanidin-3-o-glucoside and cyanidin-3-o-sophoroside which are the main biologically active components were detected in BHE. BHE is highly effective in inhibiting the proliferation of HCC cells by arresting the HCC cell cycle in the G2/M phase. BHE also downregulated the expression of conventional or classical dendritic cells-2 (cDC2) and cyclin B1 by promoting the expression of myelin transcription factor 1 (MyT1) in HCC cells. The weight and volume of xenografts were significantly decreased in the BHE treated groups when compared to the control group. BHE increased the expression of MyT1 in xenograft tissues. These findings showed that blue honeysuckle extract inhibits proliferation in vivo and in vitro by downregulating the expression of cDC2 and cyclin B1 and upregulating the expression of MyT1 in HCC cells.

Spin Hall effect of transversely spinning light.

Light carries spin angular momentum, which, in the free space, is aligned to the direction of propagation and leads to intriguing spin Hall phenomena at an interface. Recently, it was shown that a transverse-spin (T-spin) state could exist for surface waves at an interface or for bulk waves inside a judiciously engineered metamaterial, with the spin oriented perpendicular to the propagation direction. Here, we demonstrate the spin Hall effect for transversely spinning light-a T-spin-induced beam shift at the interface of a metamaterial. It is found that the beam shift takes place in the plane of incidence, in contrast to the well-known Imbert-Fedorov shifts. The observed T-spin-induced beam shift is of geometrodynamical nature, which can be rendered positive or negative controlled by the orientation of T-spin of the photons. The unconventional spin Hall effect of light found here provides a previously unexplored mechanism for manipulating light-matter interactions at interfaces.

Sorption Constant of Bisphenol A and Octylphenol Onto Size-Fractioned Dissolved Organic Matter Using a Fluorescence Method.

Dissolved organic matter (DOM) is a complex and heterogeneous mixture ubiquitously present in aquatic systems. DOM affects octylphenol (OP) and bisphenol A (BPA) distribution, transport, bioavailability, and toxicity. This study investigated OP and BPA sorption constants, log KCOC, with three size-fractioned DOM. The molecular weights of the sized fractions were low molecular weight DOM (LDOM, <1 kDa), middle molecular weight DOM (MDOM, 1-10 kDa), and high molecular weight DOM (HDOM, 10 kDa-0.45 µm). The log KCOC ranged from 5.34 to 6.14 L/kg-C for OP and from 5.59 to 6.04 L/kg-C for BPA. The OP and BPA log KCOC values were insignificantly different (p = 0.37) and had a strong positive correlation (r = 0.85, p < 0.001). The OP and BPA LDOM log KCOC was significantly higher than the HDOM and MDOM log KCOC (p = 0.012 for BPA, p = 0.023 for OP). The average specific ultraviolet absorption (SUVA254) values were 32.0 ± 5.4, 13.8 ± 1.0, and 17.9 ± 2.8 L/mg-C/m for LDOM, MDOM, and HDOM, respectively. The log KCOC values for both OP and BPA had a moderately positive correlation with the SUVA254 values (r = 0.79-0.84, p < 0.002), which suggested the aromatic group content in the DOM had a positive impact on sorption behavior.

SKF83959, an agonist of phosphatidylinositol-linked dopamine receptors, prevents renewal of extinguished conditioned fear and facilitates extinction.

Fear-related anxiety disorders, such as social phobia and post-traumatic stress disorder, are partly explained by an uncontrollable state of fear. An emerging literature suggests dopamine receptor-1 (D1 receptor) in the amygdala is involved in the regulation of fear memory. An early study has reported that amygdaloid D1 receptor (D1R) is not coupled to the classic cAMP-dependent signal transduction. Here, we investigated whether SKF83959, a typical D1R agonist that mainly activates a D1-like receptor-dependent phosphatidylinositol (PI) signal pathway, facilitates fear extinction and reduces the return of extinguished fear. Interestingly, long-term loss of fearful memories can be induced through a combination of SKF83959 (1 mg/kg/day, i.p., once daily for one week) pharmacotherapy and extinction training. Furthermore, sub-chronic administration of SKF83959 after fear conditioning reduced fear renewal and reinstatement in the mice. We found that the activation D1R and PI signaling in the amygdala was responsible for the effect of SKF83959 on fear extinction. Additionally, SKF83959 significantly promoted the elevation of brain-derived neurotrophic factor (BDNF) expression, possibly by the cAMP response element binding protein (CREB) -directed gene transcription. Given the beneficial effects on extinction, SKF83959 may emerge as a candidate pharmacological approach for improving cognitive-behavioral therapy on fear-related anxiety disorders.

Metformin produces anxiolytic-like effects in rats by facilitating GABAA receptor trafficking to membrane.

BACKGROUND AND PURPOSE: Altered function or expression of GABAA receptors contributes to anxiety disorders. Benzodiazepines are widely prescribed for the treatment of anxiety. However, the long-term use of benzodiazepines increases the risk of developing drug dependence and tolerance. Thus, it is urgent to explore new therapeutic approaches. Metformin is widely used to treat Type 2 diabetes and other metabolic syndromes. However, the role of metformin in psychiatric disorders, especially anxiety, remains largely unknown. EXPERIMENTAL APPROACH: We examined the effects of metformin on anxiety-like behaviour of rats in open field test and elevated plus maze test. We also observed the effect of metformin (10 µM, in vitro; 100 mg·kg-1 , in vivo) on the trafficking of GABAA receptors, as mechanisms underlying the anxiolytic effects of metformin. KEY RESULTS: Metformin (100 mg·kg-1 , i.p. 30 min) displayed a robust and rapid anxiolytic effect, without tolerance. Metformin up-regulated the surface expression of GABAA receptors and increased miniature inhibitory postsynaptic currents (mIPSCs). AMP-activated protein kinase (AMPK) activated by metformin-induced stimulation of forkhead box O3a (FoxO3a) transcriptional activity, followed by increased expression of GABAA receptor-associated protein (GABARAP) and its binding to GABAA receptors finally resulted in the membrane insertion of GABAA receptors. CONCLUSIONS AND IMPLICATIONS: Metformin increased mIPSCs by up-regulating the membrane insertion of GABAA receptors, via a pathway involving AMPK, FoxO3a, and the GABAA receptor-associated protein. Thus metformin has a potential new use in the treatment of anxiety disorders.

SAR405, a Highly Specific VPS34 Inhibitor, Disrupts Auditory Fear Memory Consolidation of Mice via Facilitation of Inhibitory Neurotransmission in Basolateral Amygdala.

BACKGROUND: Autophagy has been demonstrated to play an important role in memory deficits as well as the degradation of neurotransmitter receptors. SAR405 is a newly discovered inhibitor that can specifically inhibit vacuolar sorting protein 34 and prevent autophagosome biogenesis. However, the effects of SAR405 on memory processes remain largely unknown. METHODS: Western blotting, immunofluorescence, and transmission electron microscopy were used to assess the level of autophagy after fear conditioning and SAR405 treatment. Behavioral tests, biotinylation assay, electrophysiology, and co-immunoprecipitation were used to unravel the mechanisms of SAR405 in memory consolidation. RESULTS: SAR405 infusion into the basolateral amygdala impaired long-term memory through autophagy inhibition. Furthermore, the trafficking of gamma-aminobutyric acid type A receptors (GABAARs) following fear conditioning was disrupted by SAR405, and the decreased frequency and amplitude of miniature inhibitory postsynaptic currents induced by fear conditioning were also reversed by SAR405, suggesting that SAR405 disrupted memory consolidation through blockade of the downregulated inhibitory neurotransmission in basolateral amygdala. GABAAR-associated protein (GABARAP) and its interaction with GABAAR γ2 subunit were found to be upregulated after fear conditioning, and SAR405 could suppress this increased interaction. Moreover, disruption of the GABARAP-GABAAR binding by a trans-activating transcriptional activator-GABARAP inhibitory peptide blocked the decrease in surface expression of GABAARs and attenuated long-term memory. CONCLUSIONS: The present study suggests that SAR405 can prevent the memory consolidation via intervening autophagy and GABAAR trafficking and has a potential therapeutic value for disorders characterized by exaggerated fear memories, such as posttraumatic stress disorder.

Dorsal raphe projection inhibits the excitatory inputs on lateral habenula and alleviates depressive behaviors in rats.

Hypofunction of the serotonergic (5-HT) system has close relationship with the symptoms in major depressive disorders (MDD), however, the underlying neural circuitry mechanisms are not fully understood. Lateral habenula (LHb) plays a crucial role in aversive behaviors and is activated in conditions of depression. It has been reported that 5-HT inhibits the excitability of LHb neurons, leading to the hypothesis that decreased transmission of 5-HT would elevate the activity of LHb and therefore mediates depressive symptoms. Using retrograde tract tracing with cholera toxin subunit B, we find that dorsal raphe nucleus (DRN) sends primary 5-HT projection to the LHb. In vitro slice patch-clamp recording reveals that opto-stimulation of DRN inputs to the LHb suppresses the frequency of miniature excitatory postsynaptic current, while increases paired pulse ratio in LHb neurons, indicating 5-HT projection presynaptically suppresses the excitability of LHb neurons. In chronic unpredictable mild stress (CUMS) rat model of depression, optogenetic stimulation of DRN-LHb projection alleviates the depressive symptoms in CUMS models. Meanwhile, opto-inhibition of this circuit results in elevated c-fos expression in LHb and induces depression-like behaviors. This study demonstrates that the 5-HT projection from DRN to LHb suppresses the excitability of LHb neurons, and hypofunction of 5-HT transmission induces depressive behavior via the activation of LHb. Our results reveal the functional connectivity of DRN-LHb circuit and its antidepressant action, which may provide a novel target for the treatment of depression.

Improved Slow Light Capacity In Graphene-based Waveguide.

We have systematically investigated the wideband slow light in two-dimensional material graphene, revealing that graphene exhibits much larger slow light capability than other materials. The slow light performances including material dispersion, bandwidth, dynamic control ability, delay-bandwidth product, propagation loss, and group-velocity dispersion are studied, proving graphene exhibits significant advantages in these performances. A large delay-bandwidth product has been obtained in a simple yet functional grating waveguide with slow down factor c/v(g) at 163 and slow light bandwidth Δω at 94.4 nm centered at 10.38 µm, which is several orders of magnitude larger than previous results. Physical explanation of the enhanced slow light in graphene is given. Our results indicate graphene is an excellent platform for slow light applications, promoting various future slow light devices based on graphene.

Ellagic acid induces cell cycle arrest and apoptosis through TGF-ß/Smad3 signaling pathway in human breast cancer MCF-7 cells.

Breast cancer represents the second leading cause of cancer-related deaths among women worldwide and preventive therapy could reverse or delay the devastating impact of this disease. Ellagic acid (EA), a dietary flavonoid polyphenol which is present in abundance in pomegranate, muscadine grapes, walnuts and strawberries, has been shown to inhibit cancer cells proliferation and induce apoptosis. Here, we investigated the growth inhibitory effects of EA on MCF-7 breast cancer cells. In the present study, we first found that EA inhibits the proliferation of MCF-7 breast cancer cells mainly mediated by arresting cell cycle in the G0/G1 phase. Moreover, gene expression profiling of MCF-7 breast cancer cell line treated with EA for 6, 12 and 24 h was performed using cDNA microarray. A total of 4,738 genes were found with a >2.0-fold change after 24 h of EA treatment. Among these genes, 2,547 were downregulated and 2,191 were upregulated. Furthermore, the changes of 16 genes, which belong to TGF-ß/Smads signaling pathway, were confirmed by real-time RT-PCR and/or western blot analysis. TGF-ß/Smads signaling pathway was found as the potential molecular mechanism of EA to regulate breast cancer cell cycle arrest in vitro. Therefore, the regulation of TGF-ß/Smads pathway in breast cancer cells could be a novel therapeutic approach for the treatment of patients with breast cancer. Further studies with in vitro models, as well as an analysis of additional human samples, are still needed to confirm the molecular mechanisms of EA in inhibition or prevention of breast cancer growth.

Ellagic acid exerts anti-proliferation effects via modulation of Tgf-ß/Smad3 signaling in MCF-7 breast cancer cells.

Ellagic acid has been shown to inhibit tumor cell growth. However, the underlying molecular mechanisms remain elusive. In this study, our aim was to investigate whether ellagic acid inhibits the proliferation of MCF- 7 human breast cancer cells via regulation of the TGF-ß/Smad3 signaling pathway. MCF-7 breast cancer cells were transfected with pEGFP-C3 or pEGFP-C3/Smad3 plasmids, and treated with ellagic acid alone or in combination with SIS3, a specific inhibitor of Smad3 phosphorylation. Cell proliferation was assessed by MTT assay and the cell cycle was detected by flow cytometry. Moreover, gene expression was detected by RT-PCR, real-time PCR and Western blot analysis. The MTT assay showed that SIS3 attenuated the inhibitory activity of ellagic acid on the proliferation of MCF-7 cells. Flow cytometry revealed that ellagic acid induced G0/G1 cell cycle arrest which was mitigated by SIS3. Moreover, SIS3 reversed the effects of ellagic acid on the expression of downstream targets of the TGF-ß/Smad3 pathway. In conclusion, ellagic acid leads to decreased phosphorylation of RB proteins mainly through modulation of the TGF-ß/Smad3 pathway, and thereby inhibits the proliferation of MCF-7 breast cancer cells.

Expression and prognostic value of tumor stem cell markers ALDH1 and CD133 in colorectal carcinoma.

The identification of cancer stem cells (CSCs) has improved the understanding of tumor occurrence and development. According to CSC theory, colorectal carcinoma (CRC) may be derived from these few cells. Thus, markers for CSCs may lead to the identification of CSCs and investigation of the correlation with various clinicopathological features and survival time in human CRC patients. Aldehyde dehydrogenase 1 (ALDH1) and CD133 (also known as Prominin-1 or AC133) were involved in the current study. The aim of the present study was to identify CSCs through markers of CSCs and to explore the value of the CSC markers, ALDH1 and CD133, in human CRC. The correlation between ALDH1 and CD133 protein expression and the various clinicopathological parameters were investigated through immunohistochemistry (IHC). In addition, the Kaplan-Meier method was used to estimate patients' overall survival. Correlation of the survival differences between ALDH1- or CD133-positive expression and negative controls was analyzed by the log-rank test. Furthermore, the correlation between the expression of ALDH1 and CD133 was assessed by Spearman's rank correlation. A marked correlation between the differentiation degree and expression of ALDH1 in tumor cells was demonstrated, but not with CD133 expression. In addition, it was demonstrated that low-stage tumors exhibit a higher expression of ALDH1 or CD133 staining compared with high-stage tumors. Meanwhile, CD133 expression was associated with lymph node metastasis-positive cases, but ALDH1 expression was not. Furthermore, compared with negative cases, ALDH1-positive patients exhibited a poor prognosis. However, no significant difference was identified between CD133-positive and -negative cases in terms of survival time. Overall, the results of the present study indicated that ALDH1 and CD133 may serve as useful markers of CSC to predict disease prognosis and clinicopathological characteristics of human CRC.

Identification and functional analysis of a novel mutation in the SOX10 gene associated with Waardenburg syndrome type IV.

Waardenburg syndrome type IV (WS4) is a rare genetic disorder, characterized by auditory-pigmentary abnormalities and Hirschsprung disease. Mutations of the EDNRB gene, EDN3 gene, or SOX10 gene are responsible for WS4. In the present study, we reported a case of a Chinese patient with clinical features of WS4. In addition, the three genes mentioned above were sequenced in order to identify whether mutations are responsible for the case. We revealed a novel nonsense mutation, c.1063C>T (p.Q355*), in the last coding exon of SOX10. The same mutation was not found in three unaffected family members or 100 unrelated controls. Then, the function and mechanism of the mutation were investigated in vitro. We found both wild-type (WT) and mutant SOX10 p.Q355* were detected at the expected size and their expression levels are equivalent. The mutant protein also localized in the nucleus and retained the DNA-binding activity as WT counterpart; however, it lost its transactivation capability on the MITF promoter and acted as a dominant-negative repressor impairing function of the WT SOX10.

Anti-proliferative effect of an extract of the root of Polygonum multiflorum Thunb. on MCF-7 human breast cancer cells and the possible mechanisms.

The root of Polygonum multiflorum Thunb. (PM) is utilized to treat many diseases associated with aging. Research also indicates that PM inhibits the proliferation of certain types of cancer cells. The aim of the present study was to evaluate the inhibitory effect of PM extract (PME) on the proliferation of MCF-7 cells and to investigate the underlying mechanisms. Inhibition of the proliferation of MCF-7 cells was determined by the MTT assay. Cell cycle distribution and apoptotic rates were evaluated by flow cytometry, and cell cycle and apoptosis-related protein expression was assessed by Western blotting. Apoptotic characteristics of MCF-7 cells were detected by transmission electron microscopy. The present study showed that PME at doses of 100, 150, 200 and 250 µg/ml significantly inhibited proliferation of MCF-7 cells in a time- and dose-dependent manner. Flow cytometry showed that the cell apoptotic rates were 9.1 ± 1.67 and 17.7 ± 2.93% after treatment with 100 and 200 µg/ml PME for 48 h, respectively. The proportions of cells in the G2/M phase were 37.9 ± 1.47 and 42.0 ± 1.71% after treatment with 100 and 200 µg/ml PME for 24 h, respectively. Western blot analysis showed that PME down-regulated the protein expression of Cdc25B and Cdc25C phosphatases accompanied by an increase in phospho-Cdk1, and PME promoted cytochrome c release from mitochondria into the cytosol to activate caspase-9. The present study demonstrated that PME inhibited MCF-7 cell proliferation by inducing cell cycle arrest in the G2/M phase and promoting cell apoptosis. The effects of PME on MCF-7 cells were associated with the modulation of the expression levels of proteins involved in the cell cycle and apoptosis. These data suggest that PME has promise as a treatment against breast cancer by inhibiting the proliferation of cancer cells.

Influence of plasma and cerebrospinal fluid levels of endothelin-1 and NO in reducing cerebral vasospasm after subarachnoid hemorrhage during treatment with mild hypothermia, in a dog model.

Using vascular heat-exchange controller implemented mild hypothermia treatment, the authors established the cerebral vasospasm model in which blood was injected twice into dog's foramen magnum; and it was discussed the influence of the concentration of endothelin-1 and NO in blood plasma and cerebrospinal fluid through continuing treatment of mild hypothermia at different times in secondary brain vasospasm model after subarachnoid hemorrhage. Thirty healthy mongrel dogs were randomly divided into five groups; artificial cerebrospinal fluid group (group A), normal temperature control group (group C), mild hypothermia 8 h group (group H1), mild hypothermia 16 h group (group H2), and mild hypothermia 32 h group (group H3). The authors injected the artificial CSF into dog's foramen magnum in group A while the other four groups were injected with autologous arterial blood. The normal group's temperature maintained 38.5°C. The authors set the temperature at 33.5°C in mild hypothermia groups and this was maintained for 8, 16, and 32 h, respectively. ET-1 and NO levels in the cerebrospinal fluid and plasma were assayed in each group on days 0, 7, 14, and 21. Then the changes of the diameter of blood vessels of cerebral basilar artery and overall performance categories score in each group through application of CT angiography were recorded. In the cerebral vasospasm model which was constructed by injecting the blood to dog twice, mild hypothermia treatment, through the application of vascular heat-exchange controller, could reduce cerebral vasospasm. It was observed that the duration of the mild hypothermia is directly proportional to the longer duration of the relieving of cerebral vasospasm. The reciprocal changes observed in the levels of ET-1 and NO in cerebrospinal fluid and plasma revealed that it might be possible to reduce the cerebral vasospasm by regulating the rising amplitude of ET-1 and the decrease in NO in CSF and plasma.