Approximately half of those who survive severe carbon monoxide (CO) poisoning develop delayed neurologic sequelae. Growing evidence supports the crucial role of free radicals in delayed brain injury associated with CO toxicity. Xanthine oxidase (XO) has been reported to play a pivotal role in the generation of reactive oxygen species (ROS) in CO poisoning. A recent report indicates that allopurinol both attenuated oxidative stress and possessed anti-inflammatory properties in an animal model of acute liver failure. In this study, we aimed to explore the potential of allopurinol to reduce the severity of delayed neurologic sequelae. The rats were first exposed to 1000 ppm CO for 40 min and then to 3000 ppm CO for another 20 min. Following CO poisoning, the rats were injected with allopurinol (50 mg/kg, i.p.) six times. Results showed that allopurinol significantly reduced neuronal death and suppressed expression of pro-inflammatory factors, including tumor necrosis factor-α, intercellular adhesion molecule-1, ionized calcium-binding adapter molecule 1, and degraded myelin basic protein. Furthermore, behavioral studies revealed an improved performance in the Morris water maze test. Our findings indicated that allopurinol may have protective effects against delayed neurologic sequelae caused by CO toxicity.

Long noncoding RNAs (lncRNAs) are critical gene expression regulators and are involved in several bone diseases. To explore the potential roles of lncRNAs in osteonecrosis of the femoral head (ONFH), we investigated for the first time the lncRNA expression profile of bone marrow mesenchymal stem cells (BMSCs) from patients with steroid-induced ONFH (SONFH) with microarray and bioinformatics analysis. A total of 1878 lncRNAs and 838 mRNAs were significantly up-regulated while 1842 lncRNAs and 1937 mRNAs were statistically down-regulated in the SONFH group compared with control group. The results validated by qRT-PCR were consistent with the microarray profiling data, especially involved in upregulation and downregulation of critical lncRNAs as well as mRNAs expression related to adipogenic and osteogenic differentiation. Pathway analyses revealed 40 signaling pathways with significant differences, especially the signaling pathways to regulate stem cell pluripotency. The CNC and ceRNA network indicated that lncRNA RP1-193H18.2, MALAT1 and HOTAIR were associated with abnormal osteogenic and adipogenic differentiation of BMSCs in the patients with SONFH. Our results suggest the lncRNA expression profiles were closely associated with the abnormal adipogenic and osteogenic transdifferentiation of BMSCs during the development of SONFH and explore a new insight into the molecular mechanisms of SONFH.

Quercetin is the most abundant flavonoid in fruit and vegetables and is believed to attenuate cardiovascular disease. We hypothesized that quercetin inhibits cardiac hypertrophy by blocking AP-1 (c-fos, c-jun) and activating PPAR-γ signaling pathways.

The downstream regulatory element antagonist modulator (DREAM), a multifunctional Ca2+-binding protein, binds specifically to DNA and several nucleoproteins regulating gene expression and with proteins outside the nucleus to regulate membrane excitability or calcium homeostasis. DREAM is highly expressed in the central nervous system including the hippocampus and cortex; however, the roles of DREAM in hippocampal synaptic transmission and plasticity have not been investigated. Taking advantage of transgenic mice overexpressing a Ca2+-insensitive DREAM mutant (TgDREAM), we used integrative methods including electrophysiology, biochemistry, immunostaining, and behavior tests to study the function of DREAM in synaptic transmission, long-term plasticity and fear memory in hippocampal CA1 region. We found that NMDA receptor but not AMPA receptor-mediated current was decreased in TgDREAM mice. Moreover, synaptic plasticity, such as long-term depression (LTD) but not long-term potentiation (LTP), was impaired in TgDREAM mice. Biochemical experiments found that DREAM interacts with PSD-95 and may inhibit NMDA receptor function through this interaction. Contextual fear memory was significantly impaired in TgDREAM mice. By contrast, sensory responses to noxious stimuli were not affected. Our results demonstrate that DREAM plays a novel role in postsynaptic modulation of the NMDA receptor, and contributes to synaptic plasticity and behavioral memory.

The anterior cingulate cortex (ACC) is involved in sensory, cognitive, and executive functions. Studies of synaptic transmission and plasticity in the ACC provide an understanding of basic cellular and molecular mechanisms for brain functions. Previous anatomic studies suggest complex local interactions among neurons within the ACC. However, there is a lack of functional studies of such synaptic connections between ACC neurons. In the present study, we characterized the neuronal connections in the superficial layers (I-III) of the mouse ACC using dual whole-cell patch clamp recording technique. Four types of synaptic connections were observed, which are from a pyramidal neuron to a pyramidal neuron, from a pyramidal neuron to an interneuron, from an interneuron to a pyramidal neuron and from an interneuron to an interneuron. These connections exist among neurons in layer II/III or between neurons located layer I and II/III, respectively. Moreover, reciprocal connections exist in all four types of paired neurons. Our results provide the first key evidence of functional excitatory and inhibitory connections in the ACC.

Neurabin is a scaffolding protein that interacts with actin and protein phosphatase-1. Highly enriched in the dendritic spine, neurabin is important for spine morphogenesis and synaptic formation. However, less is known about the role of neurabin in hippocampal plasticity and its possible effect on behavioral functions. Using neurabin knockout (KO) mice, here we studied the function of neurabin in hippocampal synaptic transmission, plasticity and behavioral memory. We demonstrated that neurabin KO mice showed a deficit in contextual fear memory but not auditory fear memory. Whole-cell patch clamp recordings in the hippocampal CA1 neurons showed that long-term potentiation (LTP) was significantly reduced, whereas long-term depression (LTD) was unaltered in neurabin KO mice. Moreover, increased AMPA receptor but not NMDA receptor-mediated synaptic transmission was found in neurabin KO mice, and is accompanied by decreased phosphorylation of GluR1 at the PKA site (Ser845) but no change at the CaMKII/PKC site (Ser831). Pre-conditioning with LTD induction rescued the following LTP in neurabin KO mice, suggesting the loss of LTP may be due to the saturated synaptic transmission. Our results indicate that neurabin regulates contextual fear memory and LTP in hippocampal CA1 pyramidal neurons.

NMDA receptors (NMDARs) are involved in excitatory synaptic transmission and plasticity associated with a variety of brain functions, from memory formation to chronic pain. Subunit-selective antagonists for NMDARs provide powerful tools to dissect NMDAR functions in neuronal activities. Recently developed antagonist for NR2A-containing receptors, NVP-AAM007, triggered debates on its selectivity and involvement of the NMDAR subunits in bi-directional synaptic plasticity. Here, we re-examined the pharmacological properties of NMDARs in the anterior cingulate cortex (ACC) using NVP-AAM007 as well as ifenprodil, a selective antagonist for NR2B-containing NMDARs. By alternating sequence of drug application and examining different concentrations of NVP-AAM007, we found that the presence of NVP-AAM007 did not significantly affect the effect of ifenprodil on NMDAR-mediated EPSCs. These results suggest that NVP-AAM007 shows great preference for NR2A subunit and could be used as a selective antagonist for NR2A-containing NMDARs in the ACC.

Long-term potentiation (LTP) in the hippocampal CA1 region requires the activation of N-methyl-D-aspartate receptors (NMDARs). Studies using genetic and pharmacological approaches have reported inconsistent results of the requirement of NR2B-containing NMDARs in LTP in the CA1 region. Pharmacological studies showed that NR2B-containing NMDARs are not required for LTP, while genetic studies reported that over-expression of NR2B-NMDARs enhances LTP and hippocampus-dependent memory. Here, we provide evidence showing that the functional role of NR2B-NMDARs in hippocampal LTP and memory depends on LTP-inducing and behavior-conditioning protocols. Inhibition of NR2B-NMDARs with the NR2B selective antagonist ifenprodil or Ro25-6981 suppressed LTP induced by spike-timing protocol, with no impact on LTP induced by pairing protocol or two-train high-frequency stimulation (HFS) protocol. Inhibition of NR2B-NMDARs did not affect the late phase LTP induced by four-train HFS. Ca²(+) imaging showed that there was difference in kinetics of intracellular Ca²(+) signals induced by spiking-timing and pairing protocols. Pre-training intra-CA1 infusion of ifenprodil or Ro25-6981 impaired the contextual fear memory induced by five CS-US pairings, with no effect on the memory induced by one CS-US pairing.

BACKGROUND Steroid-induced osteonecrosis of the femoral head (SONFH) is a common orthopedic disease associated with the application of glucocorticoid (GC). In this study, we detected the microRNAs (miRNAs) differentially expressed in bone marrow mesenchymal stem cells (BMSCs) from SONFH patients, and target gene predictions were performed, and the functions of the target genes was verified. MATERIAL AND METHODS BMSCs collected from patients with SONFH and femoral neck fracture (FNF) constituted the SONFH group (n=3) and FNF (control) group (n=3), respectively. MiRNA microarray analysis was utilized to detect the differentially expressed miRNAs, and quantitative real-time polymerase chain reaction (qRT-PCR) was used to verify the microarray results. The target genes and functions of the differentially expressed miRNAs were analyzed using a bioinformatics database. RESULTS The microarray results revealed that compared with the control group, 22 miRNAs were identified differentially expressed in the SONFH group, with 17 upregulated and 5 downregulated. Further qRT-PCR validation of differentially expressed miRNAs confirmed that hsa-miR-601, hsa-miR-452-3p, hsa-miR-647, and hsa-miR-516b-5p were significantly increased, whereas hsa-miR-122-3p was significantly decreased. During osteogenic differentiation, hsa-miR-601, hsa-miR-452-3p, hsa-miR-647, hsa-miR-516b-5p, and hsa-miR-127-5p were significantly downregulated, whereas hsa-miR-122-3p was significantly upregulated, and miRNAs showed a converse tendency during adipogenic differentiation. CONCLUSIONS Six miRNAs associated with osteogenic and adipogenic differentiation were identified differentially expressed in the BMSCs of SONFH patients; these miRNAs may serve as novel biomarkers or therapeutic targets for SONFH.

Buprenorphine is a μ-opioid receptor (MOR) partial agonist used to manage pain and addiction. QTC prolongation that crosses the 10 msec threshold of regulatory concern was observed at a supratherapeutic dose in two thorough QT studies for the transdermal buprenorphine product BUTRANS®. Because QTC prolongation can be associated with Torsades de Pointes (TdP), a rare but potentially fatal ventricular arrhythmia, these results have led to further investigation of the electrophysiological effects of buprenorphine. Drug-induced QTC prolongation and TdP are most commonly caused by acute inhibition of hERG current (IhERG) that contribute to the repolarizing phase of the ventricular action potentials (APs). Concomitant inhibition of inward late Na+ (INaL) and/or L-type Ca2+ (ICaL) current can offer some protection against proarrhythmia. Therefore, we characterized the effects of buprenorphine and its major metabolite norbuprenorphine on cardiac hERG, Ca2+, and Na+ ion channels, as well as cardiac APs. For comparison, methadone, a MOR agonist associated with QTC prolongation and high TdP risk, and naltrexone and naloxone, two opioid receptor antagonists, were also studied. Whole cell recordings were performed at 37°C on cells stably expressing hERG, CaV1.2, and NaV1.5 proteins. Microelectrode array (MEA) recordings were made on human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs). The results showed that buprenorphine, norbuprenorphine, naltrexone, and naloxone had no effect on IhERG, ICaL, INaL, and peak Na+ current (INaP) at clinically relevant concentrations. In contrast, methadone inhibited IhERG, ICaL, and INaL. Experiments on iPSC-CMs showed a lack of effect for buprenorphine, norbuprenorphine, naltrexone, and naloxone, and delayed repolarization for methadone at clinically relevant concentrations. The mechanism of QTC prolongation is opioid moiety-specific. This remains undefined for buprenorphine, while for methadone it involves direct hERG channel block. There is no evidence that buprenorphine use is associated with TdP. Whether this lack of TdP risk can be generalized to other drugs with QTC prolongation not mediated by acute hERG channel block warrants further study.

Studies of aberrantly expressed circular RNAs (circRNAs) can provide insights into the molecular mechanisms of osteosarcoma (OS). However, the role of circ_0001174 in OS progression remains unknown. This study is aimed to identify differentially expressed circRNAs and messenger RNAs (mRNAs) in patients with OS and to investigate potential regulatory ways of circ_0001174.

The resistance of melanoma to BRAF inhibitors remains a tough clinical challenge. In order to explore the underlying mechanism of drug resistance in melanoma, we established the resistant cell line to vemurafenib, and assessed the changes of drug-resistant cells on proliferation, apoptosis, oxidative stress and tumor stemness. Our results suggest that phosphoenolpyruvate carboxykinase1 (PCK1) is activated and inhibits the oxidative stress caused by vemurafenib in drug-resistant cells. Long term treatment of vemurafenib increases the expression of PCK1 which reduces the production of reactive oxygen species (ROS) by activating PI3K/Akt pathway. After the inhibition of PCK1 by 3-mercaptopropionic acid (3-MPA), the therapeutic sensitivity of vemurafenib is restored. In conclusion, this study disclosed that drug-resistant cells appeared to regulate their own proliferation, oxidative stress and tumor dryness by activating Akt/PCK1/ROS pathway, and shed new insights into acquiring drug resistance in melanoma.

Colorectal cancer (CRC) is an extremely common gastrointestinal malignancy. The present study aimed to identify microRNAs (miRNAs) and transcription factors (TFs) associated with tumor development.

Combinations of biomaterials and cells can effectively target delivery of cells or other therapeutic factors to the brain to rebuild damaged nerve pathways after brain injury. Porous collagen-chitosan scaffolds were prepared by a freeze-drying method based on brain tissue engineering. The scaffolds were impregnated with rat bone marrow mesenchymal stem cells. A traumatic brain injury rat model was established using the 300 g weight free fall impact method. Bone marrow mesenchymal stem cells/collagen-chitosan scaffolds were implanted into the injured brain. Modified neurological severity scores were used to assess the recovery of neurological function. The Morris water maze was employed to determine spatial learning and memory abilities. Hematoxylin-eosin staining was performed to measure pathological changes in brain tissue. Immunohistochemistry was performed for vascular endothelial growth factor and for 5-bromo-2-deoxyuridine (BrdU)/neuron specific enolase and BrdU/glial fibrillary acidic protein. Our results demonstrated that the transplantation of bone marrow mesenchymal stem cells and collagen-chitosan scaffolds to traumatic brain injury rats remarkably reduced modified neurological severity scores, shortened the average latency of the Morris water maze, increased the number of platform crossings, diminished the degeneration of damaged brain tissue, and increased the positive reaction of vascular endothelial growth factor in the transplantation and surrounding areas. At 14 days after transplantation, increased BrdU/glial fibrillary acidic protein expression and decreased BrdU/neuron specific enolase expression were observed in bone marrow mesenchymal stem cells in the injured area. The therapeutic effect of bone marrow mesenchymal stem cells and collagen-chitosan scaffolds was superior to stereotactic injection of bone marrow mesenchymal stem cells alone. To test the biocompatibility and immunogenicity of bone marrow mesenchymal stem cells and collagen-chitosan scaffolds, immunosuppressive cyclosporine was intravenously injected 12 hours before transplantation and 1-5 days after transplantation. The above indicators were similar to those of rats treated with bone marrow mesenchymal stem cells and collagen-chitosan scaffolds only. These findings indicate that transplantation of bone marrow mesenchymal stem cells in a collagen-chitosan scaffold can promote the recovery of neuropathological injury in rats with traumatic brain injury. This approach has the potential to be developed as a treatment for traumatic brain injury in humans. All experimental procedures were approved by the Institutional Animal Investigation Committee of Capital Medical University, China (approval No. AEEI-2015-035) in December 2015.

Indigenous animals show unique gut microbiota (GM) in the Tibetan plateau. However, it is unknown whether the hypertensive indigenous people in plateau also have the distinct gut bacteria, different from those living in plains. We sequenced the V3-V4 region of the gut bacteria 16S ribosomal RNA (rRNA) gene of feces samples among hypertensive patients (HPs) and healthy individuals (HIs) from 3 distinct altitudes: Tibetans from high altitude (3600-4500 m, n = 38 and 34), Hans from middle altitude (2260 m, n = 49 and 35), and Hans from low altitude (13 m, n = 34 and 35) and then analyzed the GM composition among hypertensive and healthy subgroups using the bioinformatics analysis, respectively. The GM of high-altitude Tibetan and middle-altitude Han HPs presented greater α- and β-diversities, lower ratio of Firmicutes/Bacteroidetes (F/B), and higher abundance of beneficial Verrucomicrobia and Akkermansia than the low-altitudes HPs did. The GM of high-altitude Tibetan and middle-altitude HIs showed greater α-diversity and lower ratio of F/B than the low-altitudes HIs did. But, β-diversity and abundance of Verrucomicrobia and Akkermansia among different subgroups of HIs did not show any differences. Conclusively, the high-altitude Tibetan and middle-altitude Han HPs have a distinct feature of GM, which may be important in their adaptation to hypertension in the plateau environments.

Statins have proven to exert protective effects in patients with symptomatic intracranial atherosclerotic stenosis (SICAS). It is unclear whether intensive lipid-lowering therapy (ILLT) can ameliorate atherosclerosis in asymptomatic ICAS (AICAS). A single-center, prospective cohort study was performed in 71 AICAS patients with lipid-lowering therapy. Vascular stenoses were evaluated with transcranial color-coded sonography (TCCS) before and after statin treatment. With target therapeutic level of low-density lipoprotein cholesterol (LDL-C) ≤ 1.8 mmol/L or ≥ 50% reduction from baseline after the two years of follow-up, patients were divided into intensive statin treatment (IST) group and standard statin treatment (SST) group. A total of 104 stenotic intracranial arteries were detected in 51 patients belonging to the IST group and 47 arteries in 20 patients of the SST group. In the first year, LDL-C levels were significantly decreased in the IST compared with SST groups (1.48 ± 0.26 vs. 2.20 ± 0.58, P=0.000). However, the ratio of regressed ICAS in IST was not significantly higher than that in SST (26.3% vs. 5.9%, P=0.052). Forty-nine branches in 25 patients of the IST group and 16 branches in 7 patients of the SST group were followed up for two years. The LDL-C level was decreased in the IST compared with SST groups (1.55 ± 0.29 vs. 2.36 ± 0.77, P=0.048). The ratio of regressed ICAS in the IST group was significantly higher than that in SST group (34.7% vs. 6.3%, P=0.017). We concluded that the degree of stenosis in AICAS can be ameliorated with intensive lipid-lowering therapy within two years; target LDL-C level can be reached by moderate-intensity statin treatment for Chinese AICAS patients.

Pancreatic cancer remains one of the leading causes of cancer-related deaths worldwide. Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic tumor. Many circular RNAs (circRNAs) have proven to play vital roles in the physiological and pathological processes of tumorigenesis; however, their biogenesis in PDAC remains unclear. In this study, the expression profiles of circRNAs from 10 PDAC tissues and their paired adjacent nontumor tissues were analyzed through RNA sequencing analysis. An enrichment analysis was employed to predict the functions of the differentially expressed circRNAs. Sequence alignment information and mRNA microarray projects were used to predict the RNA regulatory network. The knockdown of circRNAs by small interfering RNAs followed by wound healing and western blot assays was used to confirm their functions in a PDAC cell line. A total of 278 circRNAs were identified as differentially expressed in PDAC tissue. Of these, we found that hsa_circRNA_0007334 was significantly upregulated and may serve as a competing endogenous RNA to regulate matrix metallopeptidase 7 (MMP7) and collagen type I alpha 1 chain (COL1A1) by the competitive adsorption of hsa-miR-144-3p and hsa-miR-577 to enhance the expression and functions of MMP7 and COL1A1 in PDAC. In vitro experiments confirmed these results. The present study is the first to propose two regulatory pathways in PDAC: hsa_circRNA_0007334-hsa-miR-144-3p-MMP7 and hsa_circRNA_0007334-hsa-miR-577-COL1A1.

The mesofrontal dopaminergic circuit, which connects the midbrain motivation center to the cortical executive center, is engaged in control of motivated behaviors. In addition, deficiencies in this circuit are associated with adolescent-onset psychiatric disorders in humans. Developmental studies suggest that the mesofrontal circuit exhibits a protracted maturation through adolescence. However, whether the structure and function of this circuit are modifiable by activity in dopaminergic neurons during adolescence remains unknown. Using optogenetic stimulation and in vivo two-photon imaging in adolescent mice, we found that phasic, but not tonic, dopamine neuron activity induces the formation of mesofrontal axonal boutons. In contrast, in adult mice, the effect of phasic activity diminishes. Furthermore, our results showed that dopaminergic and glutamatergic transmission regulate this axonal plasticity in adolescence and inhibition of dopamine D2-type receptors restores this plasticity in adulthood. Finally, we found that phasic activation of dopamine neurons also induces greater changes in mesofrontal circuit activity and psychomotor response in adolescent mice than in adult mice. Together, our findings demonstrate that the structure and function of the mesofrontal circuit are modifiable by phasic activity in dopaminergic neurons during adolescence and suggest that the greater plasticity in adolescence may facilitate activity-dependent strengthening of dopaminergic input and improvement in behavioral control.

The RANKL/RANK/OPG pathway plays an important role in regulating bone remodeling and bone turnover. However, the association of the genes variants with the risk of ONFH has rarely been reported. Here, we analyzed the correlation of the 10 SNPs polymorphisms of RANKL, RANK, OPG, TRAF6, and NFATC1 genes with the risk and development of ONFH in 200 ONFH patients and 177 health controls of Chinese population with using Mass ARRAY® platform. The results showed that the recessive model of NFATC1rs9518 was significantly associated with increased ONFH risk (OR:8.223, P=0.048); the proportion of stage Ⅳ patients in the rs9518TC genotype carriers was statistically higher than that of stage Ⅲ patients (P=0.03); in the T-C haplotype carriers of Naftac1, the proportion of bilateral hips lesions was also significantly enhanced than that of unilateral hip lesions(P=0.05). In addition, the proportion of idiopathic ONFH in the TT genotype carriers of OPGrs2073617 was significantly higher than that of steroid or alcohol-induced ONFH, respectively, while in the TC genotype carriers of the SNP, the proportion of idiopathic ONFH remarkably decreased compared with that of Alcohol-induced ONFH, P=0.021. Our results were first found that NFATC1rs9518 closely associated with the risk and the development of ONFH, while OPGrs2073617 statistically correlated with the etiological classification of ONFH.

The objective of this study was to investigate a possible role of mitochondrial dihydrolipoamide dehydrogenase (DLDH) as a chemical preconditioning target for neuroprotection against ischemic injury. We used 5-methoxyindole-2-carboxylic acid (MICA), a reportedly reversible DLDH inhibitor, as the preconditioning agent and administered MICA to rats mainly via dietary intake. Upon completion of 4 week's MICA treatment, rats underwent 1h transient ischemia and 24h reperfusion followed by tissue collection. Our results show that MICA protected the brain against ischemic stroke injury as the infarction volume of the brain from the MICA-treated group was significantly smaller than that from the control group. Data were then collected without or with stroke surgery following MICA feeding. It was found that in the absence of stroke following MICA feeding, DLDH activity was lower in the MICA treated group than in the control group, and this decreased activity could be partly due to DLDH protein sulfenation. Moreover, DLDH inhibition by MICA was also found to upregulate the expression of NAD(P)H-ubiquinone oxidoreductase 1(NQO1) via the Nrf2 signaling pathway. In the presence of stroke following MICA feeding, decreased DLDH activity and increased Nrf2 signaling were also observed along with increased NQO1 activity, decreased oxidative stress, decreased cell death, and increased mitochondrial ATP output. We also found that MICA had a delayed preconditioning effect four weeks post MICA treatment. Our study indicates that administration of MICA confers chemical preconditioning and neuroprotection against ischemic stroke injury.