MiR-449b-5p inhibits human glioblastoma cell proliferation by inactivating WNT2B/Wnt/ß-catenin signaling pathway.

OBJECTIVE: As the most common primary brain cancer in adults, glioblastoma shows an extremely poor prognosis. Glioblastoma-associated deaths account for approximately 3%-4% of all malignancy-associated deaths. Numerous microRNAs (miRNAs) play important roles in the occurrence and progression of solid tumors. Herein, identifying functional miRNAs and the central molecular mechanisms would provide novel proofs for the development of targeted cancer therapies. In this study, we described the role of miR-449b-5p in restraining ontogenesis and progression of glioblastoma. PATIENTS AND METHODS: Human glioblastoma tissues were provided by our hospital. Human U251 glioblastoma cells were infected with lentivirus induced miR-449b-5p mimics or miR-449b-5p siRNA. Real-time qPCR was carried out to determine miRNA expression. Tumor spheres formation, MTT assay, and BrdU cell proliferation assay were used to evaluate the growth ability of U251 cells. Western blot assay was performed to measure protein expression. ChIP was used to detect the capacity of ß-catenin to recruit its downstream genes. Dual-Luciferase assay was conducted to detect the ability of miR-449b-5p to regulate the 3'UTR (untranslated regions) of WNT2B. TOP/FOP ratio was used to evaluate the activity of Wnt/ß-catenin signaling pathway. RESULTS: Down-regulation of miR-449b-5p expression was found in both human glioblastoma tissues and cell lines, which was negatively associated with the clinical stages. Up-regulation of miR-449b-5p inhibited tumor spheres formation, cell viability and proliferation ability of glioblastoma cells. The expression levels of WNT2B and nuclear ß-catenin were negatively associated with miR-449b-5p levels in glioblastoma cells. MiR-449b-5p inhibited Wnt/ß-catenin signaling by targeting WNT2B. CONCLUSIONS: MiR-449b-5p acts as a tumor suppressor and retards the oncogenesis of glioblastoma, which is achieved via inactivation of Wnt/ß-catenin signaling by directly targeting WNT2B.

Local infusion of an alpha-1 adrenergic agonist into the prefrontal cortex impairs spatial working memory performance in monkeys.

BACKGROUND: Stimulation of alpha-2 adrenoceptors in the monkey or rat prefrontal cortex (PFC) has been known to improve spatial working memory (SWM) and stimulation of alpha-1 adrenoceptors in the rat PFC has been reported to impair SWM. The present study attempted to replicate in monkey the rat experiments on alpha-1 adrenoceptor stimulation. METHODS: The alpha-1 adrenergic agonist phenylephrine or the alpha-2 adrenergic agonist guanfacine was infused into the dorsolateral prefrontal cortex (dlPFC) of monkeys performing the delayed-response (DR) task, a task of SWM, to see how the drugs affect SWM performance. RESULTS: Phenylephrine infusion in dlPFC significantly impaired DR performance, whereas guanfacine improved performance. The effects of both drugs were delay-dependent. Infusions outside dlPFC were ineffective. CONCLUSIONS: Stimulation of prefrontal cortical alpha-1 adrenoceptors impairs SWM function in monkeys, consistent with the parallel study in rats, whereas stimulation of alpha-2 adrenoceptors improves SWM, indicating that alpha-1 and alpha-2 adrenoceptors may have opposing roles in the PFC.

Alpha-2 adrenergic modulation of prefrontal cortical neuronal activity related to spatial working memory in monkeys.

The effects of systemically administered or iontophoretically applied clonidine (alpha-2 adrenergic agonist) and iontophoretically applied yohimbine (alpha-2 adrenergic antagonist) were examined on prefrontal cortical (PFC) neurons related to spatial working memory (SWM). Systemically administered clonidine (0.04 mg/kg) enhanced SWM-related PFC neuronal activity by 32.5 +/- 14.5%, (mean +/- SD; n = 25 neurons). The facilitatory effect of clonidine was antagonized by iontophoretically applied yohimbine. Iontophoretically applied clonidine enhanced SWM-related PFC neuronal activity by 38.2 +/- 18.6%, (n = 13 neurons), whereas similarly applied yohimbine suppressed it by 34.4 +/- 17.8% (n = 28 neurons). These results indicate that: a) systemically administered clonidine can facilitate SWM-related PFC neuronal activity through actions at alpha-2 adrenoceptors in the PFC; and b) conversely, blockade by yohimbine of alpha-2 adrenoceptors in the PFC suppresses SWM-related neuronal activity. The present study provides neurophysiological evidence that alpha-2 adrenoceptors in the PFC are involved in the cellular mechanisms underlying working memory.

[Roles of alpha-2 adrenoceptor in prefrontal cortical cognitive functions].

Studies in non-human primates have demonstrated that norepinephrine can improve, through actions at postsynaptical alpha-2A adrenoceptors, cognitive functions of the prefrontal cortex, such as attentional regulation, working memory and response inhibition. Several psychiatric disorders, including attention-deficit hyperactivity disorder (ADHD), show prominent syndromes seen in cognitive deficits of the prefrontal cortex. These basic studies help develop novel pharmacotherapies for psychiatric disorders such as ADHD.

Long-term effect of leprosy control in two Prefectures of China, 1955-1993.

In Weifang Prefecture, Shandong Province, and Wenshan Prefecture, Yunnan Province of China, leprosy was highly prevalent in the 1950s. Due to differences in geographical conditions and socioeconomic development, the decline in leprosy prevalence between 1955 and 1993 was 99.5% (10.1 to 0.05/10,000) in Weifang and 93.9% (19.7 to 1.2/10,000) in Wenshan. The decrease in the detection rate was 99.9% (35.2 to 0.05/10,000) in Weifang and 91.7% (69.9 to 5.8/10,000) in Wenshan. The decrease was more apparent in these two prefectures since the implementation of multidrug therapy (MDT) in 1986. Findings such as specific detection rates by age, sex and type, as well as the multibacillary, child, and deformity rates of patients detected since 1980 were studied. Using the detection and prevalence rates between 1980 and 1993, the number of patients until the year 2000 is extrapolated for these two prefectures.

Solubilization and purification of opioid receptor molecules of rat brain.

A P2 membrane preparation of rat brain (without cerebellum) was solubilized with CHAPS in Tris containing DTT and trypsin inhibitor. Two opiate ligands, 10b and 10cd, prepared by Liu et al, were employed consecutively in affinity chromatography, from which OPR's were eluted with Nx. The eluate was subsequently passed through a WGA affinity column and the OPR's eluted with N-GluNAc. This eluate was further purified and concentrated by preparative granular gel isoelectric focusing on SG200. Two protein peaks appeared separately at pH 5 and 7.8. The eluates from both peaks were examined for protein contents using the silver staining method, and binding activity was measured by RRA with 3H-etor. The results revealed that both samples contained active OPR purified to over 80,000 fold. The Mr was estimated by gel filtration to be 52 kD and 42 kD for OPR in the pH 5 and pH 7.8 samples respectively. OPR in the pH 5 sample have been determined to be of mu-type by their binding activity with 3H-ohm.

Measurements and analyses of fields in fused tapered single-mode fiber couplers.

Internal fields in fused couplers have been investigated for the first time by measuring the near field and far field patterns at different cross sections of the couplers. Detailed information concerning the internal fields in the couplers provides experimental evidence for the validity of the hybrid mode theory of fused couplers.