Imipramine impedes glioma progression by inhibiting YAP as a Hippo pathway independent manner and synergizes with temozolomide.

Patients with malignant glioma often suffered from depression, which leads to an increased risk of detrimental outcomes. Imipramine, an FDA-approved tricyclic antidepressant, has been commonly used to relieve depressive symptoms in the clinic. Recently, imipramine has been reported to participate in the suppression of tumour progression in several human cancers, including prostate cancer, colon cancer and lymphomas. However, the effect of imipramine on malignant glioma is largely unclear. Here, we show that imipramine significantly retarded proliferation of immortalized and primary glioma cells. Mechanistically, imipramine suppressed tumour proliferation by inhibiting yes-associated protein (YAP), a recognized oncogene in glioma, independent of Hippo pathway. In addition to inhibiting YAP transcription, imipramine also promoted the subcellular translocation of YAP from nucleus into cytoplasm. Consistently, imipramine administration significantly reduced orthotopic tumour progression and prolonged survival of tumour-bearing mice. Moreover, exogenous overexpression of YAP partially restored the inhibitory effect of imipramine on glioma progression. Most importantly, compared with imipramine or temozolomide (TMZ) monotherapy, combination therapy with imipramine and TMZ exhibited enhanced inhibitory effect on glioma growth both in vitro and in vivo, suggesting the synergism of both agents. In conclusion, we found that tricyclic antidepressant imipramine impedes glioma progression by inhibiting YAP. In addition, combination therapy with imipramine and TMZ may potentially serve as promising anti-glioma regimens, thus predicting a broad prospect of clinical application.

Expression of WW domain-containing protein 2 is correlated with pathological grade and recurrence of glioma.

OBJECTIVE: WW domain-containing protein 2 (WWP2) is an E3 ubiquitin ligase, which belongs to the NEDD4-like protein family. Recently, it is reported to play a key role in tumorigenesis and development of tumors such as prostate and lung cancer. However, there has been not related report on glioma until now. The aim of this study is to detect the expression of WWP2 and analyze its correlation to the pathological grade and tumor recurrence in patients with glioma. MATERIALS AND METHODS: Western blot and immunohistochemistry were separately used to detect the expression of WWP2 protein in 31 brain glioma tissue samples and 80 brain glioma paraffin specimens. The method of Kaplan-Meier was used to analyze the correlation between the WWP2 expression and glioma recurrence. RESULTS: The protein expression level of WWP2 in glioma tissue was significantly higher than that in nontumorous brain tissue (P < 0.05), and the protein expression level of WWP2 in high-grade glioma (Grade III-IV) was significantly higher than that in low-grade glioma (Grade I-II) (P < 0.05). Kaplan-Meier analysis indicated that the patients with high WWP2 expression had significantly shorter tumor recurrence time than the patients with low WWP2 expression (P < 0.05). CONCLUSION: Our study suggests that WWP2 may play a role in the genesis and development of glioma; it may be a potential biomarker to predict pathological grade and tumor recurrence in patients with glioma.

ß-transducin repeat-containing E3 ubiquitin protein ligase inhibits migration, invasion and proliferation of glioma cells.

ß-transducin repeat-containing E3 ubiquitin protein ligase (ß-TrCP) serves as the substrate recognition subunit for the Skp1-Cullin1-F-box protein E3 ubiquitin ligase, which recognizes the double phosphorylated DSG (X)2+nS destruction motif in various substrates that are essential for numerous aspects of tumorigenesis and regulates several important signaling pathways. However, the biological significance of ß-TrCP in glioma progression remains largely unknown. A previous study by the authors demonstrated that the levels of ß-TrCP protein expression in brain glioma tissues were significantly lower compared with non-tumorous tissues and that higher grades of gliomas exhibited lower levels of ß-TrCP expression in comparison with lower glioma grades. In addition, low ß-TrCP expression was associated with poor prognosis in patients with glioma. Subsequently, the present study aimed to investigate the effect of ß-TrCP on migratory, invasive and proliferative abilities of glioma cells. ß-TrCP plasmids were transfected into cultured U251 and U87 glioma cells, and changes in migration, invasion and proliferation were analyzed using wound healing, Transwell and EdU assays. It was identified that the overexpression of ß-TrCP inhibited migration, invasion and proliferation in glioma cells. In summary, these results indicate that ß-TrCP may serve a protective role against the progression of glioma by suppressing cell migration, invasion and proliferation. The potential mechanism of ß-TrCP I glioma cells requires additional investigation.

[Progress on treatment of rheumatoid arthritis with ethnodrugs].

Rheumatoid arthritis(RA) is a chronic autoimmune disease, belonging to the "Arthromyodynia (Bi Zheng)" category in traditional Chinese medicine. However, the ethnomedicine has a unique understanding of RA, with a long-term clinical experience accumulation and significant efficacy in the treatment of RA, and it has now become one of the important means in treatment of RA. On the basis of literature research, the understanding of RA and commonly used Tibetan medicine, Mongolian medicine, Hui medicine and other herbs and preparations were reviewed in this paper, with the aim of providing a reference for its clinical treatment of RA and research and development of innovative drugs.

Expression of ß-transducin repeat-containing E3 ubiquitin protein ligase in human glioma and its correlation with prognosis.

ß-transducin repeat-containing E3 ubiquitin protein ligase (ß-TrCP) targets a number of substrates essential for specific aspects of tumorigenesis. In addition, ß-TrCP regulates various important signaling pathways. As ß-TrCP is involved in regulating the ubiquitination and degradation of multiple oncogenes and tumor suppressors, the function of ß-TrCP varies between cancer types. At present, the association between ß-TrCP expression and clinicopathological factors in glioma is unknown. Therefore, the current study used western blotting and immunohistochemistry to investigate the expression of ß-TrCP protein in glioma tissue specimens. It was identified that ß-TrCP protein expression levels were significantly lower in glioma compared with non-tumorous human brain tissues. Furthermore, the higher the grade of glioma, the lower the level of ß-TrCP expression. Kaplan-Meier analysis demonstrated that patients with low ß-TrCP expression experienced significantly worse overall survival compared with patients with high ß-TrCP expression. The results indicate that downregulation of ß-TrCP may be associated with poor survival in patients with glioma. Together, the current data indicates that ß-TrCP may be applied as a useful indicator of glioma prognosis and may serve as an anticancer therapeutic target for glioma, however further investigation is required.

Calpain activation promotes BACE1 expression, amyloid precursor protein processing, and amyloid plaque formation in a transgenic mouse model of Alzheimer disease.

Abnormal activation of calpain is implicated in synaptic dysfunction and participates in neuronal death in Alzheimer disease (AD) and other neurological disorders. Pharmacological inhibition of calpain has been shown to improve memory and synaptic transmission in the mouse model of AD. However, the role and mechanism of calpain in AD progression remain elusive. Here we demonstrate a role of calpain in the neuropathology in amyloid precursor protein (APP) and presenilin 1 (PS1) double-transgenic mice, an established mouse model of AD. We found that overexpression of endogenous calpain inhibitor calpastatin (CAST) under the control of the calcium/calmodulin-dependent protein kinase II promoter in APP/PS1 mice caused a remarkable decrease of amyloid plaque burdens and prevented Tau phosphorylation and the loss of synapses. Furthermore, CAST overexpression prevented the decrease in the phosphorylation of the memory-related molecules CREB and ERK in the brain of APP/PS1 mice and improved spatial learning and memory. Interestingly, treatment of cultured primary neurons with amyloid-beta (Abeta) peptides caused an increase in the level of beta-site APP-cleaving enzyme 1 (BACE1), the key enzyme responsible for APP processing and Abeta production. This effect was inhibited by CAST overexpression. Consistently, overexpression of calpain in heterologous APP expressing cells up-regulated the level of BACE1 and increased Abeta production. Finally, CAST transgene prevented the increase of BACE1 in APP/PS1 mice. Thus, calpain activation plays an important role in APP processing and plaque formation, probably by regulating the expression of BACE1.

Geranylgeranyltransferase I is essential for dendritic development of cerebellar Purkinje cells.

BACKGROUND: During cerebellar development, Purkinje cells (PCs) form the most elaborate dendritic trees among neurons in the brain, but the mechanism regulating PC arborization remains largely unknown. Geranylgeranyltransferase I (GGT) is a prenyltransferase that is responsible for lipid modification of several signaling proteins, such as Rho family small GTPase Rac1, which has been shown to be involved in neuronal morphogenesis. Here we show that GGT plays an important role in dendritic development of PCs. RESULTS: We found that GGT was abundantly expressed in the developing rat cerebellum, in particular molecular layer (ML), the region enriched with PC dendrites. Inhibition or down-regulation of GGT using small interference RNA (siRNA) inhibited dendritic development of PCs. In contrast, up-regulation of GGT promoted dendritic arborization of PCs. Furthermore, neuronal depolarization induced by high K+ or treatment with brain-derived neurotrophic factor (BDNF) promoted membrane association of Rac1 and dendritic development of PCs in cultured cerebellar slices. The effect of BDNF or high K+ was inhibited by inhibition or down-regulation of GGT. CONCLUSION: Our results indicate that GGT plays an important role in Purkinje cell development, and suggest a novel role of GGT in neuronal morphogenesis in vivo.

Regulation of protein prenyltransferase in central neurons.

Geranylgeranyltransferase I (GGT) is a protein prenyltransferase that mediates lipid modification of some proteins such as Rho family small GTPases. Since the activation of Rho GTPases mediates tumorgenesis and metastasis, GGT has become an attractive target for anti-tumor drug design. Although GGT is extensively expressed in the brain, the function of GGT in central nervous system (CNS) is totally unknown. We have previously shown that GGT was involved in neuromuscular synaptogenesis. In this study, we report that neuronal activity- and brain-derived neurotropic factor (BDNF)-dependent dendritic morphogenesis requires activation of GGT. Furthermore, GGT was activated by depolarization or BDNF in cultured neurons or in hippocampus of the mice under novelty exploration test, suggesting that neuronal activity activates GGT in vitro and in vivo. In this addendum, we further discuss the significance of this study and the possible implication to the field.

[Prevalence trend of neural tube defect in Zhengzhou city, 1996-2005].

OBJECTIVE: To describe the prevalence trend and epidemiological characteristics of neural tube defects (NTDs) in perinatal in Zhengzhou city from 1996 to 2005. METHODS: Data collected from hospital were used to depict the epidemiology of NTDs in Zhengzhou. All perinatal fetuses born in hospitals had an access within 7 days after delivery. The prevalence were calculated by perinatal'year, sex, birth area (urban versus rural) and maternal age. All monitored perinatal (162,074) accounted for 32.66% from totals (496,203). RESULTS: All 238 cases were found NTDs, and the overall prevalence rate was 14.68/10,000. The annual prevalence rate presented a decreasing trend during that period. The rates in rural and urban area, in male and female birth were 29.28/10,000 and 9.63/10,000, 11.42/10,000 and 17.74/10,000 respectively. There were significant differences among maternal-age-specific prevalence rates (chi2 = 22.952, P = 0.000). The rates of <20 years group(53.76/10,000) and >35 years group(21.74/10,000) were higher than others. CONCLUSION: The prevalence rates of NTDs in rural area is higher than that in urban, female's is higher than male's in Zhengzhou. The annual prevalence rates of NTDs presents a decreasing trend in the past ten years.

TrkB-mediated activation of geranylgeranyltransferase I promotes dendritic morphogenesis.

Dendrite morphogenesis is regulated by neuronal activity or neurotrophins, which may function by activating intrinsic signaling proteins, including Rho family GTPases. Here we report that activity- and brain-derived neurotrophic factor (BDNF)-dependent dendritic morphogenesis requires activation of geranylgeranyltransferase I (GGT), a prenyltransferase that mediates lipid modification of Rho GTPases. Dendritic arborization in cultured hippocampal neurons was promoted by over-expression of GGT, and reduced by inhibition or down-regulation of GGT. Furthermore, GGT was activated by neuronal depolarization or BDNF, both of which promote dendritic arborization, in cultured hippocampal neurons. Moreover, exploration of a novel environment caused activation of GGT in the mice hippocampus, suggesting that neural activity activates GGT in vivo. Interestingly, GGT was physically associated with tropomyosin-related kinase B (TrkB), the receptor for BDNF, and this association was enhanced by depolarization. Disrupting the GGT-TrkB interaction or down-regulating GGT activity attenuated depolarization- or BDNF-induced dendrite development. Finally, the GGT effect on dendrite arborization was prevented by over-expressing Rac1 with the prenylation site deleted or mutated. Thus depolarization- or BDNF-dependent dendrite development may be mediated by GGT-induced prenylation of Rho GTPases.

[C-fos expression within PVN and NTS of the rat induced by gastric ischemia/reperfusion injury].

AIM: To investigate the effect of paraventricular nucleus (PVN) stimulation and the c-fos expression within PVN and nucleus tractus solitarius (NTS) of the rat following gastric ischemia/reperfusion injury (GI/RI). METHODS: The rat celiac artery was clamped for thirty minutes and reperfused for sixty minutes, using Fos immunohistochemical method (ABC method) examined the c-fos expression within PVN and NTS. RESULTS: (1) Both electrical and chemical stimulation of the PVN obviously attenuated the GI/ RI. (2) Bilateral electrolytic lesion of NTS could eliminate the protective effect of electrical stimulation of the PVN. (3) The Fos-like immunoreactive neurons were increased in bilateral PVN and NTS by GI/RI. CONCLUSION: The function of PVN and NTS could be affected by the GI/RI noxious stimulation. PVN, NTS were involved in the regulation of GI/RI.

[Effects of electrical stimulation of lateral hypothalamic area on gastric ischemia-reperfusion injury in rats].

The effects of electrical and chemical stimulation and electrolytic lesion of lateral hypothalamic area (LHA) on gastric ischemia-reperfusion injury (GI-RI) were investigated in rats whose celiac arteries were clamped for 30 min and reperfused for 60 min by removal of the clamp. The results are as follows. (1) Electrical stimulation of LHA could aggravate GI-RI in an intensity-dependent manner by using 0.2, 0.4 or 0.6 mA current respectively. Microinjection of L-glutamic acid into LHA resulted in a similar effect to that of electrical stimulation of LHA on GI-RI. After electrolytic lesion of bilateral LHA, the area of gastric mucosal injury induced by gastric ischemia-reperfusion (GI-R) was smaller than that by electrical stimulation of LHA plus GI-R. (2) Dorsal vagal complex (DVC) lesion or vagotomy could eliminate the effect of electrical stimulation of LHA on GI-RI. (3) Electrical stimulation of LHA increased the content of malondialdehyde (MDA) but decreased the activity of superoxide dismutase (SOD) of ischemia-reperfusion (I-R) gastric mucosa. (4) Electrical stimulation of LHA plus gastric I-R increased gastric juice volume and total acid output, but there were no significant changes in acidity, pepsin activity and gastric barrier mucus. These results indicate that the LHA is an area in the CNS exerting aggravate effects on GI-RI. The DVC and vagus may be involved in the regulative effects of LHA on GI-RI. These effects are associated with increases in gastric mucosal MDA content, gastric juice volume, and total acid output, and a decrease in SOD activity.Acidity, pepsin activity and gastric barrier mucus do not seem to play an important role.

Neuroregulative mechanism of hypothalamic paraventricular nucleus on gastric ischemia-reperfusion injury in rats.

A rat model of gastric ischemia-reperfusion injury (GI-RI) was established by clamping the celiac artery for 30 min and allowing reperfusion for 1 h, on which the regulatory effect of the paraventricular nucleus (PVN) and its neural mechanisms were investigated. The results were: 1. Electrical stimulation of the PVN obviously attenuated the GI-RI. Microinjection of L-glutamic acid into PVN produced an effect similar to that of PVN stimulation. 2. Electrolytic ablation of the PVN aggravated the GI-RI. 3. Nucleus tractus solitarius (NTS) ablation could eliminate the protective effect of electrical stimulation of PVN on GI-RI. 4. Hypophysectomy did not alter the effect of electrical stimulation of PVN. 5. Vagotomy or sympathectomy both could increase the effect of PVN stimulation on GI-RI. These results indicate that the PVN participates in the development of GI-RI as a specific area in the CNS, exerting protective effects on the GI-RI. The NTS and vagus and sympathetic nerve may be involved in the regulative mechanism of PVN on GI-RI, but the PVN mechanism here is independent of the PVN-hypophyseal pathway.

[Protective effects of paraventricular nucleus stimulation and vasopressin on gastric ischemia-reperfusion injury in rats].

The effects of paraventricular nucleus (PVN) stimulation and vasopressin on gastric ischemia-reperfusion injury (GI-RI) were investigated in male SD rats of which the celiac artery was clamped for 30 min and reperfused for 1 h by removal of the clamp. The results were as follows. Both electrical and chemical stimulation of the PVN obviously attenuated the GI-RI. Bilateral electrolytic lesion of the nucleus tractus solitarius (NTS) or microinjection of AVP-V(1) receptor antagonist into the NTS could eliminate the protective effect of electrical stimulation of the PVN on GI-RI. Hypophysectomy did not influence the effect of electrical stimulation of the PVN. Both vagotomy and sympathectomy could increase the effect of stimulating PVN on GI-RI. Microinjection of arginine-vasopressin (AVP) into the PVN also attenuated the effect on GI-RI. These results suggest that the PVN and AVP participate in the regulation of GI-RI and play an important role in protection against GI-RI. This protective effect of PVN on GI-RI might be mediated by activation of AVP-ergic neurons in the PVN, which release AVP from the descending projection fibers and activate the AVP-V(1) receptors on the NTS neurons. The vagus and sympathetic nerves are involved in the efferent pathway exerting their effects on GI-RI. Hypophysis does not seem to be involved in the protective effect of PVN stimulation.