Dysregulated CRMP Mediates Circadian Deficits in a Drosophila Model of Fragile X Syndrome / 神经科学通报·英文版

Fragile X syndrome (FXS) is the leading inherited cause of intellectual disability, resulting from the lack of functional fragile X mental retardation protein (FMRP), an mRNA binding protein mainly serving as a translational regulator. Loss of FMRP leads to dysregulation of target mRNAs. The Drosophila model of FXS show an abnormal circadian rhythm with disruption of the output pathway downstream of the clock network. Yet the FMRP targets involved in circadian regulation have not been identified. Here, we identified collapsing response mediator protein (CRMP) mRNA as a target of FMRP. Knockdown of pan-neuronal CRMP expression ameliorated the circadian defects and abnormal axonal structures of clock neurons (ventral lateral neurons) in dfmr1 mutant flies. Furthermore, specific reduction of CRMP in the downstream output insulin-producing cells attenuated the aberrant circadian behaviors. Molecular analyses revealed that FMRP binds with CRMP mRNA and negatively regulates its translation. Our results indicate that CRMP is an FMRP target and establish an essential role for CRMP in the circadian output in FXS Drosophila.

Combined analysis of CRMP4 methylation levels and CAPRA-S score predicts metastasis and outcomes in prostate cancer patients / 亚洲男科学杂志(英文版)

The present study analyzed the predictive value of combined analysis of collapsin response mediator protein 4 (CRMP4) methylation levels and the Cancer of the Prostate Risk Assessment (CAPRA-S) Postsurgical score of patients who required adjuvant hormone therapy (AHT) after radical prostatectomy (RP). We retrospectively analyzed 305 patients with prostate cancer (PCa) who received RP and subsequent androgen deprivation therapy (ADT). Two hundred and thirty patients with clinically high-risk PCa underwent immediate ADT, and 75 patients with intermediate risk PCa underwent deferred ADT. CRMP4 methylation levels in biopsies were determined, and CAPRA-S scores were calculated. In the deferred ADT group, the values of the hazard ratios for tumor progression and cancer-specific mortality (CSM) in patients with ≥15% CRMP4 methylation were 6.81 (95% CI: 2.34-19.80) and 12.83 (95% CI: 2.16-26.10), respectively. Receiver-operating characteristic curve analysis indicated that CRMP4 methylation levels ≥15% served as a significant prognostic marker of tumor progression and CSM. In the immediate ADT group, CAPRA-S scores ≥6 and CRMP4 methylation levels ≥15% were independent predictors of these outcomes (uni-and multi-variable Cox regression analyses). The differences in the 5-year progression-free survival between each combination were statistically significant. Combining CAPRA-S score and CRMP4 methylation levels improved the area under the curve compared with the CRMP4 or CAPRA-S model. Therefore, CRMP4 methylation levels ≥15% were significantly associated with a poor prognosis and their combination with CAPRA-S score accurately predicted tumor progression and metastasis for patients requiring AHT after RP.

Alleviation of Paraneoplastic Choreatic Involuntary Movements of a Lung Cancer Patient Due to Remarkable Effect of Tetrabenazine, the Agent for Treating Huntington Disease, on Paraneoplastic Chorea: A Case Report

<p>Introduction: We report a very rare case of paraneoplastic chorea due to lung cancer that was ameliorated by administering tetrabenazine, the only agent used for treating the chorea of Huntington disease. Case: A 92-year-old woman was diagnosed with lung cancer but only followed up, based on advanced age and her own wishes. Given the absence of treatments such as chemotherapy, the lung cancer was not histologically diagnosed. During follow-up, involuntary movements appeared and paraneoplastic chorea was diagnosed. Therefore, she could not live alone and was admitted to a nursing home. Triple combination therapy with valproic acid, tiapride hydrochloride and risperidone was started, and showed efficacy for her symptoms. The symptoms showed amelioration but persisted in the upper extremities, face and neck. A neurologist suggested to her family that tetrabenazine, the only medication used for Huntington’s chorea, might be effective. After admission to our hospital, her family requested tetrabenazine. As both she and her family were suffering mental distress because “she was trapped in a body that moved regardless of her will”, we initiated tetrabenazine at a dose of 12.5 mg/day. After starting tetrabenazine, chorea of the upper extremities, face and neck almost disappeared. Moreover, her speech became clear and she spoke normally with her family. Discussion: Tetrabenazine is a drug receiving insurance reimbursement only for Huntington’s chorea, but was effective in this case. In our view, this treatment palliated the patient’s physical distress and the mental distress that she and her family were experiencing due to her paraneoplastic chorea.</p>

Salidroside regulates Akt/GSK-3β/CRMP-2expression and axonal regeneration in MCAO rats / 中国药理学通报

Aim To investigate the axonal regeneration effect of salidroside in MCAO rats and its potential mechanism.Methods Thirty-six healthy adult male Sprague-Dawley rats were randomly divided into three groups: sham, MCAO, MCAO+Sal groups.The rats were subjected to focal cerebral ischemia/reperfusion with suture-occluded method.Neurological deficit testing was performed with Zea Longa scale.The protein expression of p-Akt(Ser473), Akt, p-GSK-3β(Ser9), GSK-3β, p-CRMP-2(Thr514) and CRMP-2 in side cerebral ischemic tissues were determined using Western blot analysis.NF200 immunofluorescence staining was used to evaluate axonal regeneration.Results Compared with MCAO group,salidroside significantly improved the neurological deficit,up-regulated the protein expression of NF200,p-Akt and p-GSK-3β,and inhibited the protein expression of p-CRMP-2.Conclusions Salidroside improves neurological function recovery after focal cerebral/ischemic injury in rats,which may be associated with the up-regulation of phosphorylated Akt and GSK-3β and inhibition of phosphorylated CRMP-2,thereby promoting axonal regeneration.

CRMP2 alleviates neurological deficit by reducing neuron apoptosis in rats after cerebral ischemia/reperfusion injury / 中国药理学通报

Aim To investigate the influence of the overexpression of CRMP2 on neural cell apoptosis after ischemia reperfusion injury in rats and its possible mechanism. Methods A total of 192 male adult SD rats were divided into four groups: sham group, cere-bral ischemia/reperfusion group( MCAO group) , cere-bral ischemia with blank plasmid control group( MCAO+GFP group ) , cerebral ischemia with CRMP2 eu-karyotic plasmid group ( MCAO + CRMP2/GFP group) . One day after injecting eukaryotic plasmid, the rats were operated for 120-min ischemia through MCA occlusion and reperfused. At 48 h and 1 wk, the expression of CRMP2 , p53 , Caspase-3 , Caspase-8 and BCL2 in brain tissue was tested by RT-PCR and West-ern blot. Apoptotic cells were observed by TUNEL test. TTC staining was use to detect cerebral infarction volume. The neural function of the rats were also eval-uated. Results Compared with the sham group, the expression levels of CRMP2 and BCL2 in MCAO group and MCAO +GFP group were significantly decreased ( P <0. 01 ) , while p53 , Caspase-3 , Caspase-8 and TUNEL positive cells were elevated(P<0. 01). Inter-vention of CRMP2 eukaryotic plasmid resulted in the increased expression of CRMP2 and BCL2 ( P<0. 01 ) and the decreased p53 , Caspase-3 and Caspase-8 ex-pression. In TUNEL test, overexpression of CRMP2 obviously decreased the number of TUNEL positive cells(P<0. 01). The expression of BDNF was upregu-lated after cerebral ischemic injury ( P<0. 01 ) , while overexpression of CRMP2 increased BDNF more signif-icantly ( P <0. 01 ) . TTC staining showed cerebral in-farction Volume of MCAO + CRMP2/GFP group was obviously decreased ( P <0. 01 ) , and neurologic defi-cits were significantly improved ( P <0. 01 ) . Conclu-sion The overexpression of CRMP2 reduces nerve cell apoptosis possibly by regulating the mitochondrial ap-optosis pathway after cerebral ischemia/reperfusion in-jury to protect nervous system.

Ferulic acid regulates the AKT/GSK-3beta/CRMP-2 signaling pathway in a middle cerebral artery occlusion animal model / 한국실험동물학회지

Ferulic acid, a component of the plants Angelica sinensis (Oliv.) Diels and Ligusticum chuanxiong Hort, exerts a neuroprotective effect by regulating various signaling pathways. This study showed that ferulic acid treatment prevents the injury-induced increase of collapsin response mediator protein 2 (CRMP-2) in focal cerebral ischemia. Glycogen synthase kinase-3beta (GSK-3beta) regulates CRMP-2 function through phosphorylation of CRMP-2. Moreover, the pro-apoptotic activity of GSK-3beta is inactivated by phosphorylation by Akt. This study investigated whether ferulic acid modulates the expression of CRMP-2 and its upstream targets, Akt and GSK-3beta, in focal cerebral ischemia. Male rats were treated immediately with ferulic acid (100 mg/kg, i.v.) or vehicle after middle cerebral artery occlusion (MCAO), and then cerebral cortices were collected 24 hr after MCAO. MCAO resulted in decreased levels of phospho-Akt and phospho-GSK-3beta, while ferulic acid treatment prevented the decrease in the levels of these proteins. Moreover, phospho-CRMP-2 and CRMP-2 levels increased during MCAO, whereas ferulic acid attenuated these injury-induced increases. These results demonstrate that ferulic acid regulates the Akt/GSK-3beta/CRMP-2 signaling pathway in focal cerebral ischemic injury, thereby protecting against brain injury.

CRMP-2 is involved in hypoxic preconditioning-induced neuroprotection against cerebral ischemic injuries of mice / 基础医学与临床

Objective To investigate whether conventional protein kinase C (cPKC ) βⅡ-interacting collapsin response mediator protein-2 (CRMP-2) provides neuroprotection against cerebral ischemic (I) injuries. Methods Male BALB/c mice were randomly divided into normoxic control (Nor) , HPC, Nor + Sham, HPC + Sham, Nor + I and HPC + I groups (n = 6 per group). Using our HPC and MCAO mouse models, we applied immunoprecipita-tion, two-dimensional electrophoresis and mass spectrometry to characterize cPKCβⅡ-interacting proteins and combined with SDS-PAGE and Western blot to quantitatively analyze CRMP-2 phosphorylation and degradation levels in the brain of mice after HPC and MCAO. Results The expression level of 10 cPKCβⅡ-interacting proteins changed obviously in cerebral cortex of HPC mice when compared with Nor group. One of these proteins, CRMP-2 protein level increased in particulate fraction and decreased in cytosolic fraction of cerebral cortex of HPC mice. CRMP-2 phosphorylation level in ischemic core (Ic) of cerebral cortex decreased significantly ( P < 0. 05 , n = 6) as compared with that of Nor + sham group, but CRMP-2 phosphorylation level in HPC +I group increased significantly as compared with that of Nor +I group ( P < 0. 05, n = 6). In ischemic cortex, CRMP-2 degradation (proteolysis) was observed as the appearance of 55 ku breakdown products (BDP). However, the CRMP-2 degradation level, BDPs products decreased significantly in penumbra ( P) of ischemic cortex from HPC +I group when we compared with that of Nor +I group (P < 0. 05, n = 6 ). Conclusion CRMP-2 is involved in attenuating the decrease of CRMP-2 phosphorylation in ischemic core and in inhibiting its degradation in penumbra of cerebral cortex of mice thereby to lessen the ischemic injuries.