Roscovitine rescuing neuronal loss and neuroinflammation in brain regions associated with Parkinson’s disease mice / 解剖学报

[Abstract] Objective To investigate the effect and possible mechanism of cell cycle-dependent kinase (Cdk)5 inhibitor Roscovitine on 1-methyl4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced pathological changes in brain regions associated with Parkinson’ s disease (PD) model mice. Methods The effect of Roscovitine on the relative expression levels of P25 and Cdk5 proteins was detected by Western blotting in MPP

Relationship between nucleoprotein TAR DNA/RNA binding protein 43 and mouse amyotrophic lateral sclerosis / 解剖学报

Objective Transgenic mice expressing human TAR DNA/RNA binding protein 43 (hTDP-43) mutant protein in spinal cord motor neurons were constructed using HB9 promoter to establish a disease model of amyotrophic lateral sclerosis ( ALS) and explore the mechanism of ALS induced by hTDP-43 mutation. Methods HB9 promoter junction mutant hTDP-43 vector was constructed in vitro, and the positive transgenic mouse strains were prepared by prokaryotic injection and screened (There were 8-10 mutations at Q331K and M337V). Gait analysis, rotary rod fatigue test, and suspension test were used to detect locomotion ability of mice. Immunohistochemistry, immunofluorescence staining and Western blotting were used to detect hTDP-43, phosphorylated HTDP-43 ( p-hTDP-43) , Caspase-3, cleaved Caspase-3, respectively. Expression of ubiquitin, (3-tubulinIH(Tujl) , Ki67 and cyclin-dependent kinase 5 (CDK5) proteins were also detected. Results In transgenic mice expressing mutant hTDP-43 protein in spinal motor neurons, both hind limbs were atrophied to the trunk side, and motor function showed progressive decline with increasing age. hTDP-43, p-hTDP-43, Caspase-3, and cleaved Caspase-3 were observed in spinal motor neurons Caspase-3 positive staining and ubiquitin protein positive inclusion body, and in vitro isolation and culture of spinal motor neurons, it was found that hTDP-43 and ubiquitin protein co-located in choline acetyl translocation enzyme ( ChAT) positive motor neurons, accompanied by ectopic expression of CDK5. Conclusion The mutant HDP 43 protein expressed in mouse spinal cord motor neurons can promote the re-entry of differentiated mature neurons into the cell cycle, leading to the occurrence of ALS.

Expression of CDK5 and its correlation with peripheral inflammation-related cells and prognosis in colon cancer patients / 中华普通外科杂志

Objective:To identify the clinical significance of CDK5 in colon cancer tissues.Methods:Two hundred colon cancer tissues were tested for CDK5 expression by immunohistochemistry on tissue microarrays. The correlation between CDK5 expression and clinicopathological features, prognosis and peripheral inflammation-related cells was analyzed.Results:CDK5 was low expressed in 100 cases (50.0%), and high in another 100 cases (50.0%). Longer time to tumor progression ( P=0.026) and overall survival ( P=0.035) were observed in patients with high CDK5 expression. By multivariate analysis , the expression of CDK5 was an independent risk factor for poor prognosis ( HR=0.45,95% CI: 0.21-0.99, P=0.049). The expression of CDK5 was not related to the counts of white blood cells and neutrophils ( P>0.05). Prognosis of patients with a positive lymph node ratio less than 0.15 was significantly better than that of patients with a higher lymph node ratio ( P<0.001). Conclusions:Patients with low CDK5 expression have poor prognosis, and CDK5 expression is not related to the counts of peripheral white blood cells and neutrophils.

knocking out mediated by CRISPR-Cas9 genome editing for PD-L1 attenuation and enhanced antitumor immunity

Blocking the programmed death-ligand 1 (PD-L1) on tumor cells with monoclonal antibody therapy has emerged as powerful weapon in cancer immunotherapy. However, only a minority of patients presented immune responses in clinical trials. To develop an alternative treatment method based on immune checkpoint blockade, we designed a novel and efficient CRISPR-Cas9 genome editing system delivered by cationic copolymer aPBAE to downregulate PD-L1 expression on tumor cells specifically knocking out Cyclin-dependent kinase 5 () gene . The expression of PD-L1 on tumor cells was significantly attenuated by knocking out , leading to effective tumor growth inhibition in murine melanoma and lung metastasis suppression in triple-negative breast cancer. Importantly, we demonstrated that aPBAE/Cas9-Cdk5 treatment elicited strong T cell-mediated immune responses in tumor microenvironment that the population of CD8 T cells was significantly increased while regulatory T cells (Tregs) was decreased. It may be the first case to exhibit direct PD-L1 downregulation CRISPR-Cas9 genome editing technology for cancer therapy. It will provide promising strategy for preclinical antitumor treatment through the combination of nanotechnology and genome engineering.

miR-142-5p inhibits the invasion and migration of lung adenocarcinoma H1650 cells by affecting epithelial mesenchymal transformation / 中国肿瘤生物治疗杂志

@# Objective: To study the expression of miR-142-5p in lung adenocarcinoma tissues, and to explore its effect on proliferation, invasion, migration and epithelieal-mesenchymal transition (EMT) of H1650 cells and the potential mechanisms. Methods:Atotal of 107 pairs of lung adenocarcinoma tissues and corresponding para-cancerous tissues from patients, who underwent tumor resection and were pathologically confirmed at the Department of Thoracic Surgery, the Fourth Hospital of Hebei Medical University between Jan. 2014 and Jan. 2015, were collected for this study; in addition, human lung adenocarcinoma cell lines (H1650, HCC827, A549, H1975, PC9) and human bronchial epithelial BEAS-2B cells were also used in this study. qPCR was used to detect the expression of miR-142-5p in lung adenocarcinoma tissues and cell lines. The correlation between expression of miR-142-5p and clinical features was analyzed.After transfection with miR-142-5p mimics or miR-negative control (miR-NC) plasmid, the proliferation, invasion and migration of H1650 cells were detected with CCK-8, Transwell invasion assay and Wound healing assay, respectively. The bioinforamtics tool was used to predict the target genes of miR-142-5p, and Luciferase reporter gene assay was performed to validate the regulation of miR-142-5p on target gene. Western blotting (WB) was used to detect the expressions of cyclin-dependent kinase 5 (CDK5) and EMTrelated protein. Results: Compared to Para-cancerous tissues and BEAS-2B cells, the expression of miR-142-5p was lower in lung adenocarcinoma tissues and cell lines (all P<0.01). Of the 107 cases of lung adenocarcinoma tissues, 61 cases (57.01%) showed decreased miR-142-5 expression, which was correlated with the TNM stage and lymph node metastasis (both P<0.01). Transfection of miR-142-5p mimics significantly up-regulated the expression of miR-142-5p and decreased the proliferation, invasion and migration of H1650 cells (all P<0.05 or P<0.01). Bioinformatics showed that CDK5 was a target gene of miR-142-5p. Luciferase reporter gene assay and WB validated that miR-142-5p could significantly down-regulate CDK5 expression in H1650 cells, up-regulate the expression of E-cadherin and down-regulate the expressions of N-cadherin, Twist and Snail in H1650 cells (all P<0.01). Conclusion: miR-142-5p is low expressed in lung adenocarcinoma tissues and cell lines; it suppresses the EMT process to inhibit, invasion and migration of H1650 cells via down-regulating the expression of CDK5.

Effects of Electroacupuncture on Learning-memory and P35/P25-Cyclin-dependent Kinase 5-Tau Phosphorylation Signal Pathway in Prefrontal Cortex of Rats with Alzheimer's Disease / 中国康复理论与实践

Objective:To observe the effect of electroacupuncture at Baihui (DU20) and Shenshu (BL23) acupoints on learning-memory ability and expression of the relative protein of P35/P25-cyclin-dependent kinase 5 (CDK5)-Tau phosphorylation signaling pathway in the prefrontal cortex (PFC) in rats with Alzheimer's disease (AD), so as to reveal its potential mechanisms in treating AD. Methods:Male adult Sprague-Dawley rats were randomly divided into normal control group, sham group, model group and treatment group with six rats in each group. The AD model was constructed by bilateral hippocampal injection of Aβ25-35 in latter two groups. Equal amount of normal saline was injected into the sham group. The treatment group was acupunctured at Baihui and Shenshu once a day for ten days. All the rats were tested with Morris Water Maze. Immunohistochemistry staining and Western blotting were used to detect the related protein of P35/P25-CDK5-Tau protein phosphorylation in the PFC. Results:Compared with the normal control group and the sham group, the escape latency and escape length increased (P < 0.05) and the times crossing the platform reduced (P < 0.05) in the model group; compared with the model group, the escape latency and escape length reduced (P < 0.05), and the times crossing the platform increased (P < 0.05) in the treatment group. The optical density of P35/P25 and CDK5 were significantly higher in the model group than in the normal control group and the sham group (P < 0.01), and they were lower in the treatment group than in the model group (P < 0.001). The relative expression of P35/P25, CDK5, Tau[pS199] and Tau[pS202] were higher in the model group than in the normal control group and the sham group (P < 0.05), and the expression of the above proteins was lower in the treatment group than in the model group (P < 0.05). Conclusion:Electroacupuncture could improve the learning-memory and spatial exploration ability, which associate with inhabiting the P35/P25-CDK5-Tau protein phosphorylation signaling pathway in the PFC to delay the development of AD.

Effect of electroacupuncture on the P35/P25-cyclin-dependent kinase 5-Tau pathway in hippocampus of rats with Alzheimer's disease / 针刺研究

OBJECTIVE: To investigate the effect of electroacupuncture on the P35/P25-cyclin-dependent kinase 5 (CDK5)-Tau pathway in rats with Alzheimer's disease (AD), as well as the mechanism of electroacupuncture in the prevention and treatment of AD. METHODS: Sprague-Dawley rats were randomly divided into control group, sham-operation group, model group, and electroacupuncture treatment group, with 12 rats in each group. A rat model of AD was established by injection of Aβ25-35 into the bilateral hippocampus. The rats in the electroacupuncture treatment group were given electroacupuncture at "Baihui" (GV20) and "Shenshu" (BL23) once a day, 15 min each time, for 10 days. Morris water maze was used to evaluate learning and memory abilities, immunohistochemistry was used to measure the distribution and expression of P35/P25, CDK5, and Tau5 in the hippocampus, and Western blot was used to measure the expression of the above mentioned proteins, phosphory-lated Tau(Ser199, Ser202). RESULTS: In the visual platform test, there were no significant differences in escape latency and search path between groups (P>0.05). In the hidden platform test, there were no significant differences in escape latency and search path between the control group and the sham-operation group (P>0.05); the model group had significantly longer escape latency and search path than the control group and the sham-operation group (P0.05). The model group had significantly higher protein expression of phosphorylated Tau(Ser199, Ser202) in the hippocampus than the control group and the sham-operation group (P<0.01, P<0.05). The electroacupuncture treatment group had significantly lower protein expression of phosphorylated Tau(Ser199，Ser202) than the model group (P<0.05, P<0.01). CONCLUSION: Electroacupuncture may delay the progression of AD by affecting the expression of proteins involved in the P35/P25-CDK5-Tau pathway in the hippocampus of rats.

Effect of electroacupuncture on cyclin-dependent kinase 5 and Tau protein in hippocampus of SAMP8 mice / 针刺研究

OBJECTIVE: To observe the effect of electroacupuncture (EA) and manual acupuncture (MA) on learning-memory ability, changes of ultrastructure of neurons and expression of CDK5 and Tau proteins in hippocampus of SAMP8 mice，so as to explore its mechanisms underlying improvement of Alzheimer's disease (AD)．. METHODS: A total of 45 male SAMP8 mice were randomly divided into model, EA and MA groups, with 15 mice in each group. The other 15 SAMR1 mice were used as the normal group. In the EA group, EA (2 Hz, 1 mA) was applied to bilateral "Shenshu"(BL23) and manual acupuncture was applied to "Baihui"(GV20) for 20 min. In the MA group, MA was applied to GV20 and bilateral BL23 for 20 min. Both group were treated once a day for 31 days, and with an interval of one day between every two 7 days. Morris water maze was performed to assess the animals' learning-memory ability. The morphological changes of hippocampal neurons were observed under transmission electron microscopy. The expression levels of CDK5, p25 and Tau-5 proteins in the hippocampus were detected by immunohistochemistry and Western blot, separately. RESULTS: ①Compared with the normal group, the average escape latency of Morris water maze test was prolonged in the model group(P<0.05, P<0.01), duration of swimming in the original platform quadrant and the number of original platform crossing were significantly shorter and less respectively (P<0.01). Compared with the model group, the average escape latency in the EA group was shortened (P<0.05, P <0.01), the duration of swimming in the original platform quadrant and the number of original platform crossing were significantly prolonged and increased (P<0.01); The average escape latency in the MA group was shortened (P<0.05, P <0.01)，and the duration of swimming in the original platform quadrant was prolonged (P<0.05). Compared with the EA group, the average escape latency of the MA group was prolonged (P<0.05), the duration of swimming in the original platform quadrant was shortened(P<0.05). ②Transmission electron microscopy revealed that the neurons in the hippocampal CA1 area had irregular shape and vague structure, reduction in size and number of mitochondria accompanied with swelling, and malformed changes of mitochondrial crest in the model group, which was relatively milder in both EA and MA groups. ③The expression levels of hippocampal Tau-5, p25 and CDK5 proteins were significantly up-regulated in the model group in contrast to the normal group (P<0.01, P<0.05), and obviously down-regulated in both EA and MA groups relevant to the model group (P<0.05, P<0.01). Compared with the EA group, the expression levels of p25 and CDK5 proteins were significantly increased in the MA group (P<0.05). CONCLUSION: EA of BL23 can improve the learning-memory ability in SAMP8 mice, which is associated with its effect in down-regulating the expression of hippocampal CDK5, p25 and Tau-5 proteins.

LA PÉRDIDA DE FUNCIÓN DE LA QUINASA DEPENDIENTE DE CICLINA 5 (CDK5) ALTERA EL CITOESQUELETO Y REDUCE LA INFECCIÓN in vitro POR EL VIRUS DEL DENGUE 2 / The loss of function of Cyclin-Dependent Kinase 5 (CDK5) alters the Cytoskeleton and decrease the in vitro Dengue Virus-2 infection

RESUMEN La quinasa dependiente de ciclina 5 (CDK5) regula diversas funciones en neuronas, células endoteliales y epiteliales, entre ellas la dinámica del citoesqueleto. Así mismo, se ha reportado que componentes del citoesqueleto, tales como, filamentos de actina y microtúbulos juegan un rol importante durante la infección por el virus dengue (DENV). El objetivo del presente trabajo fue evaluar por dos métodos, inhibición química y silenciamiento génico, la participación de CDK5 durante la infección por DENV-2. La actividad antiviral de roscovitina fue evaluada usando ensayos de Unidades Formadoras de Placa (PFU). La eficiencia de transfección y el silenciamiento de CDK5, empleando miARNs artificiales, se determinó por citometría de flujo. El efecto sobre la proteína de envoltura viral y elementos del citoesqueleto se evidenció mediante microscopia avanzada de fluorescencia y análisis de imágenes. Roscovitina mostró actividad antiviral en etapas pre y post-infectivas en una forma dependiente de la dosis. El tratamiento con roscovitina y miRCDK5 mostró ser efectivo reduciendo la cantidad de CDK5 en células no infectadas. En células infectadas y transfectadas con miRCDK5, así como tratadas con el inhibidor, se observó una reducción significativa de la proteína de envoltura viral; sin embargo, no se encontró reducción significativa de CDK5. Además, el tratamiento con roscovitina indujo cambios celulares morfológicos evidentes en células infectadas. Los resultados indican la potencial participación de CDK5 durante la infección por DENV-2, posiblemente mediando la traducción proteica o la replicación del genoma viral a través de la regulación de la dinámica del citoesqueleto. Se requieren datos adicionales para esclarecer la mecanística del fenómeno usando métodos alternativos.

ABSTRACT Cyclin-Dependent Kinase 5 (CDK5) regulates several functions in neurons, endothelial, and epithelial cells, including the cytoskeleton dynamics. Likewise, it has been reported that some cytoskeleton elements, such as actin filaments and microtubules, play an essential role during Dengue virus (DENV) infection. This work aimed to evaluate the role of CDK5 during DENV-2 infection by two methods, chemical inhibition, and gene silencing. The antiviral activity of roscovitine was evaluated using Plaque Forming Units (PFU) assay. The transfection efficiency and knockdown of CDK5, using artificial miRNAs, was carried out by flow cytometry. The effect on the viral envelope protein and cytoskeleton elements was evidenced by advanced fluorescence microscopy and image analysis. Roscovitine showed antiviral activity in pre and post-infection stages in a dose-dependent manner. Treatment with roscovitine and miRCDK5 decrease the amount of CDK5 in uninfected cells. In cells infected and transfected with miRCDK5, as well as treated with the inhibitor, a significant reduction of the viral envelope protein was observed; however, no significant reduction of CDK5 was found. Also, evident morphological cellular changes were observed during the treatment with roscovitine in infected cells. The results indicate the potential participation of CDK5 during DENV-2 infection, possibly mediating protein translation or replication of the viral genome through the cytoskeletal dynamics regulation. Additional data are required to clarify the mechanistic of these phenomena using alternative methods.

Myricetin Protects Against High Glucose-Induced β-Cell Apoptosis by Attenuating Endoplasmic Reticulum Stress via Inactivation of Cyclin-Dependent Kinase 5

BACKGROUND: Chronic hyperglycemia has deleterious effects on pancreatic β-cell function and turnover. Recent studies support the view that cyclin-dependent kinase 5 (CDK5) plays a role in β-cell failure under hyperglycemic conditions. However, little is known about how CDK5 impair β-cell function. Myricetin, a natural flavonoid, has therapeutic potential for the treatment of type 2 diabetes mellitus. In this study, we examined the effect of myricetin on high glucose (HG)-induced β-cell apoptosis and explored the relationship between myricetin and CDK5. METHODS: To address this question, we subjected INS-1 cells and isolated rat islets to HG conditions (30 mM) in the presence or absence of myricetin. Docking studies were conducted to validate the interaction between myricetin and CDK5. Gene expression and protein levels of endoplasmic reticulum (ER) stress markers were measured by real-time reverse transcription polymerase chain reaction and Western blot analysis. RESULTS: Activation of CDK5 in response to HG coupled with the induction of ER stress via the down regulation of sarcoendoplasmic reticulum calcium ATPase 2b (SERCA2b) gene expression and reduced the nuclear accumulation of pancreatic duodenal homeobox 1 (PDX1) leads to β-cell apoptosis. Docking study predicts that myricetin inhibit CDK5 activation by direct binding in the ATP-binding pocket. Myricetin counteracted the decrease in the levels of PDX1 and SERCA2b by HG. Moreover, myricetin attenuated HG-induced apoptosis in INS-1 cells and rat islets and reduce the mitochondrial dysfunction by decreasing reactive oxygen species production and mitochondrial membrane potential (Δψm) loss. CONCLUSION: Myricetin protects the β-cells against HG-induced apoptosis by inhibiting ER stress, possibly through inactivation of CDK5 and consequent upregulation of PDX1 and SERCA2b.

Restoration of Cdk5, TrkB and Soluble N-ethylmaleimide-Sensitive Factor Attachment Protein Receptor Proteins after Chronic Methylphenidate Treatment in Spontaneous Hypertensive Rats, a Model for Attention-Deficit Hyperactivity Disorder

OBJECTIVE: Synaptic vesicle mobilization and neurite outgrowth regulation molecules were examined in modulation of effects of methylphenidate (MPH) in Spontaneous Hypertensive Rats (SHRs), a model for attention-deficit hyperactivity disorder (ADHD). METHODS: We compared the changes in the protein expression level of Cyclin dependent kinase 5 (Cdk5) and molecular substrates of Cdk5; tropomyosin receptor kinase B (TrkB), syntaxin 1A (STX1A) and synaptosomal-associated protein 25 (SNAP25). Comparisons were made in prefrontal cortex of vehicle (distilled water i.p. for 7 days)-treated SHRs, vehicle-treated Wistar Kyoto Rats (WKYs) and MPH (2 mg/kg i.p. for 7 days) treated SHRs. RESULTS: The Cdk5 level of vehicle-treated SHRs was significantly decreased compared to the Cdk5 level of vehicle-treated WKY rats, but was restored to the expression level of vehicle-treated WKYs in MPH-treated SHR. The ratio of p25/p35 was significantly decreased in MPH-treated SHR compared to vehicle-treated SHR. Moreover, TrkB, STX1A and SNAP25 of vehicle-treated SHRs were significantly decreased compared to vehicle-treated WKY rats, but were restored to the expression level of vehicle-treated WKYs in MPH-treated SHR. CONCLUSION: The results show that Cdk5, TrkB, STX1A, and SNAP25 were involved in the modulation of MPH effects in prefrontal cortex of SHRs and play important role in treatment of ADHD.

Effect of Wuzang Wenyang Huayu Decoction on Neurofibrillary Tangles by Inhibiting Cyclin-dependent Kinase-5 Over-expression in SAMP8 Mice / 中国实验方剂学杂志

Objective: To explore the mechanism of Wuzang Wenyang Huayu decoction in improving the cognitive competence and the pharmacological mechanism for neurofibrillary tangles related to cyclin-dependent kinase-5(CDK-5).Method: The 10 SAMR1 mice were used as normal group,40 SAMP8 mice were randomly divided into model group,donepezil group (0.4 mg·kg-1·d-1),high and low dose Wuzang Wenyang Huayu decoction groups (5,1.25 g·kg-1·d-1).Drugs were administered by gastric lavage for 4 continuous weeks.Directional navigation and space exploration ability were evaluated with Morris amaze.Real-time PCR was used to measure the mRNA expression of CDK-5 in brain nerve tissues.Western blot was used to detect the protein expression of CDK-5 and phosphorylation of Tau protein.Meanwhile,neurofibrillary tangles in brain tissue were detected with silver staining method.Result: As compared with normal group,both CDK-5 expression and Tau protein phosphorylation in brain nerve tissues were remarkably increased in model group (PPPPPPConclusion: Wuzang Wenyang Huayu decoction can markedly improve the cognitive competence of SAMP8 mice,and the mechanism may be related to its inhibition on CDK-5 over-expression,and down-regulation of Tau protein phosphorylation and neurofibrillary tangles in brain tissue.

Neurogenesis and gliogenesis modulation in cerebral ischemia by CDK5 RNAi-based therapy / Modulación de la neurogénesis y la gliogénesis en la isquemia cerebral mediante una terapia basada en la interferencia de CDK5

Abstract Introduction: Cerebral ischemia is the third cause of death risk in Colombia and the first cause of physical disability worldwide. Different studies on the silencing of the cyclin-dependent kinase 5 (CDK5) have shown that reducing its activity is beneficial in ischemic contexts. However, its effect on neural cell production after cerebral ischemia has not been well studied yet. Objective: To evaluate CDK5 silencing on the production of neurons and astrocytes after a focal cerebral ischemia in rats. Materials and methods: We used 40 eight-week-old male Wistar rats. Both sham and ischemia groups were transduced at CA1 hippocampal region with an adeno-associated viral vector using a noninterfering (shSCRmiR) and an interfering sequence for CDK5 (shCDK5miR). We injected 50 mg/kg of bromodeoxyuridine intraperitoneally from hour 24 to day 7 post-ischemia. We assessed the neurological abilities during the next 15 days and we measured the immunoreactivity of bromodeoxyuridine (BrdU), doublecortin (DCX), NeuN, and glial fibrillary acid protein (GFAP) from day 15 to day 30 post-ischemia. Results: Our findings showed that CDK5miR-treated ischemic animals improved their neurological score and presented increased BrdU+ cells 15 days after ischemia, which correlated with higher DCX and lower GFAP fluorescence intensities, and, although mature neurons populations did not change, GFAP immunoreactivity was still significantly reduced at 30 days post-ischemia in comparison with untreated ischemic groups. Conclusion: CDK5miR therapy generated the neurological recovery of ischemic rats associated with the induction of immature neurons proliferation and the reduction of GFAP reactivity at short and longterm post-ischemia.

Resumen Introducción. La isquemia cerebral es la tercera causa de riesgo de muerte en Colombia y la primera causa de discapacidad física en el mundo. En diversos estudios en los que se silenció la cinasa 5 dependiente de la ciclina (CDK5) se ha demostrado que la reducción de su actividad es beneficiosa frente a la isquemia. Sin embargo, su efecto sobre la neurogénesis después de la isquemia no se ha dilucidado suficientemente. Objetivo. Evaluar el silenciamiento de la CDK5 en la neurogénesis y la gliogénesis después de la isquemia cerebral focal en ratas. Materiales y métodos. Se usaron 40 machos de rata Wistar de ocho semanas de edad. Los grupos de control y los isquémicos sometidos a transducción en la región del hipocampo CA1, se inyectaron intraperitonealmente por estereotaxia con 50 mg/kg de bromodesoxiuridina (BrdU) a partir de las 24 horas y hasta el día 7 después de la isquemia, con un vector viral asociado a adenovirus usando una secuencia no interferente (SCRmiR) y una interferente (CDK5miR). Se evaluó la capacidad neurológica durante los quince días siguientes y se detectó la capacidad de inmunorreacción para la BrdU, la proteína doblecortina (DCX), los núcleos neuronales (NeuN), y la proteína fibrilar acídica de la glía (Glial Fibrillary Acidic Protein, GFAP) a los 15 y 30 días de la isquemia. Resultados. Los animales isquémicos tratados con CDK5miR mejoraron su puntuación neurológica y presentaron un incremento de la BrdU+ a los 15 días de la isquemia, lo cual se correlacionó con una mayor intensidad de la DCX+ y una menor de la GFAP+. No hubo modificación de los NeuN+, pero sí una reducción significativa de la GFAP+ a los 30 días de la isquemia en los animales tratados comparados con los animales isquémicos no tratados. Conclusión. La terapia con CDK5miR generó la recuperación neurológica de ratas isquémicas asociada con la inducción de la neurogénesis y el control de la capacidad de reacción de la proteína GFAP a corto y largo plazo después de la isquemia.

Regulation on intercross effect between Cdk5 mediated apoptosis and autophagy after cerebral ischemia / 中国药理学通报

Cyclin-dependent kinase 5 (Cdk5),as a key neuro-nal regulator,has received extensively attention. In our previous experiments, we have preliminary confirmed the importance of the regulation on neuronal apoptosis after cerebral ischemia by Cdk5 signal path. According to the documents reported, we found that there were signal transductions between apoptosis and autophagy, which acted the"rapier"position after cerebral is-chemia. Furthermore,Cdk5 could mediate protein kinase B(Akt or PKB) to play bidirectional regulation on the intercross be-tween apoptosis and autophagy. So,there would be of great sig-nificance to reveal the signal transduction relationship between apoptosis and autophagy mediated by Cdk5. Owing to the impor-tance of the intercross-effect between the two programmed cell death paths,we aimed at the imparity viewpoints between apop-tosis and autophagy after cerebral ischemia, raising the sugges-tions as follows:it is appropriate to reveal the effects of Cdk5 on Akt kinase dynamically, and discuss the double regulation mechanism of co-regulators between apoptosis and autophagy af-ter cerebral ischemia, which would provide references for the following researches.

Regulation of thin recipe of Buyang Huanwudecoction on Cdk5 expression of rats after cerebral ischemia / 中国药理学通报

Aim To evaluate the regulation of thin recipe of Buyang Huanwu decoction on cyclin-dependent kinase 5(Cdk5)expressions in hippocampus tissue of rats after cerebral ischemia.Methods Male SD rats were divided into sham-operation group,MCAO group,Buyang Huanwu decoction group(ig.3.15 g·kg-1)and its thin recipe composition group(ig.2.41 g·kg-1).Each group was then divided into five subgroups based on the time after administration for 1,3,7,14,28 d respectively.Cdk5 protein and mRNA levels in each group were examined by using immunohistochemistry,Western blot and real-time PCR respectively.Results The up-regulation of Cdk5 was observed in model rat hippocampus after cerebral ischemia 1 day,and kept increasing with the aggravation of ischemia injury,the peaked expression was observed after 7～14 d,while the downtrend was observed after 28 days compared with the corresponding sham-operation groups(P0.05).Conclusion The thin recipe of Buyang Huanwu decoction could exert the protective effect by regulating Cdk5 after cerebral ischemia.

The Mechanism of Neuroprotective Effects of Puerarin for the Treatment of Acute Spinal Ischemia-reperfusion Injury in Rats / 中国医科大学学报

Objective To explore the mechanism of neuropmtective effects of puerarin for the treatment of acute spinal ischenia-reperfusion injury in a rat model.Methods Acute spinal ischemia-reperfusion injury was induced via aortic occlusion in 28 male Sprague-Dawley rats.The animals were randomly divided into four groups,as follows:group negative contrast (NC sham operation),group positive control group (IR+ S ischemia/reperfusion + saline),group puerarin (IR+P ischemia/reperfusion + puerarin),group mscovitine (IR+R ischemia/reperfusion + roscovitine).The motor function,spinal infarction volume,apoptosis indices,and CDK5 and P25 activities were examined.Results Spinal ischemia-reperfusion caused the injury of the spines and was associated with motor deficit,elevation of CDK5 and P25 activities,and increase in the spinal apoptosis and spinal infarction volume.Puerarin improved motor function and decreased apoptosis,spinal infarction volume,and CDK5 and P25 activities.Conclusion The findings of the present study indicated that puerarin treatment-mediated reduction of spinal injury was associated with the inhibition of CDK5 and P25,and that the inhibition was one among the neuroprotective mechanisms of puerarin against acute ischemia/reperfusioninduced spinal injury in rats.

Relationship between CDKAL1 gene rs7756992 A>G polymorphism and susceptibility to type 2 diabetes mellitus: A meta-analysis / 第二军医大学学报

Objective To review the relationship between CDKAL1 gene rs7756992 A>G polymorphism and the susceptibility to type 2 diabetes mellitus (T2DM). Methods Electronic databases including China National Knowledge Infrastructure (CNKI) 5 Wanfang database, EMBASE, PubMed and ScienceDirect were searched. Case-control studies on the relationship between CDKAL1 gene rs7756992 A>G polymorphism and the susceptibility lo T2DM were selected based on the inclusion and exclusion criteria of original document. The pooled odds ratio (OR) with 95% confidence interval (CI) of the relationship between CDKAL1 gene rs7756992 polymorphism and the susceptibility to T2DM were calculated using different genetic models. Subgroup analysis based on the population of different ethnicities and sensitivity analysis were performed. Results Fourteen studies including 24 315 participants in T2DM group and 35 132 in control group were identified in this analysis. Meta analysis showed that CDKAL1 gene rs7756992 A>G polymorphism was associated with the susceptibility to T2DM under different genetic models (allele [G vs A]: OR- 1. 171, 95%C1: 1.122-1.223, PG allele of rs7756992 locus in CDKAL1 gene may be a risk factor for T2DM in Asian and Caucasian population.

Neuroprotective effects of Tongmai Yizhi Decoction () against Alzheimer's disease through attenuating cyclin-dependent kinase-5 expression / 中国结合医学杂志

<p><b>OBJECTIVES</b>To explore the protective effects of Tongmai Yizhi Decoction (, TYD), a Chinese herb complex prescription against the impairment of cognitive functions and memory loss in amyloid beta 1-40 (Aβ) peptide and ibotenic (IBO)-induced Alzheimer's disease (AD) model rats.</p><p><b>METHODS</b>The in vivo model was established by injecting Aβand IBO into left hippocampal CA1 area of Sprague-Dawley (SD) rat to mimic AD. Totally 32 SD rats were divided into 4 groups, including sham operation group, AD model group, TYD group [AD rats treated with TYD at the dosage of 19.44 g/(kg•d) for 4 weeks] and huperzine A group [AD rats treated with huperzine A at the dosage of 40.5 μg/(kg•d) for 4 weeks]. Spatial learning and memory level was detected by Morris Water Maze test. Histological morphology in the hippocampus was tested by hematoxylin-eosin (HE) staining. Cyclin-dependent kinase-5 (Cdk5) protein and gene expression level were investigated by Western blot analysis and real-time quantitative polymerase chain reaction (RT-qPCR), respectively.</p><p><b>RESULTS</b>Aβ1-40 and IBO treatment induced longer escape latency of rats, compared with sham operation group from day 25 (P<0.01). However, TYD and huperzine A obviously shortened the escape latency from day 26 (P<0.01). Moreover, the effect of TYD was similar to huperzine A (P>0.05). Furthermore, HE staining also showed that TYD and huperzine A reversed the neuropathological changes in the hippocampus triggered by Aβ1-40 and IBO. TYD and huperzine A effectively reduced the expression levels of Cdk5 protein and gene located in rat hippocampus, compared with the AD model group (P<0.01).</p><p><b>CONCLUSION</b>TYD could be a promising neuroprotective agent for protecting neuron from AD injury through inhibiting Cdk5 expression.</p>

Changes of collapsin response mediator protein-2 and its phosphorylated protein levels following optic nerve injury / 中华实验眼科杂志

Background Collapsin response mediator protein-2 (CRMP-2) can promote the growth of axons,but CRMP-2 occurs hyperphosphorylation under the induction of cyclin-dependent kinase-5 (CDK5) after central nervous system injury,which leads to the collapse of the growth cone and hinders the repair of nervous system.Being a central nervous system tissue,whether the expressions of CRMP-2 and its phosphorylated protein (p-CRMP-2) change after optic nerve injury are rarely studied.Objective This study was to investigate the dynamic changes of CRMP-2 and p-CRMP-2 expressions in injured optic nerve tissue.Methods Forty-eight 8-or 9-week-old BALB/c mice were randomly divided into the sham operation group and postoperative 3-,7-and 14-day group.Optic nerves were exposed and clamped at retrobulbar 2 mm for 10 seconds in the right eyes during the surgery in the postoperative 3-,7-and 14-day groups,and the same operation was performed except the clamp of optic nerve in the sham operation group.The optic nerve tissue was obtained from the eyes 3,7 and 14 days after surgery.The relative expression levels of CRMP-2 mRNA and CRMP-2,p-CRMP-2 and CDK5 proteins in the tissue were detected by real-time fluorescence quantitative PCR and Western blot,respectively.The use and care of the experimental animals complied with the Regulation for the Administration of Affair Concerning Experimental Animals of Third Military Medical University.Results No significant differences were found in the expression levels of CRMP-2 mRNA and CRMP-2 protein among the sham operation group and postoperative 3-,7-and 14-day groups (CRMP-2 mRNA:F =2.971,P =0.097;C RMP-2 protein:F=1.202,P =0.370).The relative expression levels of p-CRMP-2 protein in the optical nerve were 0.001±0.000,0.064±0.003,0.136±0.005 and 0.346±0.012,and those of CDK5 protein were 0.440±0.009,0.723±0.011,0.874±0.015 and 0.952±0.019 in the sham operation group and postoperative 3-,7-and 14-day groups respectively,showing statistically significant differences among them (p-CRMP-2:F=445.600,P ＜ 0.001;CDK5:F=186.600,P＜0.001),and the relative expression levels of p-CRMP-2 and CDK5 protein were evidently higher in the optical nerve tissue in the postoperative 3-,7-and 14-day groups than those in the sham operation group (all at P＜0.01).Conclusions There are not significant changes in the expression level of CRMP-2 in the BALB/c mice after optic nerve injury.However,the expression levels of p-CRMP-2 and CDK5 proteins are gradually upregulated as the extending of injured time.

Inhibition of Cdk5/p25 by TFP5 protects dopaminergic neurons in MPTP-induced mouse model of Parkinson's disease / 中华行为医学与脑科学杂志

Objective To study the neuroprotective role of TFP5 in a MPTP-induced mouse model of Parkinson's disease (PD).Methods C57BL/6 mice were used as experimental animals.Briefly, 5 consecutive days of intraperitoneal injection of 25 mg/Kg 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) was applied to induce mouse PD model.The mice were randomized into 5 groups including control group,model group, scrambled TFP5 peptide (Scb) group, TFP5 group and roscovitine group.On the 7th day after the first injection of MPTP,behavior tests were performed, and then western blot method was employed to detect the expression of p25 and phosphorylated MEF2D in substantia nigra.Tyrosine hydroxylase (TH) immunohistochemical staining was performed to observe the apoptosis of dopaminergic neurons in substantia nigra pars compacta (SNpc) 28 days after the first injection of MPTP.Results MPTP increased the expression of p25 (0.48±0.10 vs 0.26±0.02, P＜0.05) and phosphorylated MEF2D (0.81±0.10 vs 0.22±0.02, P＜0.05) in substantia nigra, but decreased the number of dopaminergic neurons in SNpc (348.67±24.40 vs 463.29± 19.61, P＜0.05),resulting in motor impairment in the model mice (P＜0.05).Intraperitoneal injection of 30mg/Kg of TFP5 for 3 days effectively reduced the excessive phosphorylation of MEF2D (0.25 ± 0.12 vs 0.81 ± 0.10, P＜ 0.05) in substantia nigra, rescued dopaminergic neuron reduction of SNpc (422.92±8.41 vs 348.67±24.40, P＜0.05), and improved the motor ability of the model mice (P ＜0.05).Roscovitine exerted almost same neuroprotective role as TFP5 ,while Scb had no protective effect.Conclusion TFP5 can rescue MPTP-induced damage of dopaminergic neurons in substantia nigra, and thus improve motor impairment of model mice,which may be mediated by the inhibition of Cdk5/p25 activity.