Microtubule-associated Protein 2 Expression Research Articles

Sevoflurane postconditioning ameliorates cerebral hypoxia/reoxygenation injury in zebrafish involving the Akt/GSK-3β pathway activation and the microtubule-associated protein 2 promotion

Sevoflurane postconditioning has been shown to provide neuroprotection against cerebral hypoxia-ischemia injury, but the mechanisms remain elusive. Microtubule-associated protein 2 (MAP2) is implicated in early neuronal hypoxia-ischemia injury. This study aimed to investigate whether the neuroprotective effects of sevoflurane postconditioning are related to the Akt/GSK-3β pathway and its downstream target MAP2 in zebrafish hypoxia/reoxygenation (H/R) model. Sevoflurane postconditioning or GSK-3β inhibitor TDZD-8 were used to treat H/R zebrafish. The cerebral infarction, neuronal apoptosis, and mitochondrial changes were evaluated using TTC staining, TUNEL staining, and transmission electron microscopy, respectively. The distribution of MAP2 in the brain was determined by immunofluorescence imaging. The levels of Akt, p-Akt, GSK-3β, p-GSK-3β, and MAP2 proteins were evaluated by Western blotting. The neurobehavioral recovery of zebrafish was assessed based on optokinetic response behavior. Our results indicated that sevoflurane postconditioning and TDZD-8 significantly reduced the cerebral infarction area, suppressed cell apoptosis, and improved mitochondrial integrity in zebrafish subjected to H/R. Furthermore, sevoflurane postconditioning and TDZD-8 elevated the ratios of p-Akt/Akt and p-GSK-3β/GSK-3β. However, the neuroprotective effect of sevoflurane postconditioning was effectively abolished upon suppression of MAP2 expression. In conclusion, sevoflurane postconditioning ameliorated cerebral H/R injury and facilitated the restoration of neurobehavioral function through the activation of Akt/GSK-3β pathway and promotion of MAP2 expression.

Neuroprotective potential of traditionally used medicinal plants of Manipur against rotenone-induced neurotoxicity in SH-SY5Y neuroblastoma cells

Ethnopharmacological relevanceAlternanthera sessilis (L.) R. Br. ex DC., Eryngium foetidum L., and Stephania japonica (Thunb.) Miers plants are traditionally used to treat various central nervous system disorders like paralysis, epilepsy, seizure, convulsion, chronic pain, headache, sleep disturbances, sprain, and mental disorders. However, their possible neuroprotective effects have not been evaluated experimentally so far. Aim of the studyThe study aims to examine the neuroprotective potential of the three plants against cytotoxicity induced by rotenone in SH-SY5Y neuroblastoma cells and assess its plausible mechanisms of neuroprotection. Materials and methodsThe antioxidant properties of the plant extracts were determined chemically by DPPH and ABTS assay methods. The cytotoxicity of rotenone and the cytoprotective activities of the extracts were evaluated using MTT assays. Microtubule-associated protein 2 (MAP2) expression studies in cells were performed to assess neuronal survival after rotenone and extract treatments. Mitochondrial membrane potential and intracellular levels of reactive oxygen species were evaluated using Rhodamine 123 and DCF-DA dye, respectively. Catalase, glutathione peroxidase, and superoxide dismutase activities were also measured. Apoptotic nuclei were examined using DAPI staining. Liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (LC-QTOF-MS) analysis of the plant extracts was also performed. ResultsThe methanol extracts of A. sessilis, S. japonica, and E. foetidum showed excellent free radical scavenging activities. MAP2 expression studies show that A. sessilis and S. japonica have higher neuroprotective effects against rotenone-induced neurotoxicity in SH-SY5Y cells than E. foetidum. Pre-treating cells with the plant extracts reverses the rotenone-induced increase in intracellular ROS. The plant extracts could also restore the reduced mitochondrial membrane potential induced by rotenone treatment and reinstate rotenone-induced increases in catalase, glutathione peroxidase, and superoxide dismutase activities. All the extracts inhibited rotenone-induced changes in nuclear morphology and DNA condensation, an early event of cellular apoptosis. LC-QTOF-MS analysis of the plant extracts shows the presence of neuroprotective compounds. ConclusionsThe plant extracts showed neuroprotective activities against rotenone-treated SH-SY5Y cells through antioxidant and anti-apoptotic mechanisms. These findings support the ethnopharmacological uses of these plants in treating neurological disorders. They probably are a good source of neuroprotective compounds that could be further explored to develop treatment strategies for neurodegenerative diseases like Parkinson's disease.

KAT7/HMGN1 signaling epigenetically induces tyrosine phosphorylation-regulated kinase 1A expression to ameliorate insulin resistance in Alzheimer's disease.

Epidemiological studies have revealed a correlation between Alzheimer's disease (AD) and type 2 diabetes mellitus (T2D). Insulin resistance in the brain is a common feature in patients with T2D and AD. KAT7 is a histone acetyltransferase that participates in the modulation of various genes. To determine the effects of KAT7 on insulin patients with AD. APPswe/PS1-dE9 double-transgenic and db/db mice were used to mimic AD and diabetes, respectively. An in vitro model of AD was established by Aβ stimulation. Insulin resistance was induced by chronic stimulation with high insulin levels. The expression of microtubule-associated protein 2 (MAP2) was assessed using immunofluorescence. The protein levels of MAP2, Aβ, dual-specificity tyrosine phosphorylation-regulated kinase-1A (DYRK1A), IRS-1, p-AKT, total AKT, p-GSK3β, total GSK3β, DYRK1A, and KAT7 were measured via western blotting. Accumulation of reactive oxygen species (ROS), malondialdehyde (MDA), and SOD activity was measured to determine cellular oxidative stress. Flow cytometry and CCK-8 assay were performed to evaluate neuronal cell death and proliferation, respectively. Relative RNA levels of KAT7 and DYRK1A were examined using quantitative PCR. A chromatin immunoprecipitation assay was conducted to detect H3K14ac in DYRK1A. KAT7 expression was suppressed in the AD mice. Overexpression of KAT7 decreased Aβ accumulation and MAP2 expression in AD brains. KAT7 overexpression decreased ROS and MDA levels, elevated SOD activity in brain tissues and neurons, and simultaneously suppressed neuronal apoptosis. KAT7 upregulated levels of p-AKT and p-GSK3β to alleviate insulin resistance, along with elevated expression of DYRK1A. KAT7 depletion suppressed DYRK1A expression and impaired H3K14ac of DYRK1A. HMGN1 overexpression recovered DYRK1A levels and reversed insulin resistance caused by KAT7 depletion. We determined that KAT7 overexpression recovered insulin sensitivity in AD by recruiting HMGN1 to enhance DYRK1A acetylation. Our findings suggest that KAT7 is a novel and promising therapeutic target for the resistance in AD.

Reducing polypyrimidine tract‑binding protein 1 fails to promote neuronal transdifferentiation on HT22 and mouse astrocyte cells under physiological conditions.

In contrast to prior findings that have illustrated the conversion of non-neuronal cells into functional neurons through the specific targeting of polypyrimidine tract-binding protein 1 (PTBP1), accumulated evidence suggests the impracticality of inducing neuronal transdifferentiation through suppressing PTBP1 expression in pathological circumstances. Therefore, the present study explored the effect of knocking down PTBP1 under physiological conditions on the transdifferentiation of mouse hippocampal neuron HT22 cells and mouse astrocyte (MA) cells. A total of 20 µM negative control small interfering (si)RNA and siRNA targeting PTBP1 were transfected into HT22 and MA cells using Lipo8000™ for 3 and 5 days, respectively. The expression of early neuronal marker βIII-Tubulin and mature neuronal markers NeuN and microtubule-associated protein 2 (MAP2) were detected using western blotting. In addition, βIII-tubulin, NeuN and MAP2 were labeled with immunofluorescence staining to evaluate neuronal cell differentiation in response to PTBP1 downregulation. Under physiological conditions, no significant changes in the expression of βIII-Tubulin, NeuN and MAP2 were found after 3 and 5 days of knockdown of PTBP1 protein in both HT22 and MA cells. In addition, the immunofluorescence staining results showed no apparent transdifferentiation in maker levels and morphology. The results suggested that the knockdown of PTBP1 failed to induce neuronal differentiation under physiological conditions.

Ghrelin inhibits NLRP3 inflammasome activation by upregulating autophagy to improve Alzheimer's disease.

Nod-like receptor protein 3 (NLRP3) inflammasome, autophagy, and the aggregation of β-amyloid (Aβ) are key factors in Alzheimer's disease (AD) development. Ghrelin has shown promise in providing neuroprotection for AD. However, the mechanism underlying ghrelin's ability to improve AD by modulating autophagy and the NLRP3 inflammasome requires further clarification. Primary hippocampus neurons and mice were stimulated with Aβ1-42 to create an in vitro and in vivo AD model, followed by ghrelin administration for intervention. Additionally, we subjected the cells to 3-methyladenine (3-MA) treatment. Neuron morphology, microtubule-associated protein 2 (MAP-2) expression, apoptosis, cytokine levels, and protein expression were measured using various techniques. The escape latency of mice was assessed using the Morris water maze (MWM) test, and histopathology of the hippocampus was determined using hematoxylin-eosin staining. At 1-100nM, ghrelin increased neuron/synapse numbers and MAP-2 expression dose-dependently while blocking apoptosis in Aβ1-42-treated cells. Moreover, ghrelin reduced the expression of Aβ1-42, p-Tau/Tau, p62, NLRP3, ASC, and cleaved Caspase-1, while increasing the expression of LC3II/LC3I and Beclin1 in AD cells. Furthermore, ghrelin treatment also decreased the levels of Aβ1-42, IL-1β, and IL-18 in the cells. The effects of ghrelin were reversed by 3-MA. Our in vivo experiments provided further confirmation of the above effect of ghrelin on AD. Additionally, the injection of Aβ1-42 induced increased escape latency in mice and histopathological changes in hippocampal neurons. All of these abnormalities were significantly improved following administration of ghrelin. Ghrelin mitigated Aβ1-42-induced neurotoxicity and relieved neuronal damage by upregulating autophagy to inactivate NLRP3, thus showing promising potential in treating AD.

Effects of Curcumin on Axon Growth and Myelin Sheath Formation in an In Vitro Model.

Although the beneficial effects of curcumin, extracted from rhizomes of the ginger family genus Curcuma, on the repair and regeneration of nerves have been evaluated in vitro, there are few studies concerning its effects on axon myelination. Here, we used pheochromocytoma cells as an in vitro model of peripheral nerves. Pheochromocytoma cells were cultured alone or cocultured with Schwann cells and treated with increasing concentrations of curcumin. Cell growth was observed, and the expression levels of growth-associated protein 43 (GAP-43), microtubule-associated protein 2 (MAP-2), myelin basic protein (MBP), myelin protein zero (MPZ), Krox-20, and octamer binding factor 6 (Oct-6) were quantified. We found a significant increase in expression of all six proteins following curcumin treatment, with a corresponding increase in the levels of MBP, MPZ, Krox-20, and Oct-6 mRNA. Upregulation was greater with increasing curcumin concentration, showing a concentration-dependent effect. The results suggested that curcumin can promote the growth of axons by upregulating the expression of GAP-43 and MAP-2, stimulate synthesis and secretion of myelin-related proteins, and facilitate formation of the myelin sheath in axons by upregulating the expression of Krox-20 and Oct-6. Therefore, curcumin could be widely applied in future strategies for the treatment of nerve injuries.

Use of liposome-encapsulated estetrol for treatment of neonatal hypoxic-ischemic encephalopathy

Estetrol (E4) is a natural estrogen synthesized only during pregnancy. It has strong neuroprotective and antioxidative activities. The aim of the present study was to define the neuroprotective potency of E4 encapsulated either in liposome (Lipo-E4) or in drug-in cyclodextrin (HP-β-CD) in liposome (DCL) system, and compare them with a single use of E4. In vitro studies were performed in an oxidative stress model of primary hippocampal neuronal cell cultures, followed by the lactate dehydrogenase activity and cell proliferation assays. In vivo studies were conducted by using a model of neonatal hypoxic-ischemic encephalopathy in immature rat pups. Brain samples were studied by (immuno)histochemistry for the detection of survived cells, expression of microtubule-associated protein-2, myelin basic protein, doublecortin and vascular-endothelial growth factor. Concentrations of glial fibrillary acidic protein in blood serum were studied by ELISA. In vitro, cell proliferation was significantly up-regulated in cultures treated either by DCL-E4 or E4 compared to the control cells, whereas DCL-E4 treated cells had significantly higher survival rate than the cells treated by E4 alone. Evaluation of brain samples showed that DCL-E4 and a high dose of E4 alone significantly preserve the grey and the white matter loses, and diminish GFAP expression in blood. Although DCL-E4 and E4 have similar effect on neurogenesis in the hippocampus and the cortex, DCL-E4 treatment significantly up-regulates angiogenesis in the hippocampus compared to a single use of E4. Present work reveals for the first time that liposome-encapsulated E4 might be a better alternative to a single use of E4.

MiR-29c Inhibits TNF-α-Induced ROS Production and Apoptosis in Mouse Hippocampal HT22 Cell Line.

Recent reports have suggested that abnormal miR-29c expression in hippocampus have been implicated in the pathophysiology of some neurodegenerative and neuropsychiatric diseases. However, the underlying effect of miR-29c in regulating hippocampal neuronal function is not clear. In this study, HT22 cells were infected with lentivirus containing miR-29c or miR-29c sponge. Cell counting kit-8 (CCK8) and lactate dehydrogenase (LDH) assay kit were applied to evaluate cell viability and toxicity before and after TNF-α administration. Reactive oxygen species (ROS) generation and mitochondrial membrane potential (MMP) were measured with fluorescent probes. Hoechst 33258 staining and TUNEL assay were used to evaluate cell apoptosis. The expression of key mRNA/proteins (TNFR1, Bcl-2, Bax, TRADD, FADD, caspase-3, -8 and -9) in the apoptosis pathway was detected by PCR or WB. In addition, the protein expression of microtubule-associated protein-2 (MAP-2), nerve growth-associated protein 43 (GAP-43) and synapsin-1 (SYN-1) was detected by WB. As a result, we found that miR-29c overexpression could improve cell viability, attenuate LDH release, reduce ROS production and inhibit MMP depolarization in TNF-α-treated HT22 cells. Furthermore, miR-29c overexpression was found to decrease apoptotic rate, along with decreased expression of Bax, cleaved caspase-3, cleaved caspase-9, and increased expression of Bcl-2 in TNF-α-treated HT22 cells. However, miR-29c sponge exhibited an opposite effects. In addition, in TNF-α-treated HT22 cells, miR-29c overexpression could decrease the expressions of TNFR1, TRADD, FADD and cleaved caspase-8. However, in HT22 cells transfected with miR-29c sponge, TNF-α-induced the expressions of TNFR1, TRADD, FADD and cleaved caspase-8 was significantly exacerbated. At last, TNF-α-induced the decreased expression of MAP-2, GAP-43 and SYN-1 was reversed by miR-29c but exacerbated by miR-29c sponge. Overall, our study demonstrated that miR-29c protects against TNF-α-induced HT22 cells injury through alleviating ROS production and reduce neuronal apoptosis. Therefore, miR-29c might be a potential therapeutic agent for TNF-α accumulation and toxicity-related brain diseases.

Testosterone Influence on Microtubule-Associated Proteins and Spine Density in Hippocampus: Implications on Learning and Memory

The thorny protrusions or spines increase the neuronal surface area, facilitate synaptic interconnections among neurons, and play an essential role in the hippocampus. Increasing evidence suggests that testosterone, the gonadal hormone, plays an important role in neurogenesis and synaptic plasticity. The role of testosterone on microtubule-associated proteins on dendritic neurite stability in the hippocampus and its impact on learning disability is not elucidated. Adult male Wistar albino rats were randomly selected for the control, castrated, castrated + testosterone, and control + testosterone groups. Bilateral orchidectomy was done, and the testosterone propionate was administered during the entire trial period, i.e., 14 days. The learning assessments were done using working/reference memory versions of the 8-arm radial maze and hippocampal tissues processed for histological and protein expressions. There were reduced expressions of microtubule-associated protein 2 (MAP2), postsynaptic density protein 95 (PSD95), and androgen receptor (AR) and increased expression of pTau in the castrated group. Conversely, the expression of MAP2, PSD95, and AR was increased, and the pTau expression was reduced in the hippocampus of the castrated rat administrated with testosterone. Androgen-depleted rats showed impaired synaptic plasticity in the hippocampus associated with contracted microtubule dynamics. Along with learning disability, there was an increased number of reference memory errors and working memory errors in castrated rats. Observations suggest that androgen regulates expression of neural tissue-specific MAPs and plays a vital role in hippocampus synaptic plasticity and that a similar mechanism may underlie neurological disorders in aging and hypogonadal men.

A3 adenosine receptor agonist IB-MECA reverses chronic cerebral ischemia-induced inhibitory avoidance memory deficit

BackgroundChronic cerebral ischemia (CCI) is a major cause of subcortical ischemic vascular dementia. Here, we examined the neuroprotective action of the A3 adenosine receptor agonist N6-(3-iodobenzyl)-adenosine-5′-N-methylcarboxamide (IB-MECA) on white matter lesions following CCI. MethodsA CCI mouse model was established using unilateral common carotid artery occlusion. IB-MECA and 3-propyl-6-ethyl-5-[(ethylthio)carbonyl]-2 phenyl-4-propyl-3-pyridine carboxylate (MRS1523), an antagonist of the A3 adenosine receptor, were administered by intraperitoneal injection. The inhibitory avoidance test was used to examine changes in memory performance. Microtubule-associated protein 2 (MAP-2) and neurofilament were assessed by immunohistochemistry, while expressions of phosphorylated extracellular signal-regulated kinase (ERK), ERK, interferon-beta (IFN-β), and glial fibrillary acidic protein (GFAP) were assessed by western blot assay. ResultsThe memory retention score was reduced in vehicle-treated mice compared with IB-MECA-treated (p < 0.05) mice. Compared to sham-operated mice, p-ERK, GFAP and IFN-β were increased, while MAP-2 and neurofilament were reduced in vehicle-treated mice (p < 0.01 for each). IB-MECA reduced ERK phosphorylation (p < 0.01) and GFAP expression (p < 0.05), but upregulated MAP-2 and IFN-β (p < 0.01 for both), compared with vehicle. MRS1523 suppressed the effects of IB-MECA on the memory deficit, ERK phosphorylation, and on MAP-2, neurofilament, GFAP and IFN-β levels. ConclusionOur results suggest that A3 adenosine receptor stimulation ameliorates CCI-induced memory deficits, modulates the ERK signaling pathway, preserves MAP-2 and neurofilament expression, regulates GFAP expression, and upregulates the anti-inflammatory cytokine IFN-β. Thus, the A3 adenosine receptor may be a therapeutic target for treatment of cognitive disorders and cerebral inflammatory diseases.

Total Ginsenoside Extract from Panax ginseng Enhances Neural Stem Cell Proliferation and Neuronal Differentiation by Inactivating GSK-3β.

To study the effects of total ginsenosides (TG) extract from Panax ginseng on neural stem cell (NSC) proliferation and differentiation and their underlying mechanisms. The migration of NSCs after treatment with various concentrations of TG extract (50, 100, or 200 µ g/mL) were monitored. The proliferation of NSCs was examined by a combination of cell counting kit-8 and neurosphere assays. NSC differentiation mediated by TG extract was evaluated by Western blotting and immunofluorescence staining to monitor the expression of nestin and microtubule associated protein 2 (MAP2). The GSK-3β/β-catenin pathway in TG-treated NSCs was examined by Western blot assay. The NSCs with constitutively active GSK-3β mutant were made by adenovirus-mediated gene transfection, then the proliferation and differentiation of NSCs mediated by TG were further verified. TG treatment significantly enhanced NSC migration (P<0.01 or P<0.05) and increased the proliferation of NSCs (P<0.01 or P<0.05). TG mediation also significantly upregulated MAP2 expression but downregulated nestin expression (P<0.01 or P<0.05). TG extract also significantly induced GSK-3β phosphorylation at Ser9, leading to GSK-3β inactivation and, consequently, the activation of the GSK-3β/β-catenin pathway (P<0.01 or P<0.05). In addition, constitutive activation of GSK-3β in NSCs by the transfection of GSK-3β S9A mutant was found to significantly suppress TG-mediated NSC proliferation and differentiation (P<0.01 or P<0.05). TG promoted NSC proliferation and neuronal differentiation by inactivating GSK-3β.

Effect of transcutaneous auricular vagus nerve stimulation on the expressions of GFAP and MAP2 in ischemic penumbra of rats with middle cerebral artery ischemia

To observe the effects of transcutaneous auricular vagus nerve stimulation (taVNS) on the motor function and the expression of glial fibrillary acidic protein (GFAP) and microtubule associated protein 2 (MAP2) in cerebral ischemic penumbra of rats with middle cerebral artery occlusion (MCAO) and explore the mechanism of taVNS in the improvement of motor function in MCAO rats. A total of 48 male SD rats were randomized into a sham-operation group, a model group, a transcutaneous auricular non-vagus nerve stimulation (tnVNS) group and a taVNS group, with 12 rats in each group. The suture-occluded method was adopted to prepare MCAO rat model. The auricular rim was stimulated in the tnVNS group and the concha stimulated in the taVNS group, 2 mA in intensity, 10 Hz in frequency, 30 min each time, once a day, for 14 days consecutively. The nerve functional assessment was recorded in each group. The expressions of nicotinic acetylcholine receptor (α7nAchR) in the cerebral ischemic penumbra and the spleen were detected by using Western blot. With the immunofluorescence, the expressions of GFAP and MAP2 were detected. After modeling, compared with the sham-operation group, the nerve functional score was increased in the model group, the tnVNS group and the taVNS group (P<0.01), suggesting the success of modeling. After treatment, the score was increased in the model group (P<0.01) as compared with the sham-operation group. Compared with the model group, the neurological deficit score was reduced in the taVNS group (P<0.01). Compared with the sham-operation group, GFAP expression was increased and MAP2 expression was reduced remarkably in the cerebral ischemic penumbra in the model group (P<0.05). In comparison with the model group, GFAP expression was reduced, while MAP2 expression was increased remarkably in the cerebral ischemic penumbra in the taVNS group (P<0.05). There were no significant differences in the abovementioned indexes between the model group and tnVNS group (P>0.05). The differences in the expression of α7nAchR in the cerebral ischemic penumbra and the spleen had no statistical significance among groups (P>0.05). TaVNS is effective on neuroprotection in MCAO rats, which may be related to its function of inhibition of GFAP expression and promotion of MAP2 expression in the ischemic penumbra.

Construction of a circRNA-miRNA-mRNA network revealed the potential mechanism of Buyang Huanwu Decoction in the treatment of cerebral ischemia

Buyang Huanwu Decoction (BHD) is a traditional Chinese herbal medicine that is effective for treating cerebral ischemia (CI). However, the molecular mechanisms of BHD in CI have not been fully elucidated. In this study, we integrated the circular RNA (circRNA)-microRNA (miRNA)-messenger RNA (mRNA) network of middle cerebral artery occlusion (MACO) rats treated with BHD. SD rats were randomly divided into a control group, model group, model+BHD group (2.5, 5, 10g/kg) and model+butylphthalide (NBP) group (54mg/kg). The neurological functions of the rats were evaluated by a modified neurological severity scoring (mNSS) system. Pathological lesions were assessed by Nissl staining, and the effects of BHD on neurovascular unit (NVU) associated protein microtubule-associated protein 2 (MAP2), glial fibrillary acidic protein (GFAP) and von Willebrand factor (VWF) were assessed by immunohistochemistry. CeRNA and miRNA microarrays were used to establish the circRNA, miRNA, and mRNA profiles. Finally, a circRNA-miRNA-mRNA ternary transcription network was constructed. BHD improved the neurobehavioral test scores (P<0.01) and the histopathological changes in ischemic brain tissue in MCAO rats. The expression of MAP2 and VWF decreased and the expression of GFAP increased in the ischemic side brain tissue of MCAO rats (P<0.01), and treatment with BHD reversed the above changes (P<0.01 or 0.05). We identified seven, three, and 86 significantly dysregulated circRNAs, miRNAs, and mRNAs, respectively, that were associated with the neuroprotective effects of BHD. Furthermore, bioinformatics analysis showed that these targets may exert therapeutic effects through multiple pathways, such as the VEGF and Hippo signaling pathways. Finally, we constructed a circRNA-miRNA-mRNA network. In brief, our study provides novel insights into ceRNA-mediated gene regulation in the progression of NVU after CI and the mechanism of action for BHD.

Effect of acupuncture serum on expression of microtubule associated protein-2 and nerve growth associated protein-43 in Mg2+-free-cultured hippocampal neurons of neonatal rats

To observe the effect of acupuncture serum on the expression of microtubule associated protein-2 (MAP-2) and nerve growth associated protein-43 (GAP-43) in cultured hippocampal neurons of convulsive rats. The acute convulsion model was induced by intraperitoneal injection of pentylenetetrazol in SD rats who were then randomized into model group and acupuncture group. Rats of the acupuncture group received manual acupuncture stimulation of "Baihui" (GV20) and "Dazhui" (GV14) for 30 min, once daily for 7 days. Then, the blood samples taken from the abdominal aorta of rats in the convulsion model and acupuncture groups were processed into serum samples, i.e. non-acupuncture serum and acupuncture se-rum. The primary-cultured hippocampal neurons of fetal rats were cultured for 10 days and then divided into normal extracellular fluid (normal) group, magnesium (Mg2+) free extracellular fluid group, acupuncture serum group and non-acupuncture serum group. At the 10th day, the neurons in the normal group were cultured continuously in extracellular fluid for 3 h, and then cultured in DMEM/F12(1∶1) medium (planting fluid); neurons in the Mg2+ free group were cultured in magnesium-free fluid medium to induce epileptic-like discharge; neurons in the acupuncture serum group were cultured in the mixed medium of planting fluid and 10% acupuncture serum; and neurons in the non-acupuncture serum were cultured in the mixed culture medium of planting fluid and non-acupuncture serum (10%). At last, these neurons in the above-mentioned groups were cultured in the magnesium-free extracellular fluid continuously for 2, 12 and 48 h, respectively, followed by detecting the expression levels of MAP-2 and GAP-43 proteins at the 3 time points by using immunofluorescence and Western blot, separately. The rate of MAP-2 positive cells and protein expression at 2, 12 and 48 h, and the rate of GAP-43 positive cells and protein expression at 12 and 48 h in the hippocampal neurons were significantly down-regulated in the Mg2+ free group in contrast to the normal group (P<0.05，P<0.01). Compared to the Mg2+ free group, the rates of MAP-2 and GAP-43 positive cells and protein expression at 2, 12 and 48 h were considerably up-regulated in the acupuncture serum group (P<0.05，P<0.01), but not in the non-acupuncture serum group (P>0.05). Acupuncture serum can significantly up-regulate the expression of MAP-2 and GAP-43 proteins in hip-pocampal neurons, which may play a positive role in improving synaptic plasticity and neuronal damage in convulsion rats.

Umbilical Cord Blood Cells Express mRNA for Neuronal Genes MAP2 and NEFL.

Hematopoietic tissue-derived cells including stem cells have been shown to differentiate into or fuse with solid organ tissue-specific cells. Among hematopoietic tissue cells, umbilical cord blood (UCB)-derived stem cells have the advantage of a higher engraftment potential. It was the purpose of this study to gather evidence on a molecular level of UCB-derived cells and stem cells generating or fusing with solid-organ tissue specific cells such as CNS-specific cells as a model for potential treatment of injured tissue.Fresh UCB was obtained by standard UCB banking procedures. Apheresis-derived mononuclear cells (adult MNC) were obtained from normal stem cells donors who underwent a 4-day G-CSF mobilization treatment. UCB cells (4 individual UCB harvests) and adult MNC (4 individuals) were selected for CD133/1+ or CD14+ or CD3+ cells by immunomagnetobead separation (autoMACS; Miltenyi Biotec). Each specimen contained between 8 and 20 × 106 selected cells at a purity of >90%.Real-time PCR was performed on the ABI Prism 7900 using the Assays-on-Demand for various neuronal genes such as Neurofilament (NEFL), Microtubule-associated protein 2 (MAP2), βTubulin 3 (TUBB3) and Nestin (NES), and the cylophilin Pre-Developed Assay Reagent (Applied Biosystems) without multiplexing. The ddCt method was used to calculate fold-difference in neuronal gene expression in the cell specimens relative to Stratagene's normal lymph node RNA.Neuronal cell-specific NEFL and MAP2 expression was found in both, UCB and adult MNC, but not TUBB3 or NES expression. The MAP2 expression was in favor of CD133−, CD14− and CD3− selected cells, whereas NEFL expression was significantly higher in CD3+ selected cells as compared with CD3− cells in both, UCB cells and adult MNC. [Display omitted] These preliminary results indicate that UCB and mobilized adult blood contain cell subsets that express mRNA for neuronal cell specific genes. NEFL expression seems to be higher in CD3-selected cells, whereas MAP2 and NEFL gene expression in progenitor cell subsets (CD133+) was found to be less.As shown by us in a clinical sex-mismatched UCB transplant setting and by others hematopoietic tissue-derived neuronal-like cells are identified in CNS tissue. Circulating cells expressing neuronal-specific genes could contribute to homeostasis of CNS tissue as known for the hematopoietic tissue.

Optimal Ratio of Wnt3a Expression in Human Mesenchymal Stem Cells Promotes Axonal Regeneration in Spinal Cord Injured Rat Model.

ObjectiveThrough our previous clinical trials, the demonstrated therapeutic effects of MSC in chronic spinal cord injury (SCI) were found to be not sufficient. Therefore, the need to develop stem cell agent with enhanced efficacy is increased. We transplanted enhanced Wnt3a-secreting human mesenchymal stem cells (hMSC) into injured spines at 6 weeks after SCI to improve axonal regeneration in a rat model of chronic SCI. We hypothesized that enhanced Wnt3a protein expression could augment neuro-regeneration after SCI. MethodsThirty-six Sprague-Dawley rats were injured using an Infinite Horizon (IH) impactor at the T9–10 vertebrae and separated into five groups : 1) phosphate-buffered saline injection (injury only group, n=7); 2) hMSC transplantation (MSC, n=7); 3) hMSC transfected with pLenti vector (without Wnt3a gene) transplantation (pLenti-MSC, n=7); 4) hMSC transfected with Wnt3a gene transplantation (Wnt3a-MSC, n=7); and 5) hMSC transfected with enhanced Wnt3a gene (1.7 fold Wnt3a mRNA expression) transplantation (1.7 Wnt3a-MSC, n=8). Six weeks after SCI, each 5×105 cells/15 µL at 2 points were injected using stereotactic and microsyringe pump. To evaluate functional recovery from SCI, rats underwent Basso-Beattie-Bresnahan (BBB) locomotor test on the first, second, and third days post-injury and then weekly for 14 weeks. Axonal regeneration was assessed using growth-associated protein 43 (GAP43), microtubule-associated protein 2 (MAP2), and neurofilament (NF) immunostaining. ResultsFourteen weeks after injury (8 weeks after transplantation), BBB score of the 1.7 Wnt3a-MSC group (15.0±0.28) was significantly higher than that of the injury only (10.0±0.48), MSC (12.57±0.48), pLenti-MSC (12.42±0.48), and Wnt3a-MSC (13.71±0.61) groups (p<0.05). Immunostaining revealed increased expression of axonal regeneration markers GAP43, MAP2, and NF in the Wnt3a-MSC and 1.7 Wnt3a-MSC groups. ConclusionOur results showed that enhanced gene expression of Wnt3a in hMSC can potentiate axonal regeneration and improve functional recovery in a rat model of chronic SCI.

Microtubule-Associated Protein 2 as a DHEA Binding Protein in Endometrial Cancer

Dehydroepiandrosterone (DHEA) is an androgen secreted by the adrenal glands, but its binding affinity for the androgen receptor is very low. DHEA is transformed into androstenedione by 3β-hydroxysteroid dehydrogenase (HSD) and then into testosterone by 17β-HSD type 5, or into estrone by aromatase. DHEA is also converted into androstenediol by 17β-HSD type 1. Therefore, DHEA is considered to play an important role as a precursor hormone for sex steroid hormones. We performed a search for a protein having an amino acid sequence homology to the DHEA binding site of 17β-HSD type 1, and found that microtubule-associated protein 2 (MAP2) binds to DHEA (Laurine E et al., J Biol Chem. 2003). MAP2 expression is necessary for neurite extension and cessation of cell division. MAP2 is known to suppress migration and invasion and affect the assembly, stabilization, and bundling of microtubules in melanoma cells, but the function of MAP2 in endometrial cancer has not been clarified. In this study, we investigated the expression of MAP2 and its association with DHEA in order to clarify the direct non-receptor action of DHEA in endometrial cancer. We employed frozen and formalin-fixed paraffin-embedded (FFPE) tissues of 35 endometrial cancer tissues (G1, n=12; G2, n=10; G3, n=9; Serous, n=4). Hormone concentrations were measured by liquid chromatograph-tandem mass spectrometer from the frozen sample, and immunohistochemistry of MAP2 was performed using FFPE tissues. We also examined MAP2 immunoreactivity using 59 normal endometrial tissues (proliferative phase, n=33; secretory phase, n=26) of FFPE tissue microarray slides. MAP2 immunoreactivity was found in the cytoplasm of endometrial cancer cells, and the MAP2-positive rate was significantly higher in type 1 (G1 and G2) than in type 2 (G2 and G3). The cell proliferation marker Ki-67 index was significantly lower in the MAP2-positive group. MAP2 was also detected in the glandular epithelial cells of the normal endometrium. The MAP2-positive rate was lower in the proliferative phase than in the secretory phase. Furthermore, the concentration of DHEA in the cancer tissue was significantly higher in the MAP2-positive group than in the MAP2-negative group. MAP2 is known to act on the stability of microtubules and is thought to be involved in the suppression of proliferation and infiltration in cancer cells. It was suggested that DHEA is involved in the stabilization of MAP2 and suppresses the progression of cancer in a hormone receptor-independent manner.

Astragaloside IV Protects 6-Hydroxydopamine-Induced SH-SY5Y Cell Model of Parkinson's Disease via Activating the JAK2/STAT3 Pathway.

ObjectivesAstragaloside IV (AS-IV), the main active component of Astragalus membranaceus, bears anti-inflammatory, antioxidant, and neuroprotective activity. Parkinson’s disease (PD) is a common neurodegenerative disease. This study explored the protective effect of AS-IV on the cell model of PD.Materials and MethodsSH-SY5Y cells were incubated with different concentrations (10, 50, 100, 150, and 200 μM) of 6-hydroxydopamine (6-OHDA) for 0, 3, 6, 12, 24, and 48 h to establish the PD cell model. Different concentrations (0, 25, 50, 100, 150, and 200 μM) of AS-IV or 15 mM JAK2/STAT3 pathway inhibitor SC99 was added for intervention 2 h before 6-OHDA treatment. The viability and morphological damage of 6-OHDA-treated SH-SY5Y cells were measured using MTT assay and Hoechst 33258 staining. The expression of microtubule associated protein 2 (MAP2) was detected by immunofluorescence staining. The levels of inflammation and oxidative stress were measured using ELISA. Apoptosis of 6-OHDA-treated SH-SY5Y cells was detected using flow cytometry, and phosphorylation level of JAK2 and STAT3 were detected using Western blot analysis.ResultsThe survival rate of SH-SY5Y cells treated with 100 μM 6-OHDA for 24 h was about 50%. AS-IV (25–100 μM) significantly improved the viability (all p < 0.01), increased MAP2 expression, and repaired the morphological damage induced by 6-OHDA. AS-IV inhibited IL-1β, IL-6, and TNF-α level (all p < 0.05), reduced MDA and ROS content and increased SOD concentration, thereby reducing inflammation and oxidative stress (all p < 0.01) in 6-OHDA-treated SH-SY5Y cells. Moreover, AS-IV decreased apoptosis rate and Bax/Bcl-2 ratio induced by 6-OHDA (all p < 0.05). Mechanically, AS-IV significantly increased the phosphorylation of JAK2 and STAT3 (p < 0.01); the addition of SC99 decreased the cell viability, increased the apoptosis rate, enhanced the levels of inflammatory factors and oxidative stress.ConclusionAS-IV enhanced the cell viability, and inhibited apoptosis, inflammation and oxidative stress of 6-OHDA-treated SH-SY5Y cells via activating the JAK2/STAT3 signaling pathway. This study may confer novel insights for the management of PD.

Ghrelin peptide improves glial conditioned medium effects on neuronal differentiation of human adipose mesenchymal stem cells

The influences of ghrelin on neural differentiation of adipose-derived mesenchymal stem cells (ASCs) were investigated in this study. The expression of typical neuronal markers, such as protein gene product 9.5 (PGP9.5) and Microtubule Associated Protein 2 (MAP2), as well as glial Fibrillary Acid Protein (GFAP) as a glial marker was evaluated in ASCs in different conditions. In particular, 2 µM ghrelin was added to control ASCs and to ASCs undergoing neural differentiation. For this purpose, ASCs were cultured in Conditioned Media obtained from Olfactory Ensheathing cells (OEC-CM) or from Schwann cells (SC-CM). Data on marker expression were gathered after 1 and 7 days of culture by fluorescence immunocytochemistry and flow cytometry. Results show that only weak effects were induced by the addition of only ghrelin. Instead, dynamic ghrelin-induced modifications were detected on the increased marker expression elicited by glial conditioned media. In fact, the combination of ghrelin and conditioned media consistently induced a further increase of PGP9.5 and MAP2 expression, especially after 7 days of treatment. The combination of ghrelin with SC-CM produced the most evident effects. Weak or no modifications were found on conditioned medium-induced GFAP increases. Observations on the ghrelin receptor indicate that its expression in control ASCs, virtually unchanged by the addition of only ghrelin, was considerably increased by CM treatment. These increases were enhanced by combining ghrelin and CM treatment, especially at 7 days. Overall, it can be assumed that ghrelin favors a neuronal rather than a glial ASC differentiation.

Icariside II promotes the differentiation of human amniotic mesenchymal stem cells into dopaminergic neuron-like cells.

The purpose of thisstudy is to observe the effect of icariside II (ICS II) on the differentiation of human amniotic mesenchymal stem cells (hAMSCs) into dopaminergic neuron-like cells, the involvement of PI3K signaling pathway inhibitors. After identifying hAMSCs by flow cytometry, hAMSCs were induced and treated with ICS II at 10 μmol/L, 3 μmol/L, 1 μmol/L, and 0 μmol/L. hAMSCs in the LY294002+3μM ICS II group were pretreated with 20 μmol/L LY294002, a PI3K-specific inhibitor, for 1 h, and then hAMSCs were induced with 3 μmol/L ICS II. On the 21st day of induction, immunofluorescence was used to detect expression of the neuronal nuclei (NeuN), neuron-specific enolase (NSE), microtubule-associated protein-2 (MAP-2), glial fibrillary acidic protein (GFAP), and tyrosine hydroxylase (TH) antigens in each induced cell group. Western blotting was used to detect the relative protein expression of NSE, MAP-2, GFAP, and TH. ELISA was used to detect the dopamine concentration in the induction medium supernatant of each group. After 21 d of ICS II induction, immunofluorescence showed that GFAP expression was not obvious in any hAMSC group. The NeuN, NSE, MAP-2, and TH fluorescent proteins were expressed in each group. NeuN was expressed in the nucleus and cytoplasm, while NSE, MAP-2, and TH were mainly expressed in the cytoplasm. The positive cell rates of NeuN, NSE, MAP-2, and TH in the 10 μmol/L, 3 μmol/L, and 1 μmol/L ICS II groups were higher than those in the LY294002+3μM ICS II and control groups. After 21 d of induction, the Western blot results showed that the protein expression levels of NSE, MAP-2, and TH in the 10 μmol/L, 3 μmol/L, and 1 μmol/L ICS II groups were significantly higher than those in the LY294002+3μM ICS II and control groups. The MAP-2 protein expression levels in the 10 μmol/L and 3 μmol/L groups were higher than that in the 1 μmol/L group. After 21 d of induction, the dopamine concentrations in the culture supernatants of the 10 μmol/L, 3 μmol/L, and 1 μmol/L ICS II groups were higher than those in the LY294002+3μM ICS II and control groups. In our experiment, ICS II induced hAMSCs to differentiate into dopaminergic neuron-like cells, and the optimal concentration range of ICS II was 3-10 μmol/L. Moreover, the PI3K signaling pathway is involved in the above differentiation process.