[Lianmei Qiwu Decoction relieves diabetic cardiac autonomic neuropathy by regulating AMPK/TrkA/TRPM7 signaling pathway].

This study investigated the effect of Lianmei Qiwu Decoction(LMQWD) on the improvement of cardiac autonomic nerve remodeling in the diabetic rat model induced by the high-fat diet and explored the underlying mechanism of LMQWD through the AMP-activated protein kinase(AMPK)/tropomyosin receptor kinase A(TrkA)/transient receptor potential melastatin 7(TRPM7) signaling pathway. The diabetic rats were randomly divided into a model group, an LMQWD group, an AMPK agonist group, an unloaded TRPM7 adenovirus group(TRPM7-N), an overexpressed TRPM7 adenovirus group(TRPM7), an LMQWD + unloaded TRPM7 adenovirus group(LMQWD+TRPM7-N), an LMQWD + overexpressed TRPM7 adenovirus group(LMQWD+TRPM7), and a TRPM7 channel inhibitor group(TRPM7 inhibitor). After four weeks of treatment, programmed electrical stimulation(PES) was employed to detect the arrhythmia susceptibility of rats. The myocardial cell structure and myocardial tissue fibrosis of myocardial and ganglion samples in diabetic rats were observed by hematoxylin-eosin(HE) staining and Masson staining. The immunohistochemistry, immunofluorescence, real-time quantitative polymerase chain reaction(RT-PCR), and Western blot were adopted to detect the distribution and expression of TRPM7, tyrosine hydroxylase(TH), choline acetyltransferase(ChAT), growth associated protein-43(GAP-43), nerve growth factor(NGF), p-AMPK/AMPK, and other genes and related neural markers. The results showed that LMQWD could significantly reduce the arrhythmia susceptibility and the degree of fibrosis in myocardial tissues, decrease the levels of TH, ChAT, and GAP-43 in the myocardium and ganglion, increase NGF, inhibit the expression of TRPM7, and up-regulate p-AMPK/AMPK and p-TrkA/TrkA levels. This study indicated that LMQWD could attenuate cardiac autonomic nerve remodeling in the diabetic state, and its mechanism was associated with the activation of AMPK, further phosphorylation of TrkA, and inhibition of TRPM7 expression.

Taurine Ameliorates Oxidative Stress in Spinal Cords of Diabetic Rats via Keap1-Nrf2 Signaling.

Hyperglycemia associated with diabetes mellitus (DM) causes oxidative stress, which is involved in the onset and development of diabetic neuropathy. Taurine, a powerful antioxidant, is an effective inhibitor of oxidative stress. The present experiment was conducted to explore the effect of taurine treatment on alterations in body weight, blood glucose, oxidative stress, and Keap1-Nrf2 signaling in the spinal cords of DM rats. The DM rat model was established by STZ injection, and taurine was administered in the drinking water. Body weight and blood glucose were recorded during the experiment. The expression of Gap-43 and MBP proteins was examined by Western blot. Superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were examined as indicators of oxidative stress. The expression of Keap1, Nrf2, and HO-1 gene was examined by real-time PCR. The results showed that compared with the control group, the body weight was decreased, blood glucose was increased, and both Gap-43 and MBP expression were decreased in DM rats, which were all remarkably reversed by taurine treatment. Oxidative stress, as reflected by lower SOD activity and higher MDA concentration, was inhibited in taurine-treated DM rats. Supplemental taurine also downregulated the mRNA level of Keap1, while upregulating Nrf2 and HO-1 mRNA levels. These results showed that taurine inhibits oxidative stress in the spinal cords of DM rats, an effect that might involve the regulation of Keap1-Nrf2 signaling.

Pretreatment with combined low-level laser therapy and methylene blue improves learning and memory in sleep-deprived mice.

Low-level laser therapy (LLLT) and methylene blue (MB) were proved to have neuroprotective effects. In this study, we evaluated the preventive effects of LLLT and MB alone and in combination to examine their efficacy against sleep deprivation (SD)-induced cognitive impairment. Sixty Balb/c male mice were randomly divided into five groups as follows: wide platform (WP), SD, LLLT, MB, LMB (treatment with both LLLT and MB). Daily MB (0.5 mg/kg) was injected for ten consecutive days. An 810-nm, 10-Hz pulsed laser was used in LLLT every other day. We used the T-maze test, social interaction test (SIT), and shuttle box to assess learning and memory and PSD-95, GAP-43, and synaptophysin (SYN) markers to examine synaptic proteins levels in the hippocampus. Our results showed that SD decreased alternation rate in the T-maze test, sociability and social novelty in SIT, and memory index in the shuttle box. Single treatments were not able to reverse these in most of the behavioral parameters. However, behavioral tests showed a significant difference between combined therapy and the SD group. The levels of synaptic plasticity markers were also significantly reduced after SD. There was a significant difference between the MB group and SD animals in GAP-43 and SYN biomarkers. Combination treatment with LLLT and MB also increased GAP-43, PSD-95, and SYN compared to the SD group. We found that the combined use of LLLT and MB pretreatment is more effective in protecting SD-induced cognitive impairment, which may be imparted via modulation of synaptic proteins.

Achyranthes bidentata polypeptide k enhances the survival, growth and axonal regeneration of spinal cord motor neurons in vitro.

Achyranthes bidentata polypeptide k (ABPPk), a powerful active component from a traditional Chinese medicinal herb-Achyranthes bidentata Bl., has exhibited promising neuroprotective activity due to its multiple-targeting capability. However, the effect of ABPPk on the survival, growth and axonal regeneration of spinal cord motor neurons remains unclear. Here, a modified method, which is more optimized for embryonic cells in ambient carbon dioxide levels, was used for acquisition of rat embryonic spinal cord motor neurons with high survival and purity. ABPPk concentration-dependently enhanced the neuronal viability and promoted the neurite outgrowth. Co-culture of motor neurons and skeletal myocytes model indicated that ABPPk enhanced the neuromuscular junction development and maturation. A microfluidic axotomy model was further established for the axonal disconnection, and ABPPk significantly accelerated the axonal regeneration of motor neurons. Furthermore, we demonstrated that the upregulation of three neurofilament protein subunits in motor neurons might be relevant to the mechanisms of the growth-promoting effect of ABPPk. Our findings provide an experimental and theoretical basis for the development of ABPPk as a potential application in the development of treatment strategy for nerve injury diseases.

SiNiSan ameliorates depression-like behavior in rats by enhancing synaptic plasticity via the CaSR-PKC-ERK signaling pathway.

BACKGROUND: Adverse stress in early life negatively influences psychiatric health by increasing the risk of developing depression and suicide in adulthood. Clinical antidepressants, such as fluoxetine, exhibit unsatisfactory results due to their low efficacy or intolerable side effects. SiNiSan (SNS), a traditional Chinese herbal formula, has been proven to have affirmatory antidepressive effects. However, the underlying mechanism remains poorly understood. Therefore, this study aimed to explore the impact and molecular mechanism of SNS treatment in rats exposed to neonatal maternal separation (MS)-combined young-adult chronic unpredictable mild stress (CUMS). METHOD: Seventy-two neonatal male Sprague-Dawley rats were randomly divided into six groups of 12 rats each: control + ddH2O, model + ddH2O, positive (fluoxetine: 5 mg/kg), SNS-low dose (2.5 g/kg), SNS-medium dose (5 g/kg), and SNS-high dose (10 g/kg). Behavioral tests included sucrose preference test, open-field test, and forced swimming test. Calcium sensitive receptor (CaSR), protein kinase C (PKC), ERK1/2, and synapse-associated proteins (PSD-95, GAP-43, and synaptophysin [Syn]) in the hippocampus (HIP) and prefrontal cortex (PFC) were assayed using Western blot. CaSR and Syn protein expression was measured by immunohistochemistry. RESULTS: MS-combined CUMS rats exhibited depression-like behavior. SNS exerted antidepressant effects on stress-induced depression-like behavior. The levels of CaSR, PKC, and p-ERK1/2 in the HIP and PFC decreased in stressed rats. SNS treatment significantly upregulated the expression of CaSR, PKC, and p-ERK1/2 in the HIP and PFC of adult stressed rats. CONCLUSION: MS-combined CUMS could develop depression-like behavior in adult. SNS exhibited antidepressive effects accompanied by improving synaptic plasticity by activation of the CaSR-PKC-ERK signaling pathway.

Corticotropin-releasing hormone 1 receptor antagonism attenuates chronic unpredictable mild stress-induced depressive-like behaviors in rats.

Hyperactivity of the hypothalamic-pituitary-adrenal axis and impairment of the central corticotropin-releasing factor system are factors in the pathogenesis of depression. Though several antagonists of the corticotropin-releasing factor 1 receptor were effective in the recognized behavioral tests for antidepressant activity, there is still little information on the potential interactions between corticotropin-releasing factor 1 receptor inhibitors and conventional antidepressant therapy. The aim of our study was to assess the influence of CP154526, a corticotropin-releasing factor 1 receptor blocker, which presented some signs of depression. Our results revealed that CP154526 (5 and 10 mg/kg) or fluoxetine (10 mg/kg) treatment notably improved the sucrose consumption, produced anti-depressive-like behavior in open-field test, as well as immobility time in forced swimming test. The levels of interleukin-6, interleukin-1ß, tumor necrosis factor-α, and corticotropin-releasing hormone concentration in the serum were inhibited effectively by CP154526 or fluoxetine administration. Real-time quantitative PCR and western blot analysis showed the upregulated levels of brain-derived neurotrophic factor and growth associated protein 43 (GAP43) in the hypothalamus of the rats exposed to chronic unpredictable mild stress (CUMS), while different degrees of downregulation in their expression were detected after CP154526 (5 and 10 mg/kg) or fluoxetine (10 mg/kg) treatment, respectively. Thus, our data demonstrated that CP154526 exhibited antidepressant effect in CUMS rats, which might be mediated by decreasing the brain-derived neurotrophic factor and GAP43 expression in the hypothalamus.

Cell Chromatography-Based Screening of the Active Components in Buyang Huanwu Decoction Promoting Axonal Regeneration.

Buyang Huanwu decoction (BHD), a popular formulation prescribed in traditional Chinese medicine (TCM) for the treatment of ischemic stroke, has been reported to have a potential role in promoting axonal regeneration. The purpose of the study was to screen and identify bioactive compounds from BHD using live PC12 cells coupled with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Using this approach, we successfully identified six bioactive components from BHD. These components have protective effects on oxygen-glucose deprivation/reperfusion (OGD/R) injury to PC12 cells. Furthermore, calycosin-7-d-glucoside (CG) and formononetin-7-O-ß-d-glucoside (FG) could upregulate the protein expression of growth-associated protein 43 (GAP-43) and brain-derived neurotrophic factor (BDNF). This study suggests that living cells combined with HPLC-MS/MS can be used for the screening of active ingredients in TCMs.

Taurine Promotes Neuritic Growth of Dorsal Root Ganglion Cells Exposed to High Glucose in Vitro.

Diabetic neuropathy (DN) is the most common chronic complication of DM and its major pathological changes show axonal dysfunction, atrophy and loss. However, there are few reports that taurine promotes neurite growth of dorsal root ganglion (DRG) cells. In current study, DRG neurons were exposed to high glucose (HG) with or without taurine. The neurite outgrowth of DRG neurons was observed by fluorescent immunohistochemistry method. Expression of Gap-43, Akt, phosphorylated Akt, mTOR and phosphorylated mTOR was determined by Western blot assay. Our results showed that HG significantly decreased the neurite outgrowth and expression of Gap-43 in DRG neurons. Moreover, phosphorylated levels of Akt and mTOR were downregulated in DRG neurons exposed to HG. On the contrary, taurine supplementation significantly reversed the decreased neurite outgrowth and Gap-43 expression, and the downregulated phosphorylated levels of Akt and mTOR. However, the protective effects of taurine were blocked in the presence of PI3K antagonists LY294002 or Akt antagonists Perifosine. These results indicate that taurine promotes neurite outgrowth of DRG neurons exposed to HG via activating Akt/mTOR signal pathway.

Fastigial nucleus electrostimulation promotes axonal regeneration after experimental stroke via cAMP/PKA pathway.

Axon regeneration after cerebral ischemia in mammals is inadequate to restore function, illustrating the need to design better strategies for improving outcomes. Improvement of axon regeneration has been achieved through fastigial nucleus electrostimulation (FNS) in animal researches. However, the mechanisms underlying this neuroprotection remain poorly understood. Increasing the levels of the second messenger cyclic AMP (cAMP) enhances axon regeneration, making it an excellent candidate molecule that has therapeutic potential. In the present study, we examined the expression of cAMP signaling in ischemic brain tissues following focal cerebral ischemia. Adult rats were subjected to ischemia induced by middle cerebral artery occlusion (MCAO). A dipolar electrode was placed into the cerebellum to stimulate the cerebellar fastigial nucleus for 1 h after ischemia. Neurological deficits and the expressions of cAMP, PKA (protein kinase A) and ROCK (Rho-kinase) were determined. Axonal regeneration was measured by upregulation of growth-associated protein 43 (GAP43). The data indicated that FNS significantly enhanced axonal regeneration and motor function recovery after cerebral ischemia. FNS also significantly increased cAMP and PKA levels after ischemic brain injury. All the beneficial effects of FNS were blocked by Rp-cAMP, an antagonist of PKA. Our research suggested that the axonal regeneration conferred by FNS was likely achieved via the regulation of cAMP/PKA pathway.

Changes in proinflammatory cytokines, neuropeptides, and microglia in an animal model of monosodium iodoacetate-induced hip osteoarthritis.

The aim of this study was to investigate the local production of proinflammatory cytokines, pain-related sensory innervation of dorsal-root ganglia (DRG), and spinal changes in a rat model of induced hip osteoarthritis (OA). Seventy-five Sprague-Dawley rats were used, including 25 controls and 50 injected into the right hip joints (sham group, injected with 25 µl of sterile saline: N = 25; and monosodium iodoacetate (MIA) group, injected with 25 µl of sterile saline with 2 mg of MIA: N = 25). We measured the local production of TNF-α, immunoreactive (-ir) neurons for calcitonin gene-related peptide (CGRP), and growth associated protein-43 (GAP-43) in DRG, and immunoreactive neurons for ionized-calcium-binding adaptor molecule-1 (Iba-1) in the dorsal horn of spinal cord, on post-induction days 7, 14, 28, 42, and 56 (N = 5 rats/group/time point). For post-induction days 7-42, the MIA group presented significantly elevated concentrations of TNF-α than the other groups (p < 0.01), and a higher expression of CGRP-ir in FG-labeled DRG neurons than the sham group (p < 0.01). MIA rats also presented significantly more FG-labeled GAP-43-ir DRG neurons than the sham group on post-induction days 28, 42, and 56 (p < 0.05), and a significantly higher number of Iba-1-ir microglia in the ipsilateral dorsal horn than the other groups, on post-induction days 28, 42, and 56. The results suggest that in rat models, pain-related pathologies due to MIA-induced hip OA, originate from inflammation caused by cytokines, which leads to progressive, chronic neuronal damage that may cause neuropathic pain. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2978-2986, 2018.

Amygdala stimulation promotes recovery of behavioral performance in a spatial memory task and increases GAP-43 and MAP-2 in the hippocampus and prefrontal cortex of male rats.

The relationships between affective and cognitive processes are an important issue of present neuroscience. The amygdala, the hippocampus and the prefrontal cortex appear as main players in these mechanisms. We have shown that post-training electrical stimulation of the basolateral amygdala (BLA) speeds the acquisition of a motor skill, and produces a recovery in behavioral performance related to spatial memory in fimbria-fornix (FF) lesioned animals. BLA electrical stimulation rises bdnf RNA expression, BDNF protein levels, and arc RNA expression in the hippocampus. In the present paper we have measured the levels of one presynaptic protein (GAP-43) and one postsynaptic protein (MAP-2) both involved in synaptogenesis to assess whether structural neuroplastic mechanisms are involved in the memory enhancing effects of BLA stimulation. A single train of BLA stimulation produced in healthy animals an increase in the levels of GAP-43 and MAP-2 that lasted days in the hippocampus and the prefrontal cortex. In FF-lesioned rats, daily post-training stimulation of the BLA ameliorates the memory deficit of the animals and induces an increase in the level of both proteins. These results support the hypothesis that the effects of amygdala stimulation on memory recovery are sustained by an enhanced formation of new synapses.

Striatal Reinnervation Process after Acute Methamphetamine-Induced Dopaminergic Degeneration in Mice.

Methamphetamine (METH), an amphetamine derivate, may increase the risk of developing Parkinson's disease (PD). Human and animal studies have shown that METH produces persistent dopaminergic neurotoxicity in the nigrostriatal pathway, despite initial partial recovery. To determine the processes leading to early compensation, we studied the detailed morphology and distribution of tyrosine hydroxylase immunoreactive fibers (TH-ir) classified by their thickness (types I-IV) before and after METH. Applying three established neurotoxic regimens of METH: single high dose (1 × 30 mg/kg), multiple lower doses (3 × 5 mg/kg) or (3 × 10 mg/kg), we show that METH primarily damages type I fibers (the thinner ones), and to a much lesser extend types II-IV fibers including sterile axons. The striatal TH terminal partial recovery process, consisting of a progressive regrowth increases in types II, III, and IV fibers, demonstrated by co-localization of GAP-43, a sprouting marker, was observed 3 days post-METH treatment. In addition, we demonstrate the presence of growth-cone-like TH-ir structures, indicative of new terminal generation as well as improvement in motor functions after 3 days. A temporal relationship was observed between decreases in TH-expression and increases in silver staining, a marker of degeneration. Striatal regeneration was associated with an increase in astroglia and decrease in microglia expression, suggesting a possible role for the neuroimmune system in regenerative processes. Identification of regenerative compensatory mechanisms in response to neurotoxic agents could point to novel mechanisms in countering the neurotoxicity and/or enhancing the regenerative processes.

Electrical stimulation as a conditioning strategy for promoting and accelerating peripheral nerve regeneration.

The delivery of a nerve insult (a "conditioning lesion") prior to a subsequent test lesion increases the number of regenerating axons and accelerates the speed of regeneration from the test site. A major barrier to clinical translation is the lack of an ethically acceptable and clinically feasible method of conditioning that does not further damage the nerve. Conditioning electrical stimulation (CES), a non-injurious intervention, has previously been shown to improve neurite outgrowth in vitro. In this study, we examined whether CES upregulates regeneration-associated gene (RAG) expression and promotes nerve regeneration in vivo, similar to a traditional nerve crush conditioning lesion (CCL). Adult rats were divided into four cohorts based on conditioning treatment to the common peroneal (fibular) nerve: i) CES (1h, 20Hz); ii) CCL (10s crush); iii) sham CES (1h, 0Hz); or iv) naïve (unconditioned). Immunofluorescence and qRT-PCR revealed significant RAG upregulation in the dorsal root ganglia of both CES and CCL animals, evident at 3-14days post-conditioning. To mimic a clinical microsurgical nerve repair, all cohorts underwent a common peroneal nerve cut and coaptation one week following conditioning. Both CES and CCL animals increased the length of nerve regeneration (3.8-fold) as well as the total number of regenerating axons (2.2-fold), compared to the sham and naïve-conditioned animals (p<0.001). These data support CES as a non-injurious conditioning paradigm that is comparable to a traditional CCL and is therefore a novel means to potentially enhance peripheral nerve repair in the clinical setting.

Early sensory experience influences the development of multisensory thalamocortical and intracortical connections of primary sensory cortices.

The nervous system integrates information from multiple senses. This multisensory integration already occurs in primary sensory cortices via direct thalamocortical and corticocortical connections across modalities. In humans, sensory loss from birth results in functional recruitment of the deprived cortical territory by the spared senses but the underlying circuit changes are not well known. Using tracer injections into primary auditory, somatosensory, and visual cortex within the first postnatal month of life in a rodent model (Mongolian gerbil) we show that multisensory thalamocortical connections emerge before corticocortical connections but mostly disappear during development. Early auditory, somatosensory, or visual deprivation increases multisensory connections via axonal reorganization processes mediated by non-lemniscal thalamic nuclei and the primary areas themselves. Functional single-photon emission computed tomography of regional cerebral blood flow reveals altered stimulus-induced activity and higher functional connectivity specifically between primary areas in deprived animals. Together, we show that intracortical multisensory connections are formed as a consequence of sensory-driven multisensory thalamocortical activity and that spared senses functionally recruit deprived cortical areas by an altered development of sensory thalamocortical and corticocortical connections. The functional-anatomical changes after early sensory deprivation have translational implications for the therapy of developmental hearing loss, blindness, and sensory paralysis and might also underlie developmental synesthesia.

Anti-stress and neuronal cell differentiation induction effects of Rosmarinus officinalis L. essential oil.

BACKGROUND: Mood disorder accounts for 13 % of global disease burden. And while therapeutic agents are available, usually orally administered, most have unwanted side effects, and thus making the inhalation of essential oils (EOs) an attractive alternative therapy. Rosmarinus officinalis EO (ROEO), Mediterranean ROEO reported to improve cognition, mood, and memory, the effect on stress of which has not yet been determined. Here, the anti-stress effect of ROEO on stress was evaluated in vivo and in vitro. METHODS: Six-week-old male ICR mice were made to inhale ROEO and subjected to tail suspension test (TST). To determine the neuronal differentiation effect of ROEO in vitro, induction of ROEO-treated PC12 cells differentiation was observed. Intracellular acetylcholine and choline, as well as the Gap43 gene expression levels were also determined. RESULTS: Inhalation of ROEO significantly decreased the immobility time of ICR mice and serum corticosterone level, accompanied by increased brain dopamine level. Determination of the underlying mechanism in vitro revealed a PC12 differentiation-induction effect through the modulation of intracellular acetylcholine, choline, and Gap43 gene expression levels. ROEO activates the stress response system through the NGF pathway and the hypothalamus-pituitary-adrenal axis, promoting dopamine production and secretion. The effect of ROEO may be attributed to its bioactive components, specifically to α-pinene, one of its major compounds that has anxiolytic property. CONCLUSIONS: The results of this study suggest that ROEO inhalation has therapeutic potential against stress-related psychiatric disorders.

[Effect of "Xingnao Kaiqiao Zhenfa" (Acupuncture Technique for Restoring Consciousness) Combined with Rehabilitation Training on Nerve Repair and Expression of Growth-associated Protein-43 of Peri-ischemic Cortex in Ischemic Stroke Rats].

OBJECTIVE: To observe the effect of "Xingnao Kaiqiao Zhenfa" (acupuncture technique for restoring consciousness) combined with enriched rehabilitation training on motor function and expression of growth-associated protein-43 (GAP-43) of peri-ischemic cortex in ischemic stroke rats, so as to investigate its mechanism underlying improvement of ischemic stroke. METHODS: SD rats were randomly divided into sham operation, model, rehabilitation and comprehensive rehabilitation groups, which were further divided into 3 time-points:7, 14 and 21 d (n=6 in each). Cerebral ischemia(CI) model was established by occlusion of the middle cerebral artery with heat-coagulation. The rehabilitation group was treated by enriched rehabilitation training, once a day. The comprehensive rehabilitation group was treated by acupuncture combined with enriched rehabilitation training. Acupuncture was applied to bilateral "Neiguan"(PC 6) and "Shuigou"(GV 26) for 30 min, once a day. The neurological function score, balance-beam walking test and rotating-rod walking test were evaluated at the end of the corresponding treatment time. The expression of GAP-43 in peri-ischemic cortex was detected by immunohistochemistry. RESULTS: In comparison with the sham operation group, the scores of neurological function, beam walking test and rotating-rod walking test were significantly higher in the model group (P<0.01). There were no significant changes in the scores of balance-beam walking and rotating-rod walking tests in the rehabilitation group compared with the model group on day 7 (P>0.05). Compared with the model group at the other time points, the scores of neurological function, balance-beam walking test and rotating-rod walking test were significantly lower in the rehabilitation and comprehensive rehabilitation groups (P<0.05). Compared with the rehabilitation group, the scores of neurological function, balance-beam walking test and rotating-rod walking test were significantly lower in the comprehensive rehabilitation group (P<0.05). In comparison with the sham operation group, the number of GAP-43 positive cells of peri-ischemic cortex was significantly higher in the model group (P<0.01). Compared with the model group, the numbers of GAP-43 positive cells of peri-ischemic cortex were significantly increased in the rehabilitation and comprehensive rehabilitation groups (P<0.01). The number of GAP-43 positive cells of peri-ischemic cortex in the comprehensive rehabilitation group was significantly higher than that in the rehabilitation group (P<0.01). CONCLUSIONS: "Xingnao Kaiqiao Zhenfa" combined with enriched rehabilitation training can promote the recovery of nerve function in ischemic stroke rats, which may be associated with its effect in up-regulating the expression of GAP-43 in the peri-ischemic cortex.

Stimulation of ganglionated plexus attenuates cardiac neural remodeling and heart failure progression in a canine model of acute heart failure post-myocardial infarction.

BACKGROUND: Heart failure (HF) is associated with autonomic dysfunction. Vagus nerve stimulation has been shown to improve cardiac function both in HF patients and animal models of HF. The purpose of this present study is to investigate the effects of ganglionated plexus stimulation (GPS) on HF progression and autonomic remodeling in a canine model of acute HF post-myocardial infarction. METHODS AND RESULTS: Eighteen adult mongrel male dogs were randomized into the control (n=8) and GPS (n=10) groups. All dogs underwent left anterior descending artery ligation followed by 6-hour high-rate (180-220bpm) ventricular pacing to induce acute HF. Transthoracic 2-dimensional echocardiography was performed at different time points. The plasma levels of norepinephrine, B-type natriuretic peptide (BNP) and Ang-II were measured using ELISA kits. C-fos and nerve growth factor (NGF) proteins expressed in the left stellate ganglion as well as GAP43 and TH proteins expressed in the peri-infarct zone were measured using western blot. After 6h of GPS, the left ventricular end-diastolic volume, end-systolic volume and ejection fraction showed no significant differences between the 2 groups, but the interventricular septal thickness at end-systole in the GPS group was significantly higher than that in the control group. The plasma levels of norepinephrine, BNP, Ang-II were increased 1h after myocardial infarction while the increase was attenuated by GPS. The expression of c-fos and NGF proteins in the left stellate ganglion as well as GAP43 and TH proteins in cardiac peri-infarct zone in GPS group were significantly lower than that in control group. CONCLUSIONS: GPS inhibits cardiac sympathetic remodeling and attenuates HF progression in canines with acute HF induced by myocardial infarction and ventricular pacing.

A single high dose of dexamethasone increases GAP-43 and synaptophysin in the hippocampus of aged rats.

The administration of dexamethasone, a synthetic glucocorticoid receptor agonist, has been reported to modulate cognitive performance in both animals and humans. In the present study, we demonstrate the effects of a single high dose of dexamethasone on the expression and distribution of synaptic plasticity-related proteins, growth-associated protein-43 (GAP-43) and synaptophysin, in the hippocampus of 6-, 12-, 18- and 24-month-old rats. Acute dexamethasone treatment significantly altered the expression of GAP-43 at the posttranslational level by modulating the levels of phosphorylated GAP-43 and proteolytic GAP-43-3 fragment. The effect was the most pronounced in the hippocampi of the aged animals. The total GAP-43 protein was increased only in 24-month-old dexamethasone-treated animals, and was concomitant with a decrease in calpain-mediated proteolysis. Moreover, by introducing the gray level co-occurrence matrix method, a form of texture analysis, we were able to reveal the subtle differences in the expression pattern of both GAP-43 and synaptophysin in the hippocampal subfields that were not detected by Western blot analysis alone. Therefore, the current study demonstrates, through a novel combined approach, that dexamethasone treatment significantly affects both GAP-43 and synaptophysin protein expression in the hippocampus of aged rats.

Comparison of the Effects of Curcumin and RG108 on NGF-Induced PC-12 Adh Cell Differentiation and Neurite Outgrowth.

DNA methyltransferases (DNMTs) are promising epigenetic targets for the development of novel drugs, especially for neurodegenerative disorders. In recent years, there has been increased interest in small molecules that can cross the blood-brain barrier for the treatment of neurodegenerative diseases. Therefore, comparing the neuronal differentiative effects of a natural compound curcumin and a synthetic small molecule RG108 was the aim of this study. The effects of curcumin and RG108 on neuronal differentiation and neurite outgrowth were investigated in the PC-12 Adh cell line. First, a nontoxic concentration was determined to be 100 nM with WST-1 assay. Subsequently, cells were treated with 100 nM curcumin and RG108 alone or in combination with 50 nM nerve growth factor (NGF). Cell differentiations were evaluated by a real-time cell analyzer system. Neurite outgrowth was determined and morphologically shown by immunofluorescence staining with anti-beta III tubulin antibody on PC-12 Adh cells. Also, growth-associated protein-43 (GAP-43) and ß-tubulin III mRNA expression levels, associated with neurite outgrowth promotion, were determined with real-time polymerase chain reaction (RT-PCR). According to our results, 100 nM curcumin and RG108 significantly induced neurite outgrowth of PC-12 Adh cells with 50 nM NGF. Curcumin + NGF combination further increased cell differentiations and total neurite lengths more than curcumin alone and RG108 + NGF combination groups. Strikingly, curcumin and NGF combination upregulated GAP-43 and ß-tubulin mRNA expression levels excessively. In conclusion, curcumin was found to be more effective than RG108 on neuronal differentiation and neurite outgrowth of PC-12 Adh cells in a combination with NGF. Therefore, natural DNMT1 inhibitors, such as curcumin, can be a novel approach for the neurodegenerative disorders treatment.

Buyang Huanwu decoction facilitates neurorehabilitation through an improvement of synaptic plasticity in cerebral ischemic rats.

BACKGROUND: Loss of neural function is a critical but unsolved issue after cerebral ischemia insult. Neuronal plasticity and remodeling are crucial for recovery of neural functions after brain injury. Buyang Huanwu decoction, which is a classic formula in traditional Chinese medicine, can positively alter synaptic plasticity. This study assessed the effects of Buyang Huanwu decoction in combination with physical exercise on neuronal plasticity in cerebral ischemic rats. METHODS: Cerebral ischemic rats were administered Buyang Huanwu decoction and participated in physical exercise after the induction of a permanent middle cerebral artery occlusion. The neurobehavioral functions and infarct volumes were evaluated. The presynaptic (SYN), postsynaptic (GAP-43) and cytoskeletal (MAP-2) proteins in the coronal brain samples were evaluated by immunohistochemistry and western blot analyses. The ultrastructure of the neuronal synaptic junctions in the same region were analyzed using transmission electron microscopy. RESULTS: Combination treatment of Buyang Huanwu decoction and physical exercise ameliorated the neurobehavioral deficits (p < 0.05), significantly enhanced the expression levels of SYN, GAP-43 and MAP-2 (p < 0.05), and maintained the synaptic ultrastructure. CONCLUSIONS: Buyang Huanwu decoction facilitated neurorehabilitation following a cerebral ischemia insult through an improvement in synaptic plasticity. Graphical abstract The Buyang Huanwu decoction (BYHWD) combined with physical exercise (PE) attenuates synaptic disruption and promotes synaptic plasticity following cerebral ischemia (stroke).