Investigation of Naoluoxintong on the neural stem cells by facilitating proliferation and differentiation in vitro and on protecting neurons by up-regulating the expression of nestin in MCAO rats.

ETHNOPHARMACOLOGICAL RELEVANCE: The classic traditional Chinese compound Naoluoxintong (NLXT) has been proven an effective remedy for ischemic stroke (IS). The protective effect of NLXT on neural stem cells (NSCs), however, remains unclear. AIM OF THE STUDY: To investigate the protective effect of NLXT on NSCs in rats with middle cerebral artery occlusion (MCAO) and the effect of Nestin expression in vivo. MATERIALS AND METHODS: Sprague-Dawley (SD) rats were randomly divided into three groups: the sham-operated group, the MCAO model group and the NLXT group. The MCAO model in rats was established by modified Longa wire embolization method. The sham-operated group, the model group and the NLXT groups were divided into three subgroups according to the sampling time points of 1 d, 3 d and 7 d after successful model-making. Immunofluorescence staining, including bromodeoxyuridine (BrdU)/glial fibrillary acidic protein (GFAP), ß-tubulinIII/GFAP, BrdU/doublecortin (DCX) and BrdU/neuronal nuclei (NeuN), was used to detect the proliferation and survival of NSCs in the hippocampal after drug administration. Protein expression of Nestin, DCX, GFAP and NeuN in the hippocampal was detected by Western blot (WB). RESULTS: Immunofluorescence experiment of Nestin labeled: on the first day, a few Nestin-positive cells were found in the hippocampal DG area. Afterwards, the number of Nestin-labeled positive cells in the model group increased, while the number of cells in the sham group did not fluctuate significantly. The number of positive cells in each administration group increased more than that in the model and normal group. ß-tubulin III/GFAP double-labeled: a small amount of double labeled cells was expressed in the normal group, and the number subsequently fluctuated little. In the model group, ß-tubulin III/GFAP positive cells increased initially after acute ischemia, and gradually decreased afterwards. In the NLXT-treated group, ß-Tubulin III positive cells were significantly increased on day 1, 3 and 7, while GFAP positive cells had little change. BrdU/DCX double-labeled: initially, a small number of BrdU/DCX-labeled positive cells were observed in the normal group and the model group, but there was no increasing trend over time. The positive cells in the NLXT group increased over time, and those in the seven-day group were significantly higher than those in the one-day and three-day groups. BrdU/NEUN double-labeled: in the normal group, BrdU/NEUN positive cells were enriched and distributed regularly. The number of positive cells in the model group was small and decreased gradually with time, and the decrease was most obvious on the third day. The number of positive cells in the NLXT group was significantly higher than that in the model group, and the number of positive cells in the seven-day group was significantly higher than that in the one-day and three-day groups. WB results reflected those three proteins, Nestin, NeuN and DCX, showed an increase in expression, except GFAP, which showed a decreasing trend. CONCLUSIONS: Preliminarily, NLXT can promote the migration and differentiation of NSCs. It may have a protective effect on the brain by promoting repair of brain tissue damage through upregulation of Nestin after IS.

Neural stem cell phenotype of tanycyte-like ependymal cells in the circumventricular organs and central canal of adult mouse brain.

Tanycyte is a subtype of ependymal cells which extend long radial processes to brain parenchyma. The present study showed that tanycyte-like ependymal cells in the organum vasculosum of the lamina terminalis, subfornical organ and central canal (CC) expressed neural stem cell (NSC) marker nestin, glial fibrillar acidic protein and sex determining region Y. Proliferation of these tanycyte-like ependymal cells was promoted by continuous intracerebroventricular infusion of fibroblast growth factor-2 and epidermal growth factor. Tanycytes-like ependymal cells in the CC are able to form self-renewing neurospheres and give rise mostly to new astrocytes and oligodendrocytes. Collagenase-induced small medullary hemorrhage increased proliferation of tanycyte-like ependymal cells in the CC. These results demonstrate that these tanycyte-like ependymal cells of the adult mouse brain are NSCs and suggest that they serve as a source for providing new neuronal lineage cells upon brain damage in the medulla oblongata.

Shikonin­mediated inhibition of nestin affects hypoxia­induced proliferation of pulmonary artery smooth muscle cells.

The imbalance between the proliferation and apoptosis of pulmonary artery smooth muscle cells (PASMCs) is of importance in pulmonary vascular remodeling. Shikonin, a naphthoquinone compound extracted from the Chinese medicinal herb Lithospermum erythrorhizon, inhibits the proliferation of rat smooth muscle cells (SMCs). The present study was designed to investigate the effects of shikonin on the proliferation of rat PASMCs and the possible mechanisms involved. Rat PASMCs were cultured under the following five treatment conditions: Normal control; hypoxia for 24 h; hypoxia + 1 µM shikonin for 24 h; hypoxia + 2 µM shikonin for 24 h; and hypoxia + 4 µM shikonin for 24 h. The viability of PASMCs was measured using the Cell Counting Kit­8 assay, the mRNA expression of nestin (NES) in each group was measured by reverse transcription­polymerase chain reaction and the protein expression of NES was measured by western blotting. The proliferation of hypoxic PASMCs transfected with NES­specific small interfering (si)RNA decreased compared with the non­transfected group. These results indicated that hypoxia induced the proliferation of PASMCs through the enhancement of NES expression. The treatment of hypoxic PASMCs with shikonin resulted in a significant downregulation of NES expression and the inhibition of PASMC proliferation.

Increased Efficacy of Antivenom Combined with Hyperbaric Oxygen on Deinagkistrodon acutus Envenomation in Adult Rats.

BACKGROUND: Snakebites are a neglected threat to global human health with a high morbidity rate. The present study explored the efficacy of antivenom with hyperbaric oxygen (HBO) intervention on snakebites, which could provide the experimental basis for clinical adjuvant therapy. METHODS: Male Sprague-Dawley rats (n = 96) were randomized into four groups: the poison model was established by injecting Deinagkistrodon acutus (D. acutus) venom (0.8 LD50) via the caudal vein; the antivenom group was injected immediately with specific antivenom via the caudal vein after successful establishment of the envenomation model; and the antivenom + HBO group was exposed to HBO environment for 1 h once at predetermined periods of 0 h, 4 h, 12 h, and 23 h after antivenin administration. Each HBO time point had six rats; the control group was left untreated. The rats in the experimental group were euthanized at the corresponding time points after HBO therapy, and brain tissue and blood were harvested immediately. Hematoxylin and eosin (H&E) staining was used to investigate the pathological changes in the rat brain. Immunohistochemistry (IHC), real-time polymerase chain reaction (PCR), and Western blotting were used to detect the expression of Nestin mRNA and protein in the subventricular zone (SVZ) of the brain. The levels of coagulation function (prothrombin time, activated partial thromboplastin time [APTT], and fibrinogen) and oxidation/antioxidation index (malondialdehyde [MDA] and superoxide dismutase [SOD]) were analyzed. Data were analyzed using one-way analysis of variance. RESULTS: The brain tissue from rats in the poison model was observed for pathological changes using H&E staining. Tissues showed edema, decreased cell number, and disordered arrangement in the SVZ in the snake venom group. The antivenom - HBO intervention significantly alleviated these observations and was more prominent in the antivenom + HBO group. The serum levels of SOD and MDA in the snake venom group were increased and the antivenom - HBO intervention further increased the SOD levels but significantly decreased the MDA levels; however, this was enhanced within 1 h after HBO administration (MDA: F = 5.540, P = 0.008, SOD: F = 7.361, P = 0.000). Activated partial thromboplastin time (APTT) was significantly abnormal after venom administration but improved after antivenom and was even more significant in the antivenom + HBO group 5 h after envenomation (F = 25.430, P = 0.000). Only a few nestin-positive cells were observed in the envenomation model. The expression levels were significant in the antivenom and antivenom + HBO groups within 1 and 5 h after envenomation and were more significant in the antivenom + HBO group as determined by IHC, real-time PCR, and Western blotting (P < 0.05). D. acutus envenomation has neurotoxic effects in the brain of rats. CONCLUSIONS: Antivenin and HBO, respectively, induced a neuroprotective effect after D. acutus envenomation by attenuating brain edema, upregulating nestin expression in SVZ, and improving coagulopathy and oxidative stress. The intervention efficacy of antivenom with HBO was maximum within 5 h after envenomation and was more efficacious than antivenom alone.

Recovery of spinal cord injury following electroacupuncture in rats through enhancement of Wnt/ß-catenin signaling.

Electroacupuncture (EA) has been demonstrated to promote the functional recovery of neurons following spinal cord injury (SCI); however, the mechanisms underlying its effects have yet to be elucidated. The Wnt/ß-catenin signaling pathway has been implicated in the regulation of the balance between growth, proliferation and differentiation of neural precursor cells. The present study aimed to investigate the effects of EA therapy on Wnt/ß­catenin­regulated gene expression and neuronal recovery in rats with SCI. The Allen method was used to establish SCI in rats, and alterations in Wnt1 and Nestin mRNA and protein expression levels in response to SCI were determined on days 1, 3, 7 and 14 post­injury using reverse transcription­quantitative polymerase chain reaction and western blot analysis. To evaluate the effects of EA treatment on SCI, the following four treatment groups were employed: SCI, SCI + EA, SCI + lithium chloride (LiCl) and SCI + LiCl + EA. The protein expression levels of Wnt1, Nestin and nuclear ß­catenin were evaluated on day 3 post­treatment, and neuronal nuclear antigen (NeuN) protein expression levels were evaluated on day 21 post­treatment using western blot analysis. The Basso, Beattie and Bresnahan scoring method was used to evaluate spinal cord recovery on day 28 post­treatment across the four treatment groups. EA therapy at the Dazhui and Mingmen acupuncture points significantly increased the expression levels of Wnt1, Nestin, ß­catenin and NeuN, thus suggesting that EA therapy may promote spinal cord recovery following injury. The underlying mechanism was demonstrated to involve enhanced Wnt/ß­catenin signaling, which may promote the proliferation and differentiation of neural stem cells. However, further studies are required to elucidate the detailed effects and underlying molecular mechanisms of EA therapy on SCI.

Dose-dependent short- and long-term effects of ionizing irradiation on neural stem cells in murine hippocampal tissue cultures: neuroprotective potential of resveratrol.

INTRODUCTION: Radiation therapy plays an essential role in the treatment of brain tumors, but neurocognitive deficits remain a significant risk, especially in pediatric patients. In recent trials, hippocampal sparing techniques are applied to reduce these adverse effects. Here, we investigate dose-dependent effects of ionizing radiation (IR) on juvenile hippocampal neurogenesis. Additionally, we evaluate the radioprotective potential of resveratrol, a plant polyphenol recognized for its bifunctional tumor-preventive and anticancer effects. METHODS: Organotypic entorhinal-hippocampal slice cultures from transgenic nestin-CFPnuc C57BL/J6 mice, postnatal days 3-6, were irradiated on a X-ray machine (4.5, 8, 12, and 16 Gy, single doses) after about 2 weeks. Nestin-positive neural stem cells were counted at a confocal live imaging microscope 0, 2, 4, 14, 25, and 42 days after IR. Resveratrol (15 µmol/L) was added 2 hr before and 24 hr after IR. Proliferation and cell death were assessed by BrdU pulse label, 48 hr after and by propidium iodide staining 96 hr after IR. GFAP- and NeuN-positive cells were counted 42 days after IR in cryosectioned immunofluorescence-stained slices. RESULTS: The observed age-related changes of nestin-positive stem cells in the organotypic slice culture model resembled the reduction of neural stem cells in vivo. IR (4.5-16 Gy) led to a dose-dependent damage of the neural stem cell pool in the dentate gyrus. No recovery was seen within 42 days after doses from 4.5 Gy onward. The decline of nestin-positive cells was paralleled by increased cell death and decreased proliferation. The number of GFAP-positive cells was significantly enhanced. No significant change was detected in the overall NeuN-positive cell population, whereas the number of newborn, NeuN/BrdU double-positive neurons was reduced. Resveratrol treatment reversed the irradiation-induced decline of neural stem cells. CONCLUSION: The neuroprotective action of resveratrol on irradiated hippocampal tissue warrants further investigation as a possible supplement to hippocampal sparing procedures.

Fatness rather than leptin sensitivity determines the timing of puberty in female mice.

Leptin is a permissive factor for the onset of puberty. However, changes in adiposity frequently influence leptin sensitivity. Thus, the objective of the present study was to investigate how changes in body weight, fatness, leptin levels and leptin sensitivity interact to control the timing of puberty in female mice. Pre-pubertal obesity, induced by raising C57BL/6 mice in small litters, led to an early puberty onset. Inactivation of Socs3 gene in the brain or exclusively in leptin receptor-expressing cells reduced the body weight and leptin levels at pubertal onset, and increased leptin sensitivity. Notably, these female mice exhibited significant delays in vaginal opening, first estrus and onset of estrus cyclicity. In conclusion, our findings suggest that increased leptin sensitivity did not play an important role in favoring pubertal onset in female mice. Rather, changes in pubertal body weight, fatness and/or leptin levels were more important in influencing the timing of puberty.

[Effects of electroacupuncture combined with polysaccharide of gastrodia elate blume on expression of nestin and stem cell factor in thalamic ventroposterolateral nucleus in rats with focal cerebral ischemia].

OBJECTIVE: To explore the nerve regeneration mechanism of electroacupuncture (EA) combined with polysaccharide of gastrodia elate blume (PGB) for secondary thalamic damage of focal cerebral ischemia. METHODS: Forty Sprague-Dawley adult rats were randomly divided into a normal control group, a model group, an EA group, a PGB group and an EA + PGB group, 8 rats in each group. The rat model of right middle cerebral artery occlusion was prepared by suture-occluded method. Two weeks after model establishment, rats in the normal control group and model group received no treatment; rats in the EA group were treated with EA at "Baihui" (GV 20) and left "Zusanli" (ST 36), 30 min per treatment, once a day for 14 successive days; rats in the PGB group were treated with intragastric administration of PGB (100 mg/kg) , once a day for 14 days; rats in the EA + PGB group were treated with EA and PGB treatment, once a day for totally 14 days. The expressions of nestin and stem cell factor (SCF) in thalamic ventroposterolateral nucleus (VPL) were detected by immunohistochemical method. RESULTS: There were positive cells of nestin in ischemia VPL in the model group, and the number of SCF positive cells was increased compared with that in the normal control group (P<0.05). The number of positive cells of nestin and SCF in ischemia VPL in the EA group, PGB group and the EA + PGB group was increased compared with that in the model group (all P<0.05), and the average gray value of immune positive product was all reduced (all P<0.05). The number of positive cells of nestin and SCF in the EA + PGB group was higher than that in the EA group or the PGB group (all P<0.05). CONCLUSION: EA combined with PGB can significantly increase the SCF expression in ischemia VPL and promote the proliferation of neural stem cells, which is likely to be one of the nerve regeneration mechanism of acupuncture and medication tor secondary thalamic damage of local cerebral isctemia.

Leaves of Persimmon (Diospyros kaki Thunb.) Ameliorate N-Methyl-N-nitrosourea (MNU)-Induced Retinal Degeneration in Mice.

The purpose of the study was to investigate the protective effects of the ethanol extract of Diospyros kaki (EEDK) persimmon leaves to study N-methyl-N-nitrosourea (MNU)-induced retinal degeneration in mice. EEDK was orally administered after MNU injection. Retinal layer thicknesses were significantly increased in the EEDK-treated group compared with the MNU-treated group. The outer nuclear layer was preserved in the retinas of EEDK-treated mice. Moreover, EEDK treatment reduced the MNU-dependent up-regulation of glial fibrillary acidic protein (GFAP) and nestin expression in Müller and astrocyte cells. EEDK treatment also inhibited MNU-dependent down-regulation of rhodopsin expression. Quercetin exposure significantly attenuated the negative effects of H2O2 in R28 cells, suggesting that quercetin can act in an antioxidative capacity. Thus, EEDK may be considered as an agent for treating or preventing degenerative retinal diseases, such as retinitis pigmentosa and age-related macular degeneration.

[Effect of electroacupuncture intervention combined with polysaccharide of Gastrodia elata Blume on expression of nestin and stem cell factor around the ischemic locus of frontal lobe cortex in local cerebral ischemia rats].

OBJECTIVE: To observe the effect of electroacupuncture (EA), Polysaccharide of Gastrodia elata Blume (PGB), and EA + PGB on the expression of Nestin and stem cell factor (SCF) in the frontal lobe cortex around the ischemic loci of cerebral ischemia (CI) rats, so as to explore its mechanisms underlying improvement of CI. METHODS: A total of 40 Sprague-Dawley adult rats were randomly divided into normal control, CI model, EA intervention, PGB intervention and EA + PGB groups (n = 8 in each group). The CI model was prepared by middle cerebral artery occlusion. EA (2 Hz, 2 V) was applied to "Baihui" (GV 20) and left "Zusanli" (ST 36) for 30 min, once daily for 14 days. Rats of the PGB and EA + PGB groups were treated by gastrogavage of PGB at a dose of 100 mg/kg, once daily for 14 successive days. The expression of Nestin and SCF in the frontal lobe around the ischemic loci of the frontal lobe was detected by immunohistochemistry. RESULTS: Compared with the normal control group, the expression levels of regional cerebral cortical Nestin and SCF proteins were significantly increased in the model group (P < 0.05). After the treatment, the expression levels of Nestin and SCF were significantly further up-regulated in the EA, PGB and EA + PGB groups in comparison with the model group (P < 0.05). CONCLUSION: EA combined with PGB can significantly up-regulate the expression of Nestin and SCF in the frontal lobe around the ischemic loci in cerebral ischemia rats, which may contribute to their function in improving CI.

[Effects of Electroacupuncture Intervention Combined with Gastrodin on Expression of Proteins Related to Proliferation-differentiation of Neural Stem Cells in Hippocampal CA 1 and CA 3 Regions in Focal Cerebral Ischemia Rats].

OBJECTIVE: To observe the effect of electroacupuncture(EA) combined with medication on changes of expression of Nestin, glial fibrillary acidic protein (GFAP) and neuron specific enolase (NSE) in the hippocampal CA 1 and CA 3 regions of focal cerebral ischemia (FC1) rats, so as to analyze its mechanisms underlying neuroprotection. METHODS: Fifty male SD rats were randomly divided into normal control, model, EA, medication, and EA+ medication groups (n = 10 in each group). The FCI model was established by middle cerebral artery occlusion (MCAO) with thread embolus. EA (2 Hz, 2 V) was applied to the left "Hegu"(LI 4) and "Quchi" (LI 11) for 30 min, once daily for 14 days after MCAO. Rats of the medication group were given with intraperitoneal injection of gastrodin (10 mg/kg). The expression of Nestin, GFAP and NSE in the hippocampal CA 1 and CA 3 regions were detected by immunohistochemistry. RESULTS: Compared with the normal control group, the numbers of Nestin- and GFAP-immunoreaction (IR) positive cells in both CA 1 and CA 3 regions of the hippocampus were significantly increased in the model ciroup (P<0.05), while those of NSE-IR positive cells in both CA 1 and CA 3 regions were significantly decreased in the mdlgroup (P<0.05). After EA and medication interventions, the numbers of Nestin- and NSE-IR positive cells in the CA 1 and CA 3 regions were evidently increased and GFAP-IR positive neurons were considerably reduced in the EA, medication and EA+ medication groups (P<0.05). The effects of EA+ medication were significantly superior to those of both EA and simple medication in up-regulating the number of Nestin- and NSE-IR positive cells and down-regulating the number of GFAP positive neurons in CA 1 and CA 3-regions (P<0.05). CONCLUSION: EA and EA intervention combined with gastrodin can significantly up-regulate the number of Nestin- and NSE-IR positive cells, and down-regulate the number of GFAP positive cells in the CA 1 and CA 3 regions of hippocampus in focal cerebral ischemia rats, which may contribute to their effects in promoting the differentiation and proliferation of mature neurons in the hippocampus for improving cerebral functions. The effects of EA+ medication are obviously better than simple EA intervention.

Protein content and methyl donors in maternal diet interact to influence the proliferation rate and cell fate of neural stem cells in rat hippocampus.

Maternal diet during pregnancy and early postnatal life influences the setting up of normal physiological functions in the offspring. Epigenetic mechanisms regulate cell differentiation during embryonic development and may mediate gene/environment interactions. We showed here that high methyl donors associated with normal protein content in maternal diet increased the in vitro proliferation rate of neural stem/progenitor cells isolated from rat E19 fetuses. Gene expression on whole hippocampi at weaning confirmed this effect as evidenced by the higher expression of the Nestin and Igf2 genes, suggesting a higher amount of undifferentiated precursor cells. Additionally, protein restriction reduced the expression of the insulin receptor gene, which is essential to the action of IGFII. Inhibition of DNA methylation in neural stem/progenitor cells in vitro increased the expression of the astrocyte-specific Gfap gene and decreased the expression of the neuron-specific Dcx gene, suggesting an impact on cell differentiation. Our data suggest a complex interaction between methyl donors and protein content in maternal diet that influence the expression of major growth factors and their receptors and therefore impact the proliferation and differentiation capacities of neural stem cells, either through external hormone signals or internal genomic regulation.

[Effects of electroacupuncture intervention combined with polysaccharide of Gastrodia elata Blume on expression of nestin and cytokines of neural stem cells in the dentate gyrus of cerebral ischemia rats].

OBJECTIVE: To observe the effect of electroacupuncture (EA) of "Baihui" (GV 20) and "Zusanli" (ST 36) and EA plus polysaccharide of Gastrodia elata Blume (PGB) on neural stem cell (NSC) proliferation in cerebral ischemia (CI) rats, so as to explore its mechanisms underlying improvement of CI. METHODS: A total of 40 SD rats were randomly divided into normal control, CI model, EA , medication (PGB) and EA + medication groups (n = 8 in each group). The CI model was established by occlusion of the middle cerebral artery (MCAO). Two weeks after modeling, rats of the medication and EA + medication groups were administrated with PGB (100 mg/kg) once daily for 2 successive weeks. EA (2 Hz, 3 V) was applied to "Baihui" (GV 20) and left "Zusanli" (ST 36) for 30 min, once daily for 2 weeks. The expression of Nestin and stem cell factor (SCF) proteins in the dentate gyrus (DG) of hippocampus was detected by immunohistochemistry. RESULTS: Compared with the normal control group, the expression of Nestin and SCF proteins in the suprapyramidal blade (SPB) and infrapyramidal blade (IPB) of DG were significantly increased in the model group (P < 0.05). After EA intervention, the expression levels of Nestin and SCF of SPB and IPB of DG were considerably further up-regulated in both EA group and EA + medication group (P < 0.05), and the effect of EA + medication group was significantly superior to that of simple EA group and medication group (P < 0.05). CONCLUSION: EA combined with PGB can significantly up-regulate the expression of Nestin and SCF in the hippocampal DG in CI rats, and its effects are apparently superior to those of simple EA or simple medication. It suggests that EA-induced proliferation of SCF may be one of the mechanisms underlying relieving CI.