Regulatory effects of ADT-OH on the proliferation of neural precursor cells / 中国组织工程研究

BACKGROUND: Researchers believe that hydrogen sulfide (H2S), as an important cell protective molecule, may become a new treatment method to restore the physiological function of diseased cells or organ systems through the artificial regulation of endogenous H2S biosynthesis or in vitro administration of H2S donor. ADT-OH is a slow-release donor of H2S that can improve the survival rate of hippocampal nerve cells with glutamate-induced injury, but studies on the proliferation of cerebral cortical neural precursor cells are rare. OBJECTIVE: To investigate the effect of ADT-OH on the proliferation of neural precursor cells in embryonic cerebral cortex. METHODS: Neural precursor cells from cerebral cortical ventricular zone and subventricular zone of embryonic mice at embryonic 14.5 days were isolated. Neural precursor cells from one fetal mouse were inoculated into one well (24-well plate), and cultured with the medium containing 100 μmol/L ADT-OH. The size and number of neural spheres per well were measured at 3 days after culture. The proliferation rate of cultured neural precursor cells was detected by BrdU labeling. The proliferation of the cells was further verified by immunofluorescence staining with the specific antibody Ki67. The expression of cyclin D1 was finally detected by western blot assay. RESULTS AND CONCLUSION: Our experimental results showed that ADT-OH could promote the formation of neural spheres, and further detection by BrdU and Ki67 antibody showed that ADT-OH could promote the proliferation rate of neural precursor cells. Meanwhile, the expression of cyclin D1, a proliferation-related gene, was up-regulated in neural precursor cells after ADT-OH treatment. Overall, ADT-OH may promote the proliferation of neural precursor cells by regulating the expression of cyclin D1.

Transplantation of bone marrow mesenchymal stem cells for denervated muscular atrophy / 中国组织工程研究

BACKGROUND: Microscopic surgery or some adjuvant treatments can neither effectively delay nor treat denervated muscle atrophy by repairing damaged nerve cells. Studies have found that bone marrow mesenchymal stem cells have the potential for directional differentiation and repair damaged tissues under certain environmental factors. It is speculated that the cells can play a certain role in repairing denervated atrophic muscles. OBJECTIVE: To investigate whether transplantation of bone marrow mesenchymal stem cells can alleviate and retard atrophy of denervated muscles. METHODS: Primary bone marrow mesenchymal stem cells were isolated from Sprague-Dawley rats, and passage 3 cells were labeled by BrdU for cell transplantation. Thirty Sprague-Dawley rats were divided into three groups, 10 rats in each group. In the sham operation group, only the main trunk of the sciatic nerve was exposed but not clamped. In the treatment group, the main trunk of the sciatic nerve was clamped and bone marrow mesenchymal stem cell suspension was injected into the gastrocnemius muscle. In the control group, after the sciatic nerve trunk was clamped, the gastrocnemius muscle innervated by the sciatic nerve was injected with DMEM medium of equal volume (without cells and fetal bovine serum). Basso, Beattie and Bresnahan scores were used to evaluate the motor function of the rat’s left hindlimb at 1 and 2 weeks after cell transplantation. Changes in the gastrocnemius muscle fibers were observed by hematoxylin-eosin staining and BrdU immunohistochemical staining at 14 days after cell transplantation. RESULTS AND CONCLUSION: The passage 3 bone marrow mesenchymal stem cells were positive for BrdU. The labeled cells could survive in and repair the denervated muscle tissue in the treatment group. Compared with the model group, the denervated muscle fibers of the treatment group recovered from mutual fusion and re-arranged regularly. To conclude, transplantation of bone marrow mesenchymal stem cells can alleviate and retard atrophy of denervated muscles.

Hypoxia-stressed cardiomyocytes promote early cardiac differentiation of cardiac stem cells through HIF-1/Jagged1/Notch1 signaling

Hypoxia is beneficial for the differentiation of stem cells transplanted for myocardial injury, but mechanisms underlying this benefit remain unsolved. Here, we report the impact of hypoxia-induced Jagged1 expression in cardiomyocytes (CMs) for driving the differentiation of cardiac stem cells (CSCs). Forced hypoxia-inducible factor 1 (HIF-1) expression and physical hypoxia (5% O) treatment could induce Jagged1 expression in neonatal rat CMs. Pharmacological inhibition of HIF-1 by YC-1 attenuated hypoxia-promoted Jagged1 expression in CMs. An ERK inhibitor (PD98059), but not inhibitors of JNK (SP600125), Notch (DAPT), NF-B (PTDC), JAK (AG490), or STAT3 (Stattic) suppressed hypoxia-induced Jagged1 protein expression in CMs. c-Kit CSCs isolated from neonatal rat hearts using a magnetic-activated cell sorting method expressed GATA4, SM22 or vWF, but not Nkx2.5 and cTnI. Moreover, 87.3% of freshly isolated CSCs displayed Notch1 receptor expression. Direct co-culture of CMs with BrdU-labeled CSCs enhanced CSCs differentiation, as evidenced by an increased number of BrdU/Nkx2.5 cells, while intermittent hypoxia for 21 days promoted co-culture-triggered differentiation of CSCs into CM-like cells. Notably, YC-1 and DAPT attenuated hypoxia-induced differentiation. Our results suggest that hypoxia induces Jagged1 expression in CMs primarily through ERK signaling, and facilitates early cardiac lineage differentiation of CSCs in CM/CSC co-cultures HIF-1/Jagged1/Notch signaling.

Cell cycle synchronization and BrdU incorporation as a tool to study the possible selective elimination of ErbB1 gene in the micronuclei in A549 cells

Lung cancer often exhibits molecular changes, such as the overexpression of the ErbB1 gene that encodes epidermal growth factor receptor (EGFR). ErbB1 amplification and mutation are associated with tumor aggressiveness and low response to therapy. The aim of the present study was to design a schedule to synchronize the cell cycle of A549 cell line (a non-small cell lung cancer) and to analyze the possible association between the micronuclei (MNs) and the extrusion of ErbB1 gene extra-copies. After double blocking, by the process of fetal bovine serum deprivation and vincristine treatment, MNs formation was monitored with 5-bromo-2-deoxyuridine (BrdU) incorporation, which is an S-phase marker. Statistical analyses allowed us to infer that MNs may arise both in mitosis as well as in interphase. The MNs were able to replicate their DNA and this process seemed to be non-synchronous with the main cell nuclei. The presence of ErbB1 gene in the MNs was evaluated by fluorescent in situ hybridization (FISH). ErbB1 sequences were detected in the MNs, but a relation between the MNs formation and extrusion of amplified ErbB1could not be established. The present study sought to elucidate the meaning of MNs formation and its association with the elimination of oncogenes or other amplified sequences from the tumor cells.

Effect of PDGF-Rb antagonist imatinib on endometrial injury repairing in mouse model

Objective: To study the effects of PDGF-Rb antagonists imatinib on endometrial injury repairing in the mouse model. Methods: The cultured MSCs cells from male mice were marked with BrdU in vitro, and then transplanted to the female mice which suffered from radiation injury through tail vein, PDGF-Rb antagonists imatinib was injected through abdominal cavity. Four groups were arranged, which were radiation transplantation group, normal control group, imatinib intervention group and radiation control group. BrdU incorporation, SRY expression and MVD status were detected in uterus of mice. Results: SRY gene was negative expressed in normal control group and radiation control group. SRY gene presented positive in radiation transplantation group and imatinib intervention group; BrdU incorporation showed negative in radiation control group and normal control group which died in the early stage in mice; the incorporation of BrdU was higher in radiation transplantation group compared with imatinib intervention group; CD34 was positive on the uterus of all the four groups, which showed highest in radiation control group and lowest in radiation control group; The MVD in imatinib intervention group was lower than radiation control group; the difference of MVD was significantly compared with normal control group (P < 0.05). Conclusions: PDGF-Rb antagonists imatinib could inhibit the repairing function of MSCs in the endometrial lesions in mice.

Effects of baicalin on cognitive function in global cerebral ischemia/reperfusion rats and associated mechanism / 中国药理学通报

Aim To investigate the effects of baicalin on cognitive function in global cerebral ischemia reper-fusion rats, and the probable mechanism involved. Methods Sixty male Sprague-Dawley(SD) rats were randomly divided into Sham operation group ( S group) , global cerebral ischemia reperfusion group ( I/R group) , global cerebral ischemia reperfusion + ba-icalin treatment group ( I/RB group) , twenty in each. Model was induced via the bilateral occlusion of the common carotid arteries plus hemorrhagic hypotension. 12 h after reperfusion, rats in I/RB group were given baicalin (100 mg·kg-1 ) saline solution by intragas-tric administration twice per day for 7 days. Rats in S group and I/R group were given the corresponding dose of saline infusion at the same time. Morris water maze test was employed to detect spatial learning and memo-ry. BrdU immunohistochemistry was used to detect the proliferation of neural precursor cells ( NPCs ) in the brain. Expression of COX-2 in the brain tissue was measured by Western blot. Results Compared to I/R group, baicalin improved spatial learning and memory damage ( P nitive function in the rats with global cerebral ischemia reperfusion, which might be associated with its inhibi-tory effects on the expression of COX-2 , thereby in-creasing the proliferation of NPCs in the brain.

Effect of PDGF-Rb antagonist imatinib on endometrial injury repairing in mouse model

OBJECTIVE@#To study the effects of PDGF-Rb antagonists imatinib on endometrial injury repairing in the mouse model.@*METHODS@#The cultured MSCs cells from male mice were marked with BrdU in vitro, and then transplanted to the female mice which suffered from radiation injury through tail vein, PDGF-Rb antagonists imatinib was injected through abdominal cavity. Four groups were arranged, which were radiation transplantation group, normal control group, imatinib intervention group and radiation control group. BrdU incorporation, SRY expression and MVD status were detected in uterus of mice.@*RESULTS@#SRY gene was negative expressed in normal control group and radiation control group. SRY gene presented positive in radiation transplantation group and imatinib intervention group; BrdU incorporation showed negative in radiation control group and normal control group which died in the early stage in mice; the incorporation of BrdU was higher in radiation transplantation group compared with imatinib intervention group; CD34 was positive on the uterus of all the four groups, which showed highest in radiation control group and lowest in radiation control group; The MVD in imatinib intervention group was lower than radiation control group; the difference of MVD was significantly compared with normal control group (P < 0.05).@*CONCLUSIONS@#PDGF-Rb antagonists imatinib could inhibit the repairing function of MSCs in the endometrial lesions in mice.

Simultaneous application of BrdU and WST-1 measurements for detection of the proliferation and viability of airway smooth muscle cells

BACKGROUND: BrdU is a commonly used reagent in cell proliferation assays, and WST-1 measurement is widely used to detect cell viability. However, no previous study has formally reported the combination of the two assays, which may be used to detect the proliferation and viability simultaneously. In this study, we examined the effect of adding BrdU 2 h prior to the WST-1 assay and tried to test the possibility of the combined detection using rat airway smooth muscle cells. RESULTS: The WST-1 measurements obtained from the combined detection were consistent with those obtained from the separate detection, which suggested that the addition of BrdU 2 h prior to the WST-1 analysis did not affect the WST-1 results. The BrdU measurements obtained from the combined detection also demonstrated the same trend as that obtained from the separate detection, and dosages of 200, 400 and 800 ng/ml testing reagent significantly inhibited the proliferation of rat airway smooth muscle cells. CONCLUSIONS: Our study suggests that the BrdU and WST-1 measurements can be applied simultaneously without mutual interference, which may increase the efficacy and consistency of these measurements to a certain extent.

Effect and mechanisms of tetrahydroxystilbene glucoside on neuron proliferation in the hippocampus of epileptic rats / 中国比较医学杂志

Objective To explore the influence of tetrahydroxystilbene glucoside ( TSG ) on the neuron proliferation in epileptic rats and the related mechanisms.Methods 54 healthy SD male rats were randomly divided into three groups: sham-operated group, epilepsy group and epilepsy with TSG treatment group.The epilepsy group was established by stereotactic brain trace injection with kainic acid ( KA ) . TSG solution ( 3 mg/kg ) was injected intraperitoneally at 6 hours after the epilepsy group established, and then q.d.for consecutive 42 days.The sham-operated group and epilepsy group were injected with normal saline.The influence of TSG on cell proliferation of rat hippocampal dentate gyrus BrdU-positive granular cells was observed by immunohistochemistry.Results Compare with the epilepsy group, the amount of glial fibrillary acid protein ( GFAP)-positive astrocytes was significantly reduced and dentate gyrus BrdU-positive cells were significantly increased in the TSG group ( P <0.01 ) .Conclusions Tetrahydroxystilbene glucoside ( TSG) promotes neurogenesis of neural stem cells and neurons, and inhibits the growth of hippocampal dentate gyrus astrocytes in epilepsy rats.

Evaluation the regeneration effect of Liang-Xue-Yu-Chang decoction on intestinal epithelium of rats with radiation enteritis / 中华放射医学与防护杂志

Objective To study the effects of Liang-Xue-Yu-Chang decoction on intestinal epithelium of rats with radiation enteritis.Methods Sixty male SD rats were divided into three groups randomly:normal rats as control,abdominal radiation control group given distilled water after 10 Gy radiation,and abdominal radiation plus drug group given Liang-Xue-Yu-Chang decoction after 10 Gy radiation.Drugs or distilled water were chronically administered to animals for 7 days.After that,5-bromodexyridine (BrdU) was injected into abdominal cavity,SP immunohistochemistry was used to evaluate intestinal epithelium proliferating cell nuclear antigen (PCNA) and the positive cells labeled with Ki67 and BrdU.Results The number of intestinal epithelium cells with PCNA expression,positive Ki67 and BrdU were 22.0 + 2.7,71.2 + 5.7,and 26.2 + 5.9 respectively in the drug treatment group,significantly higher than those in the abdominal radiation control group (11.2 + 1.9,61.6 ± 5.5,and 11.3 ± 2.2) (t =14.629,5.420,11.582,P ＜ 0.05),but lower than those in the normal control group (30.4±5.7,86.6 ±5.1,and 32.3 ±3.2)(t =14.291,9.004,4.731,P＜0.05).Conclusion Liang-Xue-Yu-Chang decoction could improve the proliferation of intestinal epithelium in the rats with radiation enteritis.

Hippocampal Neurogenesis and Phenotypic Differentiation after Pilocarpine-Induced Seizures in Young Mice

PURPOSE: Proliferation, differentiation, and survival of hippocampal dentate granule cells have been reported to be influenced by epileptic seizures in rodent epilepsy models. However, most studies have been done in adult rat models. This study was designed to investigate hippocampal dentate granule cell neurogenesis after pilocarpine-induced seizures in young mice. METHODS: Fifteen male ICR mice at postnatal day 21 were divided into pilocarpine-treated (n=7) and control (n=8) groups. Seizures were chemically induced by intraperitoneal injection of pilocarpine (300 mg/kg). Bromodeoxyuridine (BrdU, 50 mg/kg) was subsequently administered once a day for 6 consecutive days, starting at 24 hours after pilocarpine or saline treatment. We then examined BrdU-positive cells in the hippocampal dentate gyrus by immunohistochemistry and by double-labeled immunofluorescence with confocal microscopy. RESULTS: After pilocarpine administration, every seizure behavior was grade 3 or more. Quantitative analysis revealed that BrdU-positive cells were significantly increased in the pilocarpine-treated group compared to control (230.5+/-59.5 vs. 148.6+/-40.0, P<0.001). The majority of these mitotic cells were differentiated into neurons. CONCLUSION: Our results indicated that mitotic activity in the hippocampal dentate gyrus was enhanced after pilocarpine-induced seizures in young mice, and the majority of BrdU-positive cells showed the phenotypic differentiation to neuronal cells.

The effect of behavioral training on neural stem cell differentiation in the dentate gyrus of rats with hippocampal infarction / 中华物理医学与康复杂志

Objective To explore the effect of behavioral training on the differentiation of neural stem cells in the dental gyrus (DG) in rats with hippocampus infarction. Methods Seventy-eight Sprague-Dawley rats were randomized into infarction plus behavior training group, infarction group and control group. Photochemistry method was used to induce hippocampal infarction in rats of the infarction plus behavioral training group and infarc-tion group. At 1 day after surgery, Morris water maze training was used for infarction plus behavioral training group, free-movement without training was performed for infarction group. Double staining immunofluorescence was used to detect the co-expression of bromodeoxyuridine (BrdU) with neuronal nuclei ( NeuN ) or glia fibrillary acidic protein (GFAP) in the DG at different time points. Results Few BrdU/NeuN and BrdU/GFAP double staining cells were observed in the DG of control rats. In the infarction group and infarction plus behavioral training group the number of BrdU/NeuN and BrdU/GFAP double-stained cells increased in the DG on the opposite side compared with the control group on 14th, 21st, 28th and 35th days after surgery (P < 0.05 ). There observed significantly more BrdU/NeuN and BrdU/GFAP double-stained cells in the infarction plus behavioral training group than that in the infarction group on the 14th, 21st, 28th and 35th days after surgery ( P < 0.05 ). Conclusion Behavioral training can accelerate the differentiation of neural stem cells to neuron and astrocyte, by which to promote the re-covery of neural functions.

Neurogenesis induced by seizures in the dentate gyrus is not related to mossy fiber sprouting but is age dependent in developing rats / A neurogênese induzida por crises no giro denteado não está relacionada ao brotamento de fibras musgosas, mas é dependente da idade, em ratos durante o desenvolvimento

Neurogenesis in the dentate gyrus (DG) has attracted attention since abnormal supragranular mossy fiber sprouting occurs in the same region, in temporal lobe epilepsy. Thus, we submitted developing rats to pilocarpine-induced status epilepticus (SE) to study the relationship between neurogenesis and mossy fiber sprouting. Groups were submitted to SE at: I-P9, II-P7, P8 and P9, III-P17 e IV-P21. Neurogenesis was quantified using BrdU protocol and confirmed through double staining, using neuronal pentraxin. Other animals were monitored by video system until P120 and their brain was studied (Timm and Nissl staining). The neurogenesis at P17 (p=0.007) and P21 (p=0.006) were increased. However, only P21 group showed recurrent seizures and the mossy fiber sprouting in the same region, during adult life, while P17 did not. Thus, our results suggest that neurogenesis is not related to mossy fiber sprouting neither to recurrent spontaneous seizures in pilocarpine model.

A neurogênese no giro dentado tem atraído atenção já que ela ocorre na mesma região do hipocampo que o brotamento das fibras musgosas, na epilepsia do lobo temporal. Assim, submetemos ratos em desenvolvimento ao status epilepticus induzido (SE) por pilocarpine. Grupos foram submetidos em I-P9, II-P7, P8, P9; III-P17 e IV-P21. A neurogênese foi observada usando o protocolo do BrdU e confirmada por dupla marcação com pentraxina neuronal. Outros animais foram monitorados até P120 e seus cérebros analisados (Nissl e Timm). A neurogênese nos grupos P17 (p=0,007) e P21 (p=0,006) aumentaram. Entretanto, o P21 apresentou crises espontâneas e brotamento de fibras musgosas, na mesma região onde ocorreu a neurogênese, enquanto o grupo P17 apresentou somente aumento na neurogênese. Assim, nossos resultados sugerem que o fenômeno da neurogênese não está relacionado com o brotamento de fibras musgosas nem com o aparecimento de crises espontâneas e recorrentes no modelo da pilocarpina.

Mammalin cochlear supporting cells transdifferentiation into outer hair cells / 药物分析学报

Objective To study the recovery of the outer hair cells in the bat cochlea after gentamicin exposure.Methods Bats were injected with a daily dose of gentamicin for 15 consecutive days and bromodeoxyuridine (BrdU)was given from day 16 to day 40 of this recovery phase. Hearing was assessed by overt acoustic behavior and auditory brainstem responses analysis, which was performed one day prior to the first injection and a day after the last injection (day 16). On day 40 animals were sacrificed for detection of cells that could take up BrdU. Results After 15 days of gentamicin treatment, all of the animals were proved to be deafened with significant increases of ABR thresholds,compared with control group. The findings in immunocytochemical stained samples and scanning electron microscopy revealed that BrdU labeled nuclei were observed in the cochlea in all of the deafened animals most commonly in the regions of the first-row and second-row Deiter's cells (DCs) and occasionally in the regions of the third-ruw DCs.Conclusion We suggest that, under sufficient drug and enough time, the bat cochlear supporting cells can directly transdifferentiate into the outer hair cells after aminoglycoside exposure. This transdifferentation process is essential for repair of outer hair cells and recovery of normal function after gentamicin exposure.

The Expression of Label-retaining Cells (LRCs) in Developing Rat Kidney / 대한해부학회지

Adult stem cells often have a low cycling rate and contribute to repair after injury by self-renewal and multiple cell division. In this study, we investigated the changes of the expression of label-retaining cells (LRCs) in developing rat kidneys which administered 5-bromo-2'-deoxy-uridine (BrdU) at embryonic day 18. In the cortex, BrdU-positive cells are localized mainly at embryonic day 18 and 20, but BrdU-positive cells after birth were rapidly decreased and almost not observed at day 14 after birth. In the medulla, the numerous BrdU-positive cells were markedly decreased in outer medulla at day 1 after birth and initial part of inner medulla at day 4 and 14 after birth, while the expression of BrdU-positive cells in the middle part (IMm) and terminal part of inner medulla (IMt) were not changes. At day 31 after birth as well as adult, BrdU-positive cells were remained in the IMm and IMt, which were mainly localized inner medullary collecting duct except a few BrdU-positive cells in the interstitium. Taken together, these observations suggest that the expression of LRCs were moved from cortex to medulla in developing kidney and the most LRCs are localized among renal epithelial tubular cells of the renal papilla in adult rat kidney.

Locations of Slow-Cycling Cells, Adult Stem Cells, in the Organs of Adult Mouse / 대한해부학회지

Adult stem cells possess the characteristics of self-renewal, multipotent, plasticity as well as slow cycling rate. We investigated a location of slow-cycling cells, that is, adult stem-like cells, in various organs in the 8 week-old mice which administered bromodeoxyuridine (BrdU) at neonatal phase. BrdU-retaining cells (slow-cycling cells) were observed in speramtogonia at the edge of seminiferous tubules in testes, hair root cells surrounding hair follicles, the cells in the inner nuclear layer of the retina, the myocytes in the hearts, the cells in the parenchyma and the Glisson's capsule of liver, the cells in the epithelial layer of bronchioles, and the tubular epithelial cells in the kidneys. In conclusion, various organs of adult mouse expressed slow-cycling cells, indicating that the cells may associate with normal cell turnover and repair after damages.

5-Hydroxytryptaminie and plasticity in rodents

Abstract: The attributes that characterize a molecule as neurotransmitter at CNS are: i . neuronal synthesis, ii . being present at presynapsis, iii. Ca2+-dependent release, iv. postsynaptic actions mediated by receptors, v. an elimination mechanism at synapse. Since 1964, 5-hydroxytryptamine (5-HT) was included as a neurotransmitter and is part of a set of neurotransmitters named biogenic amines. In rodents, the 5-hydroxytryptaminergic system is constituted by nine nuclei at brainstem, and divided in two groups, rostral and caudal by ther localization. The rostral group projects mainly to the telencephalon and diencephalon, while the caudal group does it to the spinal cord. 5-HT innervation to brainstem and cerebellar nuclei have been also described. The most well-known function of 5-hydroxytryptamine (5-HT) in the CNS is neuromodulation, in processes such as memory, learning, mood, sleep-wake cycle; all of these are regulated by this biogenic amine through a wide family of receptors. All the receptors are metabotropic with the sole exception of 5-HT1, which is an ionotropic receptor. The 5-HT system differentiates early in ontogenesis; 5-HT immunoreactive neurons are evident in rat fetuses at embryonic day 12 (E12), when almost any other neuronal lineage possesses a cellular commitment. This fact highlights the importance 5-HT has at neurodevelopment. Scientific works are focused in the 5-HT auto-regulatory signalling for neuropil outgrowth at ontogeny, another remarkable trait of the 5-HT system. In addition, 5-HT releases astrocyte neurotrophic factor S-100 beta, necessary for dendritic maintenance. The 5-HT set point at different stages during ontogeny remains unknown. Several target structures of the 5-HT system are dependent on the level of 5-HT activity in newborn rodents; e.g. the somatosensory cortex where proper barrel field arrangement requires an active 5-HT innervation. Moreover, besides the 5-HT level, other factors, such as the level of reelin, are determinant for the proper cytoarchitectonic organization of the neocortex. The use of 5-methoxytryptamine, an unespecific 5-HT agonist, in the prenatal period, which negatively affects the reelin level, leads to cytoarchitectonic derangement, as it has been described to occur in the presubicular cortex. 5-HT and plasticity are also related to neurogenesis in adulthood. Neurogenesis in adulthood is influenced by several factors. Some of them, such as exercise and an enriched environment, increase the rate of newly born neurons in the dentate gyrus and olfactory bulb; while others, such as mood depression (in humans), low 5-HT levels, 5-HT1A receptor blockade by antagonists, or down-regulation, account for a poor neurogenesis rate. Chronic administration of 5-HT reuptake inhibitors, such as fluoxetine, increases the number of bromodeoxiuridine- labelled (BrdU) granule cells at the dentate gyrus and hilus versus control rats. This means that fluoxetine increases the neurogenesis rate. Newly born granule cells at dentate gyrus are more likely to survive, thus contributing to maintaining the hippocampal volume unchanged. On the contrary, following chronic 5-HT antagonist administration, specifically 5-HT1A receptor blockade BrdU-labelled granule cells in dentate gyrus are 30% reduced. Reduced hippocampal volume develops in humans affected by major depression, concomitant in some cases with a decrease in 5-HT neurotransmiter level. Recent studies linking 5-HT neurogenesis stimulation in dentate gyrus explain why plastic phenomena associated to pathology could be reversed by 5-HT reuptake inhibitors like fluoxetine. These works contribute to a better understanding of both depression etiology and clinical approach.

Resumen: Se considera que la 5-hidroxitriptamina (5-HT) como un neurotransmisor en el SNC si cubre los siguientes criterios: i. síntesis y vesiculación al interior de la neurona, ii. presencia de la molécula en la presinapsis, iii . liberación en un mecanismo dependiente de Ca+2, iv. acción postsináptica mediada por receptores para la molécula y v. presencia de mecanismos de recaptura y degradación. Los cuerpos celulares de las neuronas que sintetizan 5-HT se agrupan en nueve núcleos distribuidos en el tallo cerebral. A su vez, estos núcleos se dividen en dos grandes grupos, rostral y caudal, de acuerdo con su localización. El grupo rostral inerva principalmente el telencéfalo y el diencéfalo, mientras que el grupo caudal hace lo propio con la médula espinal. La actividad del sistema 5-HT es neuromoduladora, esto es, interviene en la regulación de la actividad neuronal por medio de receptores, todos ellos metabotrópicos, con excepción del receptor 5-HT 3, que es ionotrópico. Los procesos relacionados con el sistema 5-HT comprenden la regulación del talante emocional, el aprendizaje, la memoria, la regulación del tono muscular, la ingesta de alimentos, la conducta sexual y la regulación del ciclo sueño-vigilia en humanos. Durante el desarrollo, las primeras neuronas inmunorreactivas a 5-HT se observan en el día 12 de la gestación de ratas a lo largo del borde entre el metencéfalo y el mielencéfalo rostral, en la región externa de la zona ventricular. El pico de proliferación celular para este fenotipo ocurre en E15 y, pese a que la inervación completa del SNC concluye en la tercera semana de vida post natal, al nacimiento están presentes la totalidad de las neuronas 5-HT, así como las principales proyecciones de este sistema. La relevancia de la 5-HT es notoria al observarse los procesos con que se relaciona durante el desarrollo. Uno de ellos es la elongación axónica en función de un gradiente de concentración. Al momento en que los neuroblastos intervienen en el nivel celular y se diferencian en neuronas 5-HT, sintetizan y secretan el neurotransmisor. De esta forma, el milieu posee un gradiente 5-HT que influye en la elongación axónica por medio de un asa de retroalimentación negativa. Otra forma en que la 5-HT incide en el neurodesarrollo es al promover la secreción del factor neurotrófico derivado de astrositos: S-100p. Esta proteína estimula el crecimiento neurítico en las neuronas 5-HT y contribuye a mantener la inervación 5-HT a las estructuras blanco. La administración prenatal de 5-metoxitriptamina, agonista específico 5-HT, provocó alteraciones citoarquitectónicas en la corteza presubicular de las crías evaluadas en P7. Con lo anterior se sugiere, por último, que la 5-HT influye en el desarrollo de sus estructuras blanco. El vínculo entre 5-HT y plasticidad continúa en la vida adulta, cuando la 5-HT sostiene una estrecha relación con la neurogénesis en el giro dentado. Trastornos y procesos como el estrés crónico, la depresión (en humanos) y la disminución en el nivel de 5-HT, así como la administración de antagonistas del receptor 5-HT1A, disminuyen la tasa de proliferación neuronal, evaluada mediante el marcaje de células recién generadas con bromodeoxiuridina. Esto lo efectúan en una magnitud similar a la que se observa tras la administración de un inhibidor de la síntesis de 5-HT. Por otra parte, la administración crónica de inhibidores de la recaptura de 5-HT, como la fluoxetina, incrementa la tasa de neurogénesis en ratas adultas. Estos trabajos resaltan la importancia del sistema 5-HT a lo largo de toda la vida del individuo en los fenómenos de plasticidad.

Expeiment study on the proliferation and plasticity of ependymal cells in situ in the injuried spinal cord of adult rats / 中国矫形外科杂志

[Objective]To observe the proliferation and plasticity of neural stem cells in sim in adult rats after spinal cord injury.[Method]Spinal cord injury models were made in 60 wistar rats and the dynamic expression of bromodeoxyuridine(BrDU) and polysialylated ependymal cells adhesion molecule(PSA-NCAM) were determined by immuno-histochemisty.[Result]Compared with the controls,the number of Brdupositive cells in the injured spinal cord increased strikingly on the 1 st day (P

Study of Survival and Migration of Schwann Cells Transplanted to Central Nervous System for A Long-term / 中国康复理论与实践

@#ObjectiveTo investigate Schwann cells whether survival and migration after transplanted to central nervous system for a long-term.MethodsThe Schwann cells of rat were expended in vitro, the part of them were labeled with 5'-bromodeoxyuridine (BrdU) and transplanted to rat's middle brain injured by electric needle stimulus, the others were labeled with Hoechst 33342, seeded to PLGA scaffold, and transplanted to rat's transected spinal cord. 8 and 11 months later, rat brain and spinal cord were taken out respectively, examined by BrdU immunohistochemistry and fluorescence microscope.ResultsBrdU positive cells could be seen after 8 months and migrated toward cerebral cortex. Hoechst 33342 positive cells could be identified in scaffold and transected spinal cord after 11 months under fluorescence microscope.ConclusionGrafted Schwann cells can survive in central nervous system for a long-term and migrate toward distance.

Influence of Preoperative Portal Vein Branch Ligation in Regeneration of Remaining Rat Liver with or without Jaundice

Purpose: The goal of this study is to define whether or not preoperative portal vein embolization has any additional role in the total amounts of liver regeneration and functional improvement after major hepatectomy in rat model. In addition, this study is to define obstructive jaundice has any positive or negative effect on it. METHODS: There were a total of 650 rats, divided into three experimental groups. Experiment A was done under the normal liver status, experiment B was done under the obstructive jaundice status, experiment C was done under the external biliary drainaged status. Each experimental group was divided into three groups that had been made by different surgery. One was 70% partial hepatectomy, another was 70% portal vein branch ligation, and the other was 70% portal vein ligation followed by 70% hepatectomy. Each operational group required over 60 rats for serial data collection which was taken at the operation and 6, 12, 24, 48, 72 hours after operation. RESULTS: We finally observed that there was no additional regeneration of remaining liver by doing preoperative portal vein embolization. It was same in obstructive jaundice group and external biliary drainaged group. And also, there was no significant fucntional improvement or deterioration by existence of obstructive jaundice. Conclusion: We conclude it is no worth doing preoperative portal vein embolization for getting additional liver regeneration and obstructive jaundice does not has significant positive or negative effect on liver regeneration and hepatic function in itself.