Histological and immunohistochemical effects of neuroectodermal cells transplantation after spinal cord injury in rats / Efectos histológicos e inmunohistoquímicos del trasplante de células neuroectodérmicas tras una lesión de la médula espinal en ratas

SUMMARY: In spinal cord injury, radical treatment is still a persistent hope for patients and clinicians. Our study aimed to determine the different histological changes in central, cranial and caudal sites of compressed spinal cord as a result of neuroectodermal stem cells (NESCs) transplantation in rats. For extraction of NESCs, future brains were extracted from mice embryos (10-days old) and cultured. Eighty, male rats were divided randomly into control, sham (20 rats each); while 40 rats were subjected to compressed spinal cord injury (CSCI). Seven days after spinal cord injury, rats were subdivided into 2 groups (20 rats each); an untreated and treated with NESCs injected cranial and caudal to the site of the spinal cord injury. Rats were sacrificed 4 weeks after transplantations of NESCs and specimens from the spinal cord at the central, cranial and caudal to site of spinal cord injury were proceeded to be stained with haematoxylin & eosin, osmic acid and Immunohistochemistry of glial fibrillary acidic protein (GFAP). Sections of CSCI revealed areas of hemorrhages, necrosis and cavitation limited by reactive astrocytosis, with upregulation of GFAP expression. Evidence of remyelination and mitigation of histopathological features, reactive astrocytosis in CSCI sections were more pronounced in cranial than in caudal region. NESCs transplantation ameliorated the pathological changes, promoted remyelination.

RESUMEN: En la lesión de la médula espinal, el tratamiento radical aún sigue siendo el tratamiento preferente para los pacientes y los médicos. El objetivo de este estudio fue determinar los diferentes cambios histológicos en los sitios centrales, craneales y caudales de la médula espinal comprimida, como resultado del trasplante de células madre neuroectodérmicas (NESCs) en ratas. Para la extracción de NESCs, se extrajeron y cultivaron los cerebros de embriones de ratones de 10 días de edad. Se dividieron 80 ratas macho aleatoriamente en grupos control, simulado (20 ratas cada una); mientras que 40 ratas fueron sometidas a lesión de la médula espinal comprimida (CSCI). Siete días después de la lesión de la médula espinal, las ratas se subdividieron en 2 grupos (20 ratas cada uno); un grupo no tratado y un grupo tratado con NESCs inyectado craneal y caudal en el sitio de la lesión. Las ratas fueron sacrificadas 4 semanas después de los trasplantes de NESCs y las muestras de la médula espinal en el centro, craneal y caudal del sitio de lesión fueron teñidas con hematoxilina y eosina, ácido ósmico e inmunohistoquímica de la proteína ácida fibrilar glial (GFAP). Las secciones de CSCI revelaron áreas de hemorragias, necrosis y cavitación limitadas por astrocitosis reactiva, con una regulación positiva de la expresión de GFAP. Evidencia de remielinización y mitigación de características histopatológicas, astrocitosis reactiva en secciones de CSCI fue más pronunciada en la región craneal que en la caudal. El trasplante de NESC mejoró los cambios patológicos, promoviendo la remielinización.

Does neuroectodermal stem cells transplantation restore neural regeneration and locomotor functions in compressed spinal cord injury rat model? / ¿El trasplante de células madre neuroectodérmicas restaura la regeneración neural y las funciones locomotoras en el modelo de rata con lesión de la médula espinal comprimida?

SUMMARY: The aim of this study was to determine the possible regenerative effect of neuroectodermal stem cells on the ultrastructural, and locomotor function resulting from compressed injury to the spinal cord in a rat model. Forty male rats were divided into control and sham groups (20 rats each). Compressed spinal cord injured (CSCI) were forty rats which subdivided equally into: untreated, treated by neuroectodermal stem cells (NESCs). After four weeks, all rats in different groups were scarified, samples were taken from central, cranial, and caudal to the site of spinal cord injury. Specimens were prepared for light and electron microscopic examination. The number of remyelinated axons in central, cranial and caudal regions to the injured spinal cord after transplantation of NESCs was counted. The open field test assessed the locomotor function. Results revealed that compressed spinal cord injury resulted in loss and degeneration of numerous nerve fibers, myelin splitting and degeneration of mitochondria. Four weeks after transplantation of NESCs regenerated axons were noticed in cranial and central sites, while degenerate axons were noticed caudal to the lesion. Number of remyelinated axons was significantly increased in both central and cranial to the site of spinal cord injury in comparison with caudal region which had the least number of remyelinated axons. Transplantation of NESCs improved significantly the locomotor functional activity In conclusion, neuroectodermal stem cells transplantation ameliorated the histopathological and ultrastructural changes, and improved the functional locomotor activity in CSCI rat.

RESUMEN: El objetivo de este estudio fue determinar el posible efecto regenerativo de las células madre neuroectodérmicas en la función ultraestructural y locomotora de una lesión comprimida en la médula espinal en un modelo de rata. Cuarenta ratas macho se dividieron en grupos control y sham (20 ratas en cada grupo). La médula espinal lesionada (CSCI) tenía cuarenta ratas que se subdividieron de igual forma en los siguientes grupos: no tratadas, tratadas con células madre neuroectodérmicas (NESCs). Al término de cuatro semanas, todas las ratas en los diferentes grupos fueron escarificadas, se tomaron muestras de las áreas central, craneal y caudal en relación al sitio de la lesión de la médula espinal. Las muestras fueron preparadas para examen microscópico de luz y electrónica. Se contó el número de axones remielinizados en las regiones central, craneal y caudal de la médula espinal lesionada después del trasplante de NESCs. La prueba de campo abierto evaluó la función locomotora. Los resultados revelaron que la lesión de la médula espinal comprimida provocó la pérdida y degeneración de numerosas fibras nerviosas, la división de la mielina y la degeneración de las mitocondrias. Cuatro semanas después del trasplante de NESCs, se notaron axones regenerados en los sitios craneales y centrales, mientras que los axones degenerados se notaron caudal a la lesión. El número de axones remielinizados aumentó significativamente tanto en el centro como en el cráneo hasta el sitio de la lesión de la médula espinal en comparación con la región caudal que tenía el menor número de axones remielinizados. El trasplante de NESCs mejoró significativamente la actividad funcional locomotora. En conclusión, el trasplante de células madre neuroectodérmicas mejoró los cambios histopatológicos y ultraestructurales, y mejoró la actividad locomotora funcional en la rata CSCI.

Neuroectodermal stem cells: A remyelinating potential in acute compressed spinal cord injury in rat model.

The outcomes of compressed spinal cord injury (CSCI) necessitate radical treatment. The therapeutic potential of neuroectodermal stem cells (NESCs) in a rat model of CSCI in acute and subacute stages was assessed. White Wistar rat were divided into control, sham-operated, CSCI untreated model, CSCI grafted with NESCs at 1 day after CSCI, and at 7 days after CSCI. Primary NESC cultures were prepared from brains of embryonic day 10 (E10) mice embryos. NESCs were transplanted at the site of injury using a Hamilton syringe. Locomotor functional assessment, routine histopathology, immunostaining for (GFAP), and ultrastructure techniques for evaluating the CSI were conducted. In CSCI, areas of hemorrhage, cavitation, reactive astrocytosis, upregulated GFAP expression of immunostained areas, degeneration of the axoplasm and demyelination were observed. One day after grafting with NESCs, a decrease in astrocyte reaction and pathological features, quantitative and qualitative enhancement of remyelination and improved locomotor activity were observed. Treatment with NESCs at 7 days after CSCI did not mitigatethe reactive astrocytosis and glial scar formation that hindered the ability of the NESCs to enhance remyelination of axons. In conclusion, the microenvironment and time of NESCs transplantation affect activity of astrocytes and remyelination of axons.

Histological, immunohistochemical and ultrastructural study of secondary compressed spinal cord injury in a rat model.

INTRODUCTION: Spinal cord injury (SCI) is a life-disrupting condition in which the first few days are the most critical. Secondary conditions remain the main causes of death for people with SCI. The response of different cell types to SCI and their role at different times in the progression of secondary degeneration are not well understood. The aim of this study was to study the histopathological changes of compressed spinal cord injury (CSCI) in a rat model. MATERIAL AND METHODS: Forty adult male Sprague-Dawley rats were divided into four groups. In group I, the rats were left without any surgical intervention (control). In group II, the rats were subjected to laminectomy without spinal cord compression (sham-operated). In group III, the rats were sacrificed one day after CSCI. In group IV, the rats were sacrificed seven days after CSCI. The light microscopy was employed to study the morphology using H&E, osmic acid staining and immunohistochemistry to detect glial fibrillary acidic protein (GFAP). The electron microscopy was applied for ultrastructure study. RESULTS: Histopathological examination of the posterior funiculus of the white matter revealed minute hemorrhages and localized necrotic areas on day 1, which transformed to areas of cavitation and fibrinoid necrosis surrounded by a demarcating rim of numerous astrocytes by day 7. The mean percentage of area of GFAP expression increased significantly by day 7. Osmic acid staining revealed swollen nerve fibers after one day, while numerous fibers had been lost by day 7. An ultrastructure study revealed swollen redundant thinned myelin and myelin splitting, as well as degeneration of axoplasm on day 1. On day 7, layers of the myelin sheath were folded and wrinkled with partial or complete demyelination areas. The myelin lamellae were disorganized and loose. The G-ratio was significantly greater on day 1 than day 7 after CSCI. CONCLUSIONS: In the rat model of CSCI details of the progressive spinal cord injury can be analyzed by morphological methods and may be helpful in the identification of the onset and type of clinical intervention.

A histological and immunohistochemical study of beta cells in streptozotocin diabetic rats treated with caffeine.

In this study, the histological, immunohistochemical, morphometric, and biochemical changes to pancreatic beta-cells in STZ-induced diabetes were evaluated in rats treated with different doses of caffeine. Fifty adult male Wistar albino rats were divided into five groups: the nondiabetic control group, the diabetic untreated group, and three diabetic groups treated with different doses of caffeine (10, 50, and 100 mg/kg/day). Blood glucose and serum insulin levels were measured. The pancreata were collected and processed into paraffin sections. They were stained using hematoxylin and eosin (H&E) and Masson trichrome stains. The insulin expression in beta-cells was assessed using immunohistochemistry. Morphometrically, the percentage area of anti-insulin antibody reaction, the percentage of beta-cells per total islet cell number, and the average area of the islets were determined. STZ-induced degenerative changes in beta-cells led to decreases in the number of functioning beta-cells and insulin immunoreactivity and to increases in the number of collagen fibers in the islets. In STZ-treated rats, caffeine significantly decreased blood glucose concentration while increasing blood insulin levels at the highest applied dose. It also induced a significant increase in the number of immunoreactive beta-cells. In conclusion, caffeine may have a protective role in the biochemical and microscopic changes in pancreatic beta-cells in diabetes induced in rats through STZ administration.

Effect of vitamin E and selenium against aluminum-induced nephrotoxicity in pregnant rats.

Kidney is one of the most affected organs by aluminium toxicity. This study aimed to investigate the effect of aluminium chloride on the kidney of pregnant rats and to assess the efficiency of vitamin E and selenium in ameliorating this effect. Forty virgin albino rats were randomly divided into two main groups. Control rats were further divided into negative control group (C1, n = 10) which received distilled water and positive control group (C2, n = 10) that received vitamin E (VE, 150 mg/kg/day) and selenium (NaSe 150 µg/kg/day) for 3 months through intra-gastric tube. The experimental group was divided into an E1 subgroup in which rats received aluminium chloride (AlCl3, 150 mg/kg/day, n = 10) and E2 subgroup (n = 10) in which animals received the same dose of AlCl3 plus VE and selenium at the same doses as C2 group for 3 months through intra-gastric tube. Conception of rats was allowed. AlCl3, VE and NaSe were given through intragastric tube during the whole length of the pregnancy, at the same doses as before pregnancy. At the 20th day of gestation dams were sacrificed, kidneys were dissected and processed for routine histological and immunohistochemical staining for identification of T-lymphocytes and macrophages. Integrated optical density of both cell types was assessed. AlCl3 administration induced histopathological changes in the kidney of pregnant rats and increased the density of CD3 and CD68 immunoreactive cells, suggestive of the associated aluminium-induced inflammatory process. Vitamin E and selenium minimized these harmful effects. The results suggest that diets rich in vitamin E and selenium and their supplements are advised particularly during pregnancy to alleviate the effects of possible excessive aluminium exposure.