Human dental pulp stem cells transplantation combined with treadmill training in rats after traumatic spinal cord injury

Spinal cord injury (SCI) is a disabling condition resulting in deficits of sensory and motor functions, and has no effective treatment. Considering that protocols with stem cell transplantation and treadmill training have shown promising results, the present study evaluated the effectiveness of stem cells from human exfoliated deciduous teeth (SHEDs) transplantation combined with treadmill training in rats with experimental spinal cord injury. Fifty-four Wistar rats were spinalized using NYU impactor. The rats were randomly distributed into 5 groups: Sham (laminectomy with no SCI, n=10); SCI (laminectomy followed by SCI, n=12); SHEDs (SCI treated with SHEDs, n=11); TT (SCI treated with treadmill training, n=11); SHEDs+TT (SCI treated with SHEDs and treadmill training; n=10). Treatment with SHEDs alone or in combination with treadmill training promoted functional recovery, reaching scores of 15 and 14, respectively, in the BBB scale, being different from the SCI group, which reached 11. SHEDs treatment was able to reduce the cystic cavity area and glial scar, increase neurofilament. Treadmill training alone had no functional effectiveness or tissue effects. In a second experiment, the SHEDs transplantation reduced the TNF-a levels in the cord tissue measured 6 h after the injury. Contrary to our hypothesis, treadmill training either alone or in combination, caused no functional improvement. However, SHEDs showed to be neuroprotective, by the reduction of TNF-a levels, the cystic cavity and the glial scar associated with the improvement of motor function after SCI. These results provide evidence that grafted SHEDs might be an effective therapy to spinal cord lesions, with possible anti-inflammatory action

Associação de treino locomotor em esteira e células-tronco no tratamento da lesão medular experimental

A lesão medular é considerada uma patologia incapacitante, para a qual até o momento não há tratamento eficaz. A lesão medular resulta em perda de tecido, incluindo tratos de fibras mielinizadas que carregam informações motoras e sensoriais. Além dos déficits sensitivos e motores, existem as alterações viscerais e tróficas relacionadas com o nível da lesão e o tipo de lesão. O treino locomotor em esteira e o transplante de células-tronco têm sido utilizados como estratégias de recuperação no intuito de otimizar a recuperação da lesão medular experimental em ratos, porém, vêm sendo abordadas separadamente. O objetivo deste estudo é avaliar a eficácia do treino locomotor em esteira, do transplante de células-tronco mesenquimais de dente decíduo humano (SHEDs), e da combinação entre os tratamentos avaliando a recuperação da função motora e a regeneração medular após a lesão medular traumática em ratos Wistar machos utilizando o equipamento NYU Impactor. Os objetivos específicos foram comparar os efeitos do transplante de SHEDS com o treino locomotor em esteira e a combinação entre os tratamentos quanto à recuperação da função motora e histológica; demonstrar a possível diferenciação das SHEDs transplantadas, bem como a sua integração no tecido da medula lesada. Os resultados obtidos demonstram que o transplante de SHEDs e a combinação entre os tratamentos favorece a recuperação da função motora após a lesão medular em ratos Wistar, enquanto apenas o tratamento com o treino locomotor não se mostra eficaz. Observamos neuroproteção do tecido medular evidenciada pela redução da cavidade cística nos animais tratados com a combinação de transplante de SHEDs e o treino locomotor. Houve redução da cicatriz glial e aumento na expressão de neurofilamento médio (NF-M) no grupo SHEDs. As células transplantadas sobreviveram e se integraram ao tecido, não havendo indícios de diferenciação em astrócitos e/ou neurônios. Houve um aumento na cicatriz glial no grupo lesão e no grupo lesão tratado com treino locomotor, associado a maiores áreas de cavidade cística e baixa expressão de NF-M. A partir de nossos resultados, podemos concluir que o transplante de SHEDs, assim como a combinação entre transplante de SHEDs e treino locomotor, promovem a recuperação da função motora após lesão medular por contusão. Apesar da sobrevivência e integração das SHEDs ao tecido, não houve diferenciação em astrócitos e/ou neurônios. Apenas o transplante celular foi capaz de reduzir a cicatriz glial e manter a expressão de neurofilamento.Spinal cord injury is a disabling traumatic condition and available therapeutic approaches are poorly effective. Spinal cord injury results in loss of tissue, including myelinated fiber tracts that carry sensory and motor information. In addition to motor and sensory deficits, there are visceral and trophic changes related to the level of injury and type of injury. In the search for new treatments, stem cells transplants and treadmill training have been studied separately to minimize spinal injury in experimental rats. The objective of this study is to evaluate the effectiveness of treatments between treadmill training, the transplantation of human exfoliated deciduous teeth (SHEDs), and the combination of treatments for functional recovery and regeneration of injured spinal cord in an experimental model of contusion spinal cord injury in rats Wistar reproduced by NYU Impactor device. The main goals were compare the effects of SHEDs transplantation with treadmill training and the combination of treatments for functional recovery and histology; demonstrate the possible differentiation of cells implanted, as well as their integration into the damage tissue. The results demonstrate that transplantation of SHEDs and combination of treatments promotes functional recovery after spinal cord injury in rats, while treatment with only the treadmill training is not efficient. Reduction of cystic cavity in the animals treated with the combination of transplantation and treadmill training was observed as an evidence of neuroprotection. We observed glial scar reduction and increased expression of neurofilament medium (NF-M) in the SHEDs group. The transplanted cells survived and integrated into the tissue, with no evidence of differentiation into astrocytes and/or neurons. Larger areas of cystic cavity, increase in glial scar and low expression of NF-M was seen in the treadmill training group. From our results, we conclude that transplantation of SHEDs, as well as the combination of transplant and treadmill training promotes functional recovery after spinal cord injury. Although the survival and integration of SHEDs on tissue, differentiation in astrocyte and/or neuron of transplanted the cells was not detected. Only cell transplantation was able to reduce the glial scar and to maintain the expression of neurofilament

Efeito neuroprotetor do transplante de células-tronco mesenquimais derivadas de dente decíduo humano em ratos Wistar submetidos à lesão medular

A lesão medular (LM) é uma patologia incapacitante que resulta em déficits sensoriais e motores. No Brasil, a incidência anual é de 30 novos casos de lesão medular a cada 1 milhão de indivíduos e, infelizmente, a LM permanece sem um tratamento eficaz. Células-tronco derivadas do dente decíduo humano estão entre as potenciais fontes de células-tronco para transplante após a lesão medular, cujo objetivo é de promover a proteção ou a recuperação da lesão na medula espinal. Buscou-se nesta tese avaliar os efeitos do transplante, uma hora após a lesão, das células tronco de dente decíduo humano (SHED) no período agudo, subagudo e crônico sobre a neuroproteção, proteção tecidual e recuperação funcional em ratos Wistar submetidos à lesão medular por contusão. Os principais objetivos foram: a) investigar os efeitos do transplante das SHED sobre a recuperação funcional, volume da lesão e morte neuronal; b) verificar os efeitos do transplante sobre as células progenitoras, formação da cicatriz glial e modificações astrocitárias após o modelo de contusão medular Observou-se a melhora na recuperação funcional, redução do volume da lesão e morte neuronal na medula espinal dos animais que receberam o transplante de SHED após a lesão medular. As SHED aumentam o número de células precursoras na medula espinal, no período subagudo, reduzem a expressão da proteína fibrilar glial ácida (GFAP) e aumentam a expressão do canal retificador de influxo de potássio 4.1, ambas proteínas astrocitárias. Concluímos que o transplante de células-tronco derivadas do dente decíduo humano após a lesão medular promove a recuperação funcional a partir do efeito neuroprotetor iniciado na fase aguda, confirmado pelo maior número de neurônios motores presentes seis semanas após a contusão. As SHED são capazes de aumentar o número de células precursoras e de produzir modificações astrocitárias na medula espinal de ratos lesados na fase subaguda, reduzindo a formação da cicatriz glial.Spinal cord injury (SCI) is a disabling condition that results in sensory and motor deficits. The estimated annual incidence in Brazil is of 30 new cases of spinal cord injury per 1 million of individuals; unfortunately SCI remains without an effective treatment. Stem cells from human exfoliated deciduous teeth (SHED) are one among potential sources of stem cells for transplantation after spinal cord injury in order to promote protection or tissue and functional recovery after spinal cord injury. The aim of this Thesis was to evaluate the effects of stem cells from human exfoliated deciduous teeth (SHED) transplantation, one hour after lesion, in the acute, subacute and chronic phases on neuroprotection, tissue protection and functional recovery in Wistar rats submitted to spinal cord injury by contusion The main goals were: a) to investigate the effects of SHED transplantation on functional recovery, lesion volume, and neuronal death; b) to verify the effects of the transplantation on the progenitor cells number, glial scar formation and astrocytic modifications after spinal cord contusion. Improvement of functional recovery, reduction of lesion volume and neuronal death were observed in the spinal cord of animals submitted to spinal cord injury and SHED transplantation. SHEDs increased the number of precursor cells in the spinal cord in the subacute period, reduced the expression of glial fibrillary acidic protein (GFAP) and increased the expression of the potassium influx rectifier channel 4.1, both astrocyte proteins. We conclude that transplantation of stem cells from human exfoliated deciduous teeth after spinal cord injury promotes functional recovery from the neuroprotection effect, which starts in the acute phase and is confirmed six weeks after the contusion with a higher number of motor neurons in the ventral horn of spinal cord. SHEDs are able to increase the number of precursor cells and produce astrocyte modifications in the spinal cord of injured rats in the subacute phase, reducing glial scar formation

Glial fibrillary acidic protein levels are associated with global histone H4 acetylation after spinal cord injury in rats

Emerging evidence has suggested global histone H4 acetylation status plays an important role in neural plasticity. For instance, the imbalance of this epigenetic marker has been hypothesized as a key factor for the development and progression of several neurological diseases. Likewise, astrocytic reactivity - a wellknown process that markedly influences the tissue remodeling after a central nervous system injury - is crucial for tissue remodeling after spinal cord injury (SCI). However, the linkage between the above-mentioned mechanisms after SCI remains poorly understood. We sought to investigate the relation between both glial fibrillary acidic protein (GFAP) and S100 calcium-binding protein B (S100B) (astrocytic reactivity classical markers) and global histone H4 acetylation levels. Sixty-one male Wistar rats (aged ~3 months) were divided into the following groups: sham; 6 hours post-SCI; 24 hours post-SCI; 48 hours post-SCI; 72 hours post-SCI; and 7 days post-SCI. The results suggested that GFAP, but not S100B was associated with global histone H4 acetylation levels. Moreover, global histone H4 acetylation levels exhibited a complex pattern after SCI, encompassing at least three clearly defined phases (first phase: no changes in the 6, 24 and 48 hours post-SCI groups; second phase: increased levels in the 72 hours post-SCI group; and a third phase: return to levels similar to control in the 7 days post-SCI group). Overall, these findings suggest global H4 acetylation levels exhibit distinct patterns of expression during the first week post-SCI, which may be associated with GFAP levels in the perilesional tissue. Current data encourage studies using H4 acetylation as a possible biomarker for tissue remodeling after spinal cord injury