Transgenic human embryonic stem cells overexpressing FGF2 stimulate neuroprotection following spinal cord ventral root avulsion.

Ventral root avulsion (VRA) triggers a strong glial reaction which contributes to neuronal loss, as well as to synaptic detachment. To overcome the degenerative effects of VRA, treatments with neurotrophic factors and stem cells have been proposed. Thus, we investigated neuroprotection elicited by human embryonic stem cells (hESC), modified to overexpress a human fibroblast growth factor 2 (FGF-2), on motoneurons subjected to VRA. Lewis rats were submitted to VRA (L4-L6) and hESC/FGF-2 were applied to the injury site using a fibrin scaffold. The spinal cords were processed to evaluate neuronal survival, synaptic stability, and glial reactivity two weeks post lesion. Then, qRT-PCR was used to assess gene expression of ß2-microglobulin (ß2m), TNFα, IL1ß, IL6 and IL10 in the spinal cord in vivo and FGF2 mRNA levels in hESC in vitro. The results indicate that hESC overexpressing FGF2 significantly rescued avulsed motoneurons, preserving synaptic covering and reducing astroglial reactivity. The cells were also shown to express BDNF and GDNF at the site of injury. Additionally, engraftment of hESC led to a significant reduction in mRNA levels of TNFα at the spinal cord ventral horn, indicating their immunomodulatory properties. Overall, the present data suggest that hESC overexpressing FGF2 are neuroprotective and can shift gene expression towards an anti-inflammatory environment.

Mesenchymal stem cells promote augmented response of endogenous neural stem cells in spinal cord injury of rats / Células-tronco mesenquimais ampliam a resposta de células-tronco neurais endógenas no trauma da medula espinhal em ratos

Traumatic spinal cord injury results in severe neurological deficits, mostly irreversible. The cell therapy represents a strategy for treatment particularly with the use of stem cells with satisfactory results in several experimental models. The aim of the study was to compare the treatment of spinal cord injury (SCI) with and without mesenchymal stem cells (MSC), to investigate whether MSCs migrate and/or remain at the site of injury, and to analyze the effects of MSCs on inflammation, astrocytic reactivity and activation of endogenous stem cells. Three hours after SCI, animals received bone marrow-derived MSCs (1×107 in 1mL PBS, IV). Animals were euthanized 24 hours, 7 and 21 days post-injury. The MSC were not present in the site of the lesion and the immunofluorescent evaluation showed significant attenuation of inflammatory response with reduction in macrophages labeled with anti-CD68 antibody (ED1), decreased immunoreactivity of astrocytes (GFAP+) and greater activation of endogenous stem cells (nestin+) in the treated groups. Therefore, cell transplantation have a positive effect on recovery from traumatic spinal cord injury possibly due to the potential of MSCs to attenuate the immune response.

A lesão medular resulta em déficits neurológicos graves, a maioria irreversíveis. A terapia celular representa uma estratégia para o tratamento, especialmente com a utilização de células-tronco, com resultados satisfatórios em vários modelos experimentais. O objetivo do estudo foi comparar o tratamento de lesões da medula espinal (SCI), com e sem o uso de células-tronco mesenquimais (MSC), para investigar se as MSCs migram e/ou permanecem no local de lesão, e para analisar os efeitos de MSCs sobre a inflamação, reatividade astrocitária e ativação das células-tronco endógenas. Três horas depois da SCI, os animais receberam as MSC derivadas da medula óssea (1 × 107 em 1 mL de PBS, IV). Os animais foram sacrificados 24 horas, 7 e 21 dias pós-lesão. As MSC não estavam presentes no local da lesão e a avaliação por imunofluorescência demonstrou atenuação significativa da resposta inflamatória com redução em macrófagos marcados com anticorpo anti CD68 (ED1), diminuição da imunorreatividade de astrócitos (GFAP +) e maior ativação das células-tronco endógenas (nestin+) nos grupos tratados. Assim, o transplante de células teve efeito positivo sobre a recuperação de lesão traumática da medula espinal, possivelmente devido ao potencial das MSCs para atenuar a resposta imunológica.

Mesenchymal stem cells promote augmented response of endogenous neural stem cells in spinal cord injury of rats / Células-tronco mesenquimais ampliam a resposta de células-tronco neurais endógenas no trauma da medula espinhal em ratos

Traumatic spinal cord injury results in severe neurological deficits, mostly irreversible. The cell therapy represents a strategy for treatment particularly with the use of stem cells with satisfactory results in several experimental models. The aim of the study was to compare the treatment of spinal cord injury (SCI) with and without mesenchymal stem cells (MSC), to investigate whether MSCs migrate and/or remain at the site of injury, and to analyze the effects of MSCs on inflammation, astrocytic reactivity and activation of endogenous stem cells. Three hours after SCI, animals received bone marrow-derived MSCs (1×107 in 1mL PBS, IV). Animals were euthanized 24 hours, 7 and 21 days post-injury. The MSC were not present in the site of the lesion and the immunofluorescent evaluation showed significant attenuation of inflammatory response with reduction in macrophages labeled with anti-CD68 antibody (ED1), decreased immunoreactivity of astrocytes (GFAP+) and greater activation of endogenous stem cells (nestin+) in the treated groups. Therefore, cell transplantation have a positive effect on recovery from traumatic spinal cord injury possibly due to the potential of MSCs to attenuate the immune response.(AU)

A lesão medular resulta em déficits neurológicos graves, a maioria irreversíveis. A terapia celular representa uma estratégia para o tratamento, especialmente com a utilização de células-tronco, com resultados satisfatórios em vários modelos experimentais. O objetivo do estudo foi comparar o tratamento de lesões da medula espinal (SCI), com e sem o uso de células-tronco mesenquimais (MSC), para investigar se as MSCs migram e/ou permanecem no local de lesão, e para analisar os efeitos de MSCs sobre a inflamação, reatividade astrocitária e ativação das células-tronco endógenas. Três horas depois da SCI, os animais receberam as MSC derivadas da medula óssea (1 × 107 em 1 mL de PBS, IV). Os animais foram sacrificados 24 horas, 7 e 21 dias pós-lesão. As MSC não estavam presentes no local da lesão e a avaliação por imunofluorescência demonstrou atenuação significativa da resposta inflamatória com redução em macrófagos marcados com anticorpo anti CD68 (ED1), diminuição da imunorreatividade de astrócitos (GFAP +) e maior ativação das células-tronco endógenas (nestin+) nos grupos tratados. Assim, o transplante de células teve efeito positivo sobre a recuperação de lesão traumática da medula espinal, possivelmente devido ao potencial das MSCs para atenuar a resposta imunológica.(AU)

Depletion of enteroendocrine and mucus-secreting cells is associated with colorectal carcinogenesis severity and impaired intestinal motility in rats.

This study investigated the relationship between enteroendocrine and mucus-secreting cells distribution, the severity of colonic mucosal injury and intestinal motility in experimental colorectal carcinogenesis. Using a standardized murine model of colorectal carcinogenesis, eight-weeks-old female Wistar rats weighting 147.30 ± 29.15g were randomized into two groups receiving a subcutaneous injection of 0.9% saline (control) or the chemical carcinogen 1,2-dimethylhydrazine (DMH) at 20 mg/kg per week during 10 weeks. Aberrant crypt foci (ACF) were more frequent in DMH group compared to control group (P < 0.001). The number of enteroendocrine and mucus-secreting cells, and intestinal motility was reduced in DMH animals (P < 0.05). The distribution of enteric neurons was similar in both groups. In DMH animals there was a direct correlation between colonic motility and distribution of enteroendocrine (R(2) = 0.68, P < 0.05) and mucus-secreting cells (R(2) = 0.77, P < 0.05). Inverse correlation between the number of ACF, mucus-secreting cells (R(2) = -0.57, P < 0.05), and enteroendocrine cells (R(2) = -0.74, P < 0.05) was also observed. There was inverse correlation between the severity of the mucosal lesion, the number of mucus-secreting cells (R(2) = -0.83, P < 0.05) and enteroendocrine cells (R(2) = -0.96, P < 0.05). There was a direct correlation between nucleolar organizer regions (AgNOR) and ACF number (R(2) = 0.62; P < 0.01). Inverse correlation was also found between AgNOR, the number of mucus-secreting cells (R(2) = -0.76; P < 0.001), and enteroendocrine cells (R(2) = -0.86; P < 0.001). Taken together, the results indicated that colonic malignant transformation is related to depletion of mucus-secreting and enteroendocrine cells, which was a useful indicator of the evolutionary status of intestinal neoplasm, partially explaining the intestinal motility disorders in the early stages of colorectal carcinogenesis.