Human mesenchymal stromal cell transplantation modulates neuroinflammatory milieu in a mouse model of amyotrophic lateral sclerosis

Background aims. Mesenchymal stromal cells (MSCs), after intraparenchymal, intrathecal and endovenous administration, have been previously tested for cell therapy in amyotrophic lateral sclerosis in the SOD1 (superoxide dismutase 1) mouse. However, every administration route has specific pros and cons. Methods. We administrated human MSCs (hMSCs) in the cisterna lumbaris, which is easily accessible and could be used in outpatient surgery, in the SOD1 G93A mouse, at the earliest onset of symptoms. Control animals received saline injections. Motor behavior was checked starting from 2 months of age until the mice were killed. Animals were killed 2 weeks after transplantation; lumbar motoneurons were stereologically counted, astrocytes and microglia were analyzed and quantified after immunohistochemistry and cytokine expression was assayed by means of real-time polymerase chain reaction. Results. We provide evidence that this route of administration can exert strongly positive effects. Motoneuron death and motor decay were delayed, astrogliosis was reduced and microglial activation was modulated. In addition, hMSC transplantation prevented the downregulation of the anti-inflammatory interleukin-10, as well as that of vascular endothelial growth factor observed in saline-treated transgenic mice compared with wild type, and resulted in a dramatic increase in the expression of the anti-inflammatory interleukin-13. Conclusions. Our results suggest that hMSCs, when intracistemally administered, can exert their paracrine potential, influencing the inflammatory response of the host.