Adult olfactory bulb neural precursor cell grafts provide temporary protection from motor neuron degeneration, improve motor function, and extend survival in amyotrophic lateral sclerosis mice

Amyotrophic lateral sclerosis is a fatal disease caused by degeneration of motor neurons (MNs). We transplanted multipotent neural precursor cell (NPC)-neurospheres from mouse olfactory bulb (OB) into the spinal cord of transgenic mice that develop MN degeneration because of human mutant superoxide dismutase-1 (mSOD1). Adult NPCs were isolated from the OB core of transgenic mice expressing green fluorescent protein, human wild-type SOD1, or human mSOD1. mSOD1 mice received lumbar spinal cord transplants of OB-NPC neurospheres at preclinical stages of disease (70 days old). Control mSOD1 mice received dead cells or recombinant green fluorescent protein. OB-NPCs attenuated the loss of motor function and wasting. They delayed disease onset to ∼117 days, compared with control onset at ∼90 days. The lifespan of NPC recipient mice was extended (∼170 days) compared with the lifespan of controls (∼140 days). Transplanted OB-NPCs differentiated into large spinal neurons positive for choline acetyltransferase, interneurons, and glial cells. Loss of endogenous MNs was attenuated in mSOD1 mice with transplants. New neurons formed myelinated axons and synapses. NPC-derived neurons issued axons that grew into peripheral nerve. OB-NPCs also differentiated into oligodendrocytes and astrocytes that contacted neuronal processes. We conclude that transplantation of adult OB-NPCs is therapeutic for mouse amyotrophic lateral sclerosis.