Transplantation of human adipose tissue-derived stem cells delays clinical onset and prolongs life span in ALS mouse model.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that selectively affects motor neurons in the cortex, brain stem, and spinal cord. The precise pathogenic mechanism remains unknown, and there is currently no effective therapy. We evaluated the therapeutic effects of human adipose tissue-derived stem cells (ASCs) in an animal model of ALS. Human abdominal subcutaneous fat tissues were obtained by simple liposuction from donors, and ASCs were isolated from the fat stromal vascular fraction. ASCs were found to differentiate into adipocytes, chondrocytes, osteocytes, and neurons. SOD1G93A ALS mice were divided into three groups: sham, intravenous (IV), and intracerebroventricular (ICV) groups. Human ASCs were transplanted in the ALS mice at 70 postnatal days before the appearance of clinical symptoms. Behavior of transplanted animals was assessed by rotarod test, paw grip endurance (PaGE), and reflex index. Mice in every group were sacrificed after 4 weeks posttransplantation. Transplanted ASCs were identified in the lumbar spinal cords with an antihuman mitochondria antibody and cell type-specific markers for neurons or astrocytes. Delayed onset of clinical symptoms (26 days) and extended survival of animals (24 days) were observed in ALS mice transplanted with ASCs via ICV route. ASCs were found to secrete high levels of neurotrophic factors such as NGF, BDNF, IGF-1, and VEGF. Reduction of apoptotic cell death by these factors was confirmed in cultured CNS cells and in the ALS spinal cord. These results indicate that transplantation of ASCs in ALS mice provides neuroprotective effects by production of cytokines/growth factors, delays disease progression, and prolongs the life span of ALS mice.

In vivo differentiation of undifferentiated human adipose tissue-derived mesenchymal stem cells in critical-sized calvarial bone defects.

Adult stem cells have recently drawn considerable attention for potential cell therapy applications. However, critical details about their specific in vivo environments and cellular activities are unclear. Adipose tissue-derived mesenchymal stem cells (ASCs) are attractive candidates for treating bone defects, but most studies focus on delivery of in vitro-differentiated cells. We assessed various scaffolding materials for the ability to support osteogenic differentiation of undifferentiated human ASCs in vivo, in athymic nude rat calvaria. Twenty-four 9- to 10-week-old athymic nude Sprague-Dawley rats (250 g) were used in these experiments. Fat tissue from 3 patients was harvested from abdominal tissue discarded during reconstructive breast surgery by transverse rectus abdominis myocutaneous flap, performed at the Asan Medical Center after resection of breast cancer. Human ASCs were extracted from discarded adipose tissue and isolated based on standard International Society for Cellular Therapy protocols. Adipose tissue-derived mesenchymal stem cells were seeded on polylactic glycolic acid, atelocollagen, and hydroxyapatite scaffolds, and osteogenesis was evaluated using bone mineral densitometry, histology, immunohistochemistry, and reverse transcription polymerase chain reaction. The gross appearance of scaffolds seeded with ASCs was strikingly different from that of scaffolds alone. Bone mineral densitometry analysis revealed a 2- to 3-fold increase in mineral density in ASC-seeded scaffolds. In addition, undifferentiated ASCs seeded onto hydroxyapatite scaffolds, but not onto collagen or polylactic glycolic acid scaffolds, expressed human messenger RNA for osteogenic markers such as alkaline phosphatase, osteopontin, osteocalcin, and osteonectin. These results indicate that undifferentiated human ASCs can differentiate into osteocytes or osteoblasts in athymic nude rat calvaria, and the importance of appropriate scaffolding for in vivo ASC differentiation.