The subcutaneous adipose tissue provides a clear advantage over other mesenchymal stem cell sources due to the ease with which it can be accessed, as well as the ease of isolating the residing stem cells. Human adipose-derived stem cells (hADSCs), localized in the stromal–vascular portion, can be isolated ex vivo using a combination of washing steps and enzymatic digestion. In this study, we report that microfragmented human lipoaspirated adipose tissue is a better stem cell source compared to normal lipoaspirated tissue. The structural composition of microfragments is comparable to the original tissue. Differently, however, this procedure activates the expression of antigens, such as β-tubulin III. The hADSCs derived from microfragmented lipoaspirate tissue were systematically characterized for growth features, phenotype, and multipotent differentiation potential. They fulfill the definition of mesenchymal stem cells, although with a higher neural phenotype profile. These cells also express genes that constitute the core circuitry of self-renewal such as OCT4, SOX2, and NANOG, and neurogenic lineage genes such as NEUROD1, PAX6, and SOX3. Such findings suggest further studies by evaluating Microfrag-AT hADSC action in animal models of neurodegenerative conditions.
1 September 2007 in The Journal of Pharmacology and Experimental Therapeutics
It has been shown that the blockade of CXCR1 and CXCR2 receptors prevents ischemia/reperfusion damage in several types of vascular beds. Reparixin is a recently described inhibitor of human CXCR1/R2 and rat CXCR2 receptor activation. We applied reparixin in rats following traumatic spinal cord injury and determined therapeutic temporal and dosages windows. Treatment with reparixin significantly counteracts secondary degeneration by reducing oligodendrocyte apoptosis, migration to the injury site of neutrophils and ED-1-positive cells. The observed preservation of the white matter might also be secondary to the enhanced proliferation of NG2-positive cells. The expression of macrophage-inflammatory protein-2, tumor necrosis factor-α, interleukin (IL)-6, and IL-1β was also counteracted, and the proliferation of glial fibrillary acidic protein-positive cells was markedly reduced. These effects resulted in a smaller post-traumatic cavity and in a significantly improved recovery of hind limb function. The best beneficial outcome of reparixin treatment required 7-day administration either by i.p. route (15 mg/kg) or subcutaneous infusion via osmotic pumps (10 mg/kg), reaching a steady blood level of 8 μg/ml. Methylprednisolone was used as a reference drug; such treatment reduced cytokine production but failed to affect the rate of hind limb recovery.
The aim of the study was the assessment of the effects of adult neural stem cell (NSC) transplantation in a mouse model of spinal cord injury (SCI). The contusion injury was performed by means of the Infinite Horizon Device to allow the generation of reproducible traumatic lesion to the cord. We administered green fluorescent-labeled (GFP-)NSCs either by intravenous (i.v.) injection or by direct transplantation into the spinal cord (intraspinal route). We report that NSCs significantly improved recovery of hind limb function and greatly attenuated secondary degeneration. The i.v. route of NSC administration yielded better recovery than the intraspinal route of administration. About 2% of total i.v.-administered NSCs homed to the spinal cord injury site, and survived almost undifferentiated; thus the positive effect of NSC treatment cannot be ascribed to damaged tissue substitution. The NSCs homing to the injury site triggered, within 48 h, a large increase of the expression of neurotrophic factors and chemokines. One wk after transplantation, exogenous GFP-NSCs still retained their proliferation potential and produced neurospheres when recovered from the lesion site and cultured in vitro. At a later time, GFP-NSC were phagocytated by macrophages. We suggest that the process of triggering the recovery of function might be strongly related to the viability of GFP-NSC, still capable ex vivo of producing neurospheres, and their ability to modify the lesion environment in a positive fashion.
The adipose tissue is a source of inflammatory proteins, such as TNF, IL-6, and CXCL8. Most of their production occurs in macrophages that act as scavengers of dying adipocytes. The application of an orbital mechanical force for 6–10 min at 97 g to the adipose tissue, lipoaspirated and treated according to Coleman procedures, abolishes the expression of TNF-α and stimulates the expression of the anti-inflammatory protein TNF-stimulated gene-6 (TSG-6). This protein had protective and anti-inflammatory effects when applied to animal models of rheumatic diseases. We examined biopsy, lipoaspirate, and mechanically activated fat and observed that in addition to the increased TSG-6, Sox2, Nanog, and Oct4 were also strongly augmented by mechanical activation, suggesting an effect on stromal cell stemness. Human adipose tissue-derived mesenchymal stem cells (hADSCs), produced from activated fat, grow and differentiate normally with proper cell surface markers and chromosomal integrity, but their anti-inflammatory action is far superior compared to those mesenchymal stem cells (MSCs) obtained from lipoaspirate. The expression and release of inflammatory cytokines from THP-1 cells was totally abolished in mechanically activated adipose tissue-derived hADSCs. In conclusion, we report that the orbital shaking of adipose tissue enhances its anti-inflammatory properties, and derived MSCs maintain such enhanced activity.
Spinal cord injury (SCI) is a devastating disease, which leads to paralysis and is associated to substantially high costs for the individual and society. At present, no effective therapies are available. Here, the use of mechanically-activated lipoaspirate adipose tissue (MALS) in a murine experimental model of SCI is presented. Our results show that, following acute intraspinal MALS transplantation, there is an engraftment at injury site with the acute powerful inhibition of the posttraumatic inflammatory response, followed by a significant progressive improvement in recovery of function. This is accompanied by spinal cord tissue preservation at the lesion site with the promotion of endogenous neurogenesis as indicated by the significant increase of Nestin-positive cells in perilesional areas. Cells originated from MALS infiltrate profoundly the recipient cord, while the extra-dural fat transplant is gradually impoverished in stromal cells. Altogether, these novel results suggest the potential of MALS application in the promotion of recovery in SCI.