Neurogenic Effects of Cell-Free Extracts of Adipose Stem Cells

Adult stem cell response to doped bioactive borate glass

Bioactive glasses have transformed healthcare due to their versatility. Bioactive borate glass, in particular, has shown remarkable healing properties for both hard and soft tissues. Incorporating dopants into the composition of bioactive glass helps to control mechanical properties, and it increases their usefulness for clinical applications. Using a bioactive borate glass, 13-93B3 (B3), we investigated eleven dopants on the viability and migration potential of adipose stem cells (ASCs), a therapeutic source of cells used in tissue engineering and cell therapy. Our results show that under standard cell culture conditions, only Cu-doped B3 decreased cell viability, while only Y-doped B3 attracted ASCs as it dissolved in cell culture media. Using a transwell invasion assay, priming ASCs with Co, Fe, Ga, I, Sr, or Zn-doped B3 increased their homing capacity. Because there is widespread interest in optimizing and enhancing the homing efficiency of ASCs and other therapeutic cells, we then tested if priming bone marrow mesenchymal stem cells (BMSCs) with dopants also increased their homing capacity. In the case of BMSCs, there was a significant increase in invasion when cells were primed with any of the doped-B3 glasses. This work shows that incorporating dopants into borate glasses can provide a platform for a safe and efficient method that stimulates endogenous cells and healing mechanisms.

MicroRNA-27a reduces mutant hutingtin aggregation in an in vitro model of Huntington's disease

Huntington's disease (HD) is a fatal genetic disease caused by abnormal aggregation of mutant huntingtin protein (mHtt). Reduction of mHtt aggregation decreases cell death of the brain and is a promising therapeutic strategy of HD. MicroRNAs are short non-coding nucleotides which modulate various genes and dysregulated in many diseases including HD. MicroRNA miR-27a was reported to be reduced in the brain of R6/2 HD mouse model and modulate multidrug resistance protein-1 (MDR-1). Using subventricular zone-derived neuronal stem cells (NSCs), we used in vitro HD model to test the effect of miR-27a on MDR-1 and mHtt aggregation. R6/2-derived NSCs can be differentiated under condition of growth factor deprivation, and the progression of differentiation leads to a decrease of MDR-1 level and efflux function of cells. Immunocytochemistry result also confirmed that mHtt aggregation was increased with differentiation. We transfected miR-27a in the R6/2-derived differentiated NSCs, and examined phenotype of HD, mHtt aggregation. As a result, miR-27a transfection resulted in reduction of mHtt aggregation in HD cells. In addition, MDR-1, which can transport mHtt, protein level was increased by miR-27a transfection. Conversely, knock-down of MDR-1 through MDR-1 siRNA increased mHtt aggregation in vitro. Our results indicate that miR-27a could reduce mHtt level of the HD cell by augmenting MDR-1 function.

Intravenous Administration of Adipose-Derived Stem Cell Protein Extracts Improves Neurological Deficits in a Rat Model of Stroke

Treatment of adipose-derived stem cell (ADSC) substantially improves the neurological deficits during stroke by reducing neuronal injury, limiting proinflammatory immune responses, and promoting neuronal repair, which makes ADSC-based therapy an attractive approach for treating stroke. However, the potential risk of tumorigenicity and low survival rate of the implanted cells limit the clinical use of ADSC. Cell-free extracts from ADSC (ADSC-E) may be a feasible approach that could overcome these limitations. Here, we aim to explore the potential usage of ADSC-E in treating rat transient middle cerebral artery occlusion (tMCAO). We demonstrated that intravenous (IV) injection of ADSC-E remarkably reduces the ischemic lesion and number of apoptotic neurons as compared to other control groups. Although ADSC and ADSC-E treatment results in a similar degree of a long-term clinical beneficial outcome, the dynamics between two ADSC-based therapies are different. While the injection of ADSC leads to a relatively mild but prolonged therapeutic effect, the administration of ADSC-E results in a fast and pronounced clinical improvement which was associated with a unique change in the molecular signature suggesting that potential mechanisms underlying different therapeutic approach may be different. Together these data provide translational evidence for using protein extracts from ADSC for treating stroke.

Cytosolic Extract of Human Adipose Stem Cells Reverses the Amyloid Beta-Induced Mitochondrial Apoptosis via P53/Foxo3a Pathway

Human adipose stem cells (hASC) have therapeutic potential for the treatment of neurodegenerative disorders. Mitochondrial dysfunction is frequently observed in most neurodegenerative disorders, including Alzheimer’s disease. We explored the therapeutic potential of hASC cytosolic extracts to attenuate neuronal death induced by mitochondrial dysfunction in an Alzheimer’s disease (AD) in vitro models. Amyloid beta (Aβ) was used to induce cytotoxity in an immortal hippocampal cell line (HT22) and neuronal stem cells from the brain of TG2576 transgenic mice were also used to test the protective role of hASC cytosolic extracts. Cell viability and flow cytometry results demonstrated that the hASC extract prevents the toxicity and apoptosis in AD in vitro models. Moreover, JC-1 and MitoSoxRed staining followed by fluorescence microscopy and flow cytometry results showed that the hASC extract ameliorated the effect of Aβ-induced mitochondrial oxidative stress and reduced the mitochondrial membrane potential. Western blot result showed that hASC extract modulated mitochondria-associated proteins, such as Bax and Bcl2, and down-regulated cleaved caspase-3. In addition, hASC extract decreased Aβ generation and reversed up-regulated p53 and foxo3a protein level in AD in vitro model cell derived from TG2576 mice. Taken together, these findings implicate a protective role of the hASC extract in the Aβ-induced mitochondrial apoptosis via regulation of P53/foxo3a pathway, providing insight into the molecular mechanisms of hASC extract and a therapeutic strategy to ameliorate neuronal death induced by Aβ.