Conditioned medium from amniotic fluid mesenchymal stem cells could modulate Alzheimer's disease-like changes in human neuroblastoma cell line SY-SY5Y in a paracrine manner.

BACKGROUND: Alzheimer's disease is usually diagnosed by significant extracellular deposition of beta-amyloid and intracellular neurofibrillary tangle formation. Here, we investigated the paracrine effect of amniotic fluid-derived mesenchymal stem cells on AD changes in human SH-SY5Y cells. METHODS: SH-SY5Y cells were divided into five groups: Control, 0.1 µg/ml LPS, 10 µg/ml LPS, 0.1 µg/ml LPS + conditioned medium, and 10 µg/ml LPS + conditioned medium. Cells were incubated with 0.1% and 10 µg/ml LPS for 48 h, followed by incubation with the conditioned medium of amniotic fluid-derived mesenchymal stem cells for the next 24 h. Beta-amyloid plaques were monitored by Congo-red staining. Survival and apoptosis were assessed by the MTT assay and flow cytometric analysis of Annexin-V. ELISA was used to measure the levels of neprilysin, angiotensin-converting enzyme, and Matrix Metalloproteinase-9. A PCR array was used to measure the expression of genes involved in neurogenesis. RESULTS: Bright-field imaging showed beta-amyloid plaques in the group treated with 10 µg/ml LPS. We found minimal effects in groups receiving 0.1 µg/ml LPS. The data showed that the reduction in the levels of neprilysin, angiotensin-converting enzyme, and Matrix Metalloproteinase-9 in the LPS-treated cells was attenuated after incubation with the stem cell secretome (p < 0.05). Amniotic fluid stem cell secretome increased the viability of LPS-treated SH-SY5Y cells (p 0.05) and was associated with a decrease in apoptotic changes (p < 0.05). We found the modulation of several genes involved in neurogenesis in the 10 µg/ml LPS + conditioned medium group compared to cells treated with 10 µg/ml LPS alone. CONCLUSION: Amniotic fluid stem cell secretion reduces AD-like pathologies in the human neuronal lineage.

Effect of Mineral Pitch on the Proliferation of Human Adipose Derived Stem Cells on Acellular Scaffold.

Purpose: Acellular scaffold extracted from extracellular matrix (ECM) have been used for constructive and regenerative medicine. Adipose derived stem cells (ADSCs) can enhance the vascularization capacity of scaffolds. High mobility group box 1 (HMGB1) and stromal derived factor1 (SDF1) are considered as two important factors in vascularization and immunologic system. In this study, the effect of mineral pitch on the proliferation of human ADSCs was evaluated. In addition to HMGB1 and SDF1, factors expression in acellular scaffold was also assessed. Methods: To determine acellular scaffold morphology and the degree of decellularization, hematoxylin & eosin (H&E), 6-diamidino-2-phenylindole (DAPI), and Masson's trichrome staining were applied. The scaffolds were treated with mineral pitch. Also, ADSCs were seeded on the scaffolds, and adhesion of the cells to the scaffolds were assessed using field emission scanning electron microscopy (FE-SEM). In addition, the efficiency of mineral pitch to induce the proliferation of ADSCs on the scaffolds was evaluated using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay. To measure HMGB1 and SDF1 mRNA expression, real-time polymerase chain reactions (RT-PCR) was used. Results: FE-SEM showed that decellularized matrix possesses similar matrix morphology with a randomly oriented fibrillar structure and interconnecting pores. No toxicity was observed in all treatments, and cell proliferation were supported in scaffolds. The important point is that, the proliferation capacity of ADSCs on Mineral pitch loaded scaffolds significantly increased after 48 h incubation time compared to the unloaded scaffold (P<0.001). Conclusion: The results of this study suggest that mineral pitch has potentials to accelerate proliferation of ADSCs on the acellular scaffolds.

High Glucose Content Abrogated the Normal Activity of Heat Shock Protein Signaling Pathway in Human Neuroblastoma Cells.

BACKGROUND: Detrimental effects of high glucose content (HGC) were proved in different tissues such as the central nervous system. It seems that diabetic conditions could also alter the functional behavior of stem cells residing in the context of the nervous system. METHODS: The possible effects of 40 and 70 mmol glucose were examined on HSP70 signaling pathways with a specific focus on protein translation, folding values of human neuroblastoma cell line SHSY-5Y after 72 h. Human neuroblastoma cells were exposed to 5, 40 and 70 mmol glucose doses. The transcription level of genes related to HSP70 signaling was also evaluated by PCR array. RESULTS: The data from PCR array showed high glucose especially 70 mmol could potentially modulate the normal function of protein folding, endoplasmic reticulum derived protein folding and synthesis in neuroblastoma cells (p <0.05). CONCLUSIONS: Data showed that high glucose condition makes neuroblastoma cells prone to biochemical insufficiency by affecting the function of HSP70 signaling pathway and protein synthesis.

Association of Paraoxonse1 (PON1) Genotypes with the Activity of PON1 in Patients with Parkinson's Disease.

OBJECTIVE: Various numbers of factors such as oxidative stress, neurotoxins, and pesticides have been implicated in its pathophysiology of Parkinson's disease (PD). Paraoxonas1 (PON1) metabolizes xenobiotics, including pesticides. Therefore, we surveyed the relationship between PON1 polymorphisms with its activities in the pathogenesis of Parkinson's disease.. METHODS: We investigated polymorphisms of the PON1 (L55M and Q192R) by PCR-RFLP assays; we also measure the levels of PON1, TAC (total antioxidant capacity) and TOS (total oxidant status) with ELISA (Enzyme-linked immunosorbent assay) and spectrophotometric method for their activities. RESULTS: Paraoxonase and arylesterase activity of PON1 as well as their concentrations were lower in patients with PD compared with control group, but from the view of the specific activity, it was not significant between two groups. In the compare of TAC, TOS, and OSI, the TOS and OSI were higher in the patients than controls, while patients had lower levels of TAC compared with controls. Serum PON1 concentrations and activities were higher in LL (comparison with LM and MM) and RR (comparison with QR and QQ) genotypes while we did not observe any significant differences in arylesterase levels among mentioned polymorphisms. CONCLUSION: In the current study, we reported associations between PON1 polymorphisms (55, 192) and enzyme activities in Parkinson's disease as there was a significant reduction in PON1 levels in patients with Parkinson compared with healthy. Taken together, paraoxonase enzyme in subjects with different genotypes could be a potential biomarker for determining the severity and prognosis of Parkinson. However, more studies are needed to clarify its clinical values. Key words: Parkinson's disease; paraoxonase1; Polymorphism.

The Dynamics of Neurosteroids and Sex-Related Hormones in the Pathogenesis of Alzheimer's Disease.

Alzheimer's disease (AD) is commonly diagnosed by vast extracellular amyloid deposits and existence of intracellular neurofibrillary tangles. In accordance with the literature, age-related loss of sex steroid hormones in either males or females was found in relation to AD subjects. The dynamics of these hormones have been previously described in both physiological and pathological conditions with the evidence of changes in various intracellular signalings regarding the neurodegenerative disease. The potent protective effects of sex steroid hormones and their synthetic analogs are indicative of the decrease in the accumulated levels of intercellular beta-amyloid (Aß) protein and an increase of specific proteases activity, resulting in the improvement of pathological features. In the current review, we focused on the dynamic of signaling pathway related to sex steroid hormones. It is logical to hypothesize that androgen hormones have regulatory actions on the kinetics of Aß which make them as a promising preventive approach for neurodegenerative diseases in the near future.