Quantitative Characterization of Phenotypical Markers After Differentiation of SH-SY5Y Cells

BACKGROUND

The human neuroblastoma cell line, SH-SY5Y, has been widely used in neuroscience research, especially in studies related to Parkinson's disease. However, differences between clones have been demonstrated, highlighting the importance to characterize the properties of this cell line carefully.

OBJECTIVE

The aim of this study was to characterize the phenotype of undifferentiated and differentiated SH-SY5Y cells using various differentiation protocols.

METHODS

A morphological and quantitative analysis of markers related to dopaminergic and cholinergic neurons, but also other phenotypes, was performed.

RESULTS

Differentiated cells showed the typical neuronal morphology. Undifferentiated cells expressed low levels of Tyrosine Hydroxylase (TH) and higher levels of the high-affinity Choline Transporter (CHT1). Staurosporine (ST)-differentiation resulted in the highest number of THimmunoreactive cells, followed by phorbol ester Phorbol-12-Myristate-13-Acetate (PMA), whereas differentiation with Brain-Derived Neurotrophic Factor (BDNF) did not increase TH-immunoreactive cells. TH, dopamine β-hydroxylase and vesicular monoamine transporter-2 were also significantly upregulated in ST-differentiated cells compared to both undifferentiated and Retinoic Acid (RA)- differentiated cells. RA induced the highest number of CHT1-immunoreactive cells while ST- and BDNF-differentiation reduced CHT1-immunoreactive cells, indicating a decrease in the cholinergic phenotype. The presynaptic neuronal protein, α-synuclein, was significantly upregulated in RA- and ST-treated cells compared to undifferentiated cells. Ascorbic acid increased the number of CHT1-immunoreactive cells in all differentiation procedures and ST-differentiated TH-positive cells significantly.

CONCLUSION

Our findings indicate that a quantitative characterization of the phenotype is crucial when using SH-SY5Y cells to study the pathogenesis or evaluate compounds for treatment of neurodegenerative diseases.

Silica nanoparticle-exposure during neuronal differentiation modulates dopaminergic and cholinergic phenotypes in SH-SY5Y cells

BACKGROUND

Silica-ε-polycaprolactone-nanoparticles (SiPCL-NPs) represent a promising tool for laser-tissue soldering in the brain. After release of the SiPCL-NPs in the brain, neuronal differentiation might be modulated. The present study was performed to determine effects of SiPCL-NP-exposure at different stages of neuronal differentiation in neuron-like SH-SY5Y cells. The resulting phenotypes were analyzed quantitatively and signaling pathways involved in neuronal differentiation and degeneration were studied. SH-SY5Y cells were differentiated with all-trans retinoic acid or staurosporine to obtain predominantly cholinergic or dopaminergic neurons. The resulting phenotype was analyzed at the end of differentiation with and without the SiPCL-NPs given at various times during differentiation.

RESULTS

Exposure to SiPCL-NPs before and during differentiation led to a decreased cell viability of SH-SY5Y cells depending on the differentiation protocol used. SiPCL-NPs co-localized with the neuronal marker β-3-tubulin but did not alter the morphology of these cells. A significant decrease in the number of tyrosine hydroxylase (TH) immunoreactive neurons was found in staurosporine-differentiated cells when SiPCL-NPs were added at the end of the differentiation. TH-protein expression was also significantly downregulated when SiPCL-NPs were applied in the middle of differentiation. Protein expression of the marker for the dopamine active transporter (DAT) was not affected by SiPCL-NPs. SiPCL-NP-exposure predominantly decreased the expression of the high-affinity choline transporter 1 (CHT1) when the NPs were given before the differentiation. Pathways involved in neuronal differentiation, namely Akt, MAP-K, MAP-2 and the neurodegeneration-related markers β-catenin and GSK-3β were not altered by NP-exposure.

CONCLUSIONS

The decrease in the number of dopaminergic and cholinergic cells may implicate neuronal dysfunction, but the data do not provide evidence that pathways relevant for differentiation and related to neurodegeneration are impaired.

[Gait pattern of patients with hip arthritis]

Automatic recording of the kinematic and kinetic gait pattern has so far not been commonly used in the diagnosis of problems affecting the human loco motor apparatus. In recent decades gait analysis has increasingly been applied in the development of endoprostheses and sports shoes and in rehabilitation, especially of patients with neurological diseases. When a gait laboratory is set up, this demands interdisciplinary cooperation, biomechanical knowledge in physicians and (physio-)therapists, and elaboration of treatment plans allowing direct therapeutic exploitation of the gait data. There are determinant factors in gait pattern, which does not vary qualitatively in the sagittal plane (flexion/extension) with sex and age until the age of 70 years. Quantitatively there is a great deal of individual variation, and the diagnosis of a pathologic function in a particular patient can be difficult. A normal reference population was used to determine the gait pattern characteristic for 32 patients with osteoarthritis of the hip on one or on both sides, and the possible significance of the results for physical and surgical therapy is discussed. The main characteristic of this gait pattern ist the limitation of hip extension before toe-off in the late stance phase. One-third of the patients answer compensate with this increased hip flexion at heel strike, which in turn leads to an increased load on the (more severely) affected side. In consequence, the increased load might lead to progression of the osteoarthritis. In the development of endoprostheses it should be borne in mind that the design may influence the gait pattern, producing overloading of the extremity and perhaps reducing the life of the prosthesis.