Differentiation of adult human mesenchymal stem cells into dopaminergic neurons.

The striatal dopamine (DA) deficiency is known as the main cause of the clinical picture of Parkinson's disease (PD). The disease is a progressive degeneration of dopaminergic neurons in the striatum. The treatment of PD is based on compensation for the brain's supply of DA lost by drug therapy, deep brain stimulation, surgery, gene and cell therapies. Clinical studies have focused on the utility of stem cell-based therapies in PD. Embryonic and mesenchymal stem cells (MSCs) are widely used. Recently, human adipose derived stem cells (hADSCs) have been considered as a suitable source of tissue for this purpose. In this project, hADSCs differentiated into dopaminergic neurons and the specificity of the cell preparations was examined. Human adipose tissues were collected from healthy volunteers undergoing liposuction and hADSCs were isolated by collagenase-based enzymatic method. Flow cytometry was performed using the surface cluster of differentiation (CD) markers to confirm the cell typical properties. Then hADSCs were differentiated to dopaminergic neurons in neurobasal medium in the presence of differentiation factors and confirmed by immunocytochemistry via neuronal and dopaminergic markers. The isolated hADSCs were cultured and identified by the expression of MSCs surface markers including CD90, and CD44. These cells did not express hematopoietic surface markers such as CD45 and CD14. Differentiated cells express neuronal marker NeuN and dopaminergic marker tyrosine hydroxylase (TH). It is concluded that hADSCs can be easily taken from the patient's own body and differentiated into dopaminergic cells having a lower risk of transplant rejection.

Nerve growth factor receptors in dementia.

BACKGROUND/AIM: Nerve growth factor (NGF) promotes the survival and differentiation of sensory and sympathetic neurons. Several studies have found that certain neuropathological factors stimulate NGF receptor expression and release the truncated nerve growth factor receptor (TNGFR) to biological fluids. The aim of this pilot study was to determine urine TNGFR levels in patients with dementia and to verify whether TNGFR can be used as a biomarker of dementia. MATERIALS AND METHODS: Twelve patients with dementia and 12 healthy individuals were asked to voluntarily participate in this study. Ages, sexes, and weights were matched. The first morning urine samples were collected and the concentrations of TNGFR in the urine samples were measured by fluoroimmunoassay. RESULTS: The mean levels of TNGFR in the urine samples of the healthy control subjects and the patients with dementia were 164 ± 23 and 341 ± 66 ng / mg creatinine respectively. A positive relationship was found between the levels of TNGFR in different ages of both control and patient subgroups. This is consistent with the previous observations that pathological condition may stimulate the NGF receptor expression. CONCLUSION: These findings might be of assistance to evaluate the development of the memory loss associated with Alzheimer disease and other age-associated diseases.

Age related interaction of dopamine and serotonin synthesis in striatal synaptosomes.

Tyrosine hydroxylase and tryptophan hydroxylase are key rate limiting enzymes in the biosynthesis of dopamine and serotonin, respectively. Since both enzymes are active in striatum, and affected by age, this study was undertaken to investigate interaction between dopamine and serotonin synthesis in brain striatal synaptosomes of aging rat. Male Wistar rats (3 and 30 month old) were killed by decapitation and brain striatal synaptosomes were prepared by discontinuous Ficoll/sucrose gradient technique. Synaptosomes were incubated in the presence of added pargiline (monoamineoxidase inhibitor), dopamine or serotonin synthesized during 25 min was measured by HPLC, employing electrochemical detection. Dopamine synthesis in synaptosomes prepared from young animals was markedly inhibited by addition of 5 microM serotonin concentrations (30%) and increasing serotonin concentrations up to 50 microM caused only a smaller additional inhibition. Dopamine synthesis in synaptosomes obtained from old rats was significantly lower than that of youg animals and addition of serotonin concentrations up to 50 microM had little effect on these preparations. In case of serotonin synthesis, exogenously added 5 microM dopamine inhibited serotonin synthesis in the synaptosomes of both ages by about 40%, whereas with higher concentration of dopamine (10-50 microM) the rate of inhibition was highly pronounced in old rats as compared to that of young animals. It is concluded that dopamine and serotonin interaction may be significant, and that these should be considered in long-term treatments of Parkinson's disease with L-DOPA.

Age related interaction of dopamine and serotonin synthesis in striatal synaptosomes. / Age related interaction of dopamine and serotonin synthesis in striatal synaptosomes.

Tyrosine hydroxylase and tryptophan hydroxylase are key rate limiting enzymes in the biosynthesis of dopamine and serotonin, respectively. Since both enzymes are active in striatum, and affected by age, this study was undertaken to investigate interaction between dopamine and serotonin synthesis in brain striatal synaptosomes of aging rat. Male Wistar rats (3 and 30 month old) were killed by decapitation and brain striatal synaptosomes were prepared by discontinuous Ficoll/sucrose gradient technique. Synaptosomes were incubated in the presence of added pargiline (monoamineoxidase inhibitor), dopamine or serotonin synthesized during 25 min was measured by HPLC, employing electrochemical detection. Dopamine synthesis in synaptosomes prepared from young animals was markedly inhibited by addition of 5 microM serotonin concentrations (30

) and increasing serotonin concentrations up to 50 microM caused only a smaller additional inhibition. Dopamine synthesis in synaptosomes obtained from old rats was significantly lower than that of youg animals and addition of serotonin concentrations up to 50 microM had little effect on these preparations. In case of serotonin synthesis, exogenously added 5 microM dopamine inhibited serotonin synthesis in the synaptosomes of both ages by about 40

, whereas with higher concentration of dopamine (10-50 microM) the rate of inhibition was highly pronounced in old rats as compared to that of young animals. It is concluded that dopamine and serotonin interaction may be significant, and that these should be considered in long-term treatments of Parkinsons disease with L-DOPA.