Human neural stem cells: a model system for the study of Lesch-Nyhan disease neurological aspects.

The study of Lesch-Nyhan-diseased (LND) human brain is crucial for understanding how mutant hypoxanthine-phosphoribosyltransferase (HPRT) might lead to neuronal dysfunction. Since LND is a rare, inherited disorder caused by a deficiency of the enzyme HPRT, human neural stem cells (hNSCs) that carry this mutation are a precious source for delineating the consequences of HPRT deficiency and for developing new treatments. In our study we have examined the effect of HPRT deficiency on the differentiation of neurons in hNSCs isolated from human LND fetal brain. We have examined the expression of a number of transcription factors essential for neuronal differentiation and marker genes involved in dopamine (DA) biosynthetic pathway. LND hNSCs demonstrate aberrant expression of several transcription factors and DA markers. HPRT-deficient dopaminergic neurons also demonstrate a striking deficit in neurite outgrowth. These results represent direct experimental evidence for aberrant neurogenesis in LND hNSCs and suggest developmental roles for other housekeeping genes in neurodevelopmental disease. Moreover, exposure of the LND hNSCs to retinoic acid medium elicited the generation of dopaminergic neurons. The lack of precise understanding of the neurological dysfunction in LND has precluded development of useful therapies. These results evidence aberrant neurogenesis in LND hNSCs and suggest a role for HPRT gene in neurodevelopment. These cells combine the peculiarity of a neurodevelopmental model and a human, neural origin to provide an important tool to investigate the pathophysiology of HPRT deficiency and more broadly demonstrate the utility of human neural stem cells for studying the disease and identifying potential therapeutics.

Human skeletal muscle stem cell antiinflammatory activity ameliorates clinical outcome in amyotrophic lateral sclerosis models.

Mesenchymal stem cell (MSC) therapy is considered one of the most promising approaches for treating different neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS). We previously characterized a subpopulation of human skeletal muscle-derived stem cells (SkmSCs) with MSC-like characteristics that differentiate into the neurogenic lineage in vitro. In the present study, we evaluated the SkmSC therapeutic effects in the most characterized model of spontaneous motor neuron degeneration, the Wobbler (Wr) mouse. Before evaluating the therapeutic efficacy in the Wr mouse, we followed the route of Skm-SCs at different times after intracerebroventricular injection. Two exogenous tracers, superparamagnetic iron oxide (SPIO) nanoparticles and Hoechst 33258, were used for the in vivo and ex vivo tracking of SkmSCs. We found that the loading of both Hoechst and SPIO was not toxic and efficiently labeled SkmSCs. The magnetic resonance imaging (MRI) system 7 Tesla allowed us to localize transplanted SkmSCs along the whole ventricular system up to 18 wks after injection. The ex vivo Hoechst 33258 visualization confirmed the in vivo results obtained by MRI analyses. Behavioral observations revealed a fast and sustained improvement of motor efficacy in SkmSC-treated Wr mice associated with a relevant protection of functional neuromuscular junctions. Moreover, we found that in SkmSC-treated Wr mice, a significant increase of important human antiinflammatory cytokines occurred. This evidence is in accordance with previous findings showing the bystander effect of stem cell transplantation in neurodegenerative disorders and further strengthens the hypothesis of the possible link between inflammation, cytotoxicity and ALS.

Expression of neural and neurotrophic markers in nucleus pulposus cells isolated from degenerated intervertebral disc.

Intervertebral disc (IVD) degeneration is a common disorder of the lower spine. Since it is caused by loss of cellularity, there is interest in the comprehension of the cellular phenotypes. This study aimed to verify if stem cells isolated from nucleus pulposus of intervertebral discs (NPs-IVD), which may express neurogenic properties, may be implicated in IVD disease. NPs-IVD isolated from 14 human pathological discs were cultured under mesenchymal and neural differentiation. An induction of the neural markers GFAP, NF, MAP2, O4, and a decrement of the expression of the immature neural markers ß-tubulin III, Nestin, NG2, occurred within the neural differentiation. The expression of TrkA and p75NGFR, the receptors of NGF, was not correlated with neural induction; in contrast, TrkB, the BDNF receptor, increased and was co-expressed with acid sensing ion channel 3 (ASIC3). In the same condition, neuroinflammatory markers were over-expressed. We confirm our hypothesis that stem cells within IVD degeneration acquire neurogenic phenotype, causing the induction of markers related to inflammatory condition. These cells could promote the enrolment of neurotrophines in adaptation to the acidic microenvironment in degenerative conditions. These data could improve our knowledge about IVD cellularity and eventually lead to the development of pharmacological therapies.

Nanotechnology advances in brain tumors: the state of the art.

Primary malignant central nervous system (CNS) tumors only represent about 2% of all cancers. However, they are very often associated with high morbidity and mortality. Despite current standard-of-care therapy, such as surgery, irradiation, and chemotherapy, neither cure nor any toxic therapy against malignant CNS tumors has been developed so far. Nanotechnology may alter this situation. It offers a new promise for cancer diagnosis and treatment. This emerging technology, by developing and manufacturing materials using atomic and molecular elements, can provide a platform for the combination of diagnostics, therapeutics and delivery to the tumor, with subsequent monitoring of the response. This review focuses on recent developments in cancer nanotechnology with particular attention to nanoparticle systems, important tools for the improvement of drug delivery in brain tumor. The latest advances in both the research sector and in recent patents for cancer imaging and therapy are discussed.

Dermal fibroblasts display similar phenotypic and differentiation capacity to fat-derived mesenchymal stem cells, but differ in anti-inflammatory and angiogenic potential.

BACKGROUND: Mesenchymal stem cells (MSCs) are multipotent stem cells able to differentiate into different cell lineages. However, MSCs represent a subpopulation of a more complex cell composition of stroma cells contained in mesenchymal tissue. Due to a lack of specific markers, it is difficult to distinguish MSCs from other more mature stromal cells such as fibroblasts, which, conversely, are abundant in mesenchymal tissue. In order to find more distinguishing features between MSCs and fibroblasts, we studied the phenotypic and functional features of human adipose-derived MSCs (AD-MSCs) side by side with normal human dermal fibroblasts (HNDFs) in vitro METHODS: AD-MSCs and HNDFs were cultured, expanded and phenotypically characterized by flow cytometry (FC). Immunofluorescence was used to investigate cell differentiation. ELISA assay was used to quantify angiogenic factors and chemokines release. Cultures of endothelial cells (ECs) and a monocyte cell line, U937, were used to test angiogenic and anti-inflammatory properties. RESULTS: Cultured AD-MSCs and HNDFs display similar morphological appearance, growth rate, and phenotypic profile. They both expressed typical mesenchymal markers-CD90, CD29, CD44, CD105 and to a minor extent, the adhesion molecules CD54, CD56, CD106 and CD166. They were negative for the stem cell markers CD34, CD146, CD133, CD117. Only aldehyde dehydrogenase (ALDH) was expressed. Neither AD-MSCs nor HNDFs differed in their multi-lineage differentiation capacity; they both differentiated into osteoblast, adipocyte, and also into cardiomyocyte-like cells. In contrast, AD-MSCs, but not HNDFs, displayed strong angiogenic and anti-inflammatory activity. AD-MSCs released significant amounts of VEGF, HGF and Angiopoietins and their conditioned medium (CM) stimulated ECs proliferation and tube formations. In addition, CM-derived AD-MSCs (AD-MSCs-CM) inhibited adhesion molecules expression on U937 and release of RANTES and MCP-1. Finally, after priming with TNFα, AD-MSCs enhanced their anti-inflammatory potential; while HNDFs acquired pro-inflammatory activity. CONCLUSIONS: AD-MSCs cannot be distinguished from HNDFs in vitro by evaluating their phenotypic profile or differentiation potential, but only through the analysis of their anti-inflammatory and angiogenic properties. These results underline the importance of evaluating the angiogenic and anti-inflammatory features of MSCs preparation. Their priming with inflammatory cytokines prior to transplantation may improve their efficacy in cell-based therapies for tissue regeneration.

Stem cell patents: an innovative approach to anti-cancer drug discovery.

Over the last decade, improvements in cancer therapies have prolonged the lives of cancer patients. Despite dramatic advances in imaging technology, surgical techniques, and adjuvant radio- and chemotherapy, the overall prognosis of this disease remains dismal. In light of this, there is an urgent need for the development of more effective therapies that can target residual disseminated tumor burden. Given the heterogeneity of tumors in general, no one strategy is likely to provide a satisfactory treatment regimen. Until the middle of the 20th century, medical treatments were limited to options like drugs, surgery, antibiotics, and radiation, but in the last years stem cells, due to their pathotropism, have become particularly attractive candidates not only to replace damaged tissue in degenerative pathologies, but also to deliver therapeutic molecules in patients with disseminated metastatic cancer. Worldwide there have been over 2000 patent applications involving human and non-human stem cells, of which one quarter refer to embryonic stem cells. Over one third of all stem cell applications and one quarter of all embryonic stem cell applications have been granted. The aim of this review is primarily to focus on the recent development of stem cell patents in cancer treatments.