Stipcevic T et al. (DEC 2013)
Acta Neurologica Belgica 113 4 501--506
Stimulation of adult neural stem cells with a novel glycolipid biosurfactant
Glycolipids are amphipathic molecules which are highly expressed on cell membranes in skin and brain where they mediate several key cellular processes. Neural stem cells are defined as undifferentiated,proliferative,multipotential cells with extensive self-renewal and are responsive to brain injury. Di-rhamnolipid: α-L-rhamnopyranosyl-(1-2)α-L-rhamnopyranosyl-3-hydroxydecanoyl-3-hydroxydecanoic acid,also referred to as di-rhamnolipid BAC-3,is a glycolipid isolated from the bacteria Pseudomonas aeruginosa. In the previous studies,di-rhamnolipid enhanced dermal tissue healing and regeneration. The present study provides the first assessment of di-rhamnolipid,and glycolipid biosurfactants in general,on the nervous system. Treatment of neural stem cells isolated from the lateral ventricle of adult mice and cultured in defined media containing growth factors at 0.5 and 1 μg/ml of di-rhamnolipid increased the number of neurospheres (2.7- and 2.8-fold,respectively) compared to controls and this effect remained even after passaging in the absence of di-rhamnolipid. In addition,neural stem cells treated with di-rhamnolipid at 50 and 100 μg/ml in defined media supplemented with fetal calf serum and without growth factors exhibited increased cell viability,indicating an interaction between di-rhamnolipid and serum components in the regulation of neural stem cells and neuroprogenitors. Intracerebroventricular administration of di-rhamnolipid at 300 and 120 ng/day increased the number of neurospheres (1.3- and 1.63-fold,respectively) that could be derived from the anterior lateral ventricles of adult mice. These results indicate that di-rhamnolipid stimulates proliferation of neural stem cells and increases their endogenous pools which may have therapeutic potential in managing neurodegenerative or neuropsychiatric disorders and promoting nervous tissue regeneration following injury.
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P. Gonzalez-Sanchez et al. ( 2017)
Frontiers in cellular neuroscience 11 363
Store-Operated Calcium Entry Is Required for mGluR-Dependent Long Term Depression in Cortical Neurons.
Store-operated calcium entry (SOCE) is a Calcium (Ca2+) influx pathway activated by depletion of intracellular stores that occurs in eukaryotic cells. In neurons,the presence and functions of SOCE are still in question. Here,we show evidences for the existence of SOCE in primary mouse cortical neurons. Endoplasmic reticulum (ER)-Ca2+ depletion using thapsigargin (Tg) triggered a maintained cytosolic Ca2+ increase,which rapidly returned to basal level in the presence of the SOCE blockers 2-Aminoethoxydiphenyl borate (2-APB) and YM-58483. Neural SOCE is also engaged by activation of metabotropic glutamate receptors (mGluRs) with (S)-3,5-dihydroxyphenylglycine (DHPG) (agonist of group I mGluRs),being an essential mechanism to maintain the mGluR-driven Ca2+ signal. Activation of group I of mGluRs triggers long-term depression (LTD) in many brain regions,but the underlying mechanism and,specifically,the necessity of Ca2+ increase in the postsynaptic neuron is controversial. In primary cortical neurons,we now show that the inhibition of Ca2+ influx through SOCE impaired DHPG-LTD,pointing out a key function of calcium and SOCE in synaptic plasticity.
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(Feb 2024)
Nature Communications 15
Structure-guided engineering of immunotherapies targeting TRBC1 and TRBC2 in T cell malignancies
Peripheral T cell lymphomas are typically aggressive with a poor prognosis. Unlike other hematologic malignancies,the lack of target antigens to discriminate healthy from malignant cells limits the efficacy of immunotherapeutic approaches. The T cell receptor expresses one of two highly homologous chains [T cell receptor β-chain constant (TRBC) domains 1 and 2] in a mutually exclusive manner,making it a promising target. Here we demonstrate specificity redirection by rational design using structure-guided computational biology to generate a TRBC2-specific antibody (KFN),complementing the antibody previously described by our laboratory with unique TRBC1 specificity (Jovi-1) in targeting broader spectrum of T cell malignancies clonally expressing either of the two chains. This permits generation of paired reagents (chimeric antigen receptor-T cells) specific for TRBC1 and TRBC2,with preclinical evidence to support their efficacy in T cell malignancies. The T cell receptor β-chain is expressed in two isoforms,TRBC1 and TRBC2,with clonally expanded mature T cell lymphomas expressing one of them exclusively,while healthy T cells randomly express either TRBC1 or TRBC2. Here authors show structure-based design of a TRBC2-specific antibody,and depletion of malignant T cells carrying TRBC1 or TRBC2 with CAR-T cells against the cognate receptor chain in murine models.
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Ankam S et al. (JAN 2013)
Acta Biomaterialia 9 1 4535--45
Substrate topography and size determine the fate of human embryonic stem cells to neuronal or glial lineage
Efficient derivation of neural cells from human embryonic stem cells (hESCs) remains an unmet need for the treatment of neurological disorders. The limiting factors for current methods include being labor-intensive,time-consuming and expensive. In this study,we hypothesize that the substrate topography,with optimal geometry and dimension,can modulate the neural fate of hESCs and enhance the efficiency of differentiation. A multi-architectural chip (MARC) containing fields of topographies varying in geometry and dimension was developed to facilitate high-throughput analysis of topography-induced neural differentiation in vitro. The hESCs were subjected to direct differentiation"�
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Young KM et al. (AUG 2007)
The Journal of neuroscience : the official journal of the Society for Neuroscience 27 31 8286--96
Subventricular zone stem cells are heterogeneous with respect to their embryonic origins and neurogenic fates in the adult olfactory bulb.
We determined the embryonic origins of adult forebrain subventricular zone (SVZ) stem cells by Cre-lox fate mapping in transgenic mice. We found that all parts of the telencephalic neuroepithelium,including the medial ganglionic eminence and lateral ganglionic eminence (LGE) and the cerebral cortex,contribute multipotent,self-renewing stem cells to the adult SVZ. Descendants of the embryonic LGE and cortex settle in ventral and dorsal aspects of the dorsolateral SVZ,respectively. Both populations contribute new (5-bromo-2'-deoxyuridine-labeled) tyrosine hydroxylase- and calretinin-positive interneurons to the adult olfactory bulb. However,calbindin-positive interneurons in the olfactory glomeruli were generated exclusively by LGE-derived stem cells. Thus,different SVZ stem cells have different embryonic origins,colonize different parts of the SVZ,and generate different neuronal progeny,suggesting that some aspects of embryonic patterning are preserved in the adult SVZ. This could have important implications for the design of endogenous stem cell-based therapies in the future.
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