Nanoparticle Induced Cell Magneto-Rotation: Monitoring Morphology, Stress and Drug Sensitivity of a Suspended Single Cancer Cell

Single cell analysis has allowed critical discoveries in drug testing, immunobiology and stem cell research. In addition, a change from two to three dimensional growth conditions radically affects cell behavior. This already resulted in new observations on gene expression and communication networks and in better predictions of cell responses to their environment. However, it is still difficult to study the size and shape of single cells that are freely suspended, where morphological changes are highly significant. Described here is a new method for quantitative real time monitoring of cell size and morphology, on single live suspended cancer cells, unconfined in three dimensions. The precision is comparable to that of the best optical microscopes, but, in contrast, there is no need for confining the cell to the imaging plane. The here first introduced cell magnetorotation (CM) method is made possible by nanoparticle induced cell magnetization. By using a rotating magnetic field, the magnetically labeled cell is actively rotated, and the rotational period is measured in real-time. A change in morphology induces a change in the rotational period of the suspended cell (e.g. when the cell gets bigger it rotates slower). The ability to monitor, in real time, cell swelling or death, at the single cell level, is demonstrated. This method could thus be used for multiplexed real time single cell morphology analysis, with implications for drug testing, drug discovery, genomics and three-dimensional culturing

Phosphatase and tensin homologue: a therapeutic target for SMA

Spinal muscular atrophy (SMA) is one of the most common juvenile neurodegenerative diseases, which can be associated with child mortality. SMA is caused by a mutation of ubiquitously expressed gene, Survival Motor Neuron1 (SMN1), leading to reduced SMN protein and the motor neuron death. The disease is incurable and the only therapeutic strategy to follow is to improve the expression of SMN protein levels in motor neurons. Significant numbers of motor neurons in SMA mice and SMA cultures are caspase positive with condensed nuclei, suggesting that these cells are prone to a process of cell death called apoptosis. Searching for other potential molecules or signaling pathways that are neuroprotective for central nervous system (CNS) insults is essential for widening the scope of developmental medicine. PTEN, a Phosphatase and Tensin homologue, is a tumor suppressor, which is widely expressed in CNS. PTEN depletion activates anti-apoptotic factors and it is evident that the pathway plays an important protective role in many neurodegenerative disorders. It functions as a negative regulator of PIP3/AKT pathway and thereby modulates its downstream cellular functions through lipid phosphatase activity. Moreover, previous reports from our group demonstrated that, PTEN depletion using viral vector delivery system in SMN delta7 mice reduces disease pathology, with significant rescue on survival rate and the body weight of the SMA mice. Thus knockdown/depletion/mutation of PTEN and manipulation of PTEN medicated Akt/PKB signaling pathway may represent an important therapeutic strategy to promote motor neuron survival in SMA

Age-Related Intraneuronal Elevation of αII-Spectrin Breakdown Product SBDP120 in Rodent Forebrain Accelerates in 3×Tg-AD Mice

Spectrins line the intracellular surface of plasmalemma and play a critical role in supporting cytoskeletal stability and flexibility. Spectrins can be proteolytically degraded by calpains and caspases, yielding breakdown products (SBDPs) of various molecular sizes, with SBDP120 being largely derived from caspase-3 cleavage. SBDPs are putative biomarkers for traumatic brain injury. The levels of SBDPs also elevate in the brain during aging and perhaps in Alzheimer’s disease (AD), although the cellular basis for this change is currently unclear. Here we examined age-related SBDP120 alteration in forebrain neurons in rats and in the triple transgenic model of AD (3×Tg-AD) relative to non-transgenic controls. SBDP120 immunoreactivity (IR) was found in cortical neuronal somata in aged rats, and was prominent in the proximal dendrites of the olfactory bulb mitral cells. Western blot and densitometric analyses in wild-type mice revealed an age-related elevation of intraneuronal SBDP120 in the forebrain which was more robust in their 3×Tg-AD counterparts. The intraneuronal SBDP120 occurrence was not spatiotemporally correlated with transgenic amyloid precursor protein (APP) expression, β-amyloid plaque development, or phosphorylated tau expression over various forebrain regions or lamina. No microscopically detectable in situ activated caspase-3 was found in the nuclei of SBDP120-containing neurons. The present study demonstrates the age-dependent intraneuronal presence of an αII-spectrin cleavage fragment in mammalian forebrain which is exacerbated in a transgenic model of AD. This novel neuronal alteration indicates that impairments in membrane protein metabolism, possibly due to neuronal calcium mishandling and/or enhancement of calcium sensitive proteolysis, occur during aging and in transgenic AD mice

Yam: a neglected and underutilized crop in Brazil Inhame: uma cultura negligenciada e subutilizada no Brasil

In Brazil current studies and investments on yams are incipient. Similarly, the literature in recent decades lacks adequate information on this group of plants. The existing literature, on its turn, requires more than ever to be revised and organized. Yams have joined the so-called "neglected" group of crops for several reasons, but particularly because they are associated with poor and traditional communities. Many vegetables introduced in Brazil during the colonization period have adapted to different cropping systems, yams being an excellent example. This diversity resulted very widespread, yet poorly recognized in the country. In turn, the gardens using traditional farming systems continue to maintain and enhance yam local varieties. Studies from other countries, with an emphasis on characterization and genetic breeding, brought to light an urgent need for Brazil to invest in yams as a food rich in carbohydrates, even to the point of alterations in food public policy. Reversal of the yam's current stigma is both a challenge to the scientific community and to the population as a whole. This paper aims to raise pertinent questions about Dioscorea species, an important key group for many communities in tropical countries, yet still unrecognized as so in Brazil.<br>No Brasil, estudos e investimentos ao inhame são incipientes. Similarmente, a literatura nas últimas décadas apresenta informações insuficientes para este grupo de plantas. A literatura existente, por sua vez, exige mais que nunca ser revisada e organizada. O inhame tem-se unido ao grupo de culturas ditas "negligenciadas" por diversas razões, mas particularmente devido ao fato de estar associado às comunidades pobres e tradicionais. Muitos vegetais introduzidos no Brasil durante o período da colonização têm-se adaptado a diferentes sistemas de cultivo, sendo o inhame um excelente exemplo. Esta diversidade é resultado de uma ampla dispersão, ainda pouco conhecida no país. Por sua vez, as roças usam o sistema de agricultura tradicional de forma a manter e aumentar as variedades locais de inhame. Estudos de outros países, com ênfase na caracterização e melhoramento genético, trouxeram à luz uma necessidade urgente de o Brasil investir em inhame como uma rica fonte de carboidratos, mesmo apesar das mudanças na política alimentar pública. Reverter o atual estigma do inhame é um duplo desafio para a comunidade científica e população como um todo. Este artigo objetiva-se a trazer questões pertinentes sobre as espécies do gênero Dioscorea, um importante grupo para muitas comunidades em países tropicais, contudo ainda pouco conhecido no Brasil