Sensitivity of the mosquito Aedes aegypti (Culicidae) labral apical chemoreceptors to blood plasma components

The phagostimulants from the cellular fraction of blood induce gorging of Aedes aegypti (L.), and this process is enhanced by some plasma components. This project examines the responses of the labral apical chemoreceptors to plasma components enhancing phagostimulation. From the electrophysiological responses of the labral apical chemoreceptors four cells were identified by the waveform of their action potentials. Three of the cells (Cell 2, Cell 3 and Cell 4) responded in a dose dependent manner to NaCl. The responses of Cell 2 and Cell 3 to NaCl concentrations from 1 to 500 mmol/l can be described by a logarithmic equation. The response of Cell 2 to 150 mmol/l NaCl is modulated when a buffer is added. The magnitude of the modulation of the response is determined by the nature of the buffer: NaHCO(3) inhibits while Na(2)HPO(4) enhances the response. High osmotic pressure inhibits the response of Cell 4, regardless of how it is achieved. Cell 4 responds with a high frequency to the presence of L-alanine, the C-terminal amino acid of albumin, but shows a reduced response to the same concentration of albumin. From these results it can be concluded that labral apical chemoreceptors of A. aegypti are capable of detecting the plasma components involved in blood recognition.     

In the beginning: lessons from fertilization in mice and worms

Sexual reproduction proceeds by fertilization; formation of new individuals by the union of haploid gametes. Recent reports in Cell and in Developmental Cell may provide new insights as to how this process begins and is regulated.     

Notch and basal cells take center stage during airway epithelial regeneration

Airway epithelium is maintained by basal cells, but the mechanisms responsible for repair are poorly characterized. In this issue of Cell Stem Cell, Rock et al. (2011) show that Notch signals regulate differentiation, but not self-renewal of basal cells after injury, and that this role appears conserved in mouse and human lung.     

Dialogue between RhoA/ROCK and members of the Par complex in cell polarity

Cell polarity is essential for many biological processes and is regulated by conserved protein complexes, including the Par complex, Rho GTPases, and their regulators. In this issue of Developmental Cell, studies by Nakayama et al. and Zhang and Macara examine how interplay between Rho GTPases and the Par complex control polarized cell migration and dendritic spine morphogenesis in alternate ways.     

Myotonic Muscular Dystrophy,RNA Toxicity,and the Brain: Trouble Making the Connection?

The study of rare genetic diseases is complicated by the inaccessibility of relevant cells and tissues, especially for neurologic disorders. In this issue of Cell Stem Cell, Marteyn et?al. (2011) use human embryonic stem cells to identify deficits in neuritic outgrowth in myotonic dystrophy type 1.     

Home is where the heart is: via the FROUNT

In this issue of Cell Stem Cell, Belema-Bedada et al. (2008) describe a novel mechanism by which bone marrow-derived adult mesenchymal stem cells migrate to sites of damaged heart tissue. This process is dependent on the intracellular adaptor molecule FROUNT, which interacts with the chemokine receptor CCR2.     

The pessimist's and optimist's views of adult neurogenesis

The reports by Bonaguidi et?al. (in this issue of Cell) and Encinas et?al. (in Cell Stem Cell) come to differing conclusions about whether and how the proliferation of radial glia-like stem cells of the adult hippocampus impacts their long-term potential for neurogenesis.     

An old drug for new ideas: metformin promotes adult neurogenesis and spatial memory formation

Identifying well-tolerated, oral medications that enhance adult neurogenesis is of great clinical interest. In this issue of Cell Stem Cell, Wang et?al. (2012) demonstrate that the diabetes medication metformin enhances spatial learning in mice by activating the atypical PKC/CBP pathway in adult neural stem cells.     

Autoimmune T cells lured to a FASL web of death by MSCs

Achieving immune tolerance through cell transplantation is a promising approach for treating autoimmune disease. In this issue of Cell Stem Cell, Akiyama et?al. (2012) demonstrate that human and mouse mesenchymal stem cells can induce immune suppression by attracting and killing autoreactive T?cells, which stimulates TGFb production by macrophages and generates regulatory T?cells.     

Eukaryotic cells and their cell bodies: Cell Theory revised

BACKGROUND: Cell Theory, also known as cell doctrine, states that all eukaryotic organisms are composed of cells, and that cells are the smallest independent units of life. This Cell Theory has been influential in shaping the biological sciences ever since, in 1838/1839, the botanist Matthias Schleiden and the zoologist Theodore Schwann stated the principle that cells represent the elements from which all plant and animal tissues are constructed. Some 20 years later, in a famous aphorism Omnis cellula e cellula, Rudolf Virchow annunciated that all cells arise only from pre-existing cells. General acceptance of Cell Theory was finally possible only when the cellular nature of brain tissues was confirmed at the end of the 20th century. Cell Theory then rapidly turned into a more dogmatic cell doctrine, and in this form survives up to the present day. In its current version, however, the generalized Cell Theory developed for both animals and plants is unable to accommodate the supracellular nature of higher plants, which is founded upon a super-symplasm of interconnected cells into which is woven apoplasm, symplasm and super-apoplasm. Furthermore, there are numerous examples of multinucleate coenocytes and syncytia found throughout the eukaryote superkingdom posing serious problems for the current version of Cell Theory. SCOPE: To cope with these problems, we here review data which conform to the original proposal of Daniel Mazia that the eukaryotic cell is composed of an elemental Cell Body whose structure is smaller than the cell and which is endowed with all the basic attributes of a living entity. A complement to the Cell Body is the Cell Periphery Apparatus, which consists of the plasma membrane associated with other periphery structures. Importantly, boundary structures of the Cell Periphery Apparatus, although capable of some self-assembly, are largely produced and maintained by Cell Body activities and can be produced from it de novo. These boundary structures serve not only as mechanical support for the Cell Bodies but they also protect them from the hostile external environment and from inappropriate interactions with adjacent Cell Bodies within the organism. CONCLUSIONS: From the evolutionary perspective, Cell Bodies of eukaryotes are proposed to represent vestiges of hypothetical, tubulin-based 'guest' proto-cells. After penetrating the equally hypothetical actin-based 'host' proto-cells, tubulin-based 'guests' became specialized for transcribing, storing and partitioning DNA molecules via the organization of microtubules. The Cell Periphery Apparatus, on the other hand, represents vestiges of the actin-based 'host' proto-cells which have become specialized for Cell Body protection, shape control, motility and for actin-mediated signalling across the plasma membrane.     

EPO and super-EPO: erythropoietins direct neoangiogenesis by cardiac progenitor cells

Erythropoietin, the red blood cell-making cytokine, is also a potential cytoprotective agent in heart disease. In this issue of Cell Stem Cell, Hoch et?al. (2011) use two heart failure models, including chemotherapeutic cardiotoxicity, to reveal a mechanistic connection between reduced cardiomyocyte production of erythropoietin and neoangiogenesis by cardiac progenitors.     

Book Reviews

Book reviewed in this article:
Biomathematics and cell kinetics. Developments in Cell Biology , Volume 8. Ed. by M. Rotenberg
Cell Proliferation in the Gastrointestinal Tract. Ed. by D. R. A ppleton , J. P. S unter and A. J. W atson
Advanced Cell Biology . Ed. by L. M. S chwartz and M. M. A zar     

Safely modulating the immune system in regenerative medicine

The destruction of pluripotent stem cell-derived grafts by the host immune system presents a significant barrier to clinical translation of cell therapies. Pearl et al. (2011) report in this issue of Cell Stem Cell that a brief, nontoxic immunosuppressive regimen, achieved by blockade of leucocyte costimulatory pathways, may overcome this problem.     

Quantitative cell biology with the Virtual Cell

Cell biological processes are controlled by an interacting set of biochemical and electrophysiological events that are distributed within complex cellular structures. Computational models, comprising quantitative data on the interacting molecular participants in these events, provide a means for applying the scientific method to these complex systems. The Virtual Cell is a computational environment designed for cell biologists, to facilitate the construction of models and the generation of predictive simulations from them. This review summarizes how a Virtual Cell model is assembled and describes the physical principles underlying the calculations that are performed. Applications to problems in nucleocytoplasmic transport and intracellular calcium dynamics will illustrate the power of this paradigm for elucidating cell biology.     

Targeting gene-virotherapy of cancer

Due to concerns regarding the overlapping figures in this review that are identical to those contained in a reviewarticle that we have co-authored and published earlier,we retract the above paper we published in Cell Research.Weapologize for any confusion that may be caused by this matter,although we stand by the scientific contents containedin the Cell Research paper.     

Relief with Rapamycin: mTOR Inhibition Protects against Radiation-Induced Mucositis

In this issue of Cell Stem Cell, Iglesias-Bartolome et?al. (2012) show that mTOR inhibition with rapamycin protects against mucositis in mice, suggesting potential treatment strategies against this harmful side effect of anticancer therapies. In normal tissues, rapamycin prevents epithelial stem cell senescence by reducing oxidative stress through increased MnSOD.     

Human parthenogenetic embryo stem cells: appreciating what you have when you have it

In this issue of Cell Stem Cell, Kim et al. (2007b) show, by genome-wide single-nucleotide polymorphism analysis, that human ES cells claimed to originate from a somatic cell nuclear transfer (SCNT) embryo are actually parthenogenetic. This now permits an appreciation of the future therapeutic utility of this type of cell.     

Integrating adhesion, protrusion, and contraction during cell migration

Cell migration is fastest when the strength of the adhesion between the cell and the substrate is neither too strong nor too weak. In this issue of Cell, reveal how adhesion and cytoskeletal dynamics are integrated to optimize migration speed.     

TGFbeta and SMADs talk to NANOG in human embryonic stem cells

The TGFbeta/activin signaling pathway is important for the maintenance of human embryonic stem cells. In this issue of Cell Stem Cell, Xu et al. (2008) show that this pathway upregulates the expression of a key pluripotency gene NANOG through SMAD2/3.