Image processing tools for petabyte-scale light sheet microscopy data.

Light sheet microscopy is a powerful technique for high-speed three-dimensional imaging of subcellular dynamics and large biological specimens. However, it often generates datasets ranging from hundreds of gigabytes to petabytes in size for a single experiment. Conventional computational tools process such images far slower than the time to acquire them and often fail outright due to memory limitations.

Characterization, comparison, and optimization of lattice light sheets.

Lattice light sheet microscopy excels at the noninvasive imaging of three-dimensional (3D) dynamic processes at high spatiotemporal resolution within cells and developing embryos. Recently, several papers have called into question the performance of lattice light sheets relative to the Gaussian sheets most common in light sheet microscopy. Here, we undertake a theoretical and experimental analysis of various forms of light sheet microscopy, which demonstrates and explains why lattice light sheets provide substantial improvements in resolution and photobleaching reduction.

Mineral requirements for mitochondrial function: A connection to redox balance and cellular differentiation.

Professor Bruce Ames demonstrated that nutritional recommendations should be adjusted in order to 'tune-up' metabolism and reduce mitochondria decay, a hallmark of aging and many disease processes. A major subset of tunable nutrients are the minerals, which despite being integral to every aspect of metabolism are often deficient in the typical Western diet. Mitochondria are particularly rich in minerals, where they function as essential cofactors for mitochondrial physiology and overall cellular health.

A high-throughput flow cytometry-on-a-CMOS platform for single-cell dielectric spectroscopy at microwave frequencies.

This work presents a microfluidics-integrated label-free flow cytometry-on-a-CMOS platform for the characterization of the cytoplasm dielectric properties at microwave frequencies. Compared with MHz impedance cytometers, operating at GHz frequencies offers direct intracellular permittivity probing due to electric fields penetrating through the cellular membrane. To overcome the detection challenges at high frequencies, the spectrometer employs on-chip oscillator-based sensors, which embeds simultaneous frequency generation, electrode excitation, and signal detection capabilities.

Cytoskeletal organization in microtentacles.

Microtentacles are thin, flexible cell protrusions that have recently been described and whose presence enhances efficient attachment of circulating cells. They are found on circulating tumor cells and can be induced on a wide range of breast cancer cell lines, where they are promoted by factors that either stabilize microtubules or destabilize the actin cytoskeleton. Evidence suggests that they are relevant to the metastatic spread of cancer, so understanding their structure and formation may lead to useful therapies.

Factors that Influence the Formation and Stability of Thin, Cryo-EM Specimens.

Poor consistency of the ice thickness from one area of a cryo-electron microscope (cryo-EM) specimen grid to another, from one grid to the next, and from one type of specimen to another, motivates a reconsideration of how to best prepare suitably thin specimens. Here we first review the three related topics of wetting, thinning, and stability against dewetting of aqueous films spread over a hydrophilic substrate. We then suggest that the importance of there being a surfactant monolayer at the air-water interface of thin, cryo-EM specimens has been largely underappreciated.

Protein complexes at the microtubule organizing center regulate bipolar spindle assembly.

Bipolar spindle assembly is essential to genomic stability in dividing cells. Centrosomes or spindle pole bodies duplicated earlier at G(1)/S remain adjacent until triggered at mitotic onset to become bipolar. Pole reorientation is stabilized by microtubule interdigitation but mechanistic details for bipolarity remain incomplete.

Zinc deficiency reduces paclitaxel efficacy in LNCaP prostate cancer cells.

Chemotherapeutics used to treat prostate cancer are often from a class of drugs that target microtubule networks, such as paclitaxel. A previous report indicated that supplemental zinc sensitized prostate cancer cells to paclitaxel-induced apoptosis, suggesting that increased zinc levels might enhance paclitaxel efficacy. The effect of zinc deficiency on paclitaxel activity is not known though, so we tested this in two prostate cancer cell lines maintained under moderately zinc-deficient conditions.

Meiosis-specific failure of cell cycle progression in fission yeast by mutation of a conserved beta-tubulin residue.

The microtubule cytoskeleton is involved in regulation of cell morphology, differentiation, and cell cycle progression. Precisely controlled dynamic properties are required for these microtubule functions. To better understand how tubulin's dynamics are embedded in its primary sequence, we investigated in vivo the consequences of altering a single, highly conserved residue in beta-tubulin that lies at the interface between two structural domains.

Heme deficiency may be a factor in the mitochondrial and neuronal decay of aging.

Heme, a major functional form of iron in the cell, is synthesized in the mitochondria by ferrochelatase inserting ferrous iron into protoporphyrin IX. Heme deficiency was induced with N-methylprotoporphyrin IX, a selective inhibitor of ferrochelatase, in two human brain cell lines, SHSY5Y (neuroblastoma) and U373 (astrocytoma), as well as in rat primary hippocampal neurons. Heme deficiency in brain cells decreases mitochondrial complex IV, activates nitric oxide synthase, alters amyloid precursor protein, and corrupts iron and zinc homeostasis.