Cell-structure specific necrosis by optical-trap induced intracellular nuclear oscillation

Talin mechanotransduction in disease

Talin protein (Talin 1/2) is a mechanosensitive cytoskeleton protein. The unique structure of the Talin plays a vital role in transmitting mechanical forces. Talin proteins connect the extracellular matrix to the cytoskeleton by linking to integrins and actin, thereby mediating the conversion of mechanical signals into biochemical signals and influencing disease progression as potential diagnostic indicators, therapeutic targets, and prognostic indicators of various diseases. Most studies in recent years have confirmed that mechanical forces also have a crucial role in the development of disease, and Talin has been found to play a role in several diseases. Still, more studies need to be done on how Talin is involved in mechanical signaling in disease. This review focuses on the mechanical signaling of Talin in disease, aiming to summarize the mechanisms by which Talin plays a role in disease and to provide references for further studies.

Optical trapping with holographically structured light for single-cell studies

A groundbreaking work in 1970 by Arthur Ashkin paved the way for developing various optical trapping techniques. Optical tweezers have become an established method for the manipulation of biological objects, due to their noninvasiveness and precise controllability. Recent innovations are accelerating and now enable single-cell manipulation through holographic light structuring. In this review, we provide an overview of recent advances in optical tweezer techniques for studies at the individual cell level. Our review focuses on holographic optical tweezers that utilize active spatial light modulators to noninvasively manipulate live cells. The versatility of the technology has led to valuable integrations with microscopy, microfluidics, and biotechnological techniques for various single-cell studies. We aim to recapitulate the basic principles of holographic optical tweezers, highlight trends in their biophysical applications, and discuss challenges and future prospects.

Optical tweezers across scales in cell biology

Optical tweezers (OT) provide a noninvasive approach for delivering minute physical forces to targeted objects. Controlling such forces in living cells or in vitro preparations allows for the measurement and manipulation of numerous processes relevant to the form and function of cells. As such, OT have made important contributions to our understanding of the structures of proteins and nucleic acids, the interactions that occur between microscopic structures within cells, the choreography of complex processes such as mitosis, and the ways in which cells interact with each other. In this review, we highlight recent contributions made to the field of cell biology using OT and provide basic descriptions of the physics, the methods, and the equipment that made these studies possible.

Genetic Material Manipulation and Modification by Optical Trapping and Nanosurgery-A Perspective

Light can be employed as a tool to alter and manipulate matter in many ways. An example has been the implementation of optical trapping, the so called optical tweezers, in which light can hold and move small objects with 3D control. Of interest for the Life Sciences and Biotechnology is the fact that biological objects in the size range from tens of nanometers to hundreds of microns can be precisely manipulated through this technology. In particular, it has been shown possible to optically trap and move genetic material (DNA and chromatin) using optical tweezers. Also, these biological entities can be severed, rearranged and reconstructed by the combined use of laser scissors and optical tweezers. In this review, the background, current state and future possibilities of optical tweezers and laser scissors to manipulate, rearrange and alter genetic material (DNA, chromatin and chromosomes) will be presented. Sources of undesirable effects by the optical procedure and measures to avoid them will be discussed. In addition, first tentative approaches at cellular-level genetic and organelle surgery, in which genetic material or DNA-carrying organelles are extracted out or introduced into cells, will be presented.

Optical Tweezers: Phototoxicity and Thermal Stress in Cells and Biomolecules

For several decades optical tweezers have proven to be an invaluable tool in the study and analysis of myriad biological responses and applications. However, as with every tool, they can have undesirable or damaging effects upon the very sample they are helping to study. In this review the main negative effects of optical tweezers upon biostructures and living systems will be presented. There are three main areas on which the review will focus: linear optical excitation within the tweezers, non-linear photonic effects, and thermal load upon the sampled volume. Additional information is provided on negative mechanical effects of optical traps on biological structures. Strategies to avoid or, at least, minimize these negative effects will be introduced. Finally, all these effects, undesirable for the most, can have positive applications under the right conditions. Some hints in this direction will also be discussed.

Serum metabolomics analysis of mice that received repeated airway exposure to a water-soluble PM2.5 extract

BACKGROUND

Air pollutant exposure negatively affects human health; however, the molecular mechanisms causing disease remain largely unclear.

OBJECTIVES

To explore the effects of respiratory particulate matter (PM2.5) exposure on the serum metabolome and to identify biomarkers for risk assessment of PM2.5 exposure.

METHODS

PM2.5 from Nanjing, China, was collected, and its water-soluble extract was subjected to component analysis. BALB/c mice received acute or prolonged exposure to insoluble PM2.5 particles or its water-soluble extract, and lung tissue was submitted to histopathological analyses. Serum samples were collected pre- and post-PM2.5 exposure and analyzed by liquid chromatography/mass spectrometry.

RESULTS

Component analysis revealed that metals and inorganic ions were the most abundant components in the soluble PM2.5 samples. Acute exposure to insoluble PM2.5 particles and prolonged exposure to the water-soluble PM2.5 extract both induced severe lung injury, and the lung histopathological scores were significantly associated with PM2.5 exposure. Metabolomics analysis showed that prolonged exposure to the water-soluble PM2.5 extract was associated with statistically significant metabolite changes; the serum concentrations of 30 known metabolites, including metabolites of phospholipids, amino acids and sphingolipids, differed significantly between the control and PM2.5 exposure group. Pathway analysis identified an association of the tricarboxylic acid cycle (TCA) and the phospholipase metabolism pathway with PM2.5 exposure. The most influential metabolites for discriminating between the PM2.5-exposure group serum and the control serum were LysoPE, LysoPC, LGPC, citric acid, PAF C-18, NeuAcalpha2-3Galbeta-Cer, Lyso-PAF C-16, ganglioside GA2, 1-sn-glycero-3-phosphocholine, PC and L-tryptophan.

CONCLUSIONS

Respiratory exposure to water-soluble PM2.5 extract has developmental consequences affecting not only the respiratory system but also metabolism.