Neutrophils release decondensed chromatin or extracellular traps (NETs) in response to various physiological and pharmacological stimuli. Apart from host defensive functions, NETs play an essential role in the pathogenesis of various autoimmune, inflammatory, and malignant diseases. In recent years, studies have been performed on photo-induced NET formation, mainly activated by UV radiation. Understanding the mechanisms of NET release under the influence of UV and visible light is important to control the consequences of the damaging effects of electromagnetic radiation. Raman spectroscopy was applied to record characteristic Raman frequencies of various reactive oxygen species (ROS) and low-frequency lattice vibrational modes for citrulline. NETosis was induced by irradiation with wavelength-switchable LED sources. Fluorescence microscopy was used to visualize and quantify NET release. The ability of five wavelengths of radiation, from UV-A to red light, to induce NETosis was investigated at three different energy doses. We demonstrated, for the first time, that NET formation is activated not only by UV-A but also by three spectra of visible light: blue, green, and orange, in a dose-dependent manner. Using inhibitory analysis, we established that light-induced NETosis proceeds through NADPH oxidase and PAD4. The development of new drugs designed to suppress NETosis, especially when induced by exposure to intense UV and visible light, can help to mitigate light-induced photoaging and other damaging effects of electromagnetic radiation.

1. Recent advances in the development of experimental and theoretical approaches for studying various molecular systems have largely accelerated new fundamental research. Considerable effort in thi...

Alzheimer's disease (AD) progression is strongly linked to conformational changes of amyloid-β42 (Aβ42) in neuronal membranes. This study examined the influence of pH on Aβ42 conformation in 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) membranes using Raman spectroscopy, circular dichroism (CD), and molecular dynamics (MD) simulations. At acidic pH (5.5), Aβ42 predominantly adopted α-helical structures (∼75-80%), whereas neutral (pH 7.4) and alkaline conditions (pH 9.5) reduced α-helical content to ∼48-58% and ∼44-47%, respectively, with a corresponding rise in random-coil structures (∼20-36%). Across all pH conditions, β-sheet content remained minimal, although MD trajectories indicated transient β-bridge contacts suggestive of early aggregation. MD analyses revealed modest pH-dependent perturbations in bilayer thickness and lipid order. Consistency across experimental and computational methods highlights pH as a critical modulator of Aβ42 structural dynamics in membranes, providing mechanistic insight into its neurotoxic potential and informing future therapeutic strategies.

As the methods, instrumentation, and resolution of three-dimensional spatial analysis have improved over the past twenty years, it is now possible to image the internal microstructure of multiphase materials in detail in three dimensions. Three-dimensional X-ray microtomography offers a unique opportunity for high spatial resolution imaging that can be achieved in compact desktop systems using X-ray microfocus sources. Recently, a modern desktop cone-beam X-ray microtomography system for quantitative analysis of materials in three dimensions was installed at the Institute of Nuclear Physics of the Ministry of Energy of the Republic of Kazakhstan. This paper presents the design, description of the main components, and technical parameters of this X-ray microtomography system, called IMAX. This system is designed to acquire, process, store X-ray images, and reconstruct three-dimensional data from angular projections for the study of internal structures and non-destructive testing of materials. The system consists of a microfocus X-ray source providing an X-ray energy range from 35 to 80 keV, a flat panel scintillation detector system allowing high-resolution digital imaging, optomechanical platforms for sample positioning, and radiation shielding. The first results of test measurements using this X-ray system are presented.

Neutrophils are the first line of defense of the human immune system against pathogens. Photobiomodulation, mediated by mitochondrial photoacceptors such as cytochrome c oxidase, has emerged as a method to modulate neutrophil function through targeted light exposure. Despite the extensive characterization of neutrophil extracellular traps (NETs) formation (NETosis), the wavelength-specific modulation of neutrophil photoactivation and the involvement of redox pathways remain poorly defined. In this study, the effects of monochromatic (365 nm, 415 nm, 437 nm, and 625 nm) and dichromatic LED-light irradiation on NETs formation were systematically examined. The highest netotic responses were elicited by UV-A (365 nm) and violet-blue light (415 nm), whereas 437 nm showed the lowest induction and 625 nm stimulated a moderate netotic response. The pharmacological inhibition of NETosis induced by 365 nm and 415 nm irradiation with specific NADPH oxidase inhibitor, apocynin, and mitochondrial reactive oxygen species (mtROS) scavenger, MitoTEMPO, attenuated NETs formation by engaging both enzymatic and mitochondrial oxidative sources. Notably, mtROS played a dominant role under 415 nm stimulation in contrast to 365 nm-induced NETosis as demonstrated by higher sensitivity to MitoTEMPO. Importantly, combined simultaneous irradiation with 415 nm and 625 nm LEDs resulted in a significant suppression of NETs formation by more than 50%, highlighting a potent inhibitory synergy observed for the first time and suggesting a new approach of wavelength pairing to modulate neutrophil activation. These results were further supported by measurements of ROS production using a luminol-amplified chemiluminescence assay. Collectively, these findings delineate a wavelength- and ROS-dependent framework for light-induced neutrophil activation, with mitochondrial pathways exerting central control particularly under short-wavelength irradiation.