Dynamic Morphological Changes Research Articles

A Novel Cyanine-Based Fluorescent Dye for Targeted Mitochondrial Imaging in Neurotoxic Conditions and In Vivo Brain Studies.

Mitochondrial dysfunction is a key feature of neurodegenerative diseases, often preceding symptoms and influencing disease progression. However, real-time in vivo imaging of mitochondria in the brain is limited by existing dyes like MitoTrackers, which struggle with poor tissue penetration, phototoxicity, and inability to cross the blood-brain barrier (BBB). This study introduces Cy5-PEG4, a novel mitochondrial-targeting dye that overcomes these limitations, enabling high-resolution, non-invasive imaging of mitochondrial dynamics. Cy5-PEG4 effectively labels mitochondria in primary neuronal cells exposed to the SARS-CoV-2 RNYIAQVD peptide, revealing dose-dependent alterations in mitochondrial function that may contribute to COVID-19-related neurodegeneration. Importantly, Cy5-PEG4 crosses the BBB without causing neuroinflammation or toxicity, making it a safe tool for in vivo brain imaging and detailed studies of mitochondrial responses. In 3D cultured cells, Cy5-PEG4 captures dynamic changes in mitochondrial distribution and morphology as cell structures mature, highlighting its potential in neurobiological research, diagnostics, and therapeutic development. These findings support Cy5-PEG4 as a powerful tool for studying disease progression, identifying early biomarkers, and evaluating therapeutic strategies in neurodegenerative disorders and COVID-19.

Time-Dependent Morphological Changes in Traumatic Immature Teeth With Necrotic Pulps Following Regenerative Endodontic Treatment: A Retrospective Study.

Regenerative endodontic treatment is a promising approach for healing periapical lesions and continuous root maturation. Although previous studies have reported its outcomes, the dynamics of morphological changes over time remain unclear. Therefore, this study aimed to evaluate changes in the periapical status and root dimensions over a 60-month follow-up period. The follow-up duration, periapical status changes, calcific barrier formation, degree of apical closure and radiographic root area changes were compared with those of the last follow-up in this retrospective study. Radiographic root area changes were calculated as the difference between the total root and total canal areas. Fifty-eight patients (81 teeth) underwent regenerative endodontic treatment during the study period, of whom 32 patients (36 teeth, 62%) were included. The survival and success rates of the treated teeth were 100% and 94.4%, respectively. All teeth developed a calcific bridge in the cervical third of the root canal, indicating the presence of vital tissue. Apical narrowing (partial or total) was observed in 75% of the cases. The root maturation stage affected the percentage increase in the radiographic root area. Teeth in Cvek stages II-III showed a higher radiographic root area increase than more mature teeth. All tooth radiographic root areas increased significantly in the initial 20 months of the treatment and moderately thereafter. Regenerative endodontic treatment is a safe approach for traumatised immature teeth. The presence of a radiographic calcified bridge may be an early indication of treatment success. The main complete tooth morphological changes occur after approximately 20 months posttreatment. These findings may help clinicians better understand the time-dependent changes in the root morphology after treatment, improve the follow-up schedule and predict the progress of healing during follow-up visits.

Observation of dynamic position and morphological changes of temporomandibular joint discs under Angle's classification

Objective: To observe the dynamic changes of the temporomandibular joint (TMJ) disc in joint movement under different Angle's classification, providing reference for understanding joint functional movement and providing a basis for more accurate clinical imaging diagnosis. Methods: A total of 30 patients (13 males and 17 females) with temporomandibular disorders who were admitted to Beijing Friendship Hospital, Capital Medical University and General Hospital of the People's Liberation Army from January 2022 to April 2024 were enrolled. Thirty adults (13 males and 17 females) with different Angle's classification, with an average age of (34.4±8.5) years, were subjected to dynamic imaging of their TMJ from the closed position to the maximum opening position, and then to the closed position using MRI. The position and morphological changes of the articular discs were observed. Results: The results showed that volunteers with no displacement of the articular disc in class Ⅰ, Ⅱ, and Ⅲ relationships had different shapes of the articular disc during open and closed mouth movements. However, in the maximum opening position, the articular disc were all located directly below the maxillary nodules, and their shape is double concave. In terms of irreversible anterior displacement of the articular disc, in class Ⅰ Angle, the posterior zone of the disc contacts the anterior inclined plane of condyle from the maximum opening position back to the front of the closing position. In class Ⅱ, the posterior zone of the disc contacts the anterior inclined plane of condyle from the beginning of opening position to maximum opening position. In class Ⅲ, the posterior zone of the disc is always in contact with the anterior inclined plane of condyle throughout the entire movement process. And among them, the articular disc presents a forward displacement state at the closing position, its morphology undergoes folding phenomenon. When the openness is 2.5 cm, the articular disc moves up to a certain extent, and is closer to the anterior inclined plane of condyle, and its shape is also partially changed. When the openness is 4.3 cm, the shape of the articular disc, located between the anterior inclined plane of the joint node and the posterior inclined plane of the condyle, is typical double concave, which is sufficient to show that the articular disc is reversible when maximum opening position is reached. In terms of reversible anterior disc displacement, in class Ⅰ Angle, the posterior zone of the disc contact with the anterior inclined plane of condyle at the beginning of the opening position and the end of the closing position. In classⅡ Angle, the posterior zone of the articular disc is not in contact with the anterior inclined plane of condyle. In class Ⅲ Angle, the posterior zone of the articular disc contact with the anterior inclined plane of condyle at the end of the closing position. Conclusions: Multi level dynamic MR imaging data of the temporomandibular joint can dynamically observe the movement of the temporomandibular joint, intuitively and accurately display the position and shape of the articular disc during movement, and can serve as a useful supplement to static conventional MR imaging of the TMJ. The patient's TMJ needs to reach the maximum opening position in order to determine whether the joint disc displacement can be reversible or not.

Real-time visualisation of developing chick embryos cultured in transparent plastic films from the blastoderm stage until hatching

Real-time visualisation of chick embryo development occurring inside an opaque eggshell is a major goal of developmental biology. This goal was partially achieved when 3-day-old embryos recovered from fertilised shelled eggs, preincubated in a conventional incubator, hatched after the egg contents had been transferred into shell-less embryo culture systems constructed of transparent plastic film placed in a plastic cup. However, the hatchable shell-less embryo culture systems described thus far cannot be used to visualise the dynamic morphological changes associated with the emergence of major organ systems during the first 3 days of embryo development, as the blastoderm area needs to be covered with an opaque membrane. Here, we present the development of a chick embryo culture system that enables omnidirectional real-time visualisation of the developing embryo, beginning from the newly laid blastoderm stage embryo until hatching.

Therapeutic potential of mesenchymal stromal cells on morphological parameters in the hippocampus of rats with brain ischemia-reperfusion modeling

Ischemic stroke is an extremely important pathology with high mortality, in which more than 50 % of patients with occlusion of the main vessels remain disabled, despite early reperfusion therapy by thrombolysis or thrombectomy. As part of the regenerative strategy, stem cell transplantation in ischemic stroke became a new impetus. Cell therapy with the use of mesenchymal stromal cells demonstrated encouraging results regarding endogenous mechanisms of neuroregeneration in response to ischemic damage to brain structures. The aim of the research is to study the influence of mesenchymal stromal cells of various genesis, lysate of mesenchymal stromal cells obtained from Wharton’s jelly umbilical cord and citicoline on the dynamics of morphological changes in the hippocampal CA1 region of rats with acute cerebral ischemia-reperfusion according to light microscopy and micromorphometry data. The experiment was carried out using 200 male Wistar rats, which were subjected to ischemia-reperfusion by reversible 20-minute bilateral occlusion of the internal carotid arteries. Animals with modeled pathology were intravenously transplanted with mesenchymal stromal cells of various genesis (from Wharton’s jelly of the human umbilical cord, human and rat adipose tissue), and rat embryonic fibroblasts, lysate of mesenchymal stromal cells and citicoline were injected. Histological analysis of rat brain sections was performed on the 7th and 14th day of the experiment. Statistical analysis was performed using “Statistica 6.0” (StatSoft® Snc, USA). The significance of differences was assessed using the Student’s t-test and the nonparametric Mann-Whitney U test. During the study, it was found that modeled ischemia-reperfusion in rats caused almost complete degeneration of the structure of the pyramidal layer of hippocampal CA1 region, gave uniformity to the structure of the radiant layer, infiltration of microglia, contributed to the disruption of the arrangement of apical dendrite bundles and narrowing of blood vessels as a result of perivascular edema. Also, the modeled pathology reduced the total number of neuronal nuclei in the hippocampal CA1 area, the overwhelming majority of which had signs of pathological changes. Transplantation of mesenchymal stromal cells of various origins, lysate of mesenchymal stromal cells and citicoline contributed to a significant increase in the number of neuronal nuclei in the hippocampal CA1 zone and nuclei that did not undergo pathological changes. The most positive effect was found in the transplantation of mesenchymal stromal cells from human Wharton’s jelly-derived cells. Thus, both in the subacute and recovery periods of ischemic stroke in rats, the transplantation of human Wharton’s jelly-derived mesenchymal stromal cells was significantly surpassed the reference drug citicoline in its ability to reduce the number of pathologically changed nuclei by 1.5 times (p<0.05). At the same time, the number of pathologically unchanged nuclei significantly exceeded the number of nuclei with signs of karyorrhexis and karyopyknosis, so it would be advisable to use mesenchymal stromal cells of various genesis, lysate or citicoline in conditions of acute cerebral ischemia-reperfusion, taking into account their ability to reduce the volume of the infarct. In the future, an injectable drug will be created from the most effective culture of mesenchymal stromal cells in terms of cerebroprotective properties for cell therapy of patients with acute ischemic stroke.

Age-related changes in the hair follicle and hair shaft in women in the parietal region

Introduction. Medical trichology is a promising and modern direction of cosmetology, engaged in the study of the scalp and hair, both in the state of health and various diseases. However, with all the variety of various scientific publications, there are very few works devoted to the study of morphological changes in normal physiological aging of a person.Aim. To reveal the dynamics of morphological changes in the hair bulb and hair shaft in women in the parietal region to elderly age.Materials and methods. The work is based on the results of microscopic examination of 80 women, the study sample consisted of conditionally healthy individuals. The examined women were divided into three groups depending on their age. The first group included 27 women of the first period of mature age (26.9 ± 0.70 years). The second group consisted of 30 women of the second period of mature age (47.1 ± 1.20 years). The third group was formed by 23 women of old age (62.1 ± 1.09 years). Hair sampling was performed in the parietal region of the head by combing out the hair that had already fallen out (without pulling it out of the skin!). The width of the hair bulb and hair shaft were measured. The percentage of bulbs containing an internal root sheath to the total number of bulbs was calculated.Results and discussion. With age, a decrease in the number of hair follicles with internal root sheath (p < 0.01) along with a tendency to decrease the width of the hair follicle and hair shaft (p > 0.05) was noted in women in the parietal region.Conclusions. The results of this study add to the information available in the scientific literature about age-related changes occurring in the hair bulb and hair shaft in women by old age. The data obtained will be useful for trichologists in medical practice to create clinical recommendations for the early prevention of age-related alopecia areata.

Mitochondrial STED Imaging and Membrane Potential Monitoring with a Cationic Molecular Probe.

Mitochondria are essential organelles that not only undergo dynamic morphological changes but also exhibit functional activities such as mitochondrial membrane potential (MMP). While super-resolution techniques such as stimulated emission depletion (STED) nanoscopy can visualize the ultrastructure of mitochondria and the MMP probe can monitor mitochondria function, few dyes meet both demands. Here, a small molecule (MitoPDI-90) based on perylene diimide with cationic groups is reported and used for mitochondrial STED imaging and MMP indication. Characterized by excellent photostability, biocompatibility, and high quantum yield, MitoPDI-90 exhibits STED imaging compatibility, facilitating visualization of mitochondrial cristae and time-lapse imaging of highly dynamic mitochondria in living cells. Besides, MitoPDI-90 targets the mitochondria through electrical potential, also enabling live-cell MMP monitoring. MitoPDI-90 allows for super-resolution visualization and time-lapse imaging of mitochondria, and more importantly, indication of changes in MMP, providing insight into the functional activity of live-cell mitochondria.

Peculiarities of the Ontogenesis of Bacilli During Development from a Vegetative Cell to a Spore

Understanding the development processes of bacteria, in particular spore-forming ones, has both fundamental and applied importance, since at various stages of this process, the cells of microorganisms perform certain functions that can be regulated by influencing certain factors depending on the tasks. Literature data and the results of our research on the influence of the composition of the nutrient medium, pH, temperature, and aeration on sporulation are analyzed in the article. It isshown that the direction of bacterial cells’ development in certain ways is determined by signals that come from the surrounding environment, affect their genome, and determine the ways of cell development – growth or sporulation. Sporogenesis can also be induced by metabolites formed during microorganism development. It is emphasized that the environmental factors that influence the sporulation of bacteria have been studied in sufficient detail. However, the mechanisms of their action remain debatable. Morphological, genetic, and biochemical changes of spore-forming bacteria under the conditions of macrocyclic and microcyclic ways of their development are also highlighted, which makes it possible to correctly understand the functioning of regulatory mechanisms in the ontogenesis of microbial cells. In particular, the data of our research on the dynamics of morphological changes in the ontogenesis of a specific individual bacterial cell are presented. In addition, factors, including specific terminal products of cell metabolism, such as antibiotics, and genetic mechanisms of sporogenesis regulation of various genera and species of bacteria are described in detail. The nature of the vast majority of "sporogenes" has not been clarified, and there are only a few hypotheses regarding the mechanism of their action. However, most of the biological regulators of sporogenesis were found in the culture liquid, which indicates the cellular nature of their action. Therefore, to obtain more convincing data on the regulation of sporogenesis, studies at the cellular level are needed.

Translatome analysis in acute ischemic stroke: Astrocytes and microglia exhibit differences in poststroke alternative splicing of expressed transcripts.

Astrocytes and microglia undergo dynamic and complex morphological and functional changes following ischemic stroke, which are instrumental in both inflammatory responses and neural repair. While gene expression alterations poststroke have been extensively studied, investigations into posttranscriptional regulatory mechanisms, specifically alternative splicing (AS), remain limited. Utilizing previously reported Ribo-Tag-seq data, this study analyzed AS alterations in poststroke astrocytes and microglia from young adult male and female mice. Our findings reveal that in astrocytes, compared to the sham group, 109 differential alternative splicing (DAS) events were observed at 4 h poststroke, which increased to 320 at day 3. In microglia, these numbers were 316 and 266, respectively. Interestingly, the disparity between DAS genes and differentially expressed genes is substantial, with fewer than 10 genes shared at both poststroke time points in astrocytes and microglia. Gene ontology enrichment analysis revealed the involvement of these DAS genes in diverse functions, encompassing immune response (Adam8, Ccr1), metabolism (Acsl6, Pcyt2, Myo5a), and developmental cell growth (App), among others. Selective DAS events were further validated by semiquantitative RT-PCR. Overall, this study comprehensively describes the AS alterations in astrocytes and microglia during the hyperacute and acute phases of ischemic stroke and underscores the significance of certain hub DAS events in neuroinflammatory processes.

Emerging roles of non-coding RNAs in fibroblast to myofibroblast transition and fibrotic diseases.

The transition of fibroblasts to myofibroblasts (FMT) represents a pivotal process in wound healing, tissue repair, and fibrotic diseases. This intricate transformation involves dynamic changes in cellular morphology, gene expression, and extracellular matrix remodeling. While extensively studied at the molecular level, recent research has illuminated the regulatory roles of non-coding RNAs (ncRNAs) in orchestrating FMT. This review explores the emerging roles of ncRNAs, including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), in regulating this intricate process. NcRNAs interface with key signaling pathways, transcription factors, and epigenetic mechanisms to fine-tune gene expression during FMT. Their functions are critical in maintaining tissue homeostasis, and disruptions in these regulatory networks have been linked to pathological fibrosis across various tissues. Understanding the dynamic roles of ncRNAs in FMT bears therapeutic promise. Targeting specific ncRNAs holds potential to mitigate exaggerated myofibroblast activation and tissue fibrosis. However, challenges in delivery and specificity of ncRNA-based therapies remain. In summary, ncRNAs emerge as integral regulators in the symphony of FMT, orchestrating the balance between quiescent fibroblasts and activated myofibroblasts. As research advances, these ncRNAs appear to be prospects for innovative therapeutic strategies, offering hope in taming the complexities of fibrosis and restoring tissue equilibrium.

The multifaceted roles of mitochondria in osteoblasts: from energy production to mitochondrial-derived vesicle secretion.

Mitochondria in osteoblasts have been demonstrated to play multiple crucial functions in bone formation from intracellular adenosine triphosphate production to extracellular secretion of mitochondrial components. The present review explores the current knowledge about mitochondrial biology in osteoblasts, including mitochondrial biogenesis, bioenergetics, oxidative stress generation, and dynamic changes in morphology. Special attention is given to recent findings, including mitochondrial donut formation in osteoblasts, which actively generates mitochondrial-derived vesicles (MDVs), followed by extracellular secretion of small mitochondria and MDVs. We also discuss the therapeutic effects of targeting osteoblast mitochondria, highlighting their potential applications in improving bone health.

Fluorescence Lifetime Imaging of Lipid Heterogeneity in the Inner Mitochondrial Membrane with a Super‐photostable Environment‐Sensitive Probe

AbstractThe inner mitochondrial membrane (IMM) undergoes dynamic morphological changes, which are crucial for the maintenance of mitochondrial functions as well as cell survival. As the dynamics of the membrane are governed by its lipid components, a fluorescent probe that can sense spatiotemporal alterations in the lipid properties of the IMM over long periods of time is required to understand mitochondrial physiological functions in detail. Herein, we report a red‐emissive IMM‐labeling reagent with excellent photostability and sensitivity to its environment, which enables the visualization of the IMM ultrastructure using super‐resolution microscopy as well as of the lipid heterogeneity based on the fluorescence lifetime at the single mitochondrion level. Combining the probe and fluorescence lifetime imaging microscopy (FLIM) showed that peroxidation of unsaturated lipids in the IMM by reactive oxygen species caused an increase in the membrane order, which took place prior to mitochondrial swelling.

Fluorescence Lifetime Imaging of Lipid Heterogeneity in the Inner Mitochondrial Membrane with a Super-photostable Environment-Sensitive Probe.

The inner mitochondrial membrane (IMM) undergoes dynamic morphological changes, which are crucial for the maintenance of mitochondrial functions as well as cell survival. As the dynamics of the membrane are governed by its lipid components, a fluorescent probe that can sense spatiotemporal alterations in the lipid properties of the IMM over long periods of time is required to understand mitochondrial physiological functions in detail. Herein, we report a red-emissive IMM-labeling reagent with excellent photostability and sensitivity to its environment, which enables the visualization of the IMM ultrastructure using super-resolution microscopy as well as of the lipid heterogeneity based on the fluorescence lifetime at the single mitochondrion level. Combining the probe and fluorescence lifetime imaging microscopy (FLIM) showed that peroxidation of unsaturated lipids in the IMM by reactive oxygen species caused an increase in the membrane order, which took place prior to mitochondrial swelling.

Prediction of Dynamic Ni Morphology Changes in Patterned Ni-YSZ Anode with Physics-Informed Neural Networks

Abstract Nickel (Ni) film on patterned Ni- yttria-stabilized zirconia (YSZ) anode shows dynamic spreading and splitting during solid oxide fuel cell (SOFC) operation, where wettability of Ni on YSZ is greatly enhanced (Z. Jiao, N. Shikazono, J. Power Sources 396 119–123, 2018). In the present study, a physics-informed neural network (PINN) constrained by Cahn-Hilliard equation of phase field model is proposed to estimate the unknown parameters for predicting dynamic Ni movements of the patterned Ni-YSZ anode. The unknown parameters such as interface thickness and mobility are inversely inferred by PINN using top-view images obtained from the operando experiments. Obtained excess surface diffusivity values were three to four orders of magnitude larger than the values reported for surface diffusion in the literature. It is therefore considered that Ni spreading and splitting of patterned anode cannot be simply explained by surface diffusion, and other mechanisms should be introduced.

Nanostructuring, fractal characterization and wettability of ion irradiated Au thin films and their thickness effect

This study proposes a method for modifying the wettability of Au thin films of thicknesses 5 nm and 10 nm on Si substrates using 8 keV Ne ion beam irradiation at different fluences, thereby enabling surface wettability adjustment at the nano-scale and its thickness dependence. This advancement would be highly beneficial for applications such as high-resolution printing and nano-biotechnology. The contact angle of the irradiated region for the 5 nm thin film changed from hydrophobic to hydrophilic with increasing ion dosage, whereas for the 10 nm thin film, it changed from hydrophilic to hydrophobic under the same conditions. Fractal analysis was performed on pristine and ion beam modified surfaces to investigate the underlying nano-structuring process, with reported values for average roughness (Ra), Hurst exponent (H), fractal dimension (Df), contact angle (CA), and wettability at different ion dosages. Atomic Force Microscopy and Rutherford Backscattering Spectroscopy were used to examine surface roughness and depth profile. The process of sputtering becomes crucial when the ion range approaches the thickness of thin films, with the sputter yield showing dependence on the thickness of thin films at different ion fluence levels. Monte Carlo simulations SRIM/TRIM and TRIDYN were used for comparison with the experimental results, with TRIDYN taking into account dynamic changes in the target's morphology and composition.

Smart antibiofouling composite coatings based on photothermally-active polyaniline and thermo-responsive poly(N-isopropylacrylamide)

Marine biofouling profoundly affects the economic viability of the marine sector. With a view towards addressing this issue, this work reported the successful development of smart photo-responsive and thermo-responsive antibiofouling coatings by combining photothermally-active polyaniline (PANI) with temperature-sensitive poly(N-isopropylacrylamide) (PNIPAM). Under light irradiation, the PNIPAM/PANI coating could be photothermally heated to temperatures as high as 89.3 ± 1.6 °C, delivering a maximum antibacterial rate of 99.99 %. Impressively, light-induced temperature changes in the PNIPAM/PANI coating caused dynamic changes in film morphology and wettability. Upon lowering the temperature to below the lower critical solution temperature (LCST) of PNIPAM, the water contact angle of the PNIPAM/PANI coating decreased from 81° to 35° and the coating surface roughened appreciably, resulting in a 99.99 % release rate for both E.coli and S. aureus, thus achieving a dynamic self-cleaning effect. Furthermore, the developed PNIPAM/PANI coating demonstrated excellent resistance against protein and algae adhesion. These findings showcase the broad application potential of PNIPAM/PANI antifouling coatings in the marine sector.

Regenerative Solid Interfaces Enhance High-Performance All-Solid-State Lithium Batteries.

The performance of all-solid-state lithium batteries (ASSLBs) is significantly impacted by lithium interfacial instability, which originates from the dynamic chemical, morphological, and mechanical changes during deep Li plating and stripping. In this study, we introduce a facile approach to generate a conductive and regenerative solid interface, enhancing both the Li interfacial stability and overall cell performance. The regenerative interface is primarily composed of nanosized lithium iodide (nano-LiI), which originates in situ from the adopted solid-state electrolyte (SSE). During cell operation, the nano-LiI interfacial layer can reversibly diffuse back and forth in synchronization with Li plating and stripping. The interface and dynamic process improve the adhesion and Li+ transport between the Li anode and SSE, facilitating uniform Li plating and stripping. As a result, the metallic Li anode operates stably for over 1000 h at high current densities and even under elevated temperatures. By using metallic Li as the anode directly, we demonstrate stable cycling of all-solid-state Li-sulfur batteries for over 250 cycles at an areal capacity of >2 mA h cm-2 and room temperature. This study offers insights into the design of regenerative and Li+-conductive interfaces to tackle solid interfacial challenges for high-performance ASSLBs.

Visualizing dynamic interactions between mitochondria and lysosomes in living cells using novel pH-sensitive fluorescent probes in dual-channel

The neutral fluorescent probes 1a-1c based on D-π-A-π-D structure, with benzopyranoquinoline as the fluorophore and the electron-donating groups at both ends, were developed, which emitted dual-channel fluorescence in different pH environments. Among them, probe 1a with both N,N-diethyl group and morpholine ring as electron-donating groups exhibited the best fluorescence performance, showing a red shift of 85 nm in dual emission at 505 nm and 590 nm, and a Stokes shift of 95 nm in both channels. The neutral 1a displayed green fluorescence specifically targeting mitochondria, while the protonated form 1a+H+ resulting in red fluorescence localized in lysosomes. The ability to distinguish healthy and pathological cells such as cancer or inflammation could be achieved by observing the differences in red fluorescence within lysosomes. Probe 1a could migrate and retarget between mitochondria and lysosomes, and it was discovered by the physiological effects of chloral hydrate experiments. In addition, the dynamic changes in morphology and movement of mitochondria and lysosomes during cellular autophagy through the variation of fluorescence intensity in green and red channels induced by rapamycin and starvation conditions had been investigated deeply.

Exposure to nitrate induces intestinal inflammation, as determined by an integrated transcriptome and weighted gene co-expression network analysis in juvenile turbot (Scophthalmus maximus)

The accumulation of nitrate in recirculating aquaculture systems (RASs) may adversely affect the intestinal health of fish. To understand the toxic effects of nitrate on fish intestines, we systematically examined the dynamic changes in intestinal morphology, immunity, barrier function, and transcriptome profiles of the intestines of turbot (Scophthalmus maximus) at three time points after nitrate exposure. Our results showed that nitrates induced intestinal histopathological damage, inflammatory response, and weakened barrier in a time-dependent manner. The findings of bioinformatics analyses revealed that ECM-receptor interaction, protein digestion and absorption, focal adhesion, and the PI3K-Akt signaling pathway were the four key pathways that were significantly affected by nitrate exposure. Five different expression patterns also exhibited dynamic changes in the DEGs to deal with nitrate stress, as determined by the STEM analysis. Six hub genes related to collagen synthesis including col1a2, col5a1, col6a1, col6a2, col6a3 and LOC118282543 were identified by the WGCNA analysis, which suggested that they exerted a key role in the four key pathways associated with the response of turbot to nitrate stress. The obtained findings of the current work offered the first transcriptome map of the fish intestine associated with nitrate stress. Our findings may offer valuable information on the molecular mechanisms of the response of fish to nitrate stress and also may contribute to the welfare of fish in RAS.

Dynamic changes in perivascular space morphology predict signs of spaceflight-associated neuro-ocular syndrome in bed rest

During long-duration spaceflight, astronauts experience headward fluid shifts and expansion of the cerebral perivascular spaces (PVS). A major limitation to our understanding of the changes in brain structure and physiology induced by spaceflight stems from the logistical difficulties of studying astronauts. The current study aimed to determine whether PVS changes also occur on Earth with the spaceflight analog head-down tilt bed rest (HDBR). We examined how the number and morphology of magnetic resonance imaging-visible PVS (MV-PVS) are affected by HDBR with and without elevated carbon dioxide (CO2). These environments mimic the headward fluid shifts, body unloading, and elevated CO2 observed aboard the International Space Station. Additionally, we sought to understand how changes in MV-PVS are associated with signs of Spaceflight Associated Neuro-ocular Syndrome (SANS), ocular structural alterations that can occur with spaceflight. Participants were separated into two bed rest campaigns: HDBR (60 days) and HDBR + CO2 (30 days with elevated ambient CO2). Both groups completed multiple magnetic resonance image acquisitions before, during, and post-bed rest. We found that at the group level, neither spaceflight analog affected MV-PVS quantity or morphology. However, when taking into account SANS status, persons exhibiting signs of SANS showed little or no MV-PVS changes, whereas their No-SANS counterparts showed MV-PVS morphological changes during the HDBR + CO2 campaign. These findings highlight spaceflight analogs as models for inducing changes in MV-PVS and implicate MV-PVS dynamic compliance as a mechanism underlying SANS. These findings may lead to countermeasures to mitigate health risks associated with human spaceflight.