Neuronal guidance signaling in neurodegenerative diseases: Key regulators that function at neuron-glia and neuroimmune interfaces

The nervous system processes a vast amount of information, performing computations that underlie perception, cognition, and behavior. During development, neuronal guidance genes, which encode extracellular cues, their receptors, and downstream signal transducers, organize neural wiring to generate the complex architecture of the nervous system. It is now evident that many of these neuroguidance cues and their receptors are active during development and are also expressed in the adult nervous system. This suggests that neuronal guidance pathways are critical not only for neural wiring but also for ongoing function and maintenance of the mature nervous system. Supporting this view, these pathways continue to regulate synaptic connectivity, plasticity, and remodeling, and overall brain homeostasis throughout adulthood. Genetic and transcriptomic analyses have further revealed many neuronal guidance genes to be associated with a wide range of neurodegenerative and neuropsychiatric disorders. Although the precise mechanisms by which aberrant neuronal guidance signaling drives the pathogenesis of these diseases remain to be clarified, emerging evidence points to several common themes, including dysfunction in neurons, microglia, astrocytes, and endothelial cells, along with dysregulation of neuron-microglia-astrocyte, neuroimmune, and neurovascular interactions. In this review, we explore recent advances in understanding the molecular and cellular mechanisms by which aberrant neuronal guidance signaling contributes to disease pathogenesis through altered cell-cell interactions. For instance, recent studies have unveiled two distinct semaphorin-plexin signaling pathways that affect microglial activation and neuroinflammation. We discuss the challenges ahead, along with the therapeutic potentials of targeting neuronal guidance pathways for treating neurodegenerative diseases. Particular focus is placed on how neuronal guidance mechanisms control neuron-glia and neuroimmune interactions and modulate microglial function under physiological and pathological conditions. Specifically, we examine the crosstalk between neuronal guidance signaling and TREM2, a master regulator of microglial function, in the context of pathogenic protein aggregates. It is well-established that age is a major risk factor for neurodegeneration. Future research should address how aging and neuronal guidance signaling interact to influence an individual's susceptibility to various late-onset neurological diseases and how the progression of these diseases could be therapeutically blocked by targeting neuronal guidance pathways.

Novel insights into non-coding RNAs and their role in hydrocephalus

A large body of evidence has highlighted the role of non-coding RNAs in neurodevelopment and neuroinflammation. This evidence has led to increasing speculation that non-coding RNAs may be involved in the pathophysiological mechanisms underlying hydrocephalus, one of the most common neurological conditions worldwide. In this review, we first outline the basic concepts and incidence of hydrocephalus along with the limitations of existing treatments for this condition. Then, we outline the definition, classification, and biological role of non-coding RNAs. Subsequently, we analyze the roles of non-coding RNAs in the formation of hydrocephalus in detail. Specifically, we have focused on the potential significance of non-coding RNAs in the pathophysiology of hydrocephalus, including glymphatic pathways, neuroinflammatory processes, and neurological dysplasia, on the basis of the existing evidence. Lastly, we review the potential of non-coding RNAs as biomarkers of hydrocephalus and for the creation of innovative treatments.

Autophagy machinery as exploited by viruses

Viruses adapt and modulate cellular pathways to allow their replication in host cells. The catabolic pathway of macroautophagy, for simplicity referred to as autophagy, is no exception. In this review, we discuss anti-viral functions of both autophagy and select components of the autophagy machinery, and how viruses have evaded them. Some viruses use the membrane remodeling ability of the autophagy machinery to build their replication compartments in the cytosol or efficiently egress from cells in a non-lytic fashion. Some of the autophagy machinery components and their remodeled membranes can even be found in viral particles as envelopes or single membranes around virus packages that protect them during spreading and transmission. Therefore, studies on autophagy regulation by viral infections can reveal functions of the autophagy machinery beyond lysosomal degradation of cytosolic constituents. Furthermore, they can also pinpoint molecular interactions with which the autophagy machinery can most efficiently be manipulated, and this may be relevant to develop effective disease treatments based on autophagy modulation.

Restriction of mitochondrial oxidation of glutamine or fatty acids enhances intracellular growth of Mycobacterium abscessus in macrophages

Mycobacterium abscessus (Mab), a nontuberculous mycobacterium, is increasing in prevalence worldwide and causes treatment-refractory pulmonary diseases. However, how Mab rewires macrophage energy metabolism to facilitate its survival is poorly understood. We compared the metabolic profiles of murine bone marrow-derived macrophages (BMDMs) infected with smooth (S)- and rough (R)-type Mab using extracellular flux technology. Mab infection shifted BMDMs towards a more energetic phenotype, marked by increased oxidative phosphorylation (OXPHOS) and glycolysis, with a significantly greater enhancement in OXPHOS. This metabolic adaptation was characterized by enhanced ATP production rates, particularly in cells infected with S-type Mab, highlighting OXPHOS as a key energy source. Notably, Mab infection also modulated mitochondrial substrate preferences, increasing fatty acid oxidation capabilities while revealing significant changes in glutamine dependency and flexibility. R-type Mab infections exhibited a marked decrease in glutamine reliance but enhanced metabolic flexibility and capacity. Furthermore, targeting metabolic pathways related to glutamine and fatty acid oxidation exacerbated Mab growth within macrophages, suggesting these pathways play a protective role against infection. These insights advance our understanding of Mab's impact on host cell metabolism and propose a novel avenue for therapeutic intervention. By manipulating host mitochondrial metabolism, we identify a potential host-directed therapeutic strategy against Mab, offering a promising alternative to conventional treatments beleaguered by drug resistance. This study underscores the importance of exploring metabolic interventions to combat Mab infection, paving the way for innovative approaches in the fight against this formidable pathogen.

Immunotoxicological disruption of pregnancy as a new research area in immunotoxicology

Immune mechanisms associated with normal pregnancy have only been being substantively investigated since the early 1990s. In parallel with the progress in that area of research, in the past few years it has become increasingly clear that several xenobiotics - including a variety of environmental chemicals, pharmaceuticals, and metals are considered to be both generally immunotoxic and specifically able to affect pregnancy. Among these, there is intense interest regarding potential effects from synthetic cannabinoids, immune checkpoint inhibitors, nanometals, and microplastics, with immunotoxic events that impact on pregnancy being shown for these agents. For instance, phytocannabinoids have been shown to interfere with reproduction in mice through effects on the endocannabinoid system. Because of effects of immune enhancement, as a requirement for regulatory submission, co-inhibitory immune checkpoint molecule inhibitors were also evaluated for effects on pregnancy. Similarly, because of increasing use and concerns about incidental environmental exposures, nanometals, and micro-plastics have also been examined for effects. Several studies in humans or mice showed that exposures to each during gestation increased the risk/rate of fetal loss, in part, by disruption of the placenta-associated immune system. Furthermore, signaling by endogenous danger molecules and/or impairment of physiological intercellular mediators may have contributed to the pregnancy loss. As there are clearly a variety of immunotoxic effects that can impact on a pregnancy, this review attempts to briefly introduce immune mechanisms associated with pregnancy as well as reasons for its loss, and proposes that 'immunotoxicological disruption of pregnancy' be accepted as a new research area in immunotoxicology.

Deciphering novel enzymatic and non-enzymatic lysine lactylation in Salmonella

Lysine lactylation, a novel post-translational modification, is involved in multiple cellular processes. The role of lactylation remains largely unknown, especially in bacteria. Here, we identified 1090 lactylation sites on 469 proteins by mass spectrometry in Salmonella Typhimurium. Many proteins involved in metabolic processes, protein translation, and other biological functions are lactylated, with lactylation levels varying according to the growth phase or lactate supplementation. Lactylation is regulated by glycolysis, and inhibition of L-lactate utilization can enhance lactylation levels. In addition to the known lactylase in E. coli, the acetyltransferase YfiQ can also catalyse lactylation. More importantly, L-lactyl coenzyme A (L-La-CoA) and S,D-lactoylglutathione (LGSH) can directly donate lactyl groups to target proteins for chemical lactylation. Lactylation is involved in Salmonella invasion of eukaryotic cells, suggesting that lactylation is crucial for bacterial virulence. Collectively, we have comprehensively investigated protein lactylome and the regulatory mechanisms of lactylation in Salmonella, providing valuable insights into studying lactylation function across diverse bacterial species.

Sg-snn: a self-organizing spiking neural network based on temporal information

Neurodynamic observations indicate that the cerebral cortex evolved by self-organizing into functional networks, These networks, or distributed clusters of regions, display various degrees of attention maps based on input. Traditionally, the study of network self-organization relies predominantly on static data, overlooking temporal information in dynamic neuromorphic data. This paper proposes Temporal Self-Organizing (TSO) method for neuromorphic data processing using a spiking neural network. The TSO method incorporates information from multiple time steps into the selection strategy of the Best Matching Unit (BMU) neurons. It enables the coupled BMUs to radiate the weight across the same layer of neurons, ultimately forming a hierarchical self-organizing topographic map of concern. Additionally, we simulate real neuronal dynamics, introduce a glial cell-mediated Glial-LIF (Leaky Integrate-and-fire) model, and adjust multiple levels of BMUs to optimize the attention topological map.Experiments demonstrate that the proposed Self-organizing Glial Spiking Neural Network (SG-SNN) can generate attention topographies for dynamic event data from coarse to fine. A heuristic method based on cognitive science effectively guides the network's distribution of excitatory regions. Furthermore, the SG-SNN shows improved accuracy on three standard neuromorphic datasets: DVS128-Gesture, CIFAR10-DVS, and N-Caltech 101, with accuracy improvements of 0.3%, 2.4%, and 0.54% respectively. Notably, the recognition accuracy on the DVS128-Gesture dataset reaches 99.3%, achieving state-of-the-art (SOTA) performance.

Updates on radiotherapy-immunotherapy combinations: Proceedings of 8th Annual ImmunoRad Conference

The annual ImmunoRad Conference has established itself as a recurrent occasion to explore the possibility of combining radiation therapy (RT) and immunotherapy (IT) for clinical cancer management. Bringing together a number of preclinical and clinical leaders in the fields of radiation oncology, immuno-oncology and IT, this annual event fosters indeed essential conversations and fruitful exchanges on how to address existing challenges to expand the therapeutic value of RT-IT combinations. The 8th edition of the ImmunoRad Conference, which has been held in October 2024 at the Weill Cornell Medical College of New York City, highlighted exciting preclinical and clinical advances at the interface between RT and IT, setting the stage for extra progress toward extended benefits for patients with an increasing variety of tumor types. Here, we critically summarize the lines of investigation that have been discussed at the occasion of the 8th Annual ImmunoRad Conference.

The methyl-CpG binding domain 2 regulates peptidylarginine deiminase 4 expression and promotes neutrophil extracellular trap formation via the Janus kinase 2 signaling pathway in experimental severe asthma

OBJECTIVE

The prognosis for severe asthma is poor, and the current treatment options are limited. The methyl-CpG binding domain protein 2 (MBD2) participates in neutrophil-mediated severe asthma through epigenetic regulation. Neutrophil extracellular traps (NETs) play a critical role in the pathogenesis of severe asthma. This study aims to detect if MBD2 can reduce NETs formation and the potential mechanism in severe asthma.

METHODS

A severe asthma model was established in C57BL/6 wild-type mice exposure to house dust mite (HDM), ovalbumin (OVA), and lipopolysaccharide (LPS). Enzyme-linked immunosorbent assay was used to measure the concentrations of IL-4, IL-17A, and IFN-γ in lung tissues. Flow cytometry was employed to determine the percentages of Th2, Th17, and Treg cells in lung tissues. Quantitative real-time polymerase chain reaction was utilized to assess the mRNA expression levels of MBD2, JAK2, and PAD4. Western blotting and immunofluorescence were conducted to detect the protein of MBD2, JAK2, PAD4, and CitH3. HL-60 cells were differentiated into neutrophil-like cells by culturing in a medium containing dimethyl sulfoxide and then stimulated with LPS. KCC-07, Ruxolitinib, and Cl-amidine were used to inhibit the expressions of MBD2, JAK2, and PAD4, respectively.

RESULTS

Severe asthma mice were characterized by pulmonary neutrophilic inflammation and increased formation of neutrophil extracellular traps (NETs). The expression of MBD2, JAK2, and PAD4 was elevated in severe asthma mice. Inhibiting the expression of MBD2, JAK2, and PAD4 reduced NETs formation and decreased airway inflammation scores, total cell counts and neutrophil counts in BALF, and percentage of Th2 and Th17 cell in lung tissues, whereas increasing Treg cell counts. In both severe asthma mice and HL-60-differentiated neutrophil-like cells in vitro, inhibiting MBD2 reduced the mRNA and protein expression of JAK2 and PAD4, and inhibiting JAK2 reduced the expression of PAD4 mRNA and protein.

CONCLUSION

MBD2 regulates PAD4 expression through the JAK2 signaling pathway to promote NETs formation in mice with severe asthma. Further bench-based and bedside-based studies targeting the MBD2, PAD4, and JAK2 signaling pathways will help open new avenues for drug development of severe asthma.

Resistance to quorum sensing inhibition spreads more slowly during host infection than antibiotic resistance

Antibiotic resistance is a rising problem and new and sustainable strategies to combat bacterial (intestinal) infections are therefore urgently needed. One promising strategy under intense investigation is the inhibition of quorum sensing, bacterial cell-to-cell communication with small molecules. A key question with respect to the application of quorum sensing inhibition is whether it will impose selective pressure for the spread of resistance. It was recently shown that resistance to quorum sensing inhibition will spread more slowly during infection of a host than resistance to traditional antibiotics.

Translation elongation: measurements and applications

Translation converts genetic information in mRNAs into functional proteins. This process occurs in four major steps: initiation, elongation, termination and ribosome recycling; each of which profoundly impacts mRNA stability and protein yield. Over recent decades, regulatory mechanisms governing these aspects of translation have been identified. In this review, we focus on the elongation phase, reviewing the experimental methods used to measure elongation rates and discussing how the measurements shed light on the factors that regulate elongation and ultimately gene expression.

Role of oxysterol 4β-hydroxycholesterol and liver X receptor alleles in pre-eclampsia

BACKGROUND

Liver X receptors (LXRs) are expressed in placenta and may be associated with pre-eclampsia (PE). Oxysterols act as agonists for LXRs. We recently proposed a new blood pressure-regulating circuit with oxysterol 4β-hydroxycholesterol (4βHC) acting as a hypotensive factor via LXRs.

MATERIALS AND METHODS

This study investigated the association between maternal plasma 4βHC, blood pressure (BP) indices, placental expression of LXR target genes, and patient characteristics using data from the Finnish Genetics of Pre-Eclampsia Consortium (FINNPEC) cohort. Plasma samples of 144 women with PE and 38 healthy pregnant controls as well as 44 PE and 40 control placental samples were available. In addition, genetic data from the FinnGen project was utilized to explore the associations of LXR alleles with PE and pregnancy hypertension.

RESULTS

There were no significant associations between 4βHC and BP or maternal and perinatal characteristics in FINNPEC cohort. However, plasma 4βHC was inversely correlated with the maternal body mass index. There were no associations with the genetic variants of LXRs with PE in FinnGen. LXR target genes APOD, SCARB1, TGM2, and LPCAT3 were expressed differently between PE and normal pregnancies in placental samples of FINNPEC.

CONCLUSIONS

Our results demonstrate that plasma 4βHC and genetic LXR variants do not play a major role in PE and BP regulation during pregnancy. However, key LXR target genes involved in lipid metabolism were expressed differently in normal and PE pregnancies. Further research is needed to understand the complexities of oxysterols, LXRs, and their potential contributions to placental function and pregnancy outcomes.

RNA Pol-II transcripts in nucleolar associated domains of cancer cell nucleoli

We performed a comparative study of the non-ribosomal gene content of nucleoli from seven cancer cell lines, using identical methods of purification and analysis. We identified unique chromosomal domains associated with the nucleolus (NADs) and genes within these domains (NAGs). Four cell lines have relatively few NAGs, which appears mostly transcriptionally inactive, consistent with literature. The remaining three lines formed a separate group with nucleoli with unique features and NADS. They constitute larger number of common NAGs, marked by ATAC-seq and having accessible promoters, with histone markers for transcriptional activity and detectable RNA Pol II bound at their promoters. The transcripts of these genes are almost entirely exported from the nucleolus. These results indicate that RNA Pol II dependent transcription in NADs can vary widely in different cell types, presumably dependent on the cell's developmental stage. Nucleolus-associated genes are likely to be distinguished marks reflecting the cell's metabolism.

Research progress on the mechanism of tumor cell ferroptosis regulation by epigenetics

Cancer remains a significant barrier to human longevity and a leading cause of mortality worldwide. Despite advancements in cancer therapies, challenges such as cellular toxicity and drug resistance to chemotherapy persist. Regulated cell death (RCD), once regarded as a passive process, is now recognized as a programmed mechanism with distinct biochemical and morphological characteristics, thereby presenting new therapeutic opportunities. Ferroptosis, a novel form of RCD characterized by iron-dependent lipid peroxidation and unique mitochondrial damage, differs from apoptosis, autophagy, and necroptosis. It is driven by reactive oxygen species (ROS)-induced lipid peroxidation and is implicated in tumorigenesis, anti-tumor immunity, and resistance, particularly in tumors undergoing epithelial-mesenchymal transition. Moreover, ferroptosis is associated with ischemic organ damage, degenerative diseases, and aging, regulated by various cellular metabolic processes, including redox balance, iron metabolism, and amino acid, lipid, and glucose metabolism. This review focuses on the role of epigenetic factors in tumor ferroptosis, exploring their mechanisms and potential applications in cancer therapy. It synthesizes current knowledge to provide a comprehensive understanding of epigenetic regulation in tumor cell ferroptosis, offering insights for future research and clinical applications.

Sorafenib-associated translation reprogramming in hepatocellular carcinoma cells

Sorafenib (Sfb) is a multikinase inhibitor regularly used for the management of patients with advanced hepatocellular carcinoma (HCC) that has been shown to increase very modestly life expectancy. We have shown that Sfb inhibits protein synthesis at the level of initiation in cancer cells. However, the global snapshot of mRNA translation following Sorafenib-treatment has not been explored so far. In this study, we performed a genome-wide polysome profiling analysis in Sfb-treated HCC cells and demonstrated that, despite global translation repression, a set of different genes remain efficiently translated or are even translationally induced. We reveal that, in response to Sfb inhibition, translation is tuned, which strongly correlates with the presence of established mRNA cis-acting elements and the corresponding protein factors that recognize them, including DAP5 and ARE-binding proteins. At the level of biological processes, Sfb leads to the translational down-regulation of key cellular activities, such as those related to the mitochondrial metabolism and the collagen synthesis, and the translational up-regulation of pathways associated with the adaptation and survival of cells in response to the Sfb-induced stress. Our findings indicate that Sfb induces an adaptive reprogramming of translation and provides valuable information that can facilitate the analysis of other drugs for the development of novel combined treatment strategies based on Sfb therapy.

Leveraging strain competition to address antimicrobial resistance with microbiota therapies

The enteric microbiota is an established reservoir for multidrug-resistant organisms that present urgent clinical and public health threats. Observational data and small interventional studies suggest that microbiome interventions, such as fecal microbiota products and characterized live biotherapeutic bacterial strains, could be an effective antibiotic-sparing prevention approach to address these threats. However, bacterial colonization is a complex ecological phenomenon that remains understudied in the context of the human gut. Antibiotic resistance is one among many adaptative strategies that impact long-term colonization. Here we review and synthesize evidence of how bacterial competition and differential fitness in the context of the gut present opportunities to improve mechanistic understanding of colonization resistance, therapeutic development, patient care, and ultimately public health.

Apelin-13 exerts protective effects against acute kidney injury by lysosomal function regulation

BACKGROUND

Recent studies suggest that the loss of lysosomal function is associated with acute kidney injury (AKI), potentially leading to impaired autophagy. Apelin has been known to regulate autophagy processes in cardiovascular and pulmonary diseases. We sought to explore its potential contribution in lysosomal function and autophagy modulation during AKI.

METHODS

Apelin-13 (30 μg/kg) or a vehicle control was administered to mice intraperitoneally 24 h prior to and at 0 h, 24 h, and 48 h following renal ischemia-reperfusion (I/R) injury or a sham procedure. Kidney and serum samples were collected for analysis 24 or 72 h postoperatively.

RESULTS

Our findings indicate that apelin-13 significantly mitigated renal damage and inhibited apoptosis post-AKI. Flow cytometry analysis revealed that apelin-13 treatment modulates the macrophages polarization within the kidney from M1 to M2 phenotype. Additionally, apelin-13 was found to reduce the expression of the (pro)renin receptor, restore lysosomal membrane permeability, augment lysosomal biogenesis, and enhance autophagic flux in the kidney following AKI.

CONCLUSIONS

Our study elucidates novel mechanisms underlying the protective effects of apelin in AKI through modulating lysosomal function and autophagy.

Brief biology and pathophysiology of Tekt bundles

Tektins, a family of microtubule-stabilizing proteins, are critical for cilia and flagella assembly in mammals. They maintain doublet microtubule stability and ciliary/flagellar motility. Loss of Tekt1-5 causes microtubule instability, impaired motility, and diseases like infertility, retinal degeneration, Mainzer-Saldino syndrome, and diabetic nephropathy. Pathophysiological stimuli regulate Tektin expression through transcriptional, posttranscriptional, translational, and posttranslational modifications. This review summarizes the latest findings on Tektin functions and their role in diseases.

Cefoxitin inhibits the formation of biofilm involved in antimicrobial resistance MDR Escherichia coli

The study investigates the relationship between biofilm formation and antibiotic resistance in Escherichia coli (E. coli) isolated from calves. Using biochemical and molecular methods, we identified the isolates and assessed their biofilm-forming ability through an improved crystal violet staining method. The minimum inhibitory concentrations (MICs) of 18 antibiotics against the isolates were determined using the broth microdilution method. The impact of cefoxitin on biofilm formation was analyzed using laser scanning confocal microscopy (LSCM). Additionally, qRT-PCR was employed to evaluate the expression levels of biofilm-related genes (luxS, motA, fliA, pfs, and csgD) in response to varying cefoxitin concentrations. Results indicated a significant correlation between antimicrobial resistance (AMR) and biofilm formation ability. Cefoxitin effectively reduced biofilm formation of multidrug-resistant E. coli isolates at 1/2 and 1 MIC, with enhanced inhibition at higher concentrations. The QS-related genes luxS, pfs, motA, and fliA were downregulated, leading to decreased csgD expression. At 1/2 MIC, csgD expression was significantly reduced. In conclusion, cefoxitin inhibits biofilm formation in multidrug-resistant E. coli by down-regulating key genes, offering a potential strategy to mitigate resistance and control infections in calves caused by biofilm-positive E. coli isolates.

Spatial transcriptomics combined with single-nucleus RNA sequencing reveals glial cell heterogeneity in the human spinal cord

JOURNAL/nrgr/04.03/01300535-202511000-00032/figure1/v/2024-12-20T164640Z/r/image-tiff Glial cells play crucial roles in regulating physiological and pathological functions, including sensation, the response to infection and acute injury, and chronic neurodegenerative disorders. Glial cells include astrocytes, microglia, and oligodendrocytes in the central nervous system, and satellite glial cells and Schwann cells in the peripheral nervous system. Despite the greater understanding of glial cell types and functional heterogeneity achieved through single-cell and single-nucleus RNA sequencing in animal models, few studies have investigated the transcriptomic profiles of glial cells in the human spinal cord. Here, we used high-throughput single-nucleus RNA sequencing and spatial transcriptomics to map the cellular and molecular heterogeneity of astrocytes, microglia, and oligodendrocytes in the human spinal cord. To explore the conservation and divergence across species, we compared these findings with those from mice. In the human spinal cord, astrocytes, microglia, and oligodendrocytes were each divided into six distinct transcriptomic subclusters. In the mouse spinal cord, astrocytes, microglia, and oligodendrocytes were divided into five, four, and five distinct transcriptomic subclusters, respectively. The comparative results revealed substantial heterogeneity in all glial cell types between humans and mice. Additionally, we detected sex differences in gene expression in human spinal cord glial cells. Specifically, in all astrocyte subtypes, the levels of NEAT1 and CHI3L1 were higher in males than in females, whereas the levels of CST3 were lower in males than in females. In all microglial subtypes, all differentially expressed genes were located on the sex chromosomes. In addition to sex-specific gene differences, the levels of MT-ND4 , MT2A , MT-ATP6 , MT-CO3 , MT-ND2 , MT-ND3 , and MT-CO2 in all spinal cord oligodendrocyte subtypes were higher in females than in males. Collectively, the present dataset extensively characterizes glial cell heterogeneity and offers a valuable resource for exploring the cellular basis of spinal cord-related illnesses, including chronic pain, amyotrophic lateral sclerosis, and multiple sclerosis.

Hypoxic conditions by Raman microspectroscopy - Reprogramming of fatty acids and glucose metabolism during colon cancer progression

Cellular respiration is the primary metabolic process for producing the energy (ATP) needed for survival. Disruptions in this process can lead to various diseases, including colon cancer. This paper reviews the current understanding of how excess fatty acids (FAs) and glucose (Glc) alter metabolic pathways. We focused on the impact of unsaturated fatty acids (UFAs) (eicosapentaenoic acid (EPA), linoleic acid (LA)), saturated fatty acid (SFA) (palmitic acid (PA)), and glucose on healthy human colon cells (CCD-18 Co) and cancerous colon cells (Caco-2) using Raman microspectroscopy. Our study examined the metabolic abnormalities in mitochondria and lipid droplets caused by the external intake of FAs and glucose. The results indicate that the peaks at 750 cm-1, 1004 cm-1, 1256 cm-1, 1444 cm-1, and 1656 cm-1 can serve as Raman biomarkers for monitoring metabolic pathways in colon cancer. We proved that oxidative metabolism towards glycolysis allows maintaining redox homeostasis and enables the survival and proliferation of cancer cells in hypoxic conditions. Our findings show that comparing control cells with cells supplemented with UFAs, SFA, and glucose can help detect metabolic abnormalities. Specifically, supplementation with UFAs reduces the intensity of the bands at 750 cm-1 and 1004 cm-1, while SFA and glucose increase their intensity. For the bands at 1256 cm-1, 1444 cm-1, and 1656 cm-1, palmitic acid and glucose decrease the intensity, whereas linoleic acid increases it. This paper introduces new experimental techniques, such as Raman microspectroscopy and imaging, to track and understand the metabolic changes in colon cells caused by FAs and glucose under hypoxic conditions.

Crosstalk among canonical Wnt and Hippo pathway members in skeletal muscle and at the neuromuscular junction

Skeletal muscles are essential for locomotion, posture, and metabolic regulation. To understand physiological processes, exercise adaptation, and muscle-related disorders, it is critical to understand the molecular pathways that underlie skeletal muscle function. The process of muscle contraction, orchestrated by a complex interplay of molecular events, is at the core of skeletal muscle function. Muscle contraction is initiated by an action potential and neuromuscular transmission requiring a neuromuscular junction. Within muscle fibers, calcium ions play a critical role in mediating the interaction between actin and myosin filaments that generate force. Regulation of calcium release from the sarcoplasmic reticulum plays a key role in excitation-contraction coupling. The development and growth of skeletal muscle are regulated by a network of molecular pathways collectively known as myogenesis. Myogenic regulators coordinate the differentiation of myoblasts into mature muscle fibers. Signaling pathways regulate muscle protein synthesis and hypertrophy in response to mechanical stimuli and nutrient availability. Several muscle-related diseases, including congenital myasthenic disorders, sarcopenia, muscular dystrophies, and metabolic myopathies, are underpinned by dysregulated molecular pathways in skeletal muscle. Therapeutic interventions aimed at preserving muscle mass and function, enhancing regeneration, and improving metabolic health hold promise by targeting specific molecular pathways. Other molecular signaling pathways in skeletal muscle include the canonical Wnt signaling pathway, a critical regulator of myogenesis, muscle regeneration, and metabolic function, and the Hippo signaling pathway. In recent years, more details have been uncovered about the role of these two pathways during myogenesis and in developing and adult skeletal muscle fibers, and at the neuromuscular junction. In fact, research in the last few years now suggests that these two signaling pathways are interconnected and that they jointly control physiological and pathophysiological processes in muscle fibers. In this review, we will summarize and discuss the data on these two pathways, focusing on their concerted action next to their contribution to skeletal muscle biology. However, an in-depth discussion of the non-canonical Wnt pathway, the fibro/adipogenic precursors, or the mechanosensory aspects of these pathways is not the focus of this review.

Supramolecular assembly of multi-purpose tissue engineering platforms from human extracellular matrix

Recapitulating the biophysical and biochemical complexity of the extracellular matrix (ECM) remains a major challenge in tissue engineering. Hydrogels derived from decellularized ECM provide a unique opportunity to replicate the architecture and bioactivity of native ECM, however, they exhibit limited long-term stability and mechanical integrity. In turn, materials assembled through supramolecular interactions have achieved considerable success in replicating the dynamic biophysical properties of the ECM. Here, we merge both methodologies by promoting the supramolecular assembly of decellularized human amniotic membrane (hAM), mediated by host-guest interactions between hAM proteins and acryloyl-β-cyclodextrin (AcβCD). Photopolymerization of the cyclodextrins results in the formation of soft hydrogels that exhibit tunable stress relaxation and strain-stiffening. Disaggregation of bulk hydrogels yields an injectable granular material that self-reconstitutes into shape-adaptable bulk hydrogels, supporting cell delivery and promoting neovascularization. Additionally, cells encapsulated within bulk hydrogels sense and respond to the biophysical properties of the surrounding matrix, as early cell spreading is favored in hydrogels that exhibit greater susceptibility to applied stress, evidencing proper cell-matrix interplay. Thus, this system is shown to be a promising substitute for native ECM in tissue repair and modelling.

RNA methylation: A new perspective in osteoarthritis research

Osteoarthritis (OA) is a prevalent degenerative joint disease characterized by cartilage degradation, osteophyte formation, and joint dysfunction, significantly impairing the quality of life in the elderly population. Recently, RNA modifications, as a dynamic and reversible epigenetic modification, have emerged as critical players in the onset and progression of OA. This review systematically summarizes the major types of RNA modifications involved in OA, including N6-methyladenosine (m6A), 5-methylcytosine (m5C), and 7-methylguanosine (m7G), and explores their roles in regulating chondrocyte autophagy, inflammatory responses, and key signaling pathways. with a primary focus on RNA methylation. Special emphasis is placed on the dynamic regulatory functions of key methyltransferases (e.g., METTL3, FTO, WTAP) and their potential contributions to OA pathogenesis. Furthermore, we address current research hotspots and controversies in the field, proposing future research directions, such as leveraging single-cell sequencing to decipher dynamic RNA modification changes during OA progression and uncovering the cooperative networks among various RNA modifications. Advancing our understanding of the biological roles and mechanisms of RNA modifications holds promise for innovative strategies in the early diagnosis, disease stratification, and targeted therapy of OA.

A conserved role for centriolar satellites in translation of centrosomal and ciliary proteins

Centriolar satellites are cytoplasmic particles found in the vicinity of centrosomes and cilia whose specific functional contribution has long been unclear. Here, we identify Combover as the Drosophila ortholog of the main scaffolding component of satellites, PCM1. Like PCM1, Combover localizes to cytoplasmic foci containing centrosomal proteins and its depletion or mutation results in centrosomal and ciliary phenotypes. Strikingly, however, the concentration of satellites near centrosomes and cilia is not a conserved feature, nor do Combover foci display directed movement. Proximity interaction analysis revealed not only centrosomal and ciliary proteins, but also RNA-binding proteins and proteins involved in quality control. Further work in Drosophila and vertebrate cells found satellites to be associated with centrosomal and ciliary mRNAs, as well as evidence for protein synthesis occurring directly at satellites. Given that PCM1 depletion does not affect overall protein levels, we propose that satellites instead promote the coordinate synthesis of centrosomal and ciliary proteins, thereby facilitating the formation of protein complexes.

Co-stimulation with piezoelectric PVDF films and low intensity pulsed ultrasound enhances osteogenic differentiation

Bone tissue engineering has emerged as a promising approach to address the challenges of bone fracture repair and regeneration. The application of external stimuli (mechanical and electrical) can drive specific cellular responses and osteogenic differentiation, leading to the development of more effective treatments. Piezoelectric materials modulate cellular proliferation and osteogenic differentiation under both static (without mechanical stimulation) and dynamic (with mechanical stimulation) conditions, activating distinct gene expression pathways. In this work, we investigate the combinatorial effect of poly (vinylidene fluoride) (PVDF) poled and non-poled films, and low-intensity pulsed ultrasound (LIPUS) on early-stage osteogenic differentiation of mouse pre-osteoblasts. Static culture with PVDF poled films enhanced Runx2 and Col1α1 expression without impacting alkaline phosphatase (ALP) activity. Inhibition of ERK phosphorylation using U0126 in PVDF poled films resulted in a ~ 6-8-fold increase in ALP activity, suggesting the involvement of an alternative pathway in osteogenic differentiation. Dynamic culture with LIPUS generated an electric potential of approximately 500 mV across PVDF films and an electrical field of 0-10 mV mm-1. Co-stimulation led to a ~3-fold increase of ALP activity on stimulated PVDF compared to unstimulated films. This study underscores the potential of piezoelectric materials as non-invasive electrical stimulators to enhance the efficacy of ultrasound-based therapies for bone fracture repair.

The de novo strategy for bifunctional peptides coating to enhance osteointegration capacity of the implant

Bone implants represent a significant global market; however, they are plagued by a high long-term failure rate, with approximately 19.2 % of implants failing within 10 years. This leads to considerable physical pain, mental distress for patients, and a substantial financial burden on public healthcare systems. Herein, we propose a novel strategy that using the interactions between positively charged hexa-arginine (R6) and polyphenols in EGC/Fe MPN to present the bifunctional peptides, cellular adhesive peptide (RGD) and osteogenic growth peptide (OGP), onto implant coatings. To thoroughly investigate the preparation process and the physical and chemical properties of the dual-peptide functionalized coatings, several techniques were employed, including dissipation-quartz crystal microbalance (DQCM), ellipsometry, photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). These methods provided insights into the coating's composition, stability, mechanical properties, and surface roughness. In comparison to single-peptide functionalized coatings, the dual-peptide coatings demonstrated significantly improved performance in cellular adhesion at early stages, long-term cell proliferation, migration, antioxidant activity, osteogenic differentiation, inhibition of osteoclastogenesis, and enhanced in vivo osteointegration. This study contributes to the development of multifunctional coatings tailored to the complex biological processes involved in osteointegration.

Three-dimensional bioactive collagen scaffolds incorporated with titanate nanotubes for tissue regeneration

The development of three-dimensional (3D) biomimetic scaffolds for bone and soft tissue engineering has received increasing attention due to their ability to mimic the extracellular matrix (ECM) environment. This study presents the development and characterization of a 3D collagen matrix incorporating titanate nanotubes (TNT) aiming to improve cell migration and biocompatibility, with potential applications in bioink for bone and soft tissue regeneration. TNT were hydrothermally synthesized, and their properties were characterized using materials analysis techniques. After the incorporation of human fibroblasts into the collagen matrices with or without TNT, biological characterization was performed. The results showed that the incorporation of TNT significantly improved the migration efficiency and directionality compared to collagen-only matrices, which were more evident after long-term incubation. This indicates that the addition of TNT to the collagen matrixes improves the mechanical properties, promotes biocompatibility, and induces a superior environment for cell migration. These findings contribute to the development of new biomaterials for tissue engineering and demonstrate the potential of TNT as a key component of bioengineered biomaterials for bone and soft tissue regeneration.

High-content screening morphological analysis to evaluate hepatic apoptosis induced by plant alkaloids in a Chang cell model

As interest in plant-derived compounds and their application in the pharmaceutical and functional food industries has increased, the rapid detection of chemical toxicity has become increasingly important for developing safe products. High-content screening (HCS) can quantify cellular and organelle morphological changes through image analysis; however, most HCS studies on apoptosis, a key toxicological event, have focused on the expression of apoptosis-related genes or proteins. In this study, we aimed to verify whether apoptosis can be detected solely based on cellular morphological changes. Chang cells were treated with staurosporine (STS), a well-known apoptosis inducer, and the morphological changes in the cells were quantified using HCS assays. The correlation between these HCS morphological descriptors and apoptosis rates measured using flow cytometry was determined. Chang cells were also treated with several plant-derived alkaloids known to induce apoptosis, and the same process was performed. The correlation coefficients, which were used to evaluate the correlation between HCS descriptors and apoptosis rates after STS treatment, ranged from 0.64 to 0.98, with 13 descriptors showing significant correlations. In contrast, the highest correlation coefficients between HCS descriptors and apoptosis rates after treatment with 1 of the 12 alkaloids investigated were determined to be 0.75 (at 10 μg/ml) and 0.49 (at 100 μg/ml). The apoptosis-related morphological changes induced by STS and alkaloids were observed using confocal microscopy. The present study demonstrates that HCS assays can detect apoptosis solely based on cellular morphological changes, providing a potential tool for rapid toxicity screening in early product development.

Morphometric analysis of the sperm midpiece during capacitation

In mammalian sperm, mitochondria are very densely packed and form a helical sheath in the midpiece of the flagellum. Mitochondria from somatic cells can rapidly change shape to adapt to environmental conditions. During capacitation, mammalian spermatozoa undergo morphological and physiological changes to acquire fertilization ability, evidenced by changes in sperm motility patterns (hyperactivation) and the ability to perform the acrosome reaction. Whether there are changes in sperm mitochondrial morphology during capacitation is unknown. This work aimed to quantify morphometric changes in the sperm midpiece during capacitation. Using mitochondrial fluorescent probes and a combination of freely available software, we quantified the dimensions and fluorescence intensity of the midpiece. After capacitation, the area occupied by the mitochondria decreased due to a reduction in the width but not the length of the midpiece. The decrease in the area of the midpiece occurred in spermatozoa that underwent the acrosome reaction, suggesting a reorganization of the mitochondria during capacitation. Ultrastructural analysis supported these results. The application of image processing to fluorescence microscopy images may help to identify morphological changes during capacitation.

In situ cleavage-based sortase A-mediated site-specific immobilization of beta2-adrenoceptor on gold surface for surface plasmon resonance measurement

Surface Plasmon Resonance (SPR) is a pivotal technique for measuring biomolecular interactions, with the sensor surface typically made of gold or silver and requiring proteins to be immobilized in a controlled manner. Traditional methods, such as random crosslinking via covalent amide bonds (EDC/NHS strategy), resulting in diverse protein orientations. Alternatively, site-specific immobilization strategies offer better orientation control, they are still challenged by the purification needs for protein of interests and steric hindrance produced by bulk protein tags. To address these issues, we proposed a novel protein immobilization strategy relying on in situ cleavage and Sortase A (SrtA) to immobilize functional protein on SPR sensor chips. This strategy involves the β2-adrenoceptor (β2AR) as a model, incorporating an endogenous protease recognition site (EPRS) as a linker to fuse SrtA with β2AR, which contains an SrtA recognition sequence (LPXTG) at its C-terminal. When expressed in Escherichia coli (E. coli), the protease cleaves the EPRS, releasing SrtA and β2AR. When the lysate is mixed with an oligo-Gly or oligo-Gly-modified SPR chip, transpeptidation occurs, covalently immobilizing β2AR. The efficacy of the cleavage and transpeptidation reactions was validated through SDS-PAGE, Western blot, and chromatographic analysis. The SPR chip was characterized by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) mapping, X-ray photoelectron spectroscopy (XPS), and contact angle analysis, while β2AR activity was evaluated by SPR. When compared to the EDC/NHS-based random method and the haloalkane dehalogenase (HaloTag)-mediated site-specific strategy, β2AR immobilized through the SrtA-mediated method exhibited higher activity with ligands, demonstrating precision in binding affinity evaluations. This strategy meets the benchmarks for an optimal site-specific immobilization method and holds promise for applications involving the modification of other biological interfaces or biosensors.

A double network composite hydrogel with enhanced transdermal delivery by ultrasound for endometrial injury repair and fertility recovery

Endometrial injury and resulting female infertility pose significant clinical challenges due to the notable shortcomings of traditional treatments. Herein, we proposed a double network composite hydrogel, CSMA-RC-Zn-PNS, which forms a physical barrier on damaged tissue through photo-crosslinking while enabling sustained release of the active ingredient PNS. Based on this, we developed a combined strategy to enhance transdermal delivery efficiency using ultrasound cavitation. In vitro experiments demonstrated that CSMA-RC-Zn-PNS exhibits excellent biosafety, biodegradability, and promotes cell proliferation, migration, and tube formation, along with antioxidant and antibacterial properties. In a rat endometrial injury model, the ultrasound cavitation effect was demonstrated to enhance transdermal delivery efficiency, and the ability of CSMA-RC-Zn-PNS to promote endometrial regeneration, anti-fibrosis and fertility restoration was verified. Overall, this strategy combining CSMA-RC-Zn-PNS hydrogel and ultrasound treatment shows promising applications in endometrial regeneration and female reproductive health.

Interaction of major facilitator superfamily domain containing 2A with the blood-brain barrier

The functional and structural integrity of the blood-brain barrier is crucial in maintaining homeostasis in the brain microenvironment; however, the molecular mechanisms underlying the formation and function of the blood-brain barrier remain poorly understood. The major facilitator superfamily domain containing 2A has been identified as a key regulator of blood-brain barrier function. It plays a critical role in promoting and maintaining the formation and functional stability of the blood-brain barrier, in addition to the transport of lipids, such as docosahexaenoic acid, across the blood-brain barrier. Furthermore, an increasing number of studies have suggested that major facilitator superfamily domain containing 2A is involved in the molecular mechanisms of blood-brain barrier dysfunction in a variety of neurological diseases; however, little is known regarding the mechanisms by which major facilitator superfamily domain containing 2A affects the blood-brain barrier. This paper provides a comprehensive and systematic review of the close relationship between major facilitator superfamily domain containing 2A proteins and the blood-brain barrier, including their basic structures and functions, cross-linking between major facilitator superfamily domain containing 2A and the blood-brain barrier, and the in-depth studies on lipid transport and the regulation of blood-brain barrier permeability. This comprehensive systematic review contributes to an in-depth understanding of the important role of major facilitator superfamily domain containing 2A proteins in maintaining the structure and function of the blood-brain barrier and the research progress to date. This will not only help to elucidate the pathogenesis of neurological diseases, improve the accuracy of laboratory diagnosis, and optimize clinical treatment strategies, but it may also play an important role in prognostic monitoring. In addition, the effects of major facilitator superfamily domain containing 2A on blood-brain barrier leakage in various diseases and the research progress on cross-blood-brain barrier drug delivery are summarized. This review may contribute to the development of new approaches for the treatment of neurological diseases.

Closed fixed-bed bacteria-algae biofilm reactor: A promising solution for phenol containing wastewater treatment and resource transformation

This study focuses on treating phenolic wastewater with a novel closed fixed-bed bacteria-algae biofilm reactor (CF-BABR) to enhance resource transformation for phenolic substances. The CF-BABR showed strong impact - load resistance and stable degradation efficiency, fully degrading phenolic compounds at concentrations from 0 to 150 mg/L. From the inflow to the outflow, the effective sequences, abundance, and diversity of bacteria decreased. Chlorobaculum was the dominant bacterium for phenolic pollutant degradation. The abundance of fungi decreased gradually, while their diversity increased. Kalenjinia and Cutaneotrichosporon played a synergistic role in reducing pollutant toxicity. The high - concentration pollutants at the influent led to a higher abundance of microalgal communities, and Scenedesmaceae became the most dominant algal family, which was positively correlated with the degradation of phenolic compounds. Functional gene prediction indicated that the abundance of functional genes in bacteria decreased overall along the wastewater flow. Carbohydrate metabolism and amino acid metabolism were the most active secondary pathways. In fungi, the predicted gene functions had the highest abundance in the upstream region. Metabolic intermediates such as organic acids and derivatives, lipids and lipid - like molecules, and carboxylic acids and derivatives demonstrated the degradation effect of CF-BABR on phenolic compounds.

Investigating the multifaceted role of nucleolin in cellular function and Cancer: Structure, Regulation, and therapeutic implications

Nucleolin (NCL), a highly conserved and multifunctional phosphoprotein, is primarily localized in the nucleolus and participates in various cellular compartments, including the nucleoplasm, cytoplasm, and plasma membrane. Initially discovered in the 1970 s, NCL is integral to ribosome biogenesis through its roles in ribosomal RNA transcription, processing, and assembly. Beyond ribosome synthesis, NCL plays critical roles in cellular processes such as DNA and RNA metabolism, chromatin remodeling, and cell cycle regulation, underscoring its essentiality for cell viability. Structurally, NCL comprises multiple functional domains, which facilitates interaction with various kinases and other proteins. NCL's extensive post-translational modifications influence its localization and function. Importantly, NCL has emerged as a key player in multiple pathologies, particularly cancer, where it contributes to tumor growth, metastasis, and drug resistance. On the cell surface, NCL acts as a co-receptor for growth factors and other ligands, facilitating oncogenic signaling. Additionally, its regulation of non-coding RNAs, stabilization of oncogenic mRNAs, and involvement in immune evasion highlight its potential as a therapeutic target. This review provides an unexplored in-depth overview of NCL's structure, functions, and modifications, with a focus on its role in cancer biology and its therapeutic implications.

In vitro investigation of epigenetic regulators related to chemo-resistance and stemness of CD133+VE cells sorted from U87MG cell line

Glioblastoma (GBM) is the most common and malignant adult primary brain tumor with frequent relapse and resistance to therapies. Glioma stem cells, a rare population, is thought to be the reason behind the treatment's failure. It is imperative to investigate the disease mechanisms and identify the biomarkers by which glioma stem cells would contribute to treatment relapse and resistance to already available chemotherapeutic agents. The CD133+VE cells were isolated from U87MG cell line and characterized by morphological features, cell viability, self-renewal efficiency, migration potential and karyotyping. Doxorubicin Cisplatin, Irinotecan, Etoposide and Temozolomide were used to determine the anti-proliferative effect on CD133+VE cells. Confocal microcopy was used to localize the chemotherapeutic agents in the CD133+VE cells. In quest of epigenetic biomarkers, RNA sequencing was performed to find the role of lncRNAs in stemness and resistance to therapies. U87cell line and CD133-VE cells were kept as controls for all the experiments. It was found that CD133+VEcells were highly proliferative with increased migration potential, elevated IC50 values against chemotherapeutic agents and showed distinct karyotyping related to pluripotency. Chemotherapeutic agent such as Doxorubicin was localized outside the nucleus revealing the drug resistance as evident by confocal microscopy. RNA sequencing revealed 126 differentially expressed lncRNAs (DELs) in CD133+VEcells among which lncRNA LOXL1-AS1 was highly upregulated and lncRNA PAX8-AS1 was significantly downregulated. These lncRNAs has been reported to be related to drug resistance, migration and epithelial- to- mesenchymal transmission (EMT), self-renewal and stemness properties contributing to poor prognosis and disease relapse.

Anticancer signal transduction pathways of selenium nanoparticles in mouse colorectal cancer model

Despite significant advances in the treatment of colon cancer, this disease is extremely common, often requiring serious surgery followed by long-term drug treatment. Colon and rectal cancer remain dangerous forms of cancer due to the high degree of metastasis. The development and study of the effectiveness of anticancer drugs based on nanoparticles is an urgent task of modern biomedicine. Of particular interest are attempts to move research from the in vitro level to the in vivo level of preclinical studies. In the presented study, mice were subcutaneously implanted with MC-38 cell line, a tumor was grown, and selenium nanoparticles (SeNPs) with a diameter of 100 nm obtained using the laser ablation method were administered intraperitoneally. Using morphometric measurements, it was found that injections of 1 μg/g or 10 μg/g SeNPs inhibited weight loss of mice during cancer development, reduced tumor size by 2-2.5 times, and suppressed metastasis by 1.5-3 times. Analysis of selenium levels in mouse blood, liver and tumor samples by atomic absorption spectrometry after the end of SeNPs treatment showed that the nanoparticles increased selenium levels in the blood and liver of mice without a significant dose-dependence, whereas in tumors a dose-dependent increase in selenium concentration was detected from the concentration of nanoparticles, with 10 μg/g SeNPs causing a more pronounced increase in selenium concentration. Using PCR and Western blot analysis, it was possible to establish that SeNPs injections led to an increase in the expression of genes encoding anti-inflammatory and anti-hypoxic proteins, but reduced the expression of antioxidant selenium-containing proteins and proteins responsible for the proliferation of cancer cells. Both concentrations of SeNPs led to similar effects, but increasing the concentration of nanoselenium to 10 μg/g affected the expression of a larger number of genes and the effects on expression were more "bright". Thus, the complex of presented experiments showed that injections of selenium nanoparticles in concentrations of 1 μg/g or 10 μg/g are capable to transport by the bloodstream and accumulating in the highest concentration in colon adenocarcinoma, compared with liver, which indicates the targeting of SeNPs in relation to tumors even without functionalization by specific molecules. As a result, there was a change in the expression patterns of genes and a number of proteins, and as a result, there was a decrease in tumor volume, normalization of mouse weight and maintenance of positive dynamics throughout the entire observation period.

A cortical pool of LIN-5 (NuMA) controls cytokinetic furrow formation and cytokinesis completion

In animal cells, cleavage furrow formation is controlled by localized activation of the GTPase RhoA at the equatorial membrane using cues transmitted from the spindle. Here, we explore the function of LIN-5, a well-studied protein known for its role in aster separation and spindle positioning in cleavage furrow formation. We show that the cortical pool of LIN-5, recruited by GPR-1/2 and important for cortical force generation, regulates cleavage furrow formation independently of its roles in aster separation and spindle positioning. Instead, our data suggest that enrichment of LIN-5/GPR-1/2 at the polar cortical region is essential to ensure the timely accumulation of contractile ring components-myosin II and Anillin at the equatorial cortex. We additionally define a late cytokinesis role of cortical LIN-5/GPR-1/2 in midbody stabilization and abscission. These results indicate that the cortical LIN-5/GPR-1/2 complex contributes to multiple aspects of cytokinesis independently of its roles in spindle positioning and elongation.

KIF2A stabilizes intercellular bridge microtubules to maintain mouse embryonic stem cell cytokinesis

Cytokinesis, the final stage of cell division, serves to physically separate daughter cells. In cultured naïve mouse embryonic stem cells, cytokinesis lasts unusually long. Here, we describe a novel function for the kinesin-13 member KIF2A in this process. In genome-engineered mouse embryonic stem cells, we find that KIF2A localizes to spindle poles during metaphase and regulates spindle length in a manner consistent with its known role as a microtubule minus-end depolymerase. In contrast, during cytokinesis we observe tight binding of KIF2A to intercellular bridge microtubules. At this stage, KIF2A maintains microtubule length and number and controls microtubule acetylation. We propose that the conversion of KIF2A from a depolymerase to a stabilizer is driven by both the inhibition of its ATPase activity, which increases lattice affinity, and a preference for compacted lattices. In turn, KIF2A might maintain the compacted microtubule state at the intercellular bridge, thereby dampening acetylation. As KIF2A depletion causes pluripotency problems and affects mRNA homeostasis, our results furthermore indicate that KIF2A-mediated microtubule stabilization prolongs cytokinesis to maintain pluripotency.

Phosphorylation-dependent regional motility of the ciliary kinesin OSM-3

Kinesin motor proteins, vital for intracellular microtubule-based transport, display region-specific motility within cells, a phenomenon that remains molecularly enigmatic. This study focuses on the localized activation of OSM-3, an intraflagellar transport kinesin crucial for the assembly of ciliary distal segments in Caenorhabditis elegans sensory neurons. Fluorescence lifetime imaging microscopy unveiled an extended, active conformation of OSM-3 in the ciliary base and middle segments, where OSM-3 is conveyed as cargo by kinesin-II. We demonstrate that NEKL-3, a never in mitosis kinase-like protein, directly phosphorylates the motor domain of OSM-3, inhibiting its in vitro activity. NEKL-3 and NEKL-4, localized at the ciliary base, function redundantly to restrict OSM-3 activation. Elevated levels of protein phosphatase 2A at the ciliary transition zone or middle segments triggered premature OSM-3 motility, while its deficiency resulted in reduced OSM-3 activity and shorter cilia. These findings elucidate a phosphorylation-mediated mechanism governing the regional motility of kinesins.

Sulfonamide metabolites enhance resistance transmission via conjugative transfer pathways

Human beings release thousands of antibiotics into the environment, which could generate the related transformation products (TPs), most of which have yet to be identified and lack rigorous microbial risk information. This study aimed to investigate the impact and mechanisms of 4-nitro sulfamethoxazole, N4-acetylated sulfamethoxazole, and N4-acetylated sulfadiazine, three typical sulfonamide (SAs) metabolites, on the risk of antibiotic resistance genes (ARGs) transmission. The results revealed that TPs significantly enhance the risk of conjugative transfer of RP4 plasmid at clinically and environmentally relevant concentrations (10 ng/L to 100 μg/L), with a maximum increase of up to 73-fold. These three metabolites' capabilities to enhance the conjugative transfer of ARGs are more pronounced than the parent sulfonamides. The induction mechanisms of TPs on ARGs transmission are also more complex, which primarily arise from the enhancement of reactive oxygen species, further increased cell membrane permeability and upregulated bacterial secretion systems. Transcriptomic analysis validated the aforementioned biological processes and showed that TPs also increased the activity of toxin-antitoxin system and bacterial intracellular transposon, thereby promoting the spread of ARGs. This research contributes to a better understanding of the antibiotic-like effects of TPs, which is crucial for improving our understanding of non-antibiotic drug-induced bacterial resistance risks.

Embryonic exposure to prednisone induces bone developmental toxicity in zebrafish: Characteristics and molecular mechanisms

As a synthetic glucocorticoid, prednisone has been widely used in autoimmune diseases, recurrent abortion and asthma during pregnancy. Although studies suggested that glucocorticoid exposure during pregnancy have developmental toxicity, systematic research on the characteristics of the developmental toxicity of prednisone is lacking. This study intends to construct embryonic prednisone exposure (EPE) model to observe its bone developmental toxicity characteristics of prednisone and explore the mechanism. The results showed that EPE can shortened body and head length, reduced eye and head area, decreased operculum mineralization area, reduced mineralized vertebrae number, shortened ceratohyal and palatoquadrate cartilage length, and decreased expression of key osteogenic differentiation and cartilage development genes. The toxicity to osteogenesis is more severe than chondrogenesis. The toxicity caused by exposure in the middle and terminal stages of embryogenesis is more serious and shows a concentration-effect relationship. We confirmed that Gr/Hdac6 signaling activation mediates prednisone-induced inhibition of osteoblast differentiation by epigenetically regulating the Postnb/Wnt/β-catenin signaling pathway. The results of this study systematically demonstrate the characteristics of prednisone-induced systemic, bone, and cartilage developmental toxicity, and clarify the epigenetic mechanism of its osteogenic developmental toxicity. This provides theoretical and experimental evidence for the safe use of prednisone during pregnancy and the determination of early monitoring targets for bone developmental toxicity.

Simulation of a Free Boundary Cell Migration Model through Physics Informed Neural Networks

Understanding the complexities of single-cell migration is facilitated by computational modeling, which provides important insights into the physiological processes that underlie migration mechanisms. This study developed a computational model for one-dimensional actomyosin flow in a migrating cell with moving boundaries. The model incorporates the complex interplay of actin polymerization, substrate adhesion, and actomyosin dynamics through a system of coupled nonlinear partial differential equations. A physics-informed neural network is designed to understand the dynamic behavior of actin flow and actin concentration within the cell along with the unknown moving boundaries, taking into account the computational cost of solving a dynamic model with a deformable domain. The model's capacity to depict the complex interaction between biological and physical processes within the cell is demonstrated by the numerical results, which qualitatively agree with experimental and computational data available in the literature. This study demonstrates the application of a deep learning method to simulate a challenging biophysical problem with moving boundaries. The model does not require synthetic data for training and accurately reflects the intricate biophysics of cell migration.

Immunological characterization of the rainbow trout bursa

The bursa of Fabricius is an immune organ, located in the caudo-dorsal surface of the cloaca, responsible for the development and maturation of avian B cells. A few years ago, a lymphoepithelial tissue placed caudal to the urogenital papilla of the cloaca analogous to the bursa was identified for the first time in Atlantic salmon (Salmo salar). The salmon bursa was demonstrated to involute around sexual maturation, as in birds. However, no primary lymphoid functions were identified in this tissue. In the current study, we have identified a homologous immune organ in rainbow trout (Oncorhynchus mykiss), a different salmonid species. This lymphoepithelium covering a blind sac, caudal to the anus, was identified in rainbow trout at different stages of development and it also experienced regression in an age-dependent way. It contained abundant IgM+ B cells and CD3+ cells and especially numerous was the number of MHC II-expressing cells. In contrast to Atlantic salmon, in rainbow trout, the bursa epithelium contained quite a few IgT+ B cells but very few IgD+ B cells. Thus, by flow cytometry, we could determine that the IgM+ B cells identified in the trout bursa had lost surface IgD expression. Interestingly, although an immunization of rainbow trout by bath barely had effects on the bursa at a transcriptional level, when fish were immunized anally with a model antigen, there were significant changes in the levels of transcription of immune genes in this tissue. These included secreted igm, secreted and membrane igd, bcma and prdm1-a2. Altogether these results evidence the existence of a bursa-like immune structure in another teleost species and provide novel information to understand the immune role of this tissue in fish, pointing to a relation to gut immune responses.

Establishment and validation of a clinical prediction model for colorectal adenoma risk factors

Colorectal adenomas are benign tumors of the colorectal mucosal epithelium that have malignant potential and are regarded as precancerous lesions of colorectal cancer, for which the specific risk factors are unclear. The present study aimed to identify independent risk factors for colorectal adenoma to develop a prediction model and test its predictive value. A retrospective analysis was performed using data from patients who underwent electronic colonoscopy at the Department of Proctology (Affiliated Hospital of Shandong University of Traditional Chinese Medicine; Jinan, China) from January 2013 to December 2023 and had polyps removed during colonoscopy. Patients with colorectal adenoma were included in the case group, whilst those with no visible abnormalities on endoscopy or with non-adenomatous polyps were included as a control group. The patients were randomly divided into a training and validation group in a 7:3 ratio. Variables were screened using single-component analysis and the filtered variables were employed in multivariate logistic regression to create a clinical prediction model. Finally, the model was internally and externally validated. A total of 730 patients were included in the present study, with 286 assigned to the case group and 444 to the control group. After the initial screening of 39 variables, 12 continued to the next round, resulting in four potential predictors including age, daily number of bowel movements, thrombin time and the number of polyps. A prediction model was created based on these variables. Regarding internal validation, the C-index was 0.7054 [95% confidence interval (CI), 0.6596-0.7512] and the prediction probability in the calibration curve was close to the diagonal line of the calibration graph, indicating that the prediction probability of the model was reasonable. Regarding external validation, the C-index in the validation cohort was 0.6306 (95% CI, 0.5560-0.7053) and the calibration curve also demonstrated good identification capabilities. The Hosmer-Lemeshow test revealed that the model had a reasonable calibration degree, with χ2=9.7893, degree of freedom=8 and P=0.28. The receiver operating characteristic curve and decision curve analysis for the training and validation cohorts demonstrated good efficacy and an ideal application value. In conclusion, the model constructed in the present study demonstrated moderate predictive accuracy for colorectal adenoma risk, laying the groundwork for early detection of colorectal adenoma and secondary prevention of colorectal cancer.

Expanded insights into the mechanisms of RNA-binding protein regulation of circRNA generation and function in cancer biology and therapy

RNA-binding proteins (RBPs) regulate the generation of circular RNAs (circRNAs) by participating in the reverse splicing of circRNA and thereby influencing circRNA function in cells and diseases, including cancer. Increasing evidence has demonstrated that the circRNA-RBP network plays a complex and multifaceted role in tumor progression. Thus, a better understanding of this network may provide new insights for the discovery of cancer drugs. In this review, we discuss the characteristics of RBPs and circRNAs and how the circRNA-RBP network regulates tumor cell phenotypes such as proliferation, metastasis, apoptosis, metabolism, immunity, drug resistance, and the tumor environment. Moreover, we investigate the factors that influence circRNA-RBP interactions and the regulation of downstream pathways related to tumor development, such as the tumor microenvironment and N6-methyladenosine modification. Furthermore, we discuss new ideas for targeting circRNA-RBP interactions using various RNA technologies.

Neutralizing antibody responses after a two-dose regimen with BNT162b2, CoronaVac or ChAdOx1-S in Brazil: Differential neutralization of SARS-CoV-2 omicron variants

The emergence of SARS-CoV-2 variants has reduced antibody effectiveness, affecting vaccine protection. This study evaluated neutralizing antibodies against Wuhan strain and several variants, including Alpha, Beta, Gamma, Delta, and Omicron, in Brazilians vaccinated twice with CoronaVac, ChAdOx1-S, or BNT162b2 before Delta and Omicron emerged. After the booster, strong antibody responses to the Wuhan strain were seen in all groups, but BNT162b2 resulted in higher anti-Spike and anti-RBD IgG levels. While all vaccines showed some cross-neutralization against Alpha, Beta, Gamma, and Delta, only BNT162b2 was effective against Omicron BA.2 and BA.4/5 subvariants. Furthermore, BNT162b2 vaccination showed a positive correlation between Wuhan RBD-specific IgG and Omicron neutralizing antibodies. This group demonstrated distinct clustering patterns of neutralizing antibodies against all variants, unlike those from CoronaVac and ChAdOx1-S. The findings suggest BNT162b2 offers broader neutralization capability, highlighting the benefit of booster shots with bivalent mRNA vaccines to enhance immune responses against emerging variants.

MCC in the spotlight: Its dual role in signal regulation and oncogenesis

The mutated in colorectal cancer (MCC) gene is closely associated with the onset and progression of colorectal cancer. MCC plays a critical role in regulating the cell cycle and various signaling pathways and is recognized to inhibit cancer cell proliferation via the β-catenin signaling pathway. β-catenin is a key component of the WNT signaling pathway that influences cell growth, differentiation, survival, and migration, thereby positioning MCC as an important tumor suppressor. Notably, MCC has also been implicated in other cancer types, including lung, liver, and brain cancers. However, the precise mechanisms by which MCC functions in these malignancies remain inadequately understood. Comprehensive investigations into the interactions among MCC, various signaling pathways, and metabolic processes are essential for uncovering the molecular mechanisms of cancer and the pathological features characteristic of different cancer stages. This review presents the structural characteristics of MCC and its cell growth regulation mechanisms and functional roles within tissues, with the aims of enhancing our understanding of the role of MCC in cancer biology and highlighting potential therapeutic strategies targeting this gene.

Antimicrobial potential of biopolymers against foodborne pathogens: An updated review

Biopolymers are natural polymers produced by the cells of living organisms such as plants, animals, microbes, etc. As these natural molecules possess antimicrobial activities against pathogens, they can be a suitable candidate for antimicrobials combating drug-resistant microorganisms including food-borne pathogens. Plant-derived biopolymers such as cellulose, starch, pullulans; microbes-derived chitosan, poly-L-lysine; animal-derived collagen, gelatin, spongin, etc. are proven to possess antimicrobial properties. They exert their antimicrobial activity against food-borne pathogens namely Salmonella typhi, Vibrio cholerae, Bacillus cereus, Clostridium perfringens, E. coli, Campylobacter jejuni, Staphylococcus aureus, etc. As antimicrobial resistance becomes a global phenomenon and threatens the effective prevention and treatment of infections caused by pathogens, biopolymers could be a promising candidate/substitute for conventional antimicrobials available in markets. Biopolymers can have detrimental effects on microbial cells such as disruption of the cell walls and cell membranes; damage to the DNA caused by strand breakage, unwinding, or cross-linking resulting in impeded DNA transcription and replication; lowering the amount of energy required for metabolic processes by compromising the proton motive force. Biopolymers also interfere with the quorum sensing mechanism and biofilm formation of microbes and modulate the host immune system by downregulating mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB) signaling pathways resulting in the decreased production of pro-inflammatory cytokines. Furthermore, conjugating these biopolymers with other antimicrobial agents could be a promising approach to control multidrug-resistant foodborne pathogens. This review provides an overview of the various sources of biopolymers with special reference to their antimicrobial applications, especially against foodborne pathogens, and highlights their antimicrobial mechanisms.