Intercellular Pathways Research Articles

Establishment of a Basement Membrane-Related Prognosis Model and Characterization of Tumor Microenvironment Infiltration in Acute Myeloid Leukemia.

Background: Basement membrane is a special component of extracellular matrix of epithelial and endothelial tissues, which can maintain their normal morphologies and functions. It can also participate in tumor progression and affect tumor treatment. However, the roles of basement membrane-related genes (BMGs) in acute myeloid leukemia (AML) remain unknown. Material and methods: We downloaded the data of AML and normal samples from TCGA, GTEx, and GEO. Then, we performed bioinformatics analysis to identify differential BMGs. We calculated the risk score of the training cohort and divided it into two risk groups. In addition, we also introduced external cohorts, serving as validation cohorts, to estimate the accuracy of risk score. A nomogram was established based on the risk score and clinicopathological characteristics to predict the prognosis. Based on BMGs, AML patients of TCGA were clustered into 2 subtypes. To investigate the biological features and the association between immune cells and TME, we utilized GSVA to assess pathway enrichment and ssGSEA to quantify the levels of immune cell infiltration across samples. Results: We obtained 3 differential BMGs between AML and normal samples. The training cohort was divided into high- and low-risk groups based on the risk score. The Kaplan-Meier survival analysis indicated that the two groups had significant differences. The nomogram could be used to predict the survival outcomes of AML patients. Based on the clustering result, we found significant differences between the two gene clusters. Sankey's diagram suggested that cluster B was associated with the high-risk group and poor prognosis. GSVA analysis showed that cluster B was also related to the upregulation of intercellular and intracellular signal transduction pathways. In TME, resting mast cells, follicular helper T cells, and plasma cells decreased while monocytes increased in the high-risk group. In addition, the high-risk group was more sensitive to BTK and AKT inhibitors. Conclusion: Our study indicated that the nomogram model of BMGs could predict the prognosis of AML patients. Meanwhile, BMGs were correlated with immune TME in AML. A correct and comprehensive assessment of the mechanisms of BMGs in individuals will help guide more effective treatment.

Extracellular Vesicles From Bone Marrow-Derived Macrophages Enriched in ARG1 Enhance Microglial Phagocytosis and Haematoma Clearance Following Intracerebral Haemorrhage.

Microglial phagocytosis of haematomas is crucial for neural functional recovery following intracerebral haemorrhage (ICH), a process regulated by various factors from within and outside the central nervous system (CNS). Extracellular vesicles (EVs), significant mediators of intercellular communication, have been demonstrated to play a pivotal role in the pathogenesis and progression of CNS diseases. However, the regulatory role of endogenous EVs on the phagocytic capacity of microglia post-ICH remains elusive. Utilising multi-omics analysis of brain tissue-derived EVs proteomics and single-cell RNA sequencing, this study identified that bone marrow-derived macrophages (BMDMs) potentially enhance microglial phagocytosis via EVs following ICH. By blocking BMDMs and reducing ARG1 in BMDM-derived EVs, we demonstrated that BMDMs facilitate erythrophagocytosis by delivering ARG1 to microglia via EVs post-ICH. EVs-carried ARG1 was found to augment phagocytosis by promoting RAC1-dependent cytoskeletal remodelling in microglia. Collectively, this research uncovers an intercellular communication pathway from BMDMs to microglia mediated by EVs post-ICH. This provides a novel paradigm for EV-mediated intercellular communication mechanisms and suggests a promising therapeutic potential for BMDM-derived EVs in the treatment of ICH.

N-cadherin antagonism is bronchoprotective in severe asthma models.

Severe asthma induces substantial mortality and chronic disability due to intractable airway obstruction, which may become resistant to currently available therapies including corticosteroids and β-adrenergic agonist bronchodilators. A key effector of these changes is exaggerated airway smooth muscle (ASM) cell contraction to spasmogens. No drugs in clinical use effectively prevent ASM hyperresponsiveness in asthma across all severities. We find that N-cadherin, a membrane cell-cell adhesion protein up-regulated in ASM from patients with severe asthma, is required for the development of airway obstruction induced by allergic airway inflammation in mice. Inhibition of N-cadherin by ADH-1 reduced airway hyperresponsiveness independent of allergic inflammation, prevented bronchoconstriction, and actively promoted bronchodilation of airways ex vivo. ADH-1 inhibited ASM contraction by disrupting N-cadherin-δ-catenin interactions, which decreased intracellular actin remodeling. These data provide evidence for an intercellular communication pathway mediating ASM contraction and identify N-cadherin as a potential therapeutic target for inhibiting bronchoconstriction in asthma.

Transdermal Patches: Design and Current Approaches Using Natural Polymers

One method of controlled drug delivery is the transdermal drug delivery system (TDDS), which aims to distribute the drug through the skin at a predetermined and regulated rate. It provides a number of benefits, including a longer therapeutic impact, fewer side effects, increased bioavailability, better patient compliance, and simple medication therapy discontinuation. For most compounds, the stratum corneum is thought to be the rate limiting barrier in transdermal penetration. The appendageal, transcellular, and intercellular pathways are the three main ways that drugs can enter the body. When giving medication by this route, it is important to take into account the following aspects: skin age, condition, physicochemical characteristics, and environmental conditions. Polymer matrix, membrane, drug, penetration enhancers, pressure-sensitive adhesives, backing laminates, release liner, etc. are some of the fundamental parts of TDDS. Transdermal patches are used to deliver active chemicals to the circulatory system through the skin. These patches can be classified into a variety of systems, such as reservoir, matrix, and micro-reservoir systems. Consistent methodologies are used to assess the adhesion qualities, physicochemical properties, in vitro drug release studies, in vitro skin penetration studies, skin irritation studies, and stability studies once transdermal patches have been prepared. Different medications are marketed as transdermal patches, depending on the length of the therapy. Natural polymers can be used as the means of achieving predetermined rates of drug delivery. Natural polymers are basically polysaccharides so they are biocompatible and without any side effects. Gums, mucilages, resins and plant extracts are widely used natural materials for conventional and novel dosage forms. The present article highlights the available information on natural polymers and their versatile use.

The Changes in Cross-Resistance, Fitness, and Feeding Behavior in Aphis gossypii as Their Resistance to Sulfoxaflor Declines.

The increasing resistance in Aphis gossypii field populations to sulfoxaflor and many different types of insecticides represents a significant challenge in protecting cotton production in China. Although resistant pests were able to regain their susceptibility to insecticides after the reduction in insecticide applications, some of their biological parameters remained different from susceptible strains. The resistance to sulfoxaflor was unstable in A. gossypii after the loss of selective pressure. The strain with declined resistance (Sul-D) (RR = 1.11-fold) restored its susceptibility to sulfoxaflor, acetamiprid, and imidacloprid after the sulfoxaflor-resistant (Sul-R) (RR = 51.57-fold) was maintained without insecticide pressure for 22 generations. Sul-R had a relative fitness of 0.87, and the Sul-D strain still had a relative fitness of 0.84, even if its susceptibility to sulfoxaflor was restored. Compared with the susceptible strain (Sus), the Sul-R and Sul-D strains became more active in searching for appropriate feeding positions because they generated more intercellular apoplastic stylar pathway events (C). However, the phloem-feeding ability was reduced in the Sul-R and Sul-D strains, as shown by the decrease in phloem behavioral parameters, such as phloem salivations (E1), phloem ingestion (E2), and the percentages of E1 and E2. The negative hormesis effect of sulfoxaflor on phloem feeding was observed in susceptible strain but not in Sul-R and Sul-D, as evidenced by the significant decreases in the number of E1, the duration of E1 and E2, and the percentage of E1 and E2 in the Sus strain. Sulfoxaflor resistance was unstable in A. gossypii, and there was still a fitness cost to A. gossypii after recovering susceptibility to sulfoxaflor. The phloem-feeding ability was reduced in the Sul-R and Sul-D strains compared with the Sus strain, but the negative hormesis effect of sulfoxaflor on phloem feeding was only found in the Sus strain. The outcomes of this study could contribute to a comprehensive risk assessment and provide a basis for developing a better strategy to control A. gossypii.

Transferosome as Nanocarrier for Drug Penetration Enhancement Across Skin: A Comparison with Liposome and Ethosome

Transdermal drug delivery systems have greatly attracted investigators because of their advantages over parenteral and oral delivery methods. The skin's structure usually limits drug penetration, prompting the development of vesicular transdermal drug delivery systems like ethosomes, liposomes, niosomes, transferosomes, etc., to increase drug delivery. This review aims to explore the concept of transferosome and to compare its composition and functionality with other vesicular systems. The recent applications of transferosomes in transdermal drug delivery were also discussed. An extensive literature review was conducted to gather information on the composition of transferosomes, their mechanism of action, and their comparative advantages over other vesicular systems. Transferosomes are composed of phosphatidylcholine and an edge activator, which provide an ultra-deformable characteristic, allowing them to penetrate the skin’s inner layers via paracellular and intercellular pathways. The primary mechanism guiding transferosomes into the epidermis layer of skin is the osmotic gradient. Transferosomes overcome the limitations of liposomes and ethosomes, such as low encapsulation potential for hydrophilic molecules, leaky behaviour due to an uneven membrane, a short shelf-life, and other issues. Transferosomes have shown significant potential in transdermal drug delivery, with extensive research supporting their use in various drug categories, including anti-inflammatory, anti-cancer, antidiabetics, etc. The ability of transferosomes to penetrate the skin layers effectively makes them a promising carrier for further research in the delivery of different classes of drugs.

Differences in the permeation of Licoricchalcone A-polysaccharide self-assembled nanoparticles on healthy and DNCB-induced atopic dermatitis in Balb/c mice

Nanoformulation have been widely used in skin and transdermal drug delivery. However, the differences in integral nanoparticles absorption in healthy and diseased skin have not yet fully analyzed. The present study attempted to explore the percutaneous absorption of drugs via lesional skin by using atopic dermatitis (AD) as a model, dinitrochlorobenzene (DNCB) induced AD-like skin. In here, the small molecules of insoluble Licoricchalcone A (LA) and macromolecules glycyrrhizin polysaccharide were used to prepare LA-polysaccharide self-assembled nanoparticles (GPA-SANs) by micro-precipitation. An environment-responsive dye, P4, was loaded into SAN to track the transdermal translocation of the nanoparticles, while the drug marked with coumarin 6 (C6). Compared to healthy skin, the permeability of GPA-SANs on AD-like skin is stronger, which may be due to damage to the stratum corneum of the AD-like skin and increased intercellular spaces, resulting in an increased permeability coefficient. Therefore, the storage of nanoparticles and their diffusion at the lesion site also increased accordingly. CLSM shown that the fluorescence of P4 and C6 is observed to concentrate around the hair follicles and disseminate in the surrounding area in both AD-affected and healthy skin.It can be clearly seen that fluorescence signal of C6 in the intercellular spaces of the dermis and epidermis of AD-like skin, indicating that nano-drug on the disease skin can penetrate through the intercellular pathway to achieve therapeutic. The focus of the present study is to assess the permeability of healthy and disease skin, discuss their characteristics and discrepancy, aiming to provide a reference for the further study of nano-formulations in transdermal delivery.

Single-Cell RNA Sequencing Reveals Transcriptional Signatures and Cell-Cell Communication in Diabetic Retinopathy.

Diabetic retinopathy (DR) is a major cause of vision loss in workingage individuals worldwide. Cell-to-cell communication between retinal cells and retinal pigment epithelial cells (RPEs) in DR is still unclear, so this study aimed to generate a single-cell atlas and identify receptor‒ligand communication between retinal cells and RPEs. A mouse single-cell RNA sequencing (scRNA-seq) dataset was retrieved from the GEO database (GSE178121) and was further analyzed with the R package Seurat. Cell cluster annotation was performed to further analyze cell‒cell communication. The differentially expressed genes (DEGs) in RPEs were explored through pathway enrichment analysis and the protein‒ protein interaction (PPI) network. Core genes in the PPI were verified by quantitative PCR in ARPE-19 cells. We observed an increased proportion of RPEs in STZ mice. Although some overall intercellular communication pathways did not differ significantly in the STZ and control groups, RPEs relayed significantly more signals in the STZ group. In addition, THBS1, ITGB1, COL9A3, ITGB8, VTN, TIMP2, and FBN1 were found to be the core DEGs of the PPI network in RPEs. qPCR results showed that the expression of ITGB1, COL9A3, ITGB8, VTN, TIMP2, and FBN1 was higher and consistent with scRNA-seq results in ARPE-19 cells under hyperglycemic conditions. Our study, for the first time, investigated how signals that RPEs relay to and from other cells underly the progression of DR based on scRNA-seq. These signaling pathways and hub genes may provide new insights into DR mechanisms and therapeutic targets.

Single-Cell RNA Sequencing Deconstructs the Distribution of Immune Cells Within Abdominal Aortic Aneurysms in Mice.

Inflammation is a key component in the development of abdominal aortic aneurysm (AAA), yet insights into the roles of immune cells and their interactions in this process are limited. Using single-cell RNA transcriptomic analysis, we deconstructed the CD45+ cell population in elastase-induced murine AAA at the single-cell level. We isolated each group of immune cells from murine AAA tissue at different time points and divided them into several subtypes, listed the remarkable differentially expressed genes, explored the developmental trajectories of immune cells, and demonstrated the interactions among them. Our findings reveal significant differences in several immune cell subsets, including macrophages, dendritic cells, and T cells, within the AAA microenvironment compared with the normal aorta. Especially, conventional dendritic cell type 1 exclusively existed in the AAA tissue rather than the normal aortas. Via CellChat analysis, we identified several intercellular communication pathways like visfatin, which targets monocyte differentiation and neutrophil extracellular trap-mediated interaction between neutrophils and dendritic cells, which might contribute to AAA development. Some of these pathways were validated in human AAA. Despite the absence of external pathogenic stimuli, AAA tissues develop a complex inflammatory microenvironment involving numerous immune cells. In-depth studies of the inflammatory network shall provide new strategies for patients with AAA.

A Review on Topical Gels as Drug Delivery System

The skin serves as a formidable barrier to drug penetration, primarily due to the stratum corneum. For successful transdermal drug delivery, the drug must overcome this barrier and reach the target site in sufficient concentrations. Drug molecules can penetrate the skin via the transcellular, intercellular, and appendageal pathways. The extent of drug permeation is influenced by factors such as the physicochemical properties of the drug, the nature of the vehicle, and the condition of the skin. Gels, being hydrophilic, can enhance drug permeation by increasing the hydration of the stratum corneum. Permeation enhancers, which reversibly alter the structure of the stratum corneum, can also improve drug permeation. Recent advancements in topical gel drug delivery include the use of nanotechnology, stimuli-responsive gels, combination therapy, natural polymers, and biodegradable materials. The delivery of biomolecules through the skin remains a challenge, and strategies such as iontophoresis, microneedles, and nanocarriers are being investigated. 3D printing technology enables the personalized fabrication of gels with precise drug dosing and customized release profiles. Despite significant advancements, challenges such as limited drug permeability, potential for skin irritation, and the need for long-term stability studies persist. Future research should focus on developing innovative strategies to overcome these challenges and optimize the performance of topical gels, involving the exploration of new drug-polymer combinations, advanced drug delivery technologies, and in silico modeling tools

A cyanobacterial sigma factor F controls biofilm-promoting genes through intra- and intercellular pathways

Cyanobacteria frequently constitute integral components of microbial communities known as phototrophic biofilms, which are widespread in various environments. Moreover, assemblages of these organisms, which serve as an expression platform, simplify harvesting the biomass, thereby holding significant industrial relevance. Previous studies of the model cyanobacterium Synechococcus elongatus PCC 7942 revealed that its planktonic growth habit results from a biofilm-suppression mechanism that depends on an extracellular inhibitor, an observation that opens the door to investigating cyanobacterial intercellular communication. Here, we demonstrate that the RNA polymerase sigma factor SigF1, is required for this biofilm-suppression mechanism whereas the S. elongatus paralog SigF2 is not involved in biofilm regulation. Comprehensive transcriptome analyses identified distinct regulons under the control of each of these sigma factors. sigF1 inactivation substantially lowers transcription of genes that code for the primary pilus subunit and consequently prevents pilus assembly. Moreover, additional data demonstrate absence of the biofilm inhibitor from conditioned medium of the sigF1 mutant, further validating involvement of the pilus assembly complex in secretion of the biofilm inhibitor. Consequently, expression is significantly upregulated for the ebfG-operon that encodes matrix components and the genes that encode the corresponding secretion system, which are repressed by the biofilm inhibitor in the wild type. Thus, this study uncovers a basic regulatory component of cyanobacterial intercellular communication, a field that is in its infancy. Elevated expression of biofilm-promoting genes in a sigF1 mutant supports an additional layer of regulation by SigF1 that operates via an intracellular mechanism.

Proteomics Analysis of Proteotoxic Stress Response in In-Vitro Human Neuronal Models.

Heat stroke, a hazardous hyperthermia-related illness, is characterized by CNS injury, particularly long-lasting brain damage. A root cause for hyperthermic neurological damage is heat-induced proteotoxic stress through protein aggregation, a known causative agent of neurological disorders. Stress magnitude and enduring persistence are highly correlated with hyperthermia-associated neurological damage. We used an untargeted proteomic approach using liquid chromatography-tandem mass spectrometry (LC-MS/MS) to identify and characterize time-series proteome-wide changes in dose-responsive proteotoxic stress models in medulloblastoma [Daoy], neuroblastoma [SH-SY5Y], and differentiated SH-SY5Y neuron-like cells [SH(D)]. An integrated analysis of condition-time datasets identified global proteome-wide differentially expressed proteins (DEPs) as part of the heat-induced proteotoxic stress response. The condition-specific analysis detected higher DEPs and upregulated proteins in extreme heat stress with a relatively conservative and tight regulation in differentiated SH-SY5Y neuron-like cells. Functional network analysis using ingenuity pathway analysis (IPA) identified common intercellular pathways associated with the biological processes of protein, RNA, and amino acid metabolism and cellular response to stress and membrane trafficking. The condition-wise temporal pathway analysis in the differentiated neuron-like cells detects a significant pathway, functional, and disease association of DEPs with processes like protein folding and protein synthesis, Nervous System Development and Function, and Neurological Disease. An elaborate dose-dependent stress-specific and neuroprotective cellular signaling cascade is also significantly activated. Thus, our study provides a comprehensive map of the heat-induced proteotoxic stress response associating proteome-wide changes with altered biological processes. This helps to expand our understanding of the molecular basis of the heat-induced proteotoxic stress response with potential translational connotations.

REVIEW: POTENTIAL OF NANOEMULGEL FORMULATIONS FOR TOPICAL DRUG DELIVERY

Nanoemulgel is a combination of two different formulation systems, known as nanoemulsion preparation with gel matrix. In recent years, there has been an increase in the use of topical nanoemulgel preparations because they are easy to apply and can avoid damage to various drugs in the body. Although topical nanoemulgel preparations have some limitations, they are capable of delivering lipophilic drugs topically. The purpose of this review is to summarize the potential of nanoemulgel formulations for topical drug delivery against various physiological challenges and limitations of the formula. Through the publication search, as many as 124 articles were obtained based on the screening results of 29 articles that met the inclusion criteria and were used as a review. The analysis of data for this article was conducted through a narrative review. This preparation may improve the permeability of the drug into the skin by penetrating the stratum corneum through intercellular and intracellular pathways, depending on the components used: oil phase, surfactants, co-surfactants, and gelling agents. Surfactants are responsible for damaging the structure of the skin layer by lowering the surface tension, and gelling agents are responsible for increasing the viscosity and adhesiveness of the skin. Nanoemulgel formulations for topical drug delivery can be used to treat several diseases, such as inflammation, arthritis, wounds, fungal infections, bacterial infections, and psoriasis. The nanoemulgel formulation may provide promising potential in delivering lipophilic drugs topically in the future Keywords: Nanoemulgel, nanoemulsion, gel, topical drug delivery

Synthetic Peptides Capable of Potent Multigroup Staphylococcal Quorum Sensing Activation and Inhibition in Both Cultures and Biofilm Communities.

The pathogen Staphylococcus epidermidis uses a chemical signaling process, i.e., quorum sensing (QS), to form robust biofilms and cause human infection. Many questions remain about QS in S. epidermidis, as it uses this intercellular communication pathway to both negatively and positively regulate virulence traits. Herein, we report synthetic multigroup agonists and antagonists of the S. epidermidis accessory gene regulator (agr) QS system capable of potent superactivation and complete inhibition, respectively. These macrocyclic peptides maintain full efficacy across the three major agr specificity groups, and their activity can be "mode-switched" from agonist to antagonist via subtle residue-specific structural changes. We describe the design and synthesis of these non-native peptides and demonstrate that they can appreciably decrease biofilm formation on abiotic surfaces, underscoring the potential for agr agonism as a route to block S. epidermidis virulence. Additionally, we show that both the S. epidermidis agonists and antagonists are active in S. aureus, another common pathogen with a related agr system, yet only as antagonists. This result not only revealed one of the most potent agr inhibitors known in S. aureus but also highlighted differences in the mechanisms of agr agonism and antagonism between these related bacteria. Finally, our investigations reveal unexpected inhibitory behavior for certain S. epidermidis agr agonists at sub-activating concentrations, an observation that can be leveraged for the design of future probes with enhanced potencies. Together, these peptides provide a powerful tool set to interrogate the role of QS in S. epidermidis infections and in Staphylococcal pathogenicity in general.

Single-Cell Multi-Omics Map of Cell Type-Specific Mechanistic Drivers of Multiple Sclerosis Lesions.

In progressive multiple sclerosis (MS), compartmentalized inflammation plays a pivotal role in the complex pathology of tissue damage. The interplay between epigenetic regulation, transcriptional modifications, and location-specific alterations within white matter (WM) lesions at the single-cell level remains underexplored. We examined intracellular and intercellular pathways in the MS brain WM using a novel dataset obtained by integrated single-cell multi-omics techniques from 3 active lesions, 3 chronic active lesions, 3 remyelinating lesions, and 3 control WM of 6 patients with progressive MS and 3 non-neurologic controls. Single-nucleus RNA-seq and ATAC-seq were combined and additionally enriched with newly conducted spatial transcriptomics from 1 chronic active lesion. Functional gene modules were then validated in our previously published bulk tissue transcriptome data obtained from 73 WM lesions of patients with progressive MS and 25 WM of non-neurologic disease controls. Our analysis uncovered an MS-specific oligodendrocyte genetic signature influenced by the KLF/SP gene family. This modulation has potential associations with the autocrine iron uptake signaling observed in transcripts of transferrin and its receptor LRP2. In addition, an inflammatory profile emerged within these oligodendrocytes. We observed unique cellular endophenotypes both at the periphery and within the chronic active lesion. These include a distinct metabolic astrocyte phenotype, the importance of FGF signaling among astrocytes and neurons, and a notable enrichment of mitochondrial genes at the lesion edge populated predominantly by astrocytes. Our study also identified B-cell coexpression networks indicating different functional B-cell subsets with differential location and specific tendencies toward certain lesion types. The use of single-cell multi-omics has offered a detailed perspective into the cellular dynamics and interactions in MS. These nuanced findings might pave the way for deeper insights into lesion pathogenesis in progressive MS.

Single-Nuclei RNA-Sequencing Uncovers Alterations in the Transcriptional Profile of Skeletal Muscle in Peripheral Artery Disease

BACKGROUND: Lower extremity peripheral artery disease (PAD) is caused by atherosclerotic occlusion of lower limb blood vessels, impacting >200 million people worldwide. PAD causes life-altering symptomatology such as claudication, ischemic rest pain, and gangrene, with limited effective treatment options. Herein, we performed single-nuclei RNA-sequencing (snRNAseq) to facilitate a better understanding of the complex pathobiological environment within the PAD limb and intercellular communication. METHODS: Gastrocnemius muscle specimens were collected from 20 patients with PAD and 12 non-PAD controls. Patients with PAD were classified as Rutherford category 3 (severe claudication). Non-PAD participants were of similar age, body mass index and medication usage as patients with PAD. Nuclei were isolated and snRNAseq was performed. Bioinformatic analysis was conducted to determine differences in gene expression between PAD and non-PAD nuclei, as well as analysis of intercellular signaling networks. Histological analysis of muscle specimens assessed the following: myosin heavy chain fiber distributions, myofiber cross-sectional area and myofiber denervation. RESULTS: 57,364 high-quality nuclei were captured (21,417 PAD; 35,947 non-PAD) and unsupervised clustering revealed 12 distinct nuclei populations based on their transcriptional profile. Quantification of the relative abundance of nuclei populations identified several differences, including PAD muscles having a lower percentage of type I myonuclei, muscle stem cells, and endothelial cells but a higher proportion of type II and regenerating myonuclei. Differentially expressed gene analysis of myonuclei populations uncovered upregulation of genes involved in stress response, autophagy, and atrophy in patients with PAD. Ligand-receptor interactions were used to determine how PAD alters the communication between identified nuclei populations. The inferred strength of interactions was greater in non-PAD compared to PAD patients. Further, intercellular communication network analysis revealed fibro-adipogenic progenitors as a primary signaling hub in PAD muscle. CONCLUSION: snRNAseq uncovered novel transcriptional differences and intercellular communication pathways unique to PAD muscle. This study was supported by National Institutes of Health (NIH) grant R01-HL149704 (T. Ryan). K. Kim supported by the American Heart Association grant POST903198. T. Thome supported by NIH grant F31-DK128920. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

DAMP sensing and sterile inflammation: intracellular, intercellular and inter-organ pathways.

Damage-associated molecular patterns (DAMPs) are endogenous molecules that are released from host cells as a result of cell death or damage. The release of DAMPs in tissues is associated with loss of tissue homeostasis. Sensing of DAMPs by innate immune receptors triggers inflammation, which can be beneficial in initiating the processes that restore tissue homeostasis but can also drive inflammatory diseases. In recent years, the sensing of intracellular DAMPs has received extensive attention in the field of sterile inflammation. However, emerging studies have shown that DAMPs that originate from neighbouring cells, and even from distal tissues or organs, also mediate sterile inflammatory responses. This multi-level sensing of DAMPs is crucial for intercellular, trans-tissue and trans-organ communication. Here, we summarize how DAMP-sensing receptors detect DAMPs from intracellular, intercellular or distal tissue and organ sources to mediate sterile inflammation. We also discuss the possibility of targeting DAMPs or their corresponding receptors to treat inflammatory diseases.

AN OVERVIEW ON THERAPEUTIC SCREENING USING EXPERIMENTAL MODELS OF WOUND HEALING

The complex process of wound healing is how damaged tissue heals itself. It's a process that includes homeostasis, tissue integrity coordination, and the activation of intercellular pathways. The present review was based on the therapeutic screening using experimental models of wound healing. Hemostasis and clot formation are the two main complicated events that take place during this phase. The clot has aggregated platelets encased in a fibrin network. Oxygen is necessary for almost all wound-healing processes and cell metabolism, particularly to produce energy via ATP. It stops wounds from getting infected, stimulates the growth of new blood vessels, raises the differentiation, migration, and re-epithelialization of keratinocytes, boosts the production of collagen and fibroblasts, and encourages wound contraction. Wound healing models include incision, excision and burn model. In conclusion, our understanding of wound pathophysiology will be significantly advanced by combining these strategies with cutting-edge tissue, cell, and molecular "omics" technology. Developing novel therapeutic approaches for enhanced wound care is, in fact, one of the many promising areas of the future.

Hormetic effects of thiamethoxam on Schizaphis graminum: demographics and feeding behavior

In agroecosystems, insects contend with chemical insecticides often encountered at sublethal concentrations. Insects’ exposure to these mild stresses may induce hormetic effects, which has consequences for managing insect pests. In this study, we used an electrical penetration graph (EPG) technique to investigate the feeding behavior and an age-stage, two-sex life table approach to estimate the sublethal effects of thiamethoxam on greenbug, Schizaphis graminum. The LC5 and LC10 of thiamethoxam significantly decreased longevity and fecundity of directly exposed adult aphids (F0). However, the adult longevity, fecundity, and reproductive days (RPd)—indicating the number of days in which the females produce offspring – in the progeny generation (F1) exhibited significant increase when parental aphids (F0) were treated with LC5 of the active ingredient. Subsequently, key demographic parameters such as intrinsic rate of increase (r) and net reproductive rate (R0) significantly increased at LC5 treatment. EPG recordings showed that total durations of non-probing (Np), intercellular stylet pathway (C), and salivary secretion into the sieve element (E1) were significantly increased, while mean duration of probing (Pr) and total duration of phloem sap ingestion and concurrent salivation (E2) were decreased in F0 adults exposed to LC5 and LC10. Interestingly, in the F1 generation, total duration of Np was significantly decreased while total duration of E2 was increased in LC5 treatment. Taken together, our results showed that an LC5 of thiamethoxam induces intergenerational hormetic effects on the demographic parameters and feeding behavior of F1 individuals of S. graminum. These findings have important implications on chemical control against S. graminum and highlight the need for a deeper understanding of the ecological consequences of such exposures within pest management strategies across the agricultural landscapes.

Identification of common stria vascularis cellular alteration in sensorineural hearing loss based on ScRNA-seq.

The stria vascularis (SV), located in the lateral wall of the cochlea, maintains cochlear fluid homeostasis and mechanoelectrical transduction (MET) activity required for sound wave conduction. The pathogenesis of a number of human inheritable deafness syndromes, age related hearing loss, drug-induced ototoxicity and noise-induced hearing loss results from the morphological changes and functional impairments in the development of the SV. In this study, we investigate the implications of intercellular communication within the SV in the pathogenesis of sensorineural hearing loss (SNHL). We aim to identify commonly regulated signaling pathways using publicly available single-cell transcriptomic sequencing (scRNA-seq) datasets. We analyzed scRNA-seq data, which was derived from studying the cochlear SV in mice with SNHL compared to normal adult mice. After quality control and filtering, we obtained the major cellular components of the mouse cochlear SV and integrated the data. Using Seurat's FindAllMarkers and FindMarkers packages, we searched for novel conservative genes and differential genes. We employed KEGG and GSEA to identify molecular pathways that are commonly altered among different types of SNHL. We utilized pySCENIC to discover new specific regulatory factors in SV subpopulation cells. With the help of CellChat, we identified changes in subpopulation cells showing similar trends across different SNHL types and their alterations in intercellular communication pathways. Through the analysis of the integrated data, we discovered new conserved genes to SV specific cells and identified common downregulated pathways in three types of SNHL. The enriched genes for these pathways showing similar trends are primarily associated with the Electron Transport Chain, related to mitochondrial energy metabolism. Using the CellChat package, we further found that there are shared pathways in the incoming signaling of specific intermediate cells in SNHL, and these pathways have common upstream regulatory transcription factor of Nfe2l2. Combining the results from pySCENIC and CellChat, we predicted the transcription factor Nfe2l2 as an upstream regulatory factor for multiple shared cellular pathways in IC. Additionally, it serves as an upstream factor for several genes within the Electron Transport Chain. Our bioinformatics analysis has revealed that downregulation of the mitochondrial electron transport chain have been observed in various conditions of SNHL. E2f1, Esrrb, Runx1, Yy1, and Gata2 could serve as novel important common TFs regulating the electron transport chain. Adm has emerged as a potential new marker gene for intermediate cells, while Itgb5 and Tesc show promise as potential new marker genes for marginal cells in the SV. These findings offer a new perspective on SV lesions in SNHL and provide additional theoretical evidence for the same drug treatment and prevention of different pathologies of SNHL.