Distinct Localization Research Articles

Evolutionary Insights and Expression Dynamics of the Glutathione Peroxidase (GPX) Gene Family in Water lily (Nymphaea colorata) in Response to Multiple Abiotic Stresses

The glutathione peroxidase (GPX) family in plants contains various isoenzymes, each with distinct subcellular localizations, tissue-specific expression patterns, and responses to environmental stress. In current study, we conducted genome-wide bioinformatics analyses of the GPX gene family in Nymphaea colorata, identifying five putative NcGPX genes dispersed across five of the fourteen chromosomes. Examination of the protein sequences revealed that NcGPXs comprehend three conserved cysteine residues, with predicted in-silico subcellular localizations in chloroplast, extracellular, or cytoplasm. We reported that NcGPX genes protein lengths and molecular weight (MW) ranged from 171-248 amino acids (aa) and 18.798-27.076 kDa, respectively. A comparative neighbor-joining phylogenetic study revealed that GPX genes were clustered into four main groups (Group A– D) from water lily and two closely related plant species, alongside with Arabidopsis thaliana. The universal analysis showed that segmental duplications occurred within the NcGPX gene family. Investigation of gene structure and motifs suggested that most NcGPX genes have relatively conserved exon-intron structures and motif arrangements. Promoter region exploration of NcGPX genes revealed numerous cis-acting regulatory elements associated with development, stress, and hormone responses. The identified 3D protein structures showed that water lily GPXs form conserved dimeric protein signatures. Finally, gene expression and enzymes accumulation of NcGPXs in response to different abiotic stresses, in leaves of N. colorata were analysed using real-time RT-qPCR and spectrophotometry. The results indicate that different members of the GPX gene family are co-ordinately regulated under specific environmental stress conditions, establishing a foundation for studying their gene functions and improving abiotic stress tolerance in water lily genetic breeding.

Spatiotemporal dynamics of the developing zebrafish enteric nervous system at the whole-organ level.

Neural crest cells give rise to the neurons of the enteric nervous system (ENS) that innervate the gastrointestinal (GI) tract to regulate gut motility. The immense size and distinct subregions of the gut present a challenge to understanding the spatial organization and sequential differentiation of different neuronal subtypes. Here, we profile enteric neurons (ENs) and progenitors at single-cell resolution during zebrafish embryonic and larval development to provide a near-complete picture of transcriptional changes that accompany the emergence of ENS neurons throughout the GI tract. Multiplex spatial RNA transcript analysis identifies the temporal order and distinct localization patterns of neuronal subtypes along the length of the gut. Finally, we show that functional perturbation of select transcription factors Ebf1a, Gata3, and Satb2 alters the cell fate choice, respectively, of inhibitory, excitatory, and serotonergic neuronal subtypes in the developing ENS.

BPMs regulate Arabidopsis seedling development by promoting auxin-independent degradation of the Aux/IAA protein IAA10.

After germination, seedlings undergo etiolated development (skotomorphogenesis), enabling them to grow towards the soil surface. In Arabidopsis, etiolated seedlings exhibit rapid hypocotyl elongation, apical hook formation and closed cotyledons to protect the meristem. In this study, we found that high-order mutants in the BPM gene family displayed defects in seedling development, characterized by a shorter hypocotyl, early apical hook opening, and opened cotyledons in the dark. BPM1, BPM2, BPM4, and BPM5 exhibit distinct expression patterns and subcellular localization in etiolated seedlings. In a hypocotyl segment assay the bpm mutants showed defects in auxin response indicating impaired auxin signaling in the hypocotyl. Expression of the auxin reporter DR5:GFP was also altered in the bpm1,4,5 mutant in various tissues compared to the wild type. Furthermore, we showed that BPM1 and IAA10 interact in yeast two-hybrid, BiFC, and Co-IP assays. Experiments in protoplasts indicated that BPM1 promotes ubiquitylation and degradation of IAA10, and the level of IAA10 protein is greater in the bpm1,4,5 mutant. In addition, IAA10 over-expression resulted in phenotypes similar to the bpm mutants. These results indicate that the BPMs target the Aux/IAA proteins for ubiquitylation and degradation. Overall, our findings shed light on the key roles of the BPMs in auxin signaling during seedling development.

Pil1 Co-tethering Assay to Detect Protein-Protein Interactions in the Fission Yeast Schizosaccharomyces pombe.

Protein-protein interactions play critical roles in biological processes. We previously developed the Pil1 co-tethering assay, an imaging-based method to detect protein-protein interactions in living Schizosaccharomyces pombe cells. This assay leverages the distinct localization pattern of the Pil1 protein by fusing a bait protein to Pil1 and examining whether a prey protein co-localize with the Pil1-fused bait. Here, we present an improved protocol of the Pil1 co-tethering assay. In this protocol, modified stable integration vectors (SIVs) with a NotI site as the linearization site are used to express bait and prey proteins. We expect that this protocol will enhance the application of the Pil1 co-tethering assay for studying protein-protein interactions.

PKA regulation of neuronal function requires the dissociation of catalytic subunits from regulatory subunits

Protein kinase A (PKA) plays essential roles in diverse cellular functions. However, the spatiotemporal dynamics of endogenous PKA upon activation remain debated. The classical model predicts that PKA catalytic subunits dissociate from regulatory subunits in the presence of cAMP, whereas a second model proposes that catalytic subunits remain associated with regulatory subunits following physiological activation. Here, we report that different PKA subtypes, as defined by the regulatory subunit, exhibit distinct subcellular localization at rest in CA1 neurons of cultured hippocampal slices. Nevertheless, when all tested PKA subtypes are activated by norepinephrine, presumably via the β-adrenergic receptor, catalytic subunits translocate to dendritic spines but regulatory subunits remain unmoved. These differential spatial dynamics between the subunits indicate that at least a significant fraction of PKA dissociates. Furthermore, PKA-dependent regulation of synaptic plasticity and transmission can be supported only by wildtype, dissociable PKA, but not by inseparable PKA. These results indicate that endogenous PKA regulatory and catalytic subunits dissociate to achieve PKA function in neurons.

PKA regulation of neuronal function requires the dissociation of catalytic subunits from regulatory subunits.

Protein kinase A (PKA) plays essential roles in diverse cellular functions. However, the spatiotemporal dynamics of endogenous PKA upon activation remain debated. The classical model predicts that PKA catalytic subunits dissociate from regulatory subunits in the presence of cAMP, whereas a second model proposes that catalytic subunits remain associated with regulatory subunits following physiological activation. Here, we report that different PKA subtypes, as defined by the regulatory subunit, exhibit distinct subcellular localization at rest in CA1 neurons of cultured hippocampal slices. Nevertheless, when all tested PKA subtypes are activated by norepinephrine, presumably via the β-adrenergic receptor, catalytic subunits translocate to dendritic spines but regulatory subunits remain unmoved. These differential spatial dynamics between the subunits indicate that at least a significant fraction of PKA dissociates. Furthermore, PKA-dependent regulation of synaptic plasticity and transmission can be supported only by wildtype, dissociable PKA, but not by inseparable PKA. These results indicate that endogenous PKA regulatory and catalytic subunits dissociate to achieve PKA function in neurons.

Essential magnetosome proteins MamI and MamL from magnetotactic bacteria interact in mammalian cells

To detect cellular activities deep within the body using magnetic resonance platforms, magnetosomes are the ideal model of genetically-encoded nanoparticles. These membrane-bound iron biominerals produced by magnetotactic bacteria are highly regulated by approximately 30 genes; however, the number of magnetosome genes that are essential and/or constitute the root structure upon which biominerals form is largely undefined. To examine the possibility that key magnetosome genes may interact in a foreign environment, we expressed mamI and mamL as fluorescent fusion proteins in mammalian cells. Localization and potential protein-protein interaction(s) were investigated using confocal microscopy and fluorescence correlation spectroscopy (FCS). Enhanced green fluorescent protein (EGFP)-MamI and the red fluorescent Tomato-MamL displayed distinct intracellular localization, with net-like and punctate fluorescence, respectively. Remarkably, co-expression revealed co-localization of both fluorescent fusion proteins in the same punctate pattern. An interaction between MamI and MamL was confirmed by co-immunoprecipitation. In addition, changes in EGFP-MamI distribution were accompanied by acquisition of intracellular mobility which all Tomato-MamL structures displayed. Analysis of extracts from these cells by FCS was consistent with an interaction between fluorescent fusion proteins, including an increase in particle radius. Co-localization and interaction of MamI and MamL demonstrate that select magnetosome proteins may associate in mammalian cells.

Synovial tissue myeloid dendritic cell subsets exhibit distinct tissue-niche localization and function in health and rheumatoid arthritis.

Current rheumatoid arthritis (RA) treatments do not restore immune tolerance. Investigating dendritic cell (DC) populations in human synovial tissue (ST) may reveal pathways to reinstate tolerance in RA. Using single-cell and spatial transcriptomics of ST biopsies, as well as co-culture systems, we identified condition- and niche-specific DC clusters with distinct functions. Healthy tissue contained tolerogenic AXL+ DC2s in the lining niche. In active RA, the hyperplasic lining niche was populated with inflammatory DC3s that activated CCL5-positive effector memory Tcells, promoting synovitis. Lymphoid niches that emerged in the sublining layer were enriched with CCR7+ DC2s, which interacted with naive Tcells, potentially driving the local expansion of new effector Tcells. Remission saw the resolution of these pathogenic niches but lacked recovery of tolerogenic DC2s and exhibited activation of blood precursors of ST-DC3 clusters prior to flare-ups. Targeting pathogenic DC3s or restoring tolerogenic DC2s may help restore immune homeostasis in RA joints.

Genomic Localization Bias of Secondary Metabolite Gene Clusters and Association with Histone Modifications in Aspergillus.

Fungi are well-known producers of bioactive secondary metabolites (SMs), which have been exploited for decades by humankind for various medical applications like therapeutics and antibiotics. SMs are synthesized by biosynthetic gene clusters (BGCs)-physically co-localized and co-regulated genes. Because BGCs are often regulated by histone post-translational modifications (PTMs), it was suggested that their chromosomal location is important for their expression. Studies in a few fungal species indicated an enrichment of BGCs in sub-telomeric regions; however, there is no evidence that BGCs with distinct genomic localization are regulated by different histone PTMs. Here, we used 174 Aspergillus species covering 22 sections to determine the correlation between BGC genomic localization, gene expression, and histone PTMs. We found a high abundance and diversity of SM backbone genes across the Aspergillus genus, with notable unique genes within sections. Being unique or conserved in many species, BGCs showed a strong bias for being localized in low-synteny regions, regardless of their position in chromosomes. Using chromosome-level assemblies, we also confirmed a significantly biased localization in sub-telomeric regions. Notably, SM backbone genes in sub-telomeric regions and about half of those in low-synteny regions exhibit higher gene expression variability, likely due to the similar higher variability in H3K4me3 and H3K36me3 histone PTMs; while variations in histone H3 acetylation and H3K9me3 are not correlated to genomic localization and expression variation, as analyzed in two Aspergillus species. Expression variability across four Aspergillus species further supports that BGCs tend to be located in low-synteny regions and that regulation of expression in those regions likely involves different histone PTMs than the most commonly studied modifications.

Intraspecific venom variation in the Iberian asp viper (Vipera aspis zinnikeri) across natural and intensive agricultural habitats

Snake venom composition varies at different levels. To date, comparative venom studies have seldom taken into account the role of habitat type in the occurrence of snake venom variation. Here we investigated the presence of venom variation across different populations of the Iberian asp viper (Vipera aspis zinnikeri) inhabiting two contrasting habitats: natural vs. intensive agricultural. We used shotgun proteomics to describe the protein composition of the venoms of six adults from two distinct localities. Furthermore, to test whether local conditions and habitat can alter venom composition in this taxon, we compared the SDS-PAGE profiles of 40 adult venoms from six populations, three in natural habitats and three in intensive agricultural environments. The venoms were composed of 21 toxin families, of which five (CTL, PLA2, VEGF, svSP, and svMP) comprised 69–82 % of each proteome. The relative abundances of toxin families varied considerably at inter- and intra-population levels. Linear regression performed on non-metric multidimensional scaling values showed a significant effect of locality of origin and habitat type on the differences detected between individual SDS-PAGE venom profiles. Our results suggest the presence of regional variation in V. a. zinnikeri venom, potentially reinforcing the role of local pressures in shaping snake venom composition. SignificanceThis work provides the first proteomic characterization of the venom of the Iberian asp viper, Vipera aspis zinnikeri, obtained by means of shotgun proteomics. The statistical analysis of 40 individual SDS-PAGE venom profiles highlights that venom variation in this taxon can be associated with geographical origin and habitat type of the area where each viper was collected. Our results suggest the presence of regional variation in V. a. zinnikeri venom, reinforcing the role that local pressures may play as drivers of snake venom variation.

Melatonin, Melatonin Receptors and Sleep: Moving Beyond Traditional Views.

Sleep, constituting approximately one-third of the human lifespan, is a crucial physiological process essential for physical and mental well-being. Normal sleep consists of an orderly progression through wakefulness, non-rapid eye movement (NREM) sleep, and rapid eye movement (REM) sleep, all of which are tightly regulated. Melatonin, often referred to as the "hormone of sleep," plays a pivotal role as a regulator of the sleep/wake cycle and exerts its effects through high-affinity G-protein coupled receptors known as MT1 and MT2. Selective modulation of these receptors presents a promising therapeutic avenue for sleep disorders. This review examines research on the multifaceted role of melatonin in sleep regulation, focusing on selective ligands targeting MT1 and MT2 receptors, as well as studies involving MT1 and MT2 knockout mice. Contrary to common beliefs, growing evidence suggests that melatonin, through MT1 and MT2 receptors, might not only influence circadian aspects of sleep but likely, also modulate the homeostatic process of sleep and sleep architecture, or could be the molecule linking the homeostatic and circadian regulation of sleep. Furthermore, the distinct brain localization of MT1 and MT2 receptors, with MT1 receptors primarily regulating REM sleep and MT2 receptors regulating NREM sleep, is discussed. Collectively, sleep regulation extends beyond the circulating levels and circadian peak of melatonin; it also critically involves the expression, molecular activation, and regulatory functions of MT1 and MT2 receptors across various brain regions and nuclei involved in the regulation of sleep. This research underscores the importance of ongoing investigation into the selective roles of MT1 and MT2 receptors in sleep. Such research efforts are expected to pave the way for the development of targeted MT1 or MT2 receptors ligands, thereby optimizing therapeutic interventions for sleep disorders.

Designer Electrocatalysts for the Oxygen Reduction Reaction with Controlled Platinum Nanoparticle Locality

AbstractFor global deployment of proton exchange membrane fuel cells, achieving optimal interaction between the components of the cathode active layer remains challenging. Studies addressing the effect of nanoparticle location (inside vs outside of pores) on performance and durability mostly compare porous and nonporous carbon supports, thus coming short of decoupling nanoparticle locality from carbon support effects. To address the influence of nanoparticle locality on performance and durability, new carbon‐supported electrocatalysts with designed and distinct nanoparticle localities are presented. The developed methodology allows to place Pt nanoparticles preferentially inside or outside of the mesopores of conductive carbon supports from materials under development at Cabot Corporation. Synthesis protocols are tuned to control nanoparticle size, crystallinity, and loading; this way the effect of Pt locality can be studied for two experimental carbon supports in isolation from all other parameters. For one carbon support, Pt active surface area and activity are significantly lower when nanoparticles are placed inside the pores. In contrast, for another, more graphitic carbon support, placing nanoparticles inside or outside of the carbon pores produces no appreciable difference in active surface area and performance rotating disk electrode measurements. Given their carefully tailored structure, these catalysts provide a framework for evaluating locality‐performance‐durability relationships.

Where to start? Activity-dependent alternative translation initiation generates multifunctional proteoforms in the brain

In this issue of Molecular Cell, Lee etal.1 report that alternative translation initiation can generate new proteoforms with distinct localization patterns in a neuronal activity-dependent manner.

Psoriasis localization patterns in the Swiss Psoriasis Registry (SDNTT) over 11 years: an analysis by sex and age

Real-world data on anatomically localized psoriasis and its response to systemic therapy across different age-groups and sexes is limited. This study aimed to evaluate the severity and distribution of psoriasis over time in female and male patients receiving systemic therapies, categorized by age within the Swiss psoriasis registry (SDNTT). Patient-data was obtained over 11 years through the SDNTT. The localized Psoriasis Area and Severity Index (locPASI) of the head, trunk, upper and lower extremities was analyzed over two years following the start of systemic non-/biologic treatment. A total of 316 female and 517 male patients were analyzed. Male patients had a higher baseline locPASI for legs, trunk and arms (p < 0.001), but not for the head (p = 0.961). The locPASI for the head in younger female patients (18–40 years) had a higher score than those aged 55 + (p = 0.022) and after two years, middle aged (41–54) showed a lower score compared to younger patients (p = 0.045). Younger male patients revealed a lower score after two years of therapy in the leg- and arm-area compared to older (p = 0.018 and p = 0.048, respectively). Female patients on non-biologics had a fast initial response, converging with male patients’ scores over 24 months. Over 75% locPASI reduction was observed for female head-area (81.4%), male trunk (82.7%) and legs (76.1%). Absolute locPASI ≤ 2 was achieved 3–6 months for all locations with interleukin (IL)-17, IL-12/23 and IL-23-inhibitors, except for the legs of male patients on anti-IL-17 and female patients on anti-IL-12/23 and -IL-23. After two years, male patients did not achieve a locPASI ≤ 2 for any biologic-treatment in the legs, nor for the arms on anti-TNF-α. Significant disparities in localized PASI were observed between female and male patients. The age, sex and severity of distinct localizations should be considered to optimize treatment goals.

Sex Differences in Intracranial Aneurysms: A Matched Cohort Study.

Background: Aneurysmal subarachnoid hemorrhage (SAH) predominantly affects women, accounting for 65% of cases. Women have a 1.3 times higher relative risk than men, with the incidence rising particularly in women aged 55-85 years. Women also have a higher prevalence of unruptured intracranial aneurysms (IAs), especially after the age of 50 years, and are at greater risk of aneurysm growth and rupture. This study aimed to isolate the influence of sex on rupture rate, bleeding severity, functional outcomes, and complications by using a matched cohort, while also examining the impact of sex on aneurysm localization and multiplicity. Methods: We utilized a retrospectively collected database of 300 patients with 511 IAs. Inclusion criteria included the availability of clinical data and 3D angiography for semi-automatic reconstruction of IA morphology. Female patients and their IA were matched with male patients according to clinical parameters and 21 morphological characteristics using an interactive visual exploration tool for multidimensional matching. Results: Contrary to previously published results, our study found no significant sex differences in rupture rates or vasospasm rates between male and female patients. The severity of SAH, functional outcomes, and complications such as hydrocephalus were also similar in women and men. However, women exhibited a higher prevalence of multiple aneurysms and distinct localization patterns. Conclusions: This study underscores the complex role of sex in IA development and rupture. Although sex-specific biological factors influence aneurysm characteristics, they do not necessarily translate into differences in clinical outcomes. Further research is needed to explore these factors and their impact on aneurysm development and management.

ELLA: Modeling Subcellular Spatial Variation of Gene Expression within Cells in High-Resolution Spatial Transcriptomics.

Spatial transcriptomic technologies are becoming increasingly high-resolution, enabling precise measurement of gene expression at the subcellular level. Here, we introduce a computational method called subcellular expression localization analysis (ELLA), for modeling the subcellular localization of mRNAs and detecting genes that display spatial variation within cells in high-resolution spatial transcriptomics. ELLA creates a unified cellular coordinate system to anchor diverse cell shapes and morphologies, utilizes a nonhomogeneous Poisson process to model spatial count data, leverages an expression gradient function to characterize subcellular expression patterns, and produces effective control of type I error and high statistical power. We illustrate the benefits of ELLA through comprehensive simulations and applications to four spatial transcriptomics datasets from distinct technologies, where ELLA not only identifies genes with distinct subcellular localization patterns but also associates these patterns with unique mRNA characteristics. Specifically, ELLA shows that genes enriched in the nucleus exhibit an abundance of long noncoding RNAs or protein-coding mRNAs, often characterized by longer gene lengths. Conversely, genes containing signal recognition peptides, encoding ribosomal proteins, or involved in membrane related activities tend to enrich in the cytoplasm or near the cellular membrane. Furthermore, ELLA reveals dynamic subcellular localization patterns during the cell cycle, with certain genes showing decreased nuclear enrichment in the G1 phase while others maintain their enrichment patterns throughout the cell cycle. Overall, ELLA represents a calibrated, powerful, robust, scalable, and versatile tool for modeling subcellular spatial expression variation across diverse high-resolution spatial transcriptomic platforms.

Alternative translation initiation produces synaptic organizer proteoforms with distinct localization and functions

While many mRNAs contain more than one translation initiation site (TIS), the functions of most alternative TISs and their corresponding protein isoforms (proteoforms) remain undetermined. Here, we showed that alternative usage of CUG and AUG TISs in neuronal pentraxin receptor (NPR) mRNA produced two proteoforms, of which the ratio was regulated by RNA secondary structure and neuronal activity. Downstream AUG initiation truncated the N-terminal transmembrane domain and produced a secreted NPR proteoform sufficient in promoting synaptic clustering of AMPA-type glutamate receptors. Mutations that altered the ratio of NPR proteoforms reduced AMPA receptors in parvalbumin-positive interneurons and affected learning behaviors in mice. In addition to NPR, upstream AUU-initiated N-terminal extension of C1q-like synaptic organizers anchored these otherwise secreted factors to the membrane. Together, these results uncovered the plasticity of N-terminal signal sequences regulated by alternative TIS usage as a potentially widespread mechanism in diversifying protein localization and functions.

Abstract A030: Modulation of lymphocyte adhesion and migration by iCAF and myCAF fibroblasts in PDAC

Abstract Background: Pancreatic ductal adenocarcinoma (PDAC) poses significant challenges in treatment due to its complex interaction with the tumour microenvironment (TME). Fibroblasts, a crucial component of the TME, influence tumour progression and therapeutic responses. This study explores the diversity of cancer-associated fibroblast (CAF) populations in PDAC tumours versus adjacent normal fibroblasts (ANFs), focussing on myofibroblasts (myCAFs) and inflammatory fibroblasts (iCAFs). These fibroblast subtypes exhibit distinct characteristics and localisation within the tumour. The research examines the impact of CAFs and ANFs on immune cell behaviour, particularly in relation to adhesion and migration. Methods: Tumour and juxta-tumoral tissue from patients were digested into single cell suspensions. Cells were stained with a 22-plex antibody panel by flow cytometry. Pseudo-emperipolesis assays were assessed by co-culture of lymphocytes with CAF and ANF fibroblasts. Furthermore, these were performed with or without stimulation of fibroblasts with by TGF-b or TNF-a/IFN-g, to promote myCAF or iCAF phenotypes respectively. Gene expression analysis of tumour-derived fibroblast subtypes was assessed by single-cell RNA sequencing using the 10X Genomics platform. The transcriptional profile of spatially resolved fibroblasts which were proximal or distant to tumour epithelium was determined by the NanoString GeoMx Digital Spatial Profiler (DSP) platform. Results: Flow cytometry analysis revealed that iCAFs predominated within the tumour stroma compared to myCAFs, although iCAF populations were less prevalent within ANF populations. Upon stimulation with inflammatory cytokines (TNF-α/IFN-γ), CAFs promoted lymphocyte migration in contrast to ANFs. However, TGF-β stimulation of CAF downregulated the migration of lymphocytes. As such, TGF-β or TNF-α/IFN-γ stimulation exhibited antagonistic effects on lymphocyte adhesion and migration in CAFs. Tumour-proximal fibroblasts exhibited myCAFs characteristics expressing α-SMA and PDPN, as well as ECM molecules such as collagen and integrins, suggesting a barrier to lymphocyte migration. Conversely, distal fibroblasts displayed an inflammatory profile, expressing cytokines and chemokines including CCL2, CXCL9, CXCL12, IL6, IL11 and LIF, thereby contributing to the inflammatory milieu within the tumour microenvironment. Additionally, iCAFs demonstrated higher transcription levels of hyaluronan synthase (Has1) and fibulin 2 (FBLN2) which are crucial for ECM formation and remodelling. This study identifies a differential role for iCAFs and myCAFs in the modulate of lymphocyte adhesion and migration within the PDAC microenvironment, highlighting the complex interplay between fibroblast subtypes and immune cell dynamics. Citation Format: Fouzia Zayou, Hayden Pearce, Wayne Croft, Samantha Nicol, Sandra Margielewska-Davies, Sarah Powell-Brett, Rachel Brown, Jianmin Zuo, Keith Roberts, Helen M. McGettrick, Paul Moss. Modulation of lymphocyte adhesion and migration by iCAF and myCAF fibroblasts in PDAC [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr A030.

Assessing the impact of engine and non-engine urban noises on the calls of urban frogs: a natural experiment

Urban noise can potentially disturb the acoustic signals of animals inhabiting urban areas. Although a wide variety of noises from different sources is common in cities, the impact of non-engine noise on animal calls is less studied. In a natural experiment, we evaluated the effect of different urban noises on the advertisement calls of urban frogs (Eleutherodactylus nitidus) in the metropolitan area of Puebla, Mexico. We recorded and analyzed 672 advertisement calls from 28 male frogs and the corresponding environmental noises from three distinct localities. Our analysis focused on four acoustic properties of the calls: inter-call interval, call duration, dominant frequency, and call amplitude. To standardize the amplitude measurements of sound pressure levels produced by noise and frog calls, we employed a practical approach using a reference signal for calibration. We treated the longitudinal data of different noises occurring before, during, and after advertisement calls as repeated measures within the urban locations. During our samplings, frogs called amidst spontaneous urban noises, including dog barking, fireworks, and vehicle engine sounds. Our results indicate that vehicle engine sounds and dog barking do not cause significant distortions in the calls of these urban frogs. However, we observed slight variations in the dominant frequency of calls, decreasing by 11 Hz, during and after fireworks. Given the observed plasticity of E. nitidus in response to noise, urban noises may not pose a severe problem for this urban frog.

Differences in the Expression of Autophagy Markers Microtubule-Associated Protein Light Chains 3A and 3B in Oral Premalignant Lesions and Oral Squamous Cell Carcinoma: A Cross-Sectional Study.

Background Microtubule-associated protein light chains (LC) 3A and 3B are the structural proteins of the autophagosomal membrane widely used as endogenous autophagy markers. LC3A and LC3B autophagosomes reportedly have a distinct subcellular localization yet their role in the transition from premalignant to malignant phase remains unclear. This exploratory study aimed to investigate the expression of autophagy-related proteins LC3A and LC3B in oral premalignant lesions (OPL) and oral squamous cell carcinoma (OSCC) cases. Methodology A cross-sectional study was conducted on 100 OPL and 39 OSCC samples. OPL samples comprised both dysplastic and non-dysplastic lesions. The expression of LC3A and LC3B markers was evaluated in the study samples using immunohistochemistry and associated with dysplasia in OPL and with invasive OSCC versus OPL. Fisher's exact test was used for statistical analysis. Results There was a higher ratio of LC3A positivity in non-dysplastic OPL (31/38) compared to dysplastic premalignant lesions (36/62, p=0.017). There was a higher ratio of LC3B positivity in dysplastic OPL (16/62) compared to non-dysplastic lesions (4/38) with a trend towards statistical significance (p=0.075). There was no statistical difference in the ratio ofLC3A positivity between OSCC (23/39) and premalignant (67/100) lesions, while the ratio of LC3B marker positivity was higher in OSCC cases (18/39) relative to premalignant lesions (20/100, p=0.003). Conclusion Autophagy-related proteins LC3A and LC3B may have different roles to play in a disease context manner. LC3A is likely to be negatively associated with dysplasia in OPL while LC3B expression is positively associated with carcinogenesis of OSCC, possibly including dysplasia.