Adhesion Proteins Research Articles

Senescence-Associated Alterations in Matrisome of Mesenchymal Stem Cells.

The process of aging is intimately linked to alterations at the tissue and cellular levels. Currently, the role of senescent cells in the tissue microenvironment is still being investigated. Despite common characteristics, different cell populations undergo distinctive morphofunctional changes during senescence. Mesenchymal stem cells (MSCs) play a pivotal role in maintaining tissue homeostasis. A multitude of studies have examined alterations in the cytokine profile that determine their regulatory function. The extracellular matrix (ECM) of MSCs is a less studied aspect of their biology. It has been shown to modulate the activity of neighboring cells. Therefore, investigating age-related changes in the MSC matrisome is crucial for understanding the mechanisms of tissue niche ageing. This study conducted a broad proteomic analysis of the matrisome of separated fractions of senescent MSCs, including the ECM, conditioned medium (CM), and cell lysate. This is the first time such an analysis has been conducted. It has been established that there is a shift in production towards regulatory molecules and a significant downregulation of the main structural and adhesion proteins of the ECM, particularly collagens, fibulins, and fibrilins. Additionally, a decrease in the levels of cathepsins, galectins, S100 proteins, and other proteins with cytoprotective, anti-inflammatory, and antifibrotic properties has been observed. However, the level of inflammatory proteins and regulators of profibrotic pathways increases. Additionally, there is an upregulation of proteins that can directly cause prosenescent effects on microenvironmental cells (SERPINE1, THBS1, and GDF15). These changes confirm that senescent MSCs can have a negative impact on other cells in the tissue niche, not only through cytokine signals but also through the remodeled ECM.

Expression of the membrane tetraspanin claudin 18 on cancer cells promotes T lymphocyte infiltration and antitumor immunity in pancreatic cancer

Tumors weakly infiltrated by T lymphocytes poorly respond to immunotherapy. We aimed to unveil malignancy-associated programs regulating Tcell entrance, arrest, and activation in the tumor environment. Differential expression of cell adhesion and tissue architecture programs, particularly the presence of the membrane tetraspanin claudin (CLDN)18 as a signature gene, demarcated immune-infiltrated from immune-depleted mouse pancreatic tumors. In human pancreatic ductal adenocarcinoma (PDAC) and non-small cell lung cancer, CLDN18 expression positively correlated with more differentiated histology and favorable prognosis. CLDN18 on the cell surface promoted accrual of cytotoxic T lymphocytes (CTLs), facilitating direct CTL contacts with tumor cells by driving the mobilization of the adhesion protein ALCAM to the lipid rafts of the tumor cell membrane through actin. This process favored the formation of robust immunological synapses (ISs) between CTLs and CLDN18-positive cancer cells, resulting in increased Tcell activation. Our data reveal an immune role for CLDN18 in orchestrating Tcell infiltration and shaping the tumor immune contexture.

Interplay of hypoxia and host cells in the translocation, invasion and dissemination of Taenia solium in neurocysticercosis

Neurocysticercosis, caused by the invasion of the central nervous system (CNS) by Taenia solium larvae, poses a significant global health burden. Despite its prevalence and severe neurological consequences, understanding of the molecular and signalling pathways facilitating parasite dissemination and CNS invasion is limited. The lack of comprehensive knowledge of host-parasite interactions and associated proteins involved in T. solium infection hinders the development of targeted interventions to mitigate its ability to cross the epithelia barrier. This is complicated by reduced oxygen availability in the intestine, a phenomenon called hypoxia. Hypoxia can result in epithelial barrier disruption and cell damage, thereby promoting the translocation and dissemination of T. solium. This study aims to establish the role of hypoxia in T. solium invasion and disseminated infections. The effect of hypoxia on the migration, viability and morphological characteristics of T. solium would be determined using transwell invasion assays, flow cytometry and microscopy. T. solium oncosphere development and dissemination under hypoxic and normoxic conditions will be monitored using animal models. Also, host-parasite transcriptome and proteome profiling will be performed to determine pathways triggered under hypoxic conditions. It is expected that hypoxia would promote the invasion and dissemination of T. solium by enhancing epithelial and endothelial cell permeability. , hypoxia will induce the expression of binding and adhesion proteins and other virulence markers such as enolase, serpin, and glutathione transferases that are involved in host invasion. Understanding the role of hypoxia in the translocation mechanism of T. solium can be leveraged to provide insights into host tissues dissemination and the development of appropriate interventions.

An artificial liquid–liquid phase separation-driven silk fibroin-based adhesive for rapid hemostasis and wound sealing

The powerful adhesion systems of marine organisms have inspired the development of artificial protein-based bioadhesives. However, achieving robust wet adhesion using artificial bioadhesives remains technically challenging because the key element of liquid–liquid phase separation (LLPS)-driven complex coacervation in natural adhesion systems is often ignored. In this study, mimicking the complex coacervation phenomenon of marine organisms, an artificial protein-based adhesive hydrogel (SFG hydrogel) was developed by adopting the LLPS-mediated coacervation of the natural protein silk fibroin (SF) and the anionic surfactant sodium dodecylbenzene sulfonate (SDBS). The assembled SF/SDBS complex coacervate enabled precise spatial positioning and easy self-adjustable deposition on irregular substrate surfaces, allowing for tight contact. Spontaneous liquid-to-solid maturation promoted the phase transition of the SF/SDBS complex coacervate to form the SFG hydrogel in situ, enhancing its bulk cohesiveness and interfacial adhesion. The formed SFG hydrogel exhibited intrinsic advantages as a new type of artificial protein-based adhesive, including good biocompatibility, robust wet adhesion, rapid blood-clotting capacity, and easy operation. In vitro and in vivo experiments demonstrated that the SFG hydrogel not only achieved instant and effective hemostatic sealing of tissue injuries but also promoted wound healing and tissue regeneration, thus advancing its clinical applications. Statement of significanceMarine mussels utilize the liquid–liquid phase separation (LLPS) strategy to induce the supramolecular assembly of mussel foot proteins, which plays a critical role in strong underwater adhesion of mussel foot proteins. Herein, an artificial protein-based adhesive hydrogel (named SFG hydrogel) was reported by adopting the LLPS-mediated coacervation of natural protein silk fibroin (SF) and anionic surfactant sodium dodecylbenzene sulfonate (SDBS). The assembled SFG hydrogel enabled the precise spatial positioning and easy self-adjustable deposition on substrate surfaces with irregularities, allowing tight interfacial adhesion and cohesiveness. The SFG hydrogel not only achieved instant and effective hemostatic sealing of tissue injuries but also promoted wound healing and tissue regeneration, exhibiting intrinsic advantages as a new type of artificial protein-based bioadhesives.

All-natural and triple-inspired Janus electrospun fibers with integrated functions for high-performance liquid food packaging

The liquid barrier is a central component of functional liquid packaging materials and is crucial for encapsulating liquid food. To develop high-performance liquid packaging materials for the long-term storage of liquid food, a strong and stable liquid barrier and the simultaneous integration of diverse functionalities must be realized. In this study, inspired by mussel adhesion proteins, nanoparticles are synthesized through oxidative self-polymerization. Furthermore, electrostatic spinning is used for creating multifunctional electrospun fibers for liquid food packaging, which is inspired by the superhydrophobicity of lotus leaf surface and structures of red blood cells. A unique Janus structure with a thin hydrophilic layer and a thick hydrophobic layer prevents liquid food penetration for 12 (EHN/KN electrospun fibers) and 17 days (KN/EHN electrospun fibers). The liquid infiltration mechanism of Janus electrospun fibers is elucidated using the multibody dissipative particle dynamics method, emphasizing their efficacy in avoiding liquid penetration. Moreover, multifunctional KN/EHN electrospun fibers exhibit remarkable characteristics such as water resistance (water contact angle > 150°), UV-blocking (∼100 %), degradability (70 days in soil), biosafety (∼100 %), antioxidation (> 90 %), antimicrobial (∼100 %), grapes and meat freshness retention properties. Thus, this study provides insights into sustainable, high-performance liquid food packaging for enhanced preservation.

Curvature-induced clustering of cell adhesion proteins.

Cell adhesion proteins typically form stable clusters that anchor the cell membrane to its environment. Several works have suggested that cell membrane protein clusters can emerge from a local feedback between the membrane curvature and the density of proteins. Here, we investigate the effect of such a curvature-sensing mechanism in the context of cell adhesion proteins. We show how clustering emerges in an intermediate range of adhesion and curvature-sensing strengths. We identify key differences with the tilt-induced gradient sensing mechanism we previously proposed (Lin et al., arXiv:2307.03670).

Spatial heterogeneity in tumor adhesion qualifies collective cell invasion

Collective cell invasion (CCI), a canon of most invasive solid tumors, is an emergent property of the interactions between cancer cells and their surrounding extracellular matrix (ECM). However, tumor populations invariably consist of cells expressing variable levels of adhesive proteins that mediate such interactions, disallowing an intuitive understanding of how tumor invasiveness at a multicellular scale is influenced by spatial heterogeneity of cell-cell and cell-ECM adhesion. Here, we have used a Cellular Potts model-based multiscale computational framework that is constructed on the histopathological principles of glandular cancers. In earlier efforts on homogenous cancer cell populations, this framework revealed the relative ranges of interactions, including cell-cell and cell-ECM adhesion that drove collective, dispersed, and mixed multimodal invasion. Here, we constitute a tumor core of two separate cell subsets showing distinct intra- and inter-subset cell-cell or cell-ECM adhesion strengths. These two subsets of cells are arranged to varying extents of spatial intermingling, which we call the heterogeneity index (HI). We observe that low and high inter-subset cell adhesion favors invasion of high-HI and low-HI intermingled populations with distinct intra-subset cell-cell adhesion strengths, respectively. In addition, for explored values of cell-ECM adhesion strengths, populations with high HI values collectively invade better than those with lower HI values. We then asked how spatial invasion is regulated by progressively intermingled cellular subsets that are epithelial, i.e., showed high cell-cell but poor cell-ECM adhesion, and mesenchymal, i.e., with reversed adhesion strengths to the former. Here too, inter-subset adhesion plays an important role in contextualizing the proportionate relationship between HI and invasion. An exception to this relationship is seen for cases of heterogeneous cell-ECM adhesion where sub-maximal HI patterns with higher outer localization of cells with stronger ECM adhesion collectively invade better than their relatively higher-HI counterparts. Our simulations also reveal how adhesion heterogeneity qualifies collective invasion, when either cell-cell or cell-ECM adhesion type is varied but results in an invasive dispersion when both adhesion types are simultaneously altered.

Functional study of a rare L1CAM gene c.1759G>C variant prove its pathogenicity.

L1 syndrome, a neurological disorder with an X-linked inheritance pattern, mainly results from mutations occurring in the L1 cell adhesion molecule (L1CAM) gene. The L1CAM molecule, belonging to the immunoglobulin (Ig) superfamily of neurocyte adhesion molecules, plays a pivotal role in facilitating intercellular signal transmission across membranes and is indispensable for proper neuronal development and function. This study identified a rare missense variant (c.1759G>C; p.G587R) in the L1CAM gene within a male fetus presenting with hydrocephalus. Due to a lack of functional analysis, the significance of the L1CAM mutation c.1759G>C (p.G587R) remains unknown. We aimed to perform further verification for its pathogenicity. Blood samples were obtained from the proband and his parents for trio clinical exome sequencing and mutation analysis. Expression level analysis was conducted using western blot techniques. Immunofluorescence was employed to investigate L1CAM subcellular localization, while cell aggregation and cell scratch assays were utilized to assess protein function. The study showed that the mutation (c.1759G>C; p.G587R) affected posttranslational glycosylation modification and induced alterations in the subcellular localization of L1-G587R in the cells. It resulted in the diminished expression of L1CAM on the cell surface and accumulation in the endoplasmic reticulum. The p.G587R altered the function of L1CAM protein and reduced homophilic adhesion capacity of proteins, leading to impaired adhesion and migration of proteins between cells. Our findings provide first biological evidence for the association between the missense mutation (c.1759G>c; p.G587R) in the L1CAM gene and L1 syndrome, confirming the pathogenicity of this missense mutation.

The dynamic TRPV2 ion channel proximity proteome reveals functional links of calcium flux with cellular adhesion factors NCAM and L1CAM in neurite outgrowth

TRPV2 voltage-insensitive, calcium-permeable ion channels play important roles in cancer progression, immune response, and neuronal development. Despite TRPV2’s physiological impact, underlying endogenous proteins mediating TRPV2 responses and affected signaling pathways remain elusive. Using quantitative peroxidase-catalyzed (APEX2) proximity proteomics we uncover dynamic changes in the TRPV2-proximal proteome and identify calcium signaling and cell adhesion factors recruited to the molecular channel neighborhood in response to activation.Quantitative TRPV2 proximity proteomics further revealed activation-induced enrichment of protein clusters with biological functions in neural and cellular projection. We demonstrate a functional connection between TRPV2 and the neural immunoglobulin cell adhesion molecules NCAM and L1CAM. NCAM and L1CAM stimulation robustly induces TRPV2 [Ca2+]I flux in neuronal PC12 cells and this TRPV2-specific [Ca2+]I flux requires activation of the protein kinase PKCα. TRPV2 expression directly impacts neurite lengths that are modulated by NCAM or L1CAM stimulation. Hence, TRPV2’s calcium signaling plays a previously undescribed, yet vital role in cell adhesion, and TRPV2 calcium flux and neurite development are intricately linked via NCAM and L1CAM cell adhesion proteins.

Actin Cytoskeleton Remodeling Accompanied by Redistribution of Adhesion Proteins Drives Migration of Cells in Different EMT States.

Epithelial-mesenchymal transition (EMT) is a process during which epithelial cells lose epithelial characteristics and gain mesenchymal features. Here, we used several cell models to study migratory activity and redistribution of cell-cell adhesion proteins in cells in different EMT states: EGF-induced EMT of epithelial IAR-20 cells; IAR-6-1 cells with a hybrid epithelial-mesenchymal phenotype; and their more mesenchymal derivatives, IAR-6-1-DNE cells lacking adherens junctions. In migrating cells, the cell-cell adhesion protein α-catenin accumulated at the leading edges along with ArpC2/p34 and α-actinin. Suppression of α-catenin shifted cell morphology from fibroblast-like to discoid and attenuated cell migration. Expression of exogenous α-catenin in MDA-MB-468 cells devoid of α-catenin drastically increased their migratory capabilities. The Y654 phosphorylated form of β-catenin was detected at integrin adhesion complexes (IACs). Co-immunoprecipitation studies indicated that α-catenin and pY654-β-catenin were associated with IAC proteins: vinculin, zyxin, and α-actinin. Taken together, these data suggest that in cells undergoing EMT, catenins not participating in assembly of adherens junctions may affect cell migration.

Janus Nanofibrous Patch with In Situ Grown Superlubricated Skin for Soft Tissue Repair with Inhibited Postoperative Adhesion.

The patch with a superlubricated surface shows great potential for the prevention of postoperative adhesion during soft tissue repair. However, the existing patches suffer from the destruction of topography during superlubrication coating and lack of pro-healing capability. Herein, we demonstrate a facile and versatile strategy to develop a Janus nanofibrous patch (J-NFP) with antiadhesion and reactive oxygen species (ROS) scavenging functions. Specifically, sequential electrospinning is performed with initiators and CeO2 nanoparticles (CeNPs) embedded on the different sides, followed by subsurface-initiated atom transfer radical polymerization for grafting zwitterionic polymer brushes, introducing superlubricated skin on the surface of single nanofibers. The poly(sulfobetaine methacrylate) brush-grafted patch retains fibrous topography and shows a coefficient of friction of around 0.12, which is reduced by 77% compared with the pristine fibrous patch. Additionally, a significant reduction in protein, platelet, bacteria, and cell adhesion is observed. More importantly, the CeNPs-embedded patch enables ROS scavenging as well as inhibits pro-inflammatory cytokine secretion and promotes anti-inflammatory cytokine levels. Furthermore, the J-NFP can inhibit tissue adhesion and promote repair of both rat skin wounds and intrauterine injuries. The present strategy for developing the Janus patch exhibits enormous prospects for facilitating soft tissue repair.

Rapid quantification models for assessing melamine adulteration in sport nutrition supplements via benchtop and portable NIRS instruments

Sport nutrition supplements (SNS) are vulnerable to adulteration with melamine, artificially augmenting their protein content as determined by conventional assay methodologies. Vibrational spectroscopy techniques are suitable for the detection of adulteration because they allow rapid analysis, require minimal sample preparation, and can perform numerous analyses in a short time. The aim of this study was to develop rapid quantification models for the determination of melamine adulteration in a variety of SNS matrices using NIRS (near-infrared spectroscopy) in combination with multivariate data processing. Moreover, a comparison of benchtop and portable NIR instruments was carried out. Employing a stepwise approach involving OPLS-DA and PLS analysis, matrix discrimination and prediction ability were investigated. The benchtop instrument effectively discriminated among matrices (R2Y = 0.964, Q2 = 0.933), while the portable device, although showing a slightly altered pattern, maintained favorable discrimination capability (R2Y = 0.966, Q2 = 0.931). The quantitative PLS models for each SNS matrix exhibited comparable statistical indicators for both instruments with reasonable errors for melamine content estimation and prediction (RMSEE: 0.3–2.4 %, RMSEP: 0.98–2.99 %). Higher estimation and prediction errors were observed for protein-containing samples in both acquisition modes, probably due to the tendency of protein agglomeration and adhesion to different surfaces, which affects the homogeneity of the powder. Despite data loss due to the narrower spectral range and lower resolution of the portable instrument, all models were found to be suitable for predicting melamine content in sport nutrition supplements.

Osteo-angiogenic activity of a micro/nano hierarchical SrSi-codoped hydroxyapatite coating on zirconium alloy

Numerous studies highlight the significance of biomimetic metallic implant surfaces for enhancing osseointegration through synergistic regulation of osteogenesis-angiogenesis. However, achieving clinical demands through singular structural or compositional biomimicry poses challenges. Therefore, the integration of both structural and compositional biomimicry, to closely emulate the host bone surface, is crucial for maximizing the biological activity of metallic implants. We synthesized a micro/nano hierarchical SrSi-codoped hydroxyapatite coating on Zr16Nb12Ti alloy through a simple microarc oxidation-hydrothermal reaction. Results revealed that Si doping enhances hydroxyapatite (HA) growth along the c-axis, forming large-sized nanorods. However, co-doping of Sr and Si inhibits grain growth by reducing crystal growth freedom, yielding a finer HA nanowire coating (MH-SrSi). MH-SrSi exhibits outstanding hydrophilicity attributed to the finer HA nanowires on the coating surface, promoting the adhesion of proteins and cells. Additionally, the released Sr and Si from MH-SrSi stimulate the secretion of osteogenesis-related proteins in osteoblasts and angiogenesis-related factors in endothelial cells, exhibiting a synergistic effect on promoting osteogenesis and angiogenesis. In vivo evaluation mirrors these results and shows that the micro/nano hierarchical structures of MH-SrSi elicited inward bone growth. Overall, MH-SrSi, combining structural biomimicry and compositional biomimicry, exhibits excellent osseointegration capability, making it a promising candidate for implant materials.

Phenotypic Insights Into Anti-IgLON5 Disease in IgLON5-Deficient Mice.

Anti-IgLON5 disease is an autoimmune neurodegenerative disorder characterized by various phenotypes, notably sleep and movement disorders and tau pathology. Although the disease is known to be associated with the neuronal cell adhesion protein IgLON5, the physiologic function of IgLON5 remains elusive. There are conflicting views on whether autoantibodies cause loss of function, activation of IgLON5, or inflammation-associated neuronal damage, ultimately leading to the disease. We generated IgLON5 knockout (-/-) mice to investigate the functions of IgLON5 and elucidate the pathomechanism of anti-IgLON5 disease. IgLON5 knockout (-/-) mice underwent behavioral tests investigating motor function, psychiatric function (notably anxiety and depression), social and exploratory behaviors, spatial learning and memory, and sensory perception. Histologic analysis was conducted to investigate tau aggregation in mice with tauopathy. IgLON5-/- mice had poorer performance in the wire hang and rotarod tests (which are tests for motor function) than wild-type mice. Moreover, IgLON5-/- mice exhibited decreased anxiety-like behavior and/or hyperactivity in behavior tests, including light/dark transition test and open field test. IgLON5-/- mice also exhibited poorer remote memory in the contextual fear conditioning test. However, neither sleeping disabilities assessed by EEG nor tau aggregation was detected in the knockout mice. These results suggest that IgLON5 is associated with activity, anxiety, motor ability, and contextual fear memory. Comparing the various phenotypes of anti-IgLON5 disease, anti-IgLON5 disease might partially be associated with loss of function of IgLON5; however, other phenotypes, such as sleep disorders and tau aggregation, can be caused by gain of function of IgLON5 and/or neuronal damage due to inflammation. Further studies are needed to elucidate the role of IgLON5 in the pathogenesis of anti-IgLON5 diseases.

Antheraea proylei J. Sericin Induces Apoptosis in a Caspase-dependent Manner in A549 and HeLa Cells.

In spite of much progress in cancer, the global cancer burden is still significant and increasing. Sericin, an adhesive protein of silk cocoons, has been shown to be a potential protein in various biomedical applications, including cancer therapeutics. The present study evaluates the anticancer property of sericin from cocoons of Antheraea proylei J (SAP) against human lung cancer (A549) and cervical cancer (HeLa) cell lines. This is the first report of anti-cancer activity of the non-mulberry silkworm A. proylei J. Establish the antiproliferative potential of SAP. 2. Identify the molecular mechanism of cell death induced by SAP on two different cell lines. To investigate the anticancer activity of sericin preparation from cocoons of A. proylei. SAP was prepared from cocoons of A. proylei J. by the process of the degumming method. Cytotoxic activity was assessed by MTT assay, and genotoxicity was assessed by comet assay. Cleavage of caspase and PARP proteins and phosphorylation of MAPK pathway members were analysed by Western blotting. Cell cycle analysis was done by flow cytometer. SAP causes cytotoxicity to A549 and HeLa cell lines with the IC50 values 3.8 and 3.9 μg/μl respectively. SAP induces apoptosis in a dose-dependent manner through caspase-3 and p38, MAPK pathways in A549 and HeLa cells. Moreover, in A549 and HeLa cells, SAP induces cell cycle arrest at the S phase in a dose-dependent manner. The difference in the molecular mechanisms of apoptosis induced by SAP in A549 and HeLa cell lines may be due to the difference in the genotypes of the cancer cell lines. However, further investigation is warranted. The overall results of the present study envisage the possibility of using SAP as an anti-tumorigenic agent.

Functional profiling of resident cells during vascular aging

Introduction: Depending on surrounding cell types, substrate mechanics, and chemical agonists, vascular cell types – including endothelial (ECs) and smooth muscle cells (VSMC) — modulate their behavior to maintain homeostasis. Aging perturbs this homeostasis resulting in EC and SMC dysfunction, marked by impaired barrier integrity and pathological ECM remodeling. Endothelial-to-mesenchymal transition (EndMT) in ECs and “dedifferentiation” of VSMCs towards a synthetic phenotype are phenomenon under investigation as cellular drivers of the widespread dysregulation seen with aging. The overall goal of this project is to understand the effect of cross-talk between ECM and growth factor signaling on vascular cell plasticity during aging. Materials and Methods: Human aortic endothelial cells (HAECs) were seeded onto transwell inserts after seven days treatment with or without TGF-β. After growing to confluence on the insert, cells were subjected to a FITC-dextran transwell assay. A parallel group of cells was seeded onto fibronectin coated glass-bottom dishes and stained for the expression of focal adhesion proteins and cell-type markers. Mouse aortic smooth muscle cells (maSMCs) were isolated from C57Bl6 mice at 3 (young), 6 (early middle-aged; EMA), 9 (middle-age; MA), or greater than 18 months of age (old). Cells were seeded onto dye-quenched (DQ) collagen type I (Col-I) substrate before gain of fluorescence was measured in proximity to the cell as well as in the surrounding media. A parallel group of cells were allowed to grow in media containing FITC Col-I, and gain of fluorescence was measured in proximity to the cells. Each cell type (3M, 6M, 9M, and 18M) in both experiments (DQ and FITC) were further treated with MMP inhibitor, TG2 inhibitor and TGF-β1 to measure their impacts on Col-I turnover. Results: Barrier function was not impaired in ECs cultured with TGF-β1, relative to their untreated counterparts. Mouse aortic SMCs isolated from older mice had decreased rates of Col-I cleavage and were more susceptible to MMP inhibition than their younger counterparts. Conclusions: maSMCs from older mice have lower Col-I turnover than their younger counterparts. This is consistent with bulk tissue behavior, as it is well known that relative collagen levels increase in the elastic vasculature as we age. TGF-β1 treatment did not have an effect on permeability of 4kd FITC-dextran, it is feasible that there will be an impact on the larger 70kd fragments. Travis Brady is supported by the NASEM Ford Foundation Pre-doctoral Fellowship. 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.

Effects of antagonism of thromboxane-prostanoid receptor on alcohol-associated liver disease

Backgrounds: Alcohol-associated liver disease (ALD) is one of the leading causes of liver diseases. Thromboxane-prostanoid receptor (TP-R) is widely expressed in the liver and is activated by thromboxane A2 (TXA2). A previous study reported an increase in TP-R mRNA level in liver after ethanol feeding. Preclinical studies have documented that TP-R antagonists exert a protective effect against cardiovascular and liver diseases. In particular, TP-R antagonist is reported to attenuate ALD in rodents. However, the mechanism(s) by which antagonizing TP-R attenuates ALD remains unclear. Methods: Herein, we used the chronic plus binge ethanol feeding model. Briefly, male, C57BL/6 wild-type mice (8-week) were fed a Lieber-Decarli ethanol (5% v/v) diet (ET, n = 10) or isocaloric control diet (CON, n = 6) for ten days followed by a single binge administration of ethanol or maltose-dextrin via oral gavage. A cohort of ethanol-fed mice received SQ 29,548, a TP-R antagonist (ET+SQ, n = 8) by oral administration. Results: Western blot analysis showed that the protein level of thromboxane A2 synthase 1 ( P<0.05), responsible for TXA2 production, was upregulated in the mouse liver upon ethanol exposure. Of note, ethanol feeding significantly increased plasma aspartate transferase (AST) level ( P<0.05), which was abolished by SQ administration ( P<0.05). Moreover, compared with CON mice, ET mice showed an increase in liver protein levels of pro-inflammatory markers, including TNFa ( P<0.05), cluster of differentiation 68 (CD68, P<0.001), and vascular cell adhesion protein 1 ( P<0.05). In addition, the pro-fibrogenic markers including collagen type 1 alpha 1 chain (COL1A1, P<0.05) and matrix metalloproteinase 9 (MMP9, P<0.01) were also increased in ET mice. However, these alterations were not found in ET+SQ mice compared to their controls. In particular, ET+SQ mice exhibited a marked reduction in hepatic protein levels of CD68 ( P<0.001), COL1A1 ( P<0.001), and MMP9 ( P<0.01) versus ET mice. Interestingly, we noted that ethanol consumption decreases the protein level of NADH:ubiquinone oxidoreductase subunit B8 (NDUFB8), a component of mitochondrial complex I, in mouse liver ( P<0.05), which was reversed by SQ administration( P<0.05). Conclusion: These findings suggest that blockade of TP-R activity attenuates ethanol-induced liver inflammation and fibrosis possibly through improving the function of mitochondrial complex I. This study was supported by the NIH-NIAAA P50 award-Alcohol Center of Research-Nebraska (P50AA030407-5130). 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.

Molecular and functional characterization of reversible-sunitinib-tolerance state in human renal cell carcinoma.

Therapy failure with the tyrosine kinase inhibitor (TKI) sunitinib remains a great challenge in metastatic renal cell carcinoma (mRCC). Growing evidence indicates that the tumour subpopulation can enter a transient, non-mutagenic drug-tolerant state to endure the treatment underlying the minimal residual disease and tumour relapse. Drug tolerance to sunitinib remains largely unexplored in RCC. Here, we show that sunitinib-tolerant 786-O/S and Caki-2/S cells are induced by prolonged drug treatment showing reduced drug sensitivity, enhanced clonogenicity, and DNA synthesis. Sunitinib-tolerance developed via dynamic processes, including (i) engagement of c-MET and AXL pathways, (ii) alteration of stress-induced p38 kinase and pro-survival BCL-2 signalling, (iii) extensive actin remodelling, which was correlated with activation of focal adhesion proteins. Remarkably, the acute drug response in both sensitive and sunitinib-tolerant cell lines led to dramatic fine-tuning of the actin-cytoskeleton and boosted cellular migration and invasion, indicating that the drug-response might depend on cell state transition rather than pre-existing mutations. The drug-tolerant state was transiently acquired, as the cells resumed initial drug sensitivity after >10 passages under drug withdrawal, reinforcing the concept of dynamic regulation and phenotypic heterogeneity. Our study described molecular events contributing to the reversible switch into sunitinib-tolerance, providing possible novel therapeutic opportunities in RCC.

Presynaptic regulators in memory formation.

The intricate molecular and structural sequences guiding the formation and consolidation of memories within neuronal circuits remain largely elusive. In this study, we investigate the roles of two pivotal presynaptic regulators, the small GTPase Rab3, enriched at synaptic vesicles, and the cell adhesion protein Neurexin-1, in the formation of distinct memory phases within the Drosophila mushroom body Kenyon cells. Our findings suggest that both proteins play crucial roles in memory-supporting processes within the presynaptic terminal, operating within distinct plasticity modules. These modules likely encompass remodeling and maturation of existing active zones (AZs), as well as the formation of new AZs.

The clinical characteristics of neutrophil extracellular trap in patients with severe cerebral venous sinus thrombosis and its prognostic value in acute and subacute patients

Objective: To explore the clinical characteristics of neutrophil extracellular trap (NET) in patients with severe cerebral venous sinus thrombosis (CVST) and to study their prognostic value in the acute and subacute phases. Methods: This study is a retrospective case series analysis. Clinical and pathological data of 52 patients with severe cerebral venous sinus thrombosis who underwent endovascular treatment in the Department of Neurosurgery, Tianjin Huanhu Hospital from June 2019 to June 2022 were retrospectively analyzed. There were 20 males and 32 females, with an age of (40.1±13.6) years(range:18 to 66 years). Forty-five healthy physical examinees were included in the control group. High-resolution MRI was used to stage the thrombus, with 11 cases in the acute group, 28 cases in the subacute group, and 13 cases in the chronic group. Thrombus specimens were obtained through endovascular treatment, and the fluorescence intensity of NET in peripheral blood at different time points was analyzed by immunofluorescence contrast,including the double-stranded DNA structure and adhesion protein components (citrolinated histone H3 (CitH3), myeloperoxidase-DNA complex(MPO-DNA), neutrophil elastase (NE)). The NET markers were determined by ELISA. Spearman rank correlation analysis was used to analyze the correlation between the NET markers in peripheral blood of patients with severe cerebral venous sinus thrombosis in the acute and subacute phases and the volume of venous sinus thrombus, the degree of venous sinus recanalization after treatment, and the discharge modified Rankin scale(mRS)score. The accuracy of NET markers in predicting the prognosis of patients with severe cerebral venous sinus thrombosis was analyzed by drawing receiver operating characteristic (ROC) curve and calculating the area under the curve (AUC). Results: The results of immunofluorescence staining and ELISA showed that no NET structure was formed in the peripheral blood of the control group, while CitH3, MPO-DNA and NE levels in the peripheral blood of CVST patients were increased, among which the acute stage group was the highest, followed by the subacute group, and the chronic group was the lowest. Spearman correlation analysis showed that CitH3, MPO-DNA and NE levels in peripheral blood of patients in acute group and subacute group were positively correlated with thrombus volume and mRS score at discharge (P<0.05). The levels of CitH3 and MPO-DNA in peripheral blood of patients with complete venous sinus recanalization were lower than those of patients with partial venous sinus recanalization (P<0.01). ROC curve analysis results showed that MPO-DNA and NE had no predictive ability for the prognosis of CVST patients (P values were 0.614 and 0.324, respectively), and the AUC of CitH3 was 0.800 (95%CI: 0.638~0.962, P=0.032), the best cut-off value was 13.5 μg/L, the sensitivity was 100%, and the specificity was 58.8%. Conclusions: A large number of NET are formed in patients with severe cerebral venous sinus thrombosis in acute stage. Patients with severe cerebral venous sinus thrombosis in acute stage and subacute stage with high peripheral blood NET content has a low rate of complete sinus revascularization and poor neurological function recovery after treatment.