Cell Polarity Research Articles

Abstract A007: Emergence of metastasis-initiating cells during lung adenocarcinoma progression

Abstract Metastatic lung adenocarcinoma (LUAD) is responsible for the most cancer-related deaths worldwide, and only a subset of cells is capable of metastasizing. Our lab has previously shown that these metastasis-initiating cells express the transmembrane glycoprotein called L1CAM and exhibit characteristics of a fetal lung developmental continuum, ranging from early progenitor states to more differentiated states. The exact signal by which progenitor cells with high metastatic potentials are generated remains unknown. Here, we demonstrate that L1CAM facilitates the signaling cascades necessary to initiate and maintain metastasis-initiating cells in LUAD. Mechanistically, L1CAM interacts with the planar cell polarity (PCP) complex and activates the transcription factor c-Jun. Activated c-Jun, as part of the AP-1 complex, binds to enhancer sites of progenitor genes and promotes the emergence of a metastasis-capable progenitor state. Pharmacological ablation of these metastatic progenitor cells by a cytotoxic L1CAM antibody effectively eliminated LUAD metastasis in vivo. Our findings identify a novel L1CAM-mediated mechanism that maintains a progenitor state essential for metastasis and can be targeted therapeutically. Citation Format: Jin Suk Park, Yasemin Kaygusuz, Carson Kenum, Mohamed I. Gatie, Lan He, Roshan Sharma, Ronan Chaligné, Abdul G. Khan, Ivo C. Lorenz, Paul J. Balderes, Tuomas Tammela, Anna-Katerina Hadjantonakis, Karuna Ganesh, Charles M. Rudin, Joan Massagué. Emergence of metastasis-initiating cells during lung adenocarcinoma progression [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr A007.

Abstract 4138754: Analysis of Polarization Changes in Ascending Aortic Endothelial Cells Induced by Aortic Valve Regurgitation

Background: Fragility of the ascending aortic wall has been reported in patients with aortic regurgitation (AR), thought to be affected by turbulence in the ascending aorta. However, the mechanism behind this effect is unclear. We hypothesized that turbulence in the ascending aorta of AR patients causes changes in the polarization of endothelial cells. This study aimed to clarify that the polarization of endothelial cells in the ascending aortic wall is altered in AR patients. Methods: Twenty patients who underwent ascending aortic replacement at our institution from October 2022 to July 2023 were included: ten with thoracic aortic aneurysms (TAA) and ten with TAA and AR. The polarization of endothelial cells in the greater curvature of the ascending aortic wall collected during surgery was evaluated by measuring the ratio of the long axis to the short axis, the angle between the long axis and the blood flow axis, and the alignment of the Golgi apparatus and nucleus parallel to the blood flow. Results: There were no significant differences in patient background between the AR and non-AR groups. Additionally, there was no significant difference in the diameter of the ascending aorta between the two groups (AR vs. non-AR, 47.7±3.8 mm vs. 44.5±2.2 mm, p=0.479). The long axis to short axis ratio (aspect ratio) of endothelial cells in the ascending aorta was significantly smaller in the AR group than in the non-AR group. The angle (θ) between the long axis of the endothelial cells and the blood flow axis was significantly smaller in the AR group than in the non-AR group. The ratio of Golgi apparatus and nucleus alignment parallel to the blood flow was significantly lower in the AR group than in the non-AR group. Degeneration of the aortic tunica media was also observed in the AR group compared to the non-AR group. Conclusion: The results of this study suggest that the presence of AR alters the polarization of endothelial cells in the ascending aortic wall.

Abstract 4137337: Targeting Macrophage NCOR1 to Alleviate Inflammation in Heart Failure with Preserved Ejection Fraction

Background: Inflammatory response is a key player in heart failure with preserved ejection fraction, however the underlying mechanisms remain unclear. Recent evidence indicates that macrophage inflammation driven by the transcriptional coregulatory protein NCOR1 could play a pivotal role in disease states. Hypothesis: NCOR1 orchestrates macrophage inflammation and cardiac dysfunction in HFpEF. Methods: HFpEF was induced in mice using a validated model combining high-fat diet and L-NAME for 15 weeks. Cardiac function was assessed using high-resolution ultrasound imaging and LV samples were used to study macrophage polarization and inflammation by FACS. We generated myeloid-specific NCOR1-KO mice to investigate the in vivo effects of macrophage NCOR1 depletion on HFpEF. In vitro experiments included RAW 264.7 cells polarization and the assessment of macrophage phenotype switching in the presence or the absence of NCOR1. To study the crosstalk of macrophages with the surrounding cardiac cells, cardiomyocytes (H9c2) and endothelial cells (HAECS) were exposed to conditioned media from cultured RAW. Results: The expression of macrophage markers in human LV specimens showed an increase in pro-inflammatory macrophages (M1) and a decrease in regulatory macrophages (M2) as compared to age-matched control mice. HFpEF mice showed increased expression of vascular adhesion molecules (ICAM1, ICAM2, E-selectin) and a significant recruitment of M1 macrophages as proved by qPCR, WB, and flow cytometry analysis. Of interest, diastolic dysfunction - assessed by E/A ratio and isovolumic relaxation time (IVRT) – and lung congestion were significantly reduced in mice with macrophage NCOR1 deletion as compared to WT littermates, while exercise tolerance was significantly improved. These findings were associated with a reduction of myocardial inflammation (TNF-a, IL6, IL-1b) in Ncor1-KO mice. In vitro assays showed that stimulation of macrophages with PA induced M1 type switch and increased NCOR1, TNF-a, IL-6, and IL-1b levels, whereas NCOR1 depletion prevented detrimental changes of macrophage conditional medium (Fig.1). Conclusion: Targeting macrophage NCOR1 could represent a promising approach to blunt myocardial inflammation in HFpEF.

Abstract 4137240: MHCII hi LYVE1 lo CCR2 hi Interstitial Macrophages Promote Medial Fibrosis in Pulmonary Arterioles and Contribute to Pulmonary Hypertension

Background: Pulmonary hypertension (PH) is a lethal disease characterized in part by progressive pulmonary arteriole (PA) remodeling. Excessive PA fibrosis and macrophage infiltration are often present in PH, but potential association is obscure. We invesitgated the link between interstitial macrophage (iMΦ) infiltration and PA fibrosis in PH and idiopathic pulmonary arterial hypertension (IPAH). Methods: Lung tissue samples from patients with IPAH (n=11) and experimental PH (sugen-5416 and hypoxia, hypoxia, or monocrotaline, n=5) animals (adult male and female SD rats) were obtained to analyze the extent of fibrosis in PA adventitia and media and their correlation to disease severity. Single-cell RNA sequencing, immunohistological analyses, iMΦs and PA smooth muscle cells (PASMCs) coculture, and transgenic animal experiments were used to investigate the cell heterogeneity and molecular mechanisms by which iMΦs promote PA medial fibrosis. Data in this study were analyzed with unpaired two-tailed t-tests with Welch’s correction, Kruskal-Wallis one-way ANOVA followed by Dunn’s test, RM ANOVA with Geisser-Greenhouse correction, or Pearson correlation test, and p < 0.05 was considered statistically significant. Results: We found that increased collagen deposition and fibrosis in the PA media were correlated with PH severity, and iMΦ medial infiltration may be involved in these pathological processes. Single-cell transcriptomics suggested that ligand-receptor associations between MHCII hi LYVE1 lo CCR2 hi iMΦ and fibroblast-like vascular SMC subclusters contributed to PA medial fibrosis. Mechanistically, MHCII hi LYVE1 lo CCR2 hi iMΦs regulated PASMC phenotypic transition and collagen production through the wingless member 11 (WNT11)/planar cell polarity (PCP) pathway. Deletion of iMΦ-enriched Wnt11 in myeloid cells of PH rats ( Itgam CreERT2 ; Wnt11 fl/fl ) normalized the fibrotic PASMC phenotype and decreased PA medial fibrosis, thereby protecting against PH. Moreover, myeloid-specific C-C motif chemokine receptor 2 ( Ccr2 ) deficiency ( Itgam CreERT2 ; Ccr2 fl/fl ) in PH-PAs inhibited MHCII hi LYVE1 lo CCR2 hi iMΦ infiltration. Conclusions: PA medial fibrosis is a causative factor of PH, and the inhibition of MHCII hi LYVE1 lo CCR2 hi iMΦ pathogenicity or infiltration reverses PA medial fibrosis and thus alleviates PH.

IMMU-10. IDENTIFICATION OF A NEW THERAPEUTIC ANTIGEN FOR GLIOBLASTOMA USING A MONOCLONAL ANTIBODY LIBRARY FROM PATIENT-DERIVED TUMOR SPHERES

Abstract Glioblastoma (GBM) has a poor prognosis despite intensive treatment by surgery, radiation, and chemotherapy, thus new treatment strategies are urgently needed. Various innovative cancer therapies targeting cancer-specific cell surface antigens, such as chimeric antigen receptor T cell therapy, are developed and more cell surface antigens that is highly specific for GBM cells are needed. Although extensive transcriptome analyses or proteomic analysis of GBM cells were performed, few transcripts specific for GBM cells have been identified. However, GBM cell-specific antigen epitopes formed by post-translational modifications of proteins may have been missed by transcriptome or proteomic analysis, and could still be discovered by thoroughly searching for cancer-specific monoclonal antibodies. In this study, we aimed to identify GBM-specific antigens using a monoclonal antibody library from patient-derived tumor spheres, create CAR-T cells against the antigen, and check antitumor efficiency of the CAR-T cells. Approximately 25,000 monoclonal antibody-producing hybridomas were establishment using BALB/c mice and patient derived tumor spheres. Among them, a antibodies that bind to plural glioblastomas and not to plural normal brain cells were selected and we identified the antigen as Prostaglandin F2 receptor negative regulator (PTGFRN) by the expression cloning method. PTGFRN witch is expressed in several cancers regulate migration, angiogenesis, and cell polarity and decreases the radiosensitivity of GBM cells. We created CAR-T cells against the antigen and co-cultured it with GBM cells, which significantly increased the production of IL-2 and INF-γ. Furthermore, the CAR-T cells injected intracranial in an orthotopic xenograft model with patient-derived GBM cells, significantly reduced tumor growth. PTGFRN CAR-T-cell therapy may be a potential novel therapeutic target for GBM.

TMIC-75. ICAM-1 PROMOTES AN IMMUNOSUPPRESSIVE LANDSCAPE IN GLIOBLASTOMAS BY REGULATING THE PHENOTYPIC POLARIZATION STATE OF TUMOR ASSOCIATED MACROPHAGES

Abstract Glioblastoma (GBM) is a fatal adult CNS tumor, with a median overall survival of 12-15 months. Intercellular adhesion molecule 1 (ICAM-1) is a cell adhesion molecule whose expression is significantly greater in the mesenchymal transcriptional subtype of GBMs, whereby it is prognostic. We have previously shown that when ICAM-1 is knocked out in the tumor microenvironment (TME) of immune-competent GBM-bearing mice, these mice showed prolonged overall survival and reduced tumor volume. It is yet to be determined how ICAM-1 expression affects infiltration and functional polarization of tumor-associated macrophages (TAMs) and other immune cells in GBM, and if we can suppress the infiltration of M2-like TAMs into the TME by inhibiting ICAM-1. We used a mouse glioma model with and without knockout (KO) of the ICAM-1 gene and intracranially injected GL261 cells. ICAM-1 KO mice survived longer and had reduced tumor volume relative to wildtype, with survival and volume differences being rescued upon ICAM-1 bone marrow reconstitution. Upon endpoint, we performed cytometry by time-of-flight, and found that ICAM-1 KO tumors harbored a reduction in helper T cells, Tregs, and cytotoxic T cells, but an increased proportion in double-negative T cells relative to ICAM-1 WT tumors. ICAM-1 KO tumors also demonstrated an increased proportion of M1-like TAMs relative to M2-like. These results were validated upon administration of ISIS-3082 to tumor models, an antisense oligonucleotide for which a human-specific form has been fast-track approved for other diseases, that targets ICAM-1 transiently in peripheral immune cells prior to TME infiltration. These findings suggest that ICAM-1 expression influences immune cell infiltration, potentially modulates the functional state of TAMs towards a M1-like state, and that ICAM-1 may be targeted in TAMs to ‘reeducate’ them before entering the TME. This may be translated into clinical practice and combined with standards-of-care to render GBMs more sensitive to treatment.

Alteration of Cytoskeletal Proteins Leads to Retinal Degeneration in Drosophila.

The eye holds a special fascination for many neuroscientists because of its meticulously organized structure. Vertebrates typically possess a simple camera-type eye, whereas the compound eye structure is predominantly observed in arthropods including model organism Drosophila melanogaster. Cell shape, cell polarization, and tissue integrity are the cell biological processes crucial for shaping the eye, which directly or indirectly depends on the cytoskeleton. Henceforth the cytoskeleton, specifically actin microfilaments, essentially has a dynamic role in the normal development and growth of eye structure. This review provides insight into the roles played by the actin cytoskeleton during the development and maintenance of the Drosophila eye.

Metalloproteinases are involved in the regulation of prenatal tooth morphogenesis.

During development, tooth germs undergo various morphological changes resulting from interactions between the oral epithelium and ectomesenchyme. These processes are influenced by the extracellular matrix, the composition of which, along with cell adhesion and signalling, is regulated by metalloproteinases. Notably, these include matrix metalloproteinases (MMPs), a disintegrin and metalloproteinases (ADAMs), and a disintegrin and metalloproteinases with thrombospondin motifs (ADAMTSs). Our analysis of previously published scRNAseq datasets highlights that these metalloproteinases show dynamic expression patterns during tooth development, with expression in a wide range of cell types, suggesting multiple roles in tooth morphogenesis. To investigate this, Marimastat, a broad-spectrum inhibitor of MMPs, ADAMs, and ADAMTSs, was applied to ex-vivo cultures of mouse molar tooth germs. The treated samples exhibited significant changes in tooth germ size and morphology, including an overall reduction in size and an inversion of the typical bell shape. The cervical loop failed to extend, and the central area of the inner enamel epithelium protruded. Marimastat treatment also disrupted proliferation, cell polarization and organization compared to control tooth germs. Additionally, a decrease in laminin expression was observed, leading to a disruption in continuity of the basement membrane at the epithelial-mesenchymal junction. Elevated Hif-1α expression correlated with a disruption to blood vessel development around the tooth germs. These results reveal the crucial role of metalloproteinases in tooth growth, shape, cervical loop elongation, and the regulation of blood vessel formation during prenatal tooth development.

Life-long functional regeneration of in vivo airway epithelium by the engraftment of airway basal stem cells.

Durable and functional regeneration of the airway epithelium in vivo with transplanted stem cells has the potential to reconstitute healthy tissue in diseased airways, such as in cystic fibrosis or primary ciliary dyskinesia. Here, we present detailed protocols for the preparation and culture expansion of murine primary and induced pluripotent stem cell-derived airway basal stem cells (iBCs) and methods for their intra-airway transplantation into polidocanol-conditioned murine recipients to achieve durable in vivo airway regeneration. Reconstitution of the airway tissue resident epithelial stem cell compartment of immunocompetent mice with syngeneic donor cells leverages the extensive self-renewal and multipotent differentiation properties of basal stem cells (BCs) to durably generate a broad diversity of mature airway epithelial lineages in vivo. Engrafted donor-derived cells re-establish planar cell polarity as well as functional ciliary transport. By using this same approach, human primary BCs or iBCs transplanted into NOD-SCID gamma recipient mice similarly display engraftment and multilineage airway epithelial differentiation in vivo. The time to generate mouse or human iBCs takes ~60 d, which can be reduced to ~20 d if previously differentiated cells are thawed from cryopreserved iBC archives. The tracheal conditioning regimen and cell transplantation procedure is completed in 1 d. A competent graduate student or postdoctoral trainee should be able to perform the procedures listed in this protocol.

Contributions of the Dachsous intracellular domain to Dachsous-Fat signaling.

The protocadherins Fat and Dachsous regulate organ growth, shape, patterning, and planar cell polarity. Although Dachsous and Fat have been described as ligand and receptor, respectively, in a signal transduction pathway, there is also evidence for bidirectional signaling. Here we assess signaling downstream of Dachsous through analysis of its intracellular domain. Genomic deletions of conserved sequences within dachsous identified regions of the intracellular domain that contribute to Ds activity. Deletion of the A motif increased Dachsous protein levels and decreased wing size. Deletion of the D motif decreased Dachsous levels at cell membranes, increased wing size, and disrupted wing, leg and hindgut patterning and planar cell polarity. Co-immunoprecipitation experiments established that the D motif is necessary and sufficient for association of Dachsous with key partners including Lowfat, Dachs, Spiny-legs, Fat and MyoID. Subdivision of the D motif identified distinct regions that preferentially contribute to different Ds activities. Our results identify motifs that are essential for Dachsous function and are consistent with the hypothesis that the key function of Dachsous is regulation of Fat.

Unraveling the Role of Wnt Signaling Pathway in the Pathogenesis of Autism Spectrum Disorder (ASD): A Systematic Review.

Autism spectrum disorder (ASD), or simply autism, is a neurodevelopmental disorder characterized by social communication deficit, restricted interests, and repetitive behavior. Several studies suggested a link between autism and the dysregulation of the Wnt signaling pathway which is mainly involved in cell fate determination, cell migration, cell polarity, neural patterning, and organogenesis. Despite the absence of effective therapy, significant progress has been made in understanding the pathogenesis of ASD. Neuropharmacological studies showed that drugs acting on the Wnt pathway like Canagliflozin can alleviate autistic-like behavior in animal models. Hence, this pathway could potentially be a futuristic therapeutic target to mitigate autism's symptoms. This systematic review aims to collect and analyze evidence that elucidates how alterations in the Wnt pathway may contribute to the pathogenesis of autism in animal models at the molecular, cellular, and physiological levels. Comprehensive searches were conducted across multiple databases, including PubMed, Web of Science, Embase, and Scopus to identify relevant studies up to March 2024. The inclusion criteria encompassed experimental studies that focused on the link between autism and this pathway, and the quality assessment was ensured by SYRCLE's risk of bias tools. Collectively, the included articles highlighted the possible implication of this pathway in the abnormalities found in autism, which impacted processes such as energy metabolism, oxidative stress, and neurogenesis. These alterations could underlie autistic behavior by affecting synaptic transmission and mitochondrial function.

Fecal microbiota transplantation alleviates neuronal Apoptosis, necroptosis and M1 polarization of microglia after ischemic stroke

ObjectiveThis study aims to delve into the mechanisms underlying the improvement of neurological function in rats with ischemic stroke through fecal microbiota transplantation.Methods: A total of fifty male Sprague-Dawley rats were categorized into three groups: sham surgery, model, and fecal transplantation. We assessed behavioral and pathological alterations in the rats using modified neurological function scoring and TTC staining. Additionally, Western blot and immunofluorescence techniques were employed to examine the expression levels of RIP1, RIP3, MLKL, p-MLKL, Bcl-2, Bax, and cleaved caspase-3 in neurons of ischemic brain tissue, while iNOS and Arg1 were analyzed to evaluate microglial polarization.Results: The fecal transplantation group exhibited a decline in neurological function score compared to the model group, accompanied by a reduction in infarct volume (P < 0.05). Relative to the sham surgery group, the model group displayed a significant increase in the expression levels of necroptosis-related proteins RIP1, RIP3, p-MLKL, apoptotic proteins Bax and cleaved caspase-3, and the M1 microglial cell marker iNOS in ischemic brain tissue, while Bcl-2 expression was notably decreased (P < 0.05). Conversely, compared to the model group, the fecal transplantation group demonstrated decreased expression levels of RIP1, RIP3, p-MLKL, Bax, cleaved caspase-3, and iNOS, along with increased expression of Bcl-2.Conclusion: Fecal microbiota transplantation presents a promising avenue for enhancing neurological function in rats with ischemic stroke by inhibiting neuronal apoptosis, necroptosis, and M1 polarization of microglial cells.

The water channels aquaporin-1 and aquaporin-3 interact with and affect the cell polarity protein Scribble in 3D in vitro models of breast cancer.

Cellular changes in carcinomas include alterations in cell proliferation, cell migration, cell-cell adhesion, and cellular polarity. In vitro studies have revealed that the water channels, aquaporin-1 (AQP1) and AQP3, can influence cell migration and cell-cell adhesion. Of note, we previously showed that AQP1 overexpression reduced levels of cell-cell adhesion proteins, whereas AQP3 increased levels when overexpressed in normal epithelial cells. Expression of AQP1 and AQP3 in breast carcinoma is associated with lymph node metastasis, recurrence, and poor survival of patients with breast cancer. In this study, we investigated if AQP1 and AQP3 affected cell polarity in breast cancer by studying the relationship between the major polarity protein Scribble and AQP1 and AQP3. In breast cancer tissue samples, the protein expression of AQP1, AQP3, and Scribble did not show an obvious correlation. However, in a GST pull-down assay, AQP1 and AQP3 interacted with Scribble. AQP1 overexpression reduced the size of 3D spheroids as well as reduced Scribble levels at cell-cell contacts, whereas AQP3 overexpression showed no significant change in spheroid size compared with control, AQP3 overexpression also reduced Scribble levels at cell-cell contacts. Of note, AQP1 overexpression increased cell migration and induced cell detachment and dissemination from migrating breast cancer cell sheets, whereas AQP3 overexpression did not. Thus, AQP1 and AQP3 differentially affect 3D-grown breast cancer spheroids, and especially AQP1 may contribute to cancer development and spread via negatively affecting cellular junctions and cell polarity proteins as well as increasing cell migration and cell detachment.NEW & NOTEWORTHY Overexpression of the water channels aquaporin-1 and aquaporin-3 reduced levels of the key polarity protein Scribble at cell-cell junctions, suggesting potential implications in breast cancer progression and metastasis.

Berberine Modulates Microglial Polarization by Activating TYROBP in Alzheimer's Disease

BackgroundCharacterized by β-amyloid (Aβ) plaques, neurofibrillary tangles, and aberrant neuroinflammation in the brain, Alzheimer's disease (AD) is the most common neurodegenerative disease. Microglial polarization is a subtle mechanism which maintains immunological homeostasis and has emerged as a putative therapeutic to combat AD. Berberine (BBR) is a natural alkaloid compound with multiple pharmacological effects, and has shown considerable therapeutic potential against inflammatory disorders. However, BBR functions and underlying mechanisms in neuroinflammation remain unclear. PurposeTo examine BBR pharmacological effects and mechanisms in neuroinflammation with a view to treating AD. MethodsBBR effects on cognitive performance in 5 × FAD mice were assessed using open field, Y-maze, and Morris Water Maze (MWM) tests. Neuroinflammation-related markers and Aβ pathology were examined in brain sections from mice. Transcriptomic analyses of hippocampus tissues were also conducted. Microglial BV2 cells were also used to verify potential BBR mechanisms in neuroinflammation and microglial polarization. ResultsBBR improved cognitive performance, reduced amyloid pathology, and alleviated aberrant neuroinflammation in an AD mouse model. BBR induced microglial polarization to an M2-like phenotype, which was manifested by lowered and elevated proinflammatory and anti-inflammatory cytokine production, respectively, improved microglial uptake and Aβ clearance. Mechanistically, BBR directly interacted with TYROBP and promoted its activation by stabilizing TYROBP oligomerization. TYROBP knockdown aggravated M1-like polarization and pro-inflammatory gene expression in microglial cells in the presence of lipopolysaccharide (LPS)+Aβ, while blocked microglial M2-like polarization benefited from BBR administration. ConclusionsBBR modulated neuroinflammation by regulating microglial polarization via TYROBP activation. Our study provided new insight into BBR pharmacological actions in regulating microglial homeostasis and combating AD.

Unveiling the enigmatic roles of basophils in HIV infection: A narrative review.

The intricate interplay between the human immunodeficiency virus (HIV) and the immune system has long been a focal point in understanding disease progression. Among the myriad of immune cells, basophils, often overshadowed, have recently emerged as pivotal contributors to the complex immunological landscape of HIV infection. This paper aims to provide a succinct overview of the enigmatic roles of basophils in HIV pathogenesis, elucidating their multifaceted functions and implications. Basophils, conventionally perceived as minor players in immune responses, exhibit active participation in HIV infection. Their activation triggered by viral antigens, cytokines, and immune complexes orchestrates a cascade of immune events, influencing immune modulation, cytokine release, and the activation of adaptive immune cells. Furthermore, basophils function as antigen-presenting cells, potentially impacting viral dissemination and immune dysregulation. Additionally, basophils serve as crucial regulators in HIV infection through cytokine secretion, notably interleukin (IL)-4, IL-13, and IL-3, influencing immune cell differentiation, polarization, and antibody production. Their interactions with various immune cells intricately shape the immune response against HIV, impacting disease progression and immune equilibrium. Moreover, harnessing basophils as potential vaccine targets or immune modulators represents a compelling avenue for future research. In conclusion, the emerging understanding of basophils' multifaceted involvement in HIV infection challenges prior perceptions and underscores their significance in shaping immune responses and disease outcomes. This abstraction highlights the need for continued research to unlock the full potential of basophils, paving the way for novel strategies in combatting HIV/AIDS.

Central role of squid gene during oocyte development in the Hemiptera Rhodnius prolixus

Oocyte polarity establishment is a conserved and crucial phenomenon for embryonic development. It relies on the precise spatial localization of maternal factors deposited during oocyte development, which is essential for establishing and maintaining cell polarity and subsequently specifying embryonic axes. The heterogeneous nuclear ribonucleoprotein (hnRNP) encoded by the squid (sqd) gene has been implicated in mRNA localization and embryonic axis establishment in Drosophila melanogaster. Comparative genomics allowed for the identification of a homologue in Rhodnius prolixus. In this study, we investigated the function of Rp-sqd during oogenesis and early embryonic development. We observed persistent expression of Rp-sqd during oocyte development, with localization in the cytoplasm of ovary germarium and growing oocytes in previtellogenic and vitellogenic stages. A Parental RNA interference (RNAi) experiment targeting Rp-sqd resulted in female sterility. The ovaries showed disrupted oocyte development, disarray of follicular epithelium, and affected nurse cells integrity. Immunostaining and microscopic techniques revealed microtubule disarray and a reduction in the presence of organelles in the trophic cords that connect the germarium with the oocytes. The Rp-sqd depletion impacted the transcript expression of maternal mRNAs involved in apoptosis, axis formation, oogenesis, and cytoskeleton maintenance, indicating a pleiotropic function of Rp-sqd during oogenesis. This study provides new insights into the genetic basis of R. prolixus oogenesis, highlighting the crucial role of Rp-sqd in oocyte development, fertility, and germarium integrity. These findings contribute to our understanding of insect developmental processes, provide a foundation for future investigations into reproduction, and reveal the regulatory mechanisms governing the process.

Sigma-1 receptor modulation by fluvoxamine ameliorates valproic acid-induced autistic behavior in rats: Involvement of chronic ER stress modulation, enhanced autophagy and M1/M2 microglia polarization

Autism spectrum disorder (ASD) is a neurodevelopmental disorder. While, fluvoxamine (FVX) is an antidepressant and widely prescribed to ASD patients, clinical results are inconclusive and the mechanism of FVX in the management of ASD is unclear. This study determined the potential therapeutic impact of FVX, a sigma-1 receptor (S1R) agonist, against the valproic acid (VPA)-induced model of autism. On gestational day 12.5, Wistar pregnant rats were given a single intraperitoneal (i.p.) injection of either VPA (600 mg/kg) or normal saline (10 mL/kg, vehicle-control). Starting on postnatal day (PND) 21 to PND 50, FVX (30 mg/kg, P·O. daily) and NE-100, (S1R) antagonist, (1 mg/kg, i.p. daily) were given to male pups. Behavior tests and histopathological changes were identified at the end of the experiment. In addition, the cerebellum biomarkers of endoplasmic reticulum (ER) stress and autophagy were assessed. Microglial cell polarization to M1 and M2 phenotypes was also assessed. FVX effectively mitigated the histopathological alterations in the cerebellum caused by VPA. FVX enhanced sociability and stereotypic behaviors in addition to its noteworthy impact on autophagy enhancement, ER stress deterioration, and controlling microglial cell polarization. The current investigation confirmed that the S1R agonist, FVX, can lessen behavioral and neurochemical alterations in the VPA-induced rat model of autism.

CDC42 enhances phagocytic activity and exhibits antimicrobial functions through the recruitment of IQGAP1 in Apostichopus japonicus

Cell Division Cycle 42 protein (CDC42) is a pivotal member of the Rho family of small GTPases, integral to cell signaling and the regulation of cell polarity. CDC42 is extensively documented to participate in host immunity, particularly in processes such as phagocytosis and cell migration. Nevertheless, the precise mechanisms by which CDC42 affects host-bacteria interactions remain unclear in Echinoderms. In this study, we have isolated and characterized the CDC42 gene from Apostichopus japonicus, referred to as AjCDC42. The complete cDNA sequence of AjCDC42 extends 1282 base pairs, including a typical classical RHO domain, spanning amino acids from 6 to 179. Spatial expression analysis demonstrated that AjCDC42 is ubiquitously expressed across all examined tissues. Following infection with Vibrio splendidus and stimulation with LPS, the protein and mRNA levels of AjCDC42 were significantly upregulated in coelomocytes. Moreover, the knockdown of AjCDC42 significantly decreased V. splendidus-induced phagocytic activity in coelomocytes, leading to a reduced intracellular load of V. splendidus, as evidenced by flow cytometry and bacterial plate counting assays. Mechanistically, AjCDC42 was identified as an interacting partner of IQ Motif Containing GTPase Activating Protein 1 (AjIQGAP1) through the use of co-immunoprecipitation, immunofluorescence, and GST pull-down assays combined with mass spectrometry techniques. Additional functional analyses revealed that the knockdown of AjIQGAP1 similarly decreased the phagocytic activity and the intracellular load of V. splendidus in coelomocytes. Furthermore, we detected that decreased levels of AjCDC42 and AjIQGAP1 impaired cytoskeletal rearrangement and delayed lysosomal clearance of V. splendidus. In summary, our findings underscore the pivotal role of the AjCDC42-AjIQGAP1 axis in regulating coelomocytes phagocytosis in A. japonicus during V. splendidus infection.

Planar cell polarity zebrafish models of congenital scoliosis reveal underlying defects in notochord morphogenesis.

Congenital scoliosis (CS) is a type of vertebral malformation for which the etiology remains elusive. The notochord is pivotal for vertebrae development, but its role in CS is still understudied. Here, we generated a zebrafish knockout of ptk7a, a planar cell polarity (PCP) gene that is essential for convergence and extension (C&E) of the notochord, and detected congenital scoliosis-like vertebral malformations (CVMs). Maternal zygotic ptk7a mutants displayed severe C&E defects of the notochord. Excessive apoptosis occurred in the malformed notochord, causing a significantly reduced number of vacuolated cells, and compromising the mechanical properties of the notochord. The latter manifested as a less-stiff extracellular matrix along with a significant reduction in the number of the caveolae and severely loosened intercellular junctions in the vacuolated region. These defects led to focal kinks, abnormal mineralization, and CVMs exclusively at the anterior spine. Loss of function of another PCP gene, vangl2, also revealed excessive apoptosis in the notochord associated with CVMs. This study suggests a new model for CS pathogenesis that is associated with defects in notochord C&E and highlights an essential role of PCP signaling in vertebrae development.

Identification of a non-canonical planar cell polarity pathway triggered by light in the developing mouse retina

Identification of a non-canonical planar cell polarity pathway triggered by light in the developing mouse retina