Integrin Signaling Research Articles

DEEP PROTEOMIC PROFILING OF ACCELERATED KIDNEY AGING AND SENESCENCE BURDEN IN MACACA MULATTA

Abstract Whole-body ionizing radiation (IR) is a stressor that causes damage to DNA, lipids, and proteins, and in the latent-phase, may lead to oxidative stress, inflammation, and cellular senescence. Slowly-reproducing tissues, including kidney, are more likely to react to DNA damaging stressors, which may exacerbate aging processes. Quantitative proteomics was employed to gain molecular insights into how IR exposure may drive renal aging processes. For this analysis, kidney cortex tissues (N=38) were obtained from the Wake Forest Non-Human Primate Radiation Late Effects Cohort. Protein lysates (100 µg) were digested and peptides were desalted. Peptides were analyzed on a timsTOF HT mass spectrometer (Bruker), raw data was analyzed using protein-analysis software, and significantly-altered proteins were subjected to bioinformatic analysis. 5,472 protein groups with at least two unique peptides were identified in the kidney cortex. The influence of 1) kidney disease (KD) in irradiated individuals, 2) only kidney disease, and 3) only irradiation was studied. Interestingly, over 75% of significantly-altered proteins are significantly upregulated. This includes extracellular matrix proteins tenascin and periostin, which are potential aging biomarkers. Upon mapping this dataset to homologous human proteins, proteins associated with kidney disease among irradiated animals are related to EGF pathways, integrin signaling, and fibrosis. Significantly-altered proteins related with kidney disease, independent of irradiation, are related to EGF pathways, integrins, and fibrosis whereas significantly-altered proteins related to irradiation exposure are involved in fibrosis. Similarities in biological processes from significantly-altered proteins in either kidney disease or irradiation highlight a potential synergistic effect of irradiation on kidney disease.

Integrin adhesome axis inhibits the RPM-1 ubiquitin ligase signaling hub to regulate growth cone and axon development.

Integrin signaling plays important roles in development and disease. An adhesion signaling network called the integrin adhesome has been principally defined using bioinformatics and cell-based proteomics. To date, the adhesome has not been studied using integrated proteomic and genetic approaches. Here, proteomic studies in C. elegans identified physical associations between the RPM-1 ubiquitin ligase signaling hub and numerous adhesome components including Talin (TLN-1), Kindlin (UNC-112) and β-integrin (PAT-3). C. elegans RPM-1 is orthologous to human MYCBP2, a prominent player in nervous system development recently associated with a neurodevelopmental disorder. After curating and updating the conserved C. elegans adhesome, we identified an adhesome subnetwork physically associated with RPM-1 that has extensive links to human neurobehavioral abnormalities. Using neuron-specific, CRISPR loss-of-function strategies, we demonstrate that a PAT-3/UNC-112/TLN-1 adhesome axis regulates axon termination in mechanosensory neurons by inhibiting RPM-1. Developmental time-course studies and pharmacological results suggest TLN-1 inhibition of RPM-1 affects growth cone collapse and microtubule dynamics during axon outgrowth. These results indicate the PAT-3/UNC-112/TLN-1 adhesome axis restricts RPM-1 signaling to ensure axon outgrowth is terminated in a spatially and temporally accurate manner. Thus, our findings orthogonally validate the adhesome using an organismal setting, identify an adhesome axis that inhibits RPM-1 (MYCBP2), and highlight important new links between the adhesome and brain disorders.

Circular Adhesion Substrates Inhibiting Cell Polarization and Proliferation via Graded Texture of Geometric Micropatterns.

Most melanomas that occur on the skin surface originate from a newly formed nevus and grow outward in a circular pattern and metastasize from the nevus center. Herein, a circular microfabricated substrate is constructed to explore the growth behavior of melanoma cells. Modeling software is used to calculate appropriate parameters, including shape and size, and then the substrates are processed with microfabrication technologies. The results show that the melanoma cells on the circular adhesion substrate are oval and are significant changes in cell spread length, nuclei, area, aspect ratio, Young's modulus, and orientation angles, indicating inhibition of cell polarization. Moreover, three different layers from circular adhesion substrates are selected to construct new substrates, which indicates that the polarization degree of cells is closely related to the number of micropillar arrays on the circular geometric substrate. In addition, flow cytometry demonstrates that the circular substrate reduced the transition from resting/gap 1 phase (G0/G1) to synthesis phase (S phase), thereby decreasing DNA synthesis and proliferation, reminding a potential method for treatment strategy. More importantly, the circular adhesion substrate influences the integrin signaling pathway, which has a potential application and research prospect in the treatment of melanoma.

Involvement of PDGFR-integrin interactions in the regulation of anoikis resistance in glioblastoma progression.

The interactions between platelet-derived growth factor/PDGF receptor and integrin signaling are crucial for cells to respond to extracellular stimuli. Integrin interactions with PDGFR within the lipid rafts activate downstream cellular signaling pathways that regulate cell proliferation, cell migration, cell differentiation, and cell death processes. The mechanisms underlying PDGFR activation mediated receptor internalization, interactions with other cell-surface receptors, particularly extracellular matrix receptors, integrins, and how these cellular mechanisms switch on anchorage-independent cell survival, leading to anoikis resistance are discussed. The role of regulatory molecules such as noncoding RNAs, that can modulate several molecular and cellular processes, including autophagy, in the acquisition of anoikis resistance is also discussed. Overall, the review provides a new perspective on a complex interplay of regulatory cellular machineries involving autophagy, noncoding RNAs and cellular mechanisms of PDGFR activation, PDGFR-integrin interactions, and involvement of lipids rafts in the acquisition of anoikis resistance that regulates glioblastoma progression along with potential future strategies to develop novel therapeutics for glioblastoma multiforme.

Single-nucleus and spatial transcriptomics of paediatric ovary: Molecular insights into the dysregulated signalling pathways underlying premature ovarian insufficiency in classic galactosemia.

Classic galactosemia (CG) is an inborn error of galactose metabolism caused by mutations in the GALT gene. Premature ovarian insufficiency (POI) is a later complication that affects 80% of women with CG due to a significant decline in ovarian reserve (primordial follicle pool). The definite mechanisms underlying the early onset of POI in CG patients are not fully understood. In this study, we performed single-nucleus RNA sequencing (snRNA-seq) and spatial transcriptomics on ovary tissue biopsies from prepubertal girls diagnosed with CG to investigate dynamic changes in gene expression and altered signalling pathways in granulosa cells, oocytes, and stromal cells. We generated single-nucleus and spatial transcriptomics atlas of human ovaries from prepubertal girls diagnosed with and without CG. snRNA-seq profiling of the paediatric ovary revealed a diverse ovarian microenvironment with seven distinct major cell types. Our transcriptomic analysis revealed an increase in the expression of several endoplasmic reticulum stress and oxidative stress associated genes, which can promote apoptosis of granulosa cells in CG. PTEN/PI3K/AKT signalling, which is crucial for primordial follicle activation and survival was dysregulated as supported by upregulated PTEN transcripts and a significant reduction in phospho-AKT levels in the granulosa cells and oocytes. We also found a marked increase in expression of phospho-H2A.X, LC3A/B and CASP9 in the primordial follicles of CG ovaries suggesting DNA damage, autophagy, and accelerated follicular atresia. Furthermore, we noticed genes participating in extracellular matrix organisation, integrin and gap junction signalling, essential for structural support of the ovarian stroma were profoundly altered. Our findings provide molecular insights into the dysregulated cellular signalling pathways essential for primordial follicle growth and survival that can explain the etiology of POI in CG patients. This study has implications in the development of future therapeutic interventions to preserve ovarian function and promote femalereproductive health. Created a comprehensive single-nucleus transcriptomic atlas and spatial landscape of paediatric ovary tissue from prepubertal girls diagnosed with classic galactosemia (CG). Our transcriptomic analysis revealed activation of genes associated with ER-stress signalling, oxidative stress response and ATM signalling/DNA damage response as shown by significant increase in expression of p-EIF2A, p-H2A.X and LC3A/B in the primordial follicles of CG ovary. PTEN/PI3K/AKT signalling pathways was dysregulated evidenced by a significant reduction in phospho-AKT expression in the primordial follicles of CG ovary, suggesting impaired follicle activation and survival.

Kindlin-2 regulates the oncogenic activities of integrins and TGF-β in triple-negative breast cancer progression and metastasis

Kindlin-2, an adapter protein, is dysregulated in various human cancers, including triple-negative breast cancer (TNBC), where it drives tumor progression and metastasis by influencing several cancer hallmarks. One well-established role of Kindlin-2 involves the regulation of integrin signaling, achieved by directly binding to the cytoplasmic tail of the integrin β subunit. In this study, we present novel insights into Kindlin-2’s involvement in stabilizing the β1-Integrin:TGF-β type 1 receptor (TβRI) complexes, acting as a physical bridge that links β1-Integrin to TβRI. Loss of Kindlin-2 results in the degradation of this protein complex, leading to the inhibition of downstream oncogenic pathways. We used a diverse range of in vitro assays, including CRISPR/Cas9 gene editing, cell migration, 3D-tumorsphere formation and invasion, solid binding, co-immunoprecipitation, cell adhesion and spreading assays, as well as western blot and flow cytometry analyses, utilizing MDA-MB-231 and 4T1 TNBC cell lines. Additionally, preclinical in vivo mouse models of TNBC tumor progression and metastasis were employed to substantiate our findings. Our studies established the direct interaction between Kindlin-2 and β1-Integrin and between Kindlin-2 and TβRI. Disruption of these interactions, via CRISPR/Cas9-mediated knockout of Kindlin-2, led to the degradation of β1-Integrin and TβRI, resulting in the inhibition of oncogenic pathways downstream of both proteins, subsequently hindering tumor growth and metastasis. Treatment of Kindlin-2-deficient cells with the proteasome inhibitor MG-132 restored the expression of both β1-Integrin and TβRI. Furthermore, the rescue of Kindlin-2 expression reinstated their oncogenic activities in vitro and in vivo, while Kindlin-2 lacking domains involved in the interaction of Kindlin-2 with β1-Integrin or TβRI did not. This study identifies a novel function of Kindlin-2 in stabilizing the β1-Integrin:TβRI complexes and regulating their downstream oncogenic signaling. The translational implications of these findings are substantial, potentially unveiling new therapeutically targeted pathways crucial for the treatment of TNBC tumors.

β2 integrins impose a mechanical checkpoint on macrophage phagocytosis

Phagocytosis is an intensely physical process that depends on the mechanical properties of both the phagocytic cell and its chosen target. Here, we employed differentially deformable hydrogel microparticles to examine the role of cargo rigidity in the regulation of phagocytosis by macrophages. Whereas stiff cargos elicited canonical phagocytic cup formation and rapid engulfment, soft cargos induced an architecturally distinct response, characterized by filamentous actin protrusions at the center of the contact site, slower cup advancement, and frequent phagocytic stalling. Using phosphoproteomics, we identified β2 integrins as critical mediators of this mechanically regulated phagocytic switch. Macrophages lacking β2 integrins or their downstream effectors, Talin1 and Vinculin, exhibited specific defects in phagocytic cup architecture and selective suppression of stiff cargo uptake. We conclude that integrin signaling serves as a mechanical checkpoint during phagocytosis to pair cargo rigidity to the appropriate mode of engulfment.

An interpretable deep learning framework identifies proteomic drivers of Alzheimer's disease.

Alzheimer's disease (AD) is the leading neurodegenerative pathology in aged individuals, but many questions remain on its pathogenesis, and a cure is still not available. Recent research efforts have generated measurements of multiple omics in individuals that were healthy or diagnosed with AD. Although machine learning approaches are well-suited to handle the complexity of omics data, the models typically lack interpretability. Additionally, while the genetic landscape of AD is somewhat more established, the proteomic landscape of the diseased brain is less well-understood. Here, we establish a deep learning method that takes advantage of an ensemble of autoencoders (AEs) - EnsembleOmicsAE-to reduce the complexity of proteomics data into a reduced space containing a small number of latent features. We combine brain proteomic data from 559 individuals across three AD cohorts and demonstrate that the ensemble autoencoder models generate stable latent features which are well-suited for downstream biological interpretation. We present an algorithm to calculate feature importance scores based on the iterative scrambling of individual input features (i.e., proteins) and show that the algorithm identifies signaling modules (AE signaling modules) that are significantly enriched in protein-protein interactions. The molecular drivers of AD identified within the AE signaling modules derived with EnsembleOmicsAE were missed by linear methods, including integrin signaling and cell adhesion. Finally, we characterize the relationship between the AE signaling modules and the age of death of the patients and identify a differential regulation of vimentin and MAPK signaling in younger compared with older AD patients.

Peripheral glia and neurons jointly regulate activity-induced synaptic remodeling at the Drosophila neuromuscular junction.

In the nervous system, reliable communication depends on the ability of neurons to adaptively remodel their synaptic structure and function in response to changes in neuronal activity. While neurons are the main drivers of synaptic plasticity, glial cells are increasingly recognized for their roles as active modulators. However, the underlying molecular mechanisms remain unclear. Here, using Drosophila neuromuscular junction as a model system for a tripartite synapse, we show that peripheral glial cells collaborate with neurons at the NMJ to regulate activity-induced synaptic remodeling, in part through a protein called shriveled (Shv). Shv is an activator of integrin signaling previously shown to be released by neurons during intense stimulation at the fly NMJ to regulate activity-induced synaptic remodeling. We demonstrate that Shv is also present in peripheral glia, and glial Shv is both necessary and sufficient for synaptic remodeling. However, unlike neuronal Shv, glial Shv does not activate integrin signaling at the NMJ. Instead, it regulates synaptic plasticity in two ways: 1) maintaining the extracellular balance of neuronal Shv proteins to regulate integrin signaling, and 2) controlling ambient extracellular glutamate concentration to regulate postsynaptic glutamate receptor abundance. Loss of glial cells showed the same phenotype as loss of Shv in glia. Together, these results reveal that neurons and glial cells homeostatically regulate extracellular Shv protein levels to control activity-induced synaptic remodeling. Additionally, peripheral glia maintains postsynaptic glutamate receptor abundance and contribute to activity-induced synaptic remodeling by regulating ambient glutamate concentration at the fly NMJ.

Influence of dexamethasone-induced matrices on the TM transcriptome

Pathologic bidirectional interactions between the extracellular matrix (ECM) and cells within the human trabecular meshwork (hTM) contribute to ocular hypertension. An in vitro model is needed to study these cell-matrix interactions and their effect on outflow homeostasis. This study aimed to determine whether pathogenic ECM derived from dexamethasone (DEX)-treated hTM cultures induces clinically relevant glaucoma-like changes in healthy hTM cells at the transcriptional level. Corneoscleral rims from non-glaucoma donors were used to isolate primary hTM cells after validation according to the consensus recommendations for TM culture. Normal hTM cells (n = 5) were plated on a coverslip and treated with 100 nM DEX or ethanol for four weeks. These cultures were then decellularized, plated with primary hTM cells, and allowed to grow for another 72 h. RNA was extracted from these hTM cells for stranded total RNA-Seq. Sequencing libraries prepared using the Zymo-Seq RiboFree Total RNA library kit were pooled and sequenced using Illumina NovaSeq 6000. After quality control, sequence reads were aligned to the human genome build hg19. Differential expression (DE) analyses were performed using paired multi-factorial ANOVA. The expression of several DE genes associated with glaucoma (ANGPTL2, PDE7B, C22orf23, COL4A1, ADAM12, IFT122, SEMA6C) was validated using EvaGreen-based Droplet Digital PCR (ddPCR) assays. Gene ontology analyses of the DE genes were performed using the PANTHER and NDEx IQA databases, and functional analyses were performed with the DAVID Bioinformatics software. Using a cutoff of p-value <0.05 and fold change ≥2.0, our differential analysis identified 267 up- and 135 down-regulated genes in DEX-induced ECM-treated cells compared to the control. These differentially expressed genes were found to play a significant role in pathways such as cytokine and oxidative stress-induced inflammation, integrin signaling, matrix remodeling, and angiogenesis. These findings were further supported by previously performed proteomics studies using the same model. Using ddPCR, we validated the expression of seven genes associated with the risk of primary open-angle glaucoma. These results not only provide support for the pathogenic ECM model of steroid-induced glaucoma, but also demonstrate that the pathologic changes induced by this model are indeed found at the transcriptional level. These findings further demonstrate that matrix changes significantly influence cell expression profiles, which enable further understanding of the molecular mechanisms underlying glaucomatous changes in the TM. However, future studies with a larger and more diverse set of samples and longer time points are needed to confirm the utility of this model for mechanistic studies.

Cancer-associated fibroblasts confer ALK inhibitor resistance in EML4-ALK -driven lung cancer via concurrent integrin and MET signaling.

Cancer-associated fibroblasts (CAFs) are associated with tumor progression and modulate drug sensitivity of cancer cells. However, the underlying mechanisms are often incompletely understood and crosstalk between tumor cells and CAFs involves soluble secreted as well as adhesion proteins. Interrogating a panel of non-small cell lung cancer (NSCLC) cell lines driven by EML4-ALK fusions, we observed substantial CAF-mediated drug resistance to clinical ALK tyrosine kinase inhibitors (TKIs). Array-based cytokine profiling of fibroblast-derived conditioned- media identified HGF-MET signaling as a major contributor to CAF-mediated paracrine resistance that can be overcome by MET TKIs. However, 'Cell Type specific labeling using Amino acid Precursors' (CTAP)-based expression and phosphoproteomics in direct coculture also highlighted a critical role for the fibronectin-integrin pathway. Flow cytometry analysis confirmed activation of integrin β1 (ITGB1) in lung cancer cells by CAF coculture. Treatment with pharmacological inhibitors, cancer cell-specific silencing or CRISPR-Cas9-mediated knockout of ITGB1 overcame adhesion protein-mediated resistance. Concurrent targeting of MET and integrin signaling effectively abrogated CAF-mediated resistance of EML4-ALK -driven NSCLC cells to ALK TKIs in vitro . Consistently, combination of the ALK TKI alectinib with the MET TKI capmatinib and/or the integrin inhibitor cilengitide was significantly more efficacious than single agent treatment in suppressing tumor growth using an in vivo EML4-ALK -dependent allograft mouse model of NSCLC. In summary, these findings emphasize the complexity of resistance-associated crosstalk between CAFs and cancer cells, which can involve multiple concurrent signaling pathways, and illustrate how comprehensive elucidation of paracrine and juxtacrine resistance mechanisms can inform on more effective therapeutic approaches.

Fitness Screens Map State-Specific Glioblastoma Stem Cell Vulnerabilities.

Glioblastoma (GBM) is the most common and lethal primary brain tumor in adults and is driven by self-renewing glioblastoma stem cells (GSC) that persist after therapy and seed treatment-refractory recurrent tumors. GBM tumors display a high degree of intra- and intertumoral heterogeneity that is a prominent barrier to targeted treatment strategies. This heterogeneity extends to GSCs that exist on a gradient between two transcriptional states or subtypes termed developmental and injury response. Drug targets for each subtype are needed to effectively target GBM. To identify conserved and subtype-specific genetic dependencies across a large and heterogeneous panel of GSCs, we designed the GBM5K-targeted guide RNA library and performed fitness screens in a total of 30 patient-derived GSC cultures. The focused CRISPR screens identified the most conserved subtype-specific vulnerabilities in GSCs and elucidated the functional dependency gradient existing between the developmental and injury response states. Developmental-specific fitness genes were enriched for transcriptional regulators of neurodevelopment, whereas injury response-specific fitness genes were highlighted by several genes implicated in integrin and focal adhesion signaling. These context-specific vulnerabilities conferred differential sensitivity to inhibitors of β1 integrin, focal adhesion kinase, MEK, and OLIG2. Interestingly, the screens revealed that the subtype-specific signaling pathways drive differential cyclin D (CCND1 vs. CCND2) dependencies between subtypes. These data provide a biological insight and mechanistic understanding of GBM heterogeneity and point to opportunities for precision targeting of defined GBM and GSC subtypes to tackle heterogeneity. Significance: CRISPR-Cas9 screens in a panel of patient-derived glioblastoma stem cells reveal heterogeneity in genetic vulnerabilities across subtypes that have important implications for targeted and combination treatment strategies for glioblastoma.

Comprehensive exploration on the role of base excision repair genes in modulating immune infiltration in low-grade glioma

IntroductionGlioma is a brain tumour occurring in all age groups but common in adults. Despite advances in the understanding of tumours, we cannot improve the survival of the patients and do not have an appropriate biomarker for progression and prognosis prediction. The base excision repair mechanism maintains the integrity of the genome, preventing tumour formation. However, continuous chemical damage to the cells results in mutations that escape the repair mechanism and support tumour growth. The tumour microenvironment in cancer is crucial in determining the tumour growth, development, and response to treatments. The present study explored the significance of Base Excision Repair genes (BER) in modulating the tumour microenvironment. MethodsWe used the publically available data sets from the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) to explore the role of the base excision repair gene in the modulating tumour microenvironment. The data was analysed for the expression of base excision repair genes, their correlation with the immune markers, their prognostic potential, and enrichment analysis to understand the pathways they modulate in low-grade glioma (LGG) progression. ResultsThe analysis showed BER genes contribute an integral role in the overall and disease-free survival of LGG. Genes like MUTYH, PNKP, UNG and XRCC1 showed a correlation with the immune infiltration levels and a significant correlation with various immune markers associated with different immune cells, including tumour-associated macrophages. MUTYH, UNG and XRCC1 correlated with IDH1 mutation status, and functional enrichment analysis showed that these genes are enriched in several pathways like Wnt, PD-1 and Integrin signalling. ConclusionOur findings suggest that the BER genes MUTYH, PNKP, UNG and XRCC1 can potentially be prognostic biomarkers and highly correlate with the immune cells of the tumour microenvironment.

Integrin αV Inhibition by GMI, a Ganoderma Microsporum Immunomodulatory Protein, Abolish Stemness and Migration in EGFR-Mutated Lung Cancer Cells Resistant to Osimertinib.

Integrins, the receptors of the extracellular matrix, are critical in the proliferation and metastasis of cancer cells. GMI, a Ganoderma microsporum immunomodulatory protein, possesses anticancer and antivirus abilities. The object of this study is to investigate the role of GMI in the integrins signaling pathway in lung cancer cells that harbor the EGFR L858R/T790M double mutation and osimertinib-resistance. Liquid chromatography-mass spectrometry and western blot assay were used to investigate the effect of GMI on inhibiting the protein expressions of integrins in H1975 cells. The migration ability and xenograft tumor growth of H1975 were suppressed by GMI. To elucidate the role of the integrin family in lung cancer resistant to osimertinib (AZD-9291, Tagrisso), H1975 cells were used to establish the osimertinib-resistant cells, named H1975/TR cells. The expressions of Integrin αV and stemness markers were much higher in H1975/TR cells than in H1975 cells. GMI suppressed cell viability, tumor spheroid growth, and the expressions of integrin αV and β1 in H1975/TR cells. Furthermore, GMI suppressed the expressions of stemness markers and formation of tumor spheres via blocking integrin αV signaling cascade. This is the first study to reveal the novel function of GMI in constraining cancer stem cells and migration by abolishing the integrin αV-related signaling pathway in EGFR-mutated and osimertinib-resistant lung cancer cells.

Molecular Cloning, Tissue Distribution and Antiviral Immune Response of Duck Src.

As a founding member of the Src family of kinases, Src has been confirmed to participate in the regulation of immune responses, integrin signaling, and motility. Ducks are usually asymptomatic carriers of RNA viruses such as Newcastle disease virus and avian influenza virus, which can be deadly to chickens. The beneficial role of Src in modulating the immune response remains largely unknown in ducks. Here, we characterized the duck Src and found that it contains a 192-base-pair 5' untranslated region, a 1602-base-pair coding region, and a 2541-base-pair 3' untranslated region, encoding 533 amino acid residues. Additionally, duSrc transcripts were significantly activated in duck tissues infected by Newcastle disease virus compared to controls. The duSrc transcripts were notably widespread in all tissues examined, and the expression level was higher in liver, blood, lung, pancreas, and thymus. Moreover, we found the expression levels of IFN-β, NF-κB, IRF3, and Src were significantly increased in DEFs after infection with 5'ppp dsRNA, but there was no significant difference before and after treatment in DF1 cells. Furthermore, overexpression of duSrc followed by stimulation with 5'ppp dsRNA led to an elevation of IFN-β levels. The SH3 and PTKc domains of duSrc contributed to promoting the activity of IFN-β and NF-κB in DEFs stimulated by 5'ppp dsRNA.

Abstract Mo047: DNA METHYLATION AND TRANSCRIPTIONAL MARKERS OF MYOCARDIAL REVERSE REMODELING IN HF PATIENTS ON LVAD SUPPORT

Heart failure (HF) involves global genome modifications. Adverse structural and function remodeling that occurs in HF was initially considered to be irreversible. However, ~15% of HF patients on left ventricular assist device (LVAD) support show significant structural and functional reverse remodeling, distinguishing them as responders (R), while ~85% are non-responders (NR). DNA methylation and transcriptional changes that exert myocardial recovery is not well understood. To address this, we performed whole-genome bisulphite sequencing and RNA sequencing on paired myocardial biopsies from HF patients (n=84) before (pre-LVAD) and after LVAD unloading (post-LVAD). Post-LVAD samples showed activation of pathways including TGFβ signaling, PTEN and Fatty acid oxidation compared to pre. Integrating DNA methylation and transcriptomics data revealed hypomethylation (upregulation) of genes including Scaper, Frat1 and Magi1 and hypermethylation (downregulation) of Tpp3 and Icam. Overall, suggesting a unique ECM-specific stabilization pathway post-LVAD unloading. Segregating samples based on their response to LVAD unloading, pathways such as inflammation and fibrotic signaling were activated in postNR compared to preNR. Hypomethylation of Magi1 and hypermethylation of Tppp3 was observed in postNR suggesting cross-linking proteins and destabilization of microtubule formation as potential mechanisms of functional regression in NR. Conversly, postR showed activation of deubiquitination, oxidative phosphorylation and NLR signaling compared to preR. Finally, we observed integrin signaling, syndecan interaction, collagen degradation and wound healing pathways were activated in postR compared to postNR. Hypomethylation of actin cytoskeleton ( Myl12a ), microtubule/motor proteins ( Kif5b ) and tropomyosin ( Tpm3 ) were observed in postR, suggesting a plausible reverse remodeling mechanism mediated by ECM degradation and stabilization of myocardium in these patients. Western blot analysis also showed a trend towards an increase in collagen in postNR compared to postR (n=4, p=0.06). Finally, a mouse model of HF and recovery was used and pathways including ECM degradation and cardioprotective signaling were activated in mice that recovered from HF compared to mice that did not. Overall, our data suggests a unique ECM regulation pathway to contribute towards myocardial reverse remodeling in HF patients.

FAK Family Kinases: A Potential Therapeutic Target for Atherosclerosis.

Atherosclerosis (AS) is a chronic progressive inflammatory disease of the vascular wall and the primary pathological basis of cardiovascular and cerebrovascular disease. Focal adhesion kinase (FAK) and proline-rich tyrosine kinase 2 (Pyk2), two highly homologous members of the FAK family kinases, play critical roles in integrin signaling. They also serve as scaffolding proteins that contribute to the assembly of cellular signaling complexes that regulate cell survival, cell cycle progression, and cell motility. Research indicates that the FAK family kinases is involved in the gene regulation of vascular cells and that aberrant expression of this family is associated with pathological changes in vascular disease. These findings establish the FAK family kinases as a critical signaling mediator in atherosclerotic lesions and inhibition of its activity has the potential to attenuate the pathological progression of AS. This review highlights the indispensable role of the FAK family kinases in abnormal vascular smooth muscle cell proliferation, endothelial cell dysfunction, inflammation, and lipid metabolism associated with AS. We also summarize therapeutic targets against the FAK family kinases, providing valuable insights into therapeutic strategies for AS.

Afatinib plus PEM and CBDCA overcome osimertinib resistance in EGFR-mutated NSCLC with high thrombospondin-1 expression.

Osimertinib induces a marked response in non-small-cell lung cancer (NSCLC) patients harboring epidermal growth factor receptor (EGFR) gene mutations. However, acquired resistance to osimertinib remains an inevitable problem. In this study, we aimed to investigate osimertinib-resistant mechanisms and evaluate the combination therapy of afatinib and chemotherapy. We established osimertinib-resistant cell lines (PC-9-OR and H1975-OR) from EGFR-mutant lung adenocarcinoma cell lines PC-9 and H1975 by high exposure and stepwise method. Combination therapy of afatinib plus carboplatin (CBDCA) and pemetrexed (PEM) was effective in both parental and osimertinib-resistant cells. We found that expression of thrombospondin-1 (TSP-1) was upregulated in resistant cells using cDNA microarray analysis. We demonstrated that TSP-1 increases the expression of matrix metalloproteinases through integrin signaling and promotes tumor invasion in both PC-9-OR and H1975-OR, and that epithelial-to-mesenchymal transition (EMT) was involved in H1975-OR. Afatinib plus CBDCA and PEM reversed TSP-1-induced invasion ability and EMT changes in resistant cells. In PC-9-OR xenograft mouse models (five female Balb/c-Nude mice in each group), combination therapy strongly inhibited tumor growth compared with afatinib monotherapy (5 mg/kg, orally, five times per week) or CBDCA (75 mg/kg, intraperitoneally, one time per week) + PEM (100 mg/kg, intraperitoneally, one time per week) over a 28-day period. These results suggest that the combination of afatinib plus CBDCA and PEM, which effectively suppresses TSP-1 expression, may be a promising option in EGFR-mutated NSCLC patients after the acquisition of osimertinib resistance.

Integrin signalling in joint development, homeostasis and osteoarthritis.

Integrins are key regulators of cell-matrix interactions during joint developmentand joint tissue homeostasis, as well as inthe development of osteoarthritis (OA). The signalling cascades initiated by the interactions of integrins with a complex network of extracellular matrix (ECM) components and intracellular adaptor proteins orchestrate cellular responses necessary for maintaining joint tissue integrity. Dysregulated integrin signalling, triggered by matrix degradation products such as matrikines, disrupts this delicate balance, tipping the scales towards an environment conducive to OA pathogenesis. The interplay between integrin signalling and growth factor pathways further underscores the multifaceted nature of OA. Moreover, emerging insights into the role of endocytic trafficking in regulating integrin signalling add a new layer of complexity to the understanding of OA development. To harness the therapeutic potential of targeting integrins for mitigation of OA, comprehensive understanding of their molecular mechanisms across joint tissues is imperative. Ultimately, deciphering the complexities of integrin signalling will advance the ability to treat OA and alleviate its global burden.

A Single Trophoblast Layer Acts as the Gatekeeper at the Endothelial-Hematopoietic Crossroad in the Placenta.

During embryonic development the placental vasculature acts as a major hematopoietic niche, where endothelial to hematopoietic transition ensures emergence of hematopoietic stem cells (HSCs). However, the molecular mechanisms that regulate the placental hematoendothelial niche are poorly understood. Using a parietal trophoblast giant cell (TGC)-specific knockout mouse model and single-cell RNA-sequencing, we show that the paracrine factors secreted by the TGCs are critical in the development of this niche. Disruptions in the TGC-specific paracrine signaling leads to the loss of HSC population and the concomitant expansion of a KDR+/DLL4+/PROM1+ hematoendothelial cell-population in the placenta. Combining single-cell transcriptomics and receptor-ligand pair analyses, we also define the parietal TGC-dependent paracrine signaling network and identify Integrin signaling as a fundamental regulator of this process. Our study elucidates novel mechanisms by which non-autonomous signaling from the primary parietal TGCs maintain the delicate placental hematopoietic-angiogenic balance and ensures embryonic and extraembryonic development.