Extracellular Matrix Signaling Research Articles

Proteomic characteristics of lung adenocarcinoma tumors that are small but highly invasive

AbstractBackgroundUnderstanding the molecular mechanism of early lymph node metastasis among lung adenocarcinoma (LUAD) is essential for developing novel therapeutic agents. Proteomic studies helped generate molecular landscape for LUAD. However, the molecular basis of early lymph node metastases remains unknown in patients with LUAD.MethodsSurgically resected LUAD tissues and paired normal tissues were selected from 25 patients with stage pT1bN2M0 (group of metastases [GM]) and 27 patients with stage T2b‐3N0M0 (group of large primary focus, GL) who had not undergone any anti‐tumor treatment. 4D‐Label‐free proteomics sequencing was performed among these tissues. The clinicopathological information was retrieved from the electronic medical record system in Guangdong Provincial People's Hospital.ResultsCompared with GL tumor tissue, 89 upregulated and 155 downregulated proteins were identified in GM tumor tissue. Upregulated proteins of GM were enriched in the ECM‐receptor interaction and PI3K‐AKT pathway under Kyoto Encyclopedia of Genes and Genomes enrichment analysis. And then, the median disease‐free survival (DFS) of GM phenotype patients was used as the cut‐off value, and GM was divided into two groups with significantly different survival outcomes (DFS good vs. DFS Poor: DFS: p < 0.0001; overall survival: p = 0.0017). All members of the Microchromosome maintenance protein family were highly expressed in the DFS‐poor group, especially MCM2. Proteome‐based stratification of LUAD revealed three subtypes (S‐2, S‐2, and S‐3) related to different clinical and molecular features. S‐3 had higher catabolism‐related pathways enriched, such as amino sugar and nucleotide sugar metabolism and fructose and mannose metabolism, which has the worst prognosis (S1 vs. S2 vs. S3, RFS: p = 0.042).ConclusionsProteomics analyses revealed that the activation of the extracellular matrix and intracellular signal transduction might be the driving mechanisms for early lymph node metastasis. Higher expressed cell proliferation related pathways of early lymph node metastatic LUAD may accelerate the recurrence after curative surgery. Three proteomic subgroups of LUAD with distinct molecular and clinical characteristics were identified, the one of which characterized by enrichment of catabolism‐related pathways displayed the worst survival data.

Lactate receptor GPR81 drives breast cancer growth and invasiveness through regulation of ECM properties and Notch ligand DLL4

BackgroundThe lactate receptor GPR81 contributes to cancer development through unclear mechanisms. Here, we investigate the roles of GPR81 in three-dimensional (3D) and in vivo growth of breast cancer cells and study the molecular mechanisms involved.MethodsGPR81 was stably knocked down (KD) in MCF-7 human breast cancer cells which were subjected to RNA-seq analysis, 3D growth, in situ- and immunofluorescence analyses, and cell viability- and motility assays, combined with KD of key GPR81-regulated genes. Key findings were additionally studied in other breast cancer cell lines and in mammary epithelial cells.ResultsGPR81 was upregulated in multiple human cancer types and further upregulated by extracellular lactate and 3D growth in breast cancer spheroids. GPR81 KD increased spheroid necrosis, reduced invasion and in vivo tumor growth, and altered expression of genes related to GO/KEGG terms extracellular matrix, cell adhesion, and Notch signaling. Single cell in situ analysis of MCF-7 cells revealed that several GPR81-regulated genes were upregulated in the same cell clusters. Notch signaling, particularly the Notch ligand Delta-like-4 (DLL4), was strikingly downregulated upon GPR81 KD, and DLL4 KD elicited spheroid necrosis and inhibited invasion in a manner similar to GPR81 KD.ConclusionsGPR81 supports breast cancer aggressiveness, and in MCF-7 cells, this occurs at least in part via DLL4. Our findings reveal a new GPR81-driven mechanism in breast cancer and substantiate GPR81 as a promising treatment target.

Functional defects in cementoblasts with disrupted bone sialoprotein functional domains, in vitro

Bone sialoprotein (BSP) is a multifunctional extracellular matrix (ECM) protein present in bone and cementum. Global in vivo ablation of BSP leads to bone mineralization defects, lack of acellular cementum, and periodontal breakdown. BSP harbors three main functional domains: N-terminal collagen-binding domain, hydroxyapatite-nucleating domain, and C-terminal RGD integrin-binding signaling domain. How each of these domains contributes to BSP function(s) is not understood. We hypothesized that collagen-binding and RGD domains play distinct roles in cementoblast functions. Three CRISPR/Cas9 gene-edited cell lines were derived from control wild-type (WT) OCCM.30 murine immortalized cementoblasts: 1) deletion of the N-terminus of BSP after signal peptide, including entire collagen binding domain (Ibsp∆N-Term); 2) deletion of exon 4 (majority of collagen-binding domain; Ibsp∆Ex4); and 3) deletion of C-terminus of BSP including the integrin binding RGD domain (Ibsp∆C-Term). Compared to WT, Ibsp∆Ex4 and Ibsp∆C-Term cell lines showed reduced BSP secretion, in vitro. Abnormal cell morphology was observed in all mutant cell lines, with Ibsp∆C-Term showing highly disorganized cytoskeleton. All mutant cell lines showed significantly lower cell proliferation compared to WT at all timepoints. Ibsp∆N-Term cells showed reduced cell migration by 24 h. All mutants exhibited over 50 % significant reduced mineralization at days 6 and 10. While WT cells were largely unaffected by seeding density, mutant cells failed to mineralize at lower cell density. Mutant cell lines diverged from WT and from each other by dysregulated expression in 23 genes involved in mineralization, ECM, and cell signaling. In summary, disabling BSP functional domains led to profound and distinct changes in cementoblast cell functions, especially dysregulated gene expression and reduced mineralization, in a way did not align with a straightforward narrative where each functional domain caused specific, expected differences. Instead, the study uncovered a significant level of complexity in how different mutant forms of BSP affected cell functions, in vitro.

Dental-derived stem cells in tissue engineering: the role of biomaterials and host response.

Dental-derived stem cells (DSCs) are attractive cell sources due to their easy access, superior growth capacity and low immunogenicity. They can respond to multiple extracellular matrix signals, which provide biophysical and biochemical cues to regulate the fate of residing cells. However, the direct transplantation of DSCs suffers from poor proliferation and differentiation toward functional cells and low survival rates due to local inflammation. Recently, elegant advances in the design of novel biomaterials have been made to give promise to the use of biomimetic biomaterials to regulate various cell behaviors, including proliferation, differentiation and migration. Biomaterials could be tailored with multiple functionalities, e.g., stimuli-responsiveness. There is an emerging need to summarize recent advances in engineered biomaterials-mediated delivery and therapy of DSCs and their potential applications. Herein, we outlined the design of biomaterials for supporting DSCs and the host response to the transplantation.

Time-course of cardiac gene profiles post-acute lung injury

Abstract Patients suffering from acute lung injury (ALI) are at high risk of developing cardiac arrhythmias. In a recent study we demonstrated that bleomycin (Bleo)-induced ALI in rats exhibited significantly more spontaneous premature ventricular contractions (PVCs) from 1 to 3 weeks post induction. Although spontaneous PVCs disappeared at 4 weeks post ALI, PVCs were evoked again by electrical stimulation of the decentralized stellate ganglia in Bleo-exposed rats but not in normal rats. The molecular mechanisms underlying cardiac arrhythmia both post ALI and during the recovery of ALI remains unclear. In the current study, we aimed to utilize non-biased RNA-Seq analysis to discover the time-course changes in cardiac gene profiles both post ALI and during the recovery from ALI. We created an ALI rat model using a single tracheal instillation of bleomycin (2.5 mg/kg) with saline as a vehicle (Veh) control. Blood Troponin level was measured and compared between Veh- and Bleo-treated rats varied between W1 to Week 4 post Veh/Bleo. Cardiac tissues were harvested at W1 or W4 post Veh/Bleo for RNA-seq analysis and validation by real time RT-PCR. One week post ALI, cardiac Troponin was significantly increased in Bleo-treated rats whereas it was undetectable in Veh-treated rats. Cardiac Troponin was largely restored at W2 and was undetectable at W4 post ALI. RNA-seq analysis of the left ventricle (LV) indicated 85 downregulated and 147 upregulated genes at 1 W post ALI vs. Veh. Gene Ontology (GO) enrichment analysis demonstrated that genes related to chronic inflammatory signaling, cell adhesion signaling, and extracellular matrix (ECM) signaling pathways were upregulated at W1 post ALI, suggesting cardiac inflammation. Furthermore, genes related to oxygen carrier activity, oxygen binding and oxygen transport signaling were also significantly altered, which may be due to acute hypoxia caused by ALI. In contrast to W1, RNA-seq analysis at W4 post ALI detected a smaller number of altered genes, including 11 downregulated and 13 upregulated genes between ALI and Veh groups. Comparing these two RNA-Seq databases, 4 genes (i.e., Phactr3, Tgm1, Drd4, Selplg) were identified as changed in both the post ALI state and during the recovery from ALI. Following real time RT-PCR validation confirmed significant changes in these four gene mRNA expressions in both post ALI and during the recovery from ALI. Phactr3 was downregulated while Tgm1, Drd4 and Selplg genes were upregulated in cardiac tissues at w1 and w4 post ALI. Phactr3 gene encodes a member of the phosphatase and actin regulator protein family. Tgm1 plays an important role in stabilizing intercellular junctions in myocardial microvascular endothelial cells, by modulating β-actin filaments. Drd4 gene encodes the D4 subtype of the dopamine receptor. Selplg gene encodes a glycoprotein that regulates T lymphocytes. Future studies are needed to examine the functional roles of these genes in cardiac injury post ALI.

The Holy Grail of endometriosis biomarkers in the diagnostic process – How much would it be worth and what does it look like?

Previously, the gold standard for the diagnosis of endometriosis involved the performance of laparoscopic surgery, which allows the visualization and histological examination of the endometrial tissue. According to the latest guidelines published by the European Society of Human Reproduction and Embryology (ESHRE) in 2022, surgery is recommended only in patients with diagnostic difficulties associated with the use of non-invasive methods or in case of inappropriate or unsuccessful empirical treatment. At the same time, it is not recommended to use the measurement of biomarkers in the endometrial tissue, blood, menstrual or uterine fluids to diagnose endometriosis as the ESHRE guideline development group indicated the need of larger, multi-center prospective studies on this matter. The aim of this narrative review is to present advances in knowledge on non-invasive endometriosis diagnostic opportunities with emphasis on proteomics, the use of endometrial aspiration biopsy, iron metabolism, vitamin D-binding protein, extracellular matrix signaling pathways, epithelial−mesenchymal transformation, and other molecular pathways, together with a critical analysis of studies cited in the recent ESHRE guidelines.

IL-6 Reduces Spheroid Sizes of Osteophytic Cells Derived from Osteoarthritis Knee Joint via Induction of Apoptosis

Osteophytes in osteoarthritis (OA) joints contribute to restriction of joint movement, joint pain, and OA progression, but little is known about osteophyte regulators. Examination of gene expression related to cartilage extracellular matrix, endochondral ossification, and growth factor signaling in articular cartilage and osteophytes obtained from OA knee joints showed that several genes such as COL1A1, VCAN, BGLAP, BMP8B, RUNX2, and SOST were overexpressed in osteophytes compared with articular cartilage. Ratios of mesenchymal stem/progenitor cells, which were characterized by co-expression of CD105 and CD166, were significantly higher in osteophytic cells than articular cells. A three-dimensional culture method for cartilage and osteophyte cells was developed by modification of cultures of self-assembled spheroid cell organoids (spheroids). These spheroids cultured in the media for mesenchymal stem cells containing transforming growth factor-β3 showed characteristic morphologies and gene expression profiles of articular cartilage and osteophytes, respectively. The effects of IL-1β, tumor necrosis factor-α, and IL-6 on the spheroids of articular and osteophytic cells were studied. To the best of our knowledge, they provide the first evidence that IL-6 suppresses the spheroid size of osteophytic cells by inducing apoptosis and reducing extracellular matrix molecules. These data show that IL-6 is the suppressor of osteophyte growth and suggest that IL-6 expression and/or activity are implicated in the regulation of osteophyte formation in pathologic joints.

Comparison of Engineered Liver 3D Models and the Role of Oxygenation for Patient-Derived Tumor Cells and Immortalized Cell Lines Cocultured with Tumor Stroma in the Detection of Hepatotoxins.

In metabolically active tumors, responses of cells to drugs are heavily influenced by oxygen availability via the surrounding vasculature alongside the extracellular matrix signaling. The objective of this study is to investigate hepatotoxicity by replicating critical features of hepatocellular carcinoma (HCC). This includes replicating 3D structures, metabolic activities, and tumor-specific markers. The internal environment of spheroids comprised of cancerous human patient-derived hepatocytes using microparticles is modulated to enhance the oxygenation state and recreate cell-extracellular matrix interactions. Furthermore, the role of hepatic stellate cells in maintaining hepatocyte survival and function is explored and hepatocytes from two cellular sources (immortalized and patient-derived) to create four formulations with and without microparticles are utilized. To investigate drug-induced changes in metabolism and apoptosis in liver cells, coculture spheroids with and without microparticles are exposed to three hepatotoxic drugs. The use of microparticles increases levels of apoptotic markers in both liver models under drug treatments. This coincides with reduced levels of anti-apoptotic proteins and increased levels of pro-apoptotic proteins. Moreover, cells from different origins undergo apoptosis through distinct apoptotic pathways in response to identical drugs. This 3D microphysiological system offers a viable tool for liver cancer research to investigate mechanisms of apoptosis under different microenvironmental conditions.

Characterizing the extracellular vesicle proteomic landscape of the human airway using in vitro organotypic multi-cellular models

Extracellular vesicle (EV)-mediated intercellular communication significantly influences pulmonary cell health and disease, yet invitro methods to investigate these mechanisms are limited. We hypothesize that organotypic models of the airway can be leveraged to investigate EV-mediated intercellular signaling, focusing on EV proteomic content as a case study. Two invitro airway culture models were evaluated by mass spectrometry-based proteomics analysis: a tri-culture model consisting of alveolar epithelial, fibroblast, and lung microvascular endothelial cells and a co-culture model of alveolar epithelial and fibroblasts. EVs isolated from the tri-culture model were enriched with EV proteins regulating RNA-to-protein translation. EVs isolated from the co-culture model were enriched with EV biogenesis and extracellular matrix signaling proteins. These model-specific differences suggest that different pulmonary cell types uniquely affect EV composition and the biological pathways influenced by the EV proteome in recipient cells. These findings can inform future studies surrounding EV-related pulmonary disease pathogenesis and therapeutics.

Ecliptasaponin A attenuates renal fibrosis by regulating the extracellular matrix of renal tubular cells

Renal fibrosis is the most common manifestation of end-stage renal disease (ESRD), including diabetic kidney disease (DKD), but there is no effective treatment in renal fibrosis. Natural products are a rich source of clinical drug research and have been used in the clinical research of various diseases. In this study, we searched for traditional Chinese medicine monomers that attenuate fibrosis and assessed their effect on the fibrosis marker connective tissue growth factor (CTGF) in cells which we found ecliptasaponin A. Subsequently, we evaluated the effect of ecliptasaponin A on renal fibrosis in the classic renal fibrosis unilateral ureteral obstruction (UUO) mouse model and found that ecliptasaponin A could reduce the renal collagen fiber deposition and renal extracellular matrix (ECM) protein expression in UUO mice. In vitro, ecliptasaponin A can inhibit ECM protein expression in human kidney-2 (HK-2) cells induced by transforming growth factor-beta1 (TGFβ1). To further clarify the mechanism of ecliptasaponin A in attenuating renal fibrosis, we performed transcriptome sequencing of HK-2 cells treated with TGFβ1 and ecliptasaponin A. The functions and pathways were mainly enriched in the extracellular matrix and TGFβ signalling pathway. Matrix metalloproteinase 10 (MMP10) and matrix metalloproteinase 13 (MMP13) are the main differentially expressed genes in extracellular matrix regulation. Then, we measured MMP10 and MMP13 in the cells and found that ecliptasaponin A had a significant inhibitory effect on MMP13 expression but not on MMP10 expression. Furthermore, we overexpressed MMP13 in HK-2 cells treated with TGFβ1 and found that MMP13 promoted HK-2 cell injury. Our findings suggest that ecliptasaponin A can attenuate renal fibrosis, which may provide a new method for treating renal fibrosis clinically.

Joining forces: crosstalk between mechanosensitive PIEZO1 ion channels and integrin-mediated focal adhesions.

Both integrin-mediated focal adhesions (FAs) and mechanosensitive ion channels such as PIEZO1 are critical in mechanotransduction processes that influence cell differentiation, development, and cancer. Ample evidence now exists for regulatory crosstalk between FAs and PIEZO1 channels with the molecular mechanisms underlying this process remaining unclear. However, an emerging picture is developing based on spatial crosstalk between FAs and PIEZO1 revealing a synergistic model involving the cytoskeleton, extracellular matrix (ECM) and calcium-dependent signaling. Already cell type, cell contractility, integrin subtypes and ECM composition have been shown to regulate this crosstalk, implying a highly fine-tuned relationship between these two major mechanosensing systems. In this review, we summarize the latest advances in this area, highlight the physiological implications of this crosstalk and identify gaps in our knowledge that will improve our understanding of cellular mechanosensing.

Prediction of cell-cell communication patterns of dorsal root ganglion cells: single-cell RNA sequencing data analysis.

Abstract JOURNAL/nrgr/04.03/01300535-202406000-00042/inline-graphic1/v/2023-10-24T010719Z/r/image-tiff Dorsal root ganglion neurons transmit peripheral somatic information to the central nervous system, and dorsal root ganglion neuron excitability affects pain perception. Dorsal root ganglion stimulation is a new approach for managing pain sensation. Knowledge of the cell-cell communication among dorsal root ganglion cells may help in the development of new pain and itch management strategies. Here, we used the single-cell RNA-sequencing (scRNA-seq) database to investigate intercellular communication networks among dorsal root ganglion cells. We collected scRNA-seq data from six samples from three studies, yielding data on a total of 17,766 cells. Based on genetic profiles, we identified satellite glial cells, Schwann cells, neurons, vascular endothelial cells, immune cells, fibroblasts, and vascular smooth muscle cells. Further analysis revealed that eight types of dorsal root ganglion neurons mediated proprioceptive, itch, touch, mechanical, heat, and cold sensations. Moreover, we predicted several distinct forms of intercellular communication among dorsal root ganglion cells, including cell-cell contact, secreted signals, extracellular matrix, and neurotransmitter-mediated signals. The data mining predicted that Mrgpra3-positive neurons robustly express the genes encoding the adenosine Adora2b (A2B) receptor and glial cell line-derived neurotrophic factor family receptor alpha 1 (GFRα-1). Our immunohistochemistry results confirmed the coexpression of the A2B receptor and GFRα-1. Intrathecal injection of the A2B receptor antagonist PSB-603 effectively prevented histamine-induced scratching behaviour in a dose-dependent manner. Our results demonstrate the involvement of the A2B receptor in the modulation of itch sensation. Furthermore, our findings provide insight into dorsal root ganglion cell-cell communication patterns and mechanisms. Our results should contribute to the development of new strategies for the regulation of dorsal root ganglion excitability.

Glial Cell Adhesion Molecule (GlialCAM) Determines Proliferative versus Invasive Cell States in Glioblastoma.

The malignant brain cancer glioblastoma (GBM) contains groups of highly invasive cells that drive tumor progression as well as recurrence after surgery and chemotherapy. The molecular mechanisms that enable these GBM cells to exit the primary mass and disperse throughout the brain remain largely unknown. Here we report using human tumor specimens and primary spheroids from male and female patients that glial cell adhesion molecule (GlialCAM), which has normal roles in brain astrocytes and is mutated in the developmental brain disorder megalencephalic leukoencephalopathy with subcortical cysts (MLC), is differentially expressed in subpopulations of GBM cells. High levels of GlialCAM promote cell-cell adhesion and a proliferative GBM cell state in the tumor core. In contrast, GBM cells with low levels of GlialCAM display diminished proliferation and enhanced invasion into the surrounding brain parenchyma. RNAi-mediated inhibition of GlialCAM expression leads to activation of proinvasive extracellular matrix adhesion and signaling pathways. Profiling GlialCAM-regulated genes combined with cross-referencing to single-cell transcriptomic datasets validates functional links among GlialCAM, Mlc1, and aquaporin-4 in the invasive cell state. Collectively, these results reveal an important adhesion and signaling axis comprised of GlialCAM and associated proteins including Mlc1 and aquaporin-4 that is critical for control of GBM cell proliferation and invasion status in the brain cancer microenvironment.SIGNIFICANCE STATEMENT Glioblastoma (GBM) contains heterogeneous populations of cells that coordinately drive proliferation and invasion. We have discovered that glial cell adhesion molecule (GlialCAM)/hepatocyte cell adhesion molecule (HepaCAM) is highly expressed in proliferative GBM cells within the tumor core. In contrast, GBM cells with low levels of GlialCAM robustly invade into surrounding brain tissue along blood vessels and white matter. Quantitative RNA sequencing identifies various GlialCAM-regulated genes with functions in cell-cell adhesion and signaling. These data reveal that GlialCAM and associated signaling partners, including Mlc1 and aquaporin-4, are key factors that determine proliferative and invasive cell states in GBM.

Irisin deficiency exacerbates diet-induced insulin resistance and cardiac dysfunction in type II diabetes in mice.

Myokine Irisin is involved in the regulation of a variety of physiological conditions, metabolism, and survival. We and others have demonstrated that recombinant irisin contributes critically to modulation of insulin resistance and the improvement of cardiac function. However, whether deletion of irisin will regulates cardiac function and insulin sensitivity in type II diabetes remains unclear. We utilized the CRISPR/Cas-9 genome-editing system to delete irisin globally in mice and high fat diet (HFD)-induced type II diabetes model. We found that irisin deficiency did not result in developmental abnormality during adult stage, which illustrates normal cardiac function and insulin sensitivity in the absence of stress. The ultrastructural analysis of the transmission electronic microscope (TEM) indicated that deletion of irisin did not change the morphology of mitochondria in myocardium. Gene expression profiling showed that several key signaling pathways related to integrin signaling, extracellular matrix and insulin-like growth factors signaling were coordinately downregulated by deletion of irisin. When mice were fed with a HFD for sixteen weeks, ablation of irisin in mice exposed to HFD resulted in much severer insulin resistance, metabolic derangements, profound cardiac dysfunction and hypertrophic response and remodeling as compared with wild type control. Taken together, our results indicate that the loss of irisin exacerbates insulin resistance, metabolic disorders, and cardiac dysfunction in response to a high fat diet and promoted myocardial remodeling and hypertrophic response. This evidence reveals the molecular evidence and the critical role of irisin in modulating insulin resistance and cardiac function in type II diabetes.

Impaired autophagy contributes to the aggravated deterioration of osteoarthritis articular cartilage by peroxisome proliferator-activated receptor α deficiency, associated with decreased ERK and Akt activation

BackgroundAlthough the chondroprotection of peroxisome proliferator-activated receptor α (PPARα) activation against osteoarthritis (OA) has been revealed, the regulatory mechanism of PPARα deficiency to aggravate osteoarthritic cartilage deterioration remains unclear. Here, we aimed to investigate whether and how autophagy is involved in OA pathological progression.MethodsModel of experimental OA was established using destabilization of the medial meniscus in PPARα-KO 129S4/SvJae male mice, followed by histopathological detection of articular cartilage and immunohistochemistry detection of extracellular matrix (ECM) or autophagy-related signal molecules. Meanwhile, human OA chondrocytes obtained from total knee replacement surgery patients with OA were cultured with the pretreatment of IL-1β, followed with the treatment of PPARα agonist WY14643 and the detection of related signal molecules.ResultsPPARα deficiency aggravated cartilage damage with decreased LC3B level in combination with an increase in P62 level, accompanied with reduced p-Akt and p-ERK levels in PPARα-KO mouse model of experimental OA. On the contrary, PPARα activation by WY14643 promoted ECM synthesis in IL-1β-treated human OA chondrocytes, accompanied with increased LC3B-II/I ratio and Beclin 1 level and decreased P62 and Bcl2 levels. Meanwhile, it was observed that activated ERK and Akt by PPARα activation contributed to the enhancement of autophagy and ECM synthesis in human OA chondrocytes.ConclusionsImpaired autophagy contributed to the aggravated deterioration of osteoarthritis articular cartilage by PPARα deficiency associated with the suppression of ERK and Akt, with an implication that triggering PPARα activation ought to be a potential promising therapeutic target for OA therapy.

Inhibition of integrin receptors reduces extracellular matrix levels, ameliorating benign prostate hyperplasia

Although a high prevalence of benign prostate hyperplasia (BPH) has been documented, the risk factors are poorly understood. Metabolic syndrome increases the risk of BPH. Succinylation, a type of posttranslational modification, mostly targets metabolic processes. The level of succinylation was investigated in 4 BPH patients and 4 healthy controls. Additionally, 176 patients with BPH were analyzed by using pan-antisuccinyllysine antibody blotting. TMT-labeling proteomic and sc-RNAseq Cellchat analyses were employed to identify key signaling factors involved in the development of BPH. In vivo and in vitro experiments were used to confirm the role of integrin receptors. The global succinylation level in BPH was higher than that in the healthy prostate. Positive correlations of prostate volume with IHC score sand urodynamics testing were found in large clinical cohorts. The extracellular matrix (ECM), metabolic processes and immune signaling were involved in succinylation in BPH, as indicated by using TMT-labeling proteomic analysis, and this finding was also confirmed by sc-RNAseq CellChat analysis. The proteins upregulated in SIRT5 knockout WPMY-1 cells were also enriched in the extracellular matrix and metabolic processes. More importantly, integrin receptor inhibition in a mouse model of BPH significantly ameliorated prostate hyperplasia. High levels of succinylation modifications were found in BPH, and succinylated proteins influenced the activation of the ECM. Inhibition of ECM signaling further ameliorated prostate hyperplasia in mice.

Deciphering mechanisms of cardiomyocytes and non-cardiomyocyte transformation in myocardial remodeling of permanent atrial fibrillation

IntroductionAtrial fibrillation (AF) is the most prevalent cardiac arrhythmia, and it significantly increases the risk of cardiovascular complications and morbidity, even with appropriate treatment. Tissue remodeling has been a significant topic, while its systematic transcriptional signature remains unclear in AF. ObjectivesOur study aims to systematically investigate the molecular characteristics of AF at the cellular-level. MethodsWe conducted single-nuclei RNA-sequencig (snRNA-seq) analysis using nuclei isolated from the left atrial appendage (LAA) of AF patients and sinus rhythm. Pathological staining was performed to validate the key findings of snRNA-seq. ResultsA total of 30 cell subtypes were identified among 80, 592 nuclei. Within the LAA of AF, we observed a specific subtype of dedifferentiated cardiomyocytes (CMs) characterized by reduced expression of cardiac contractile proteins (TTN and TRDN) and heightened expression of extracellular-matrix related genes (COL1A2 and FBN1). Transcription factor prediction analysis revealed that gene expression patterns in dedifferentiated CMs were primarily regulated by CEBPG and GISLI. Additionally, we identified a distinct subtype of endothelial progenitor cells (EPCs) demonstrating elevated expression of PROM1 and KDR, a population decreased within the LAA of AF. Epicardial adipocytes disclosed a reduced release of the anti-inflammatory and anti-fibrotic factor PRG4, and an augmented secretion of VEGF signals targeting CMs. Additionally, we noted accumulation of M2-like macrophages and CD8+ T cells with high pro-inflammatory score in LAA of AF. Furthermore, the analysis of intercellular communication revealed specific pathways related to AF, such as inflammation, extracellular matrix, and vascular remodeling signals. ConclusionsThis study has discovered the presence of dedifferentiated CMs, a decrease in endothelial progenitor cells, a shift in the secretion profile of adipocytes, and an amplified inflammatory response in AF. These findings could offer crucial insights for future research on AF and serve as valuable references for investigating novel therapeutic approaches for AF.

Magnetic manipulation of Fe3O4@BaTiO3 nanochains to regulate extracellular topographical and electrical cues.

Magnetic fields play an essential role in material science and biomedical engineering. Magnetic-responsive materials can be arranged orderly in matrix to realize the construction of an aligned scaffold under magnetic induction. However, a single topological cue is insufficient to activate neural tissue regeneration, demanding more cues to promote regeneration synergistically, such as electrical stimulation and a biomimetic matrix. Herein, we propose one-dimensional (1D) magnetoelectric Fe3O4@BaTiO3 nanochains with controllable lengths under the regulation of a magnetic field. These nanochains can be oriented in the biomimetic hydrogel under magnetic guidance and induce the hydrogel microfiber to align along the direction of the nanochains, which is beneficial for cell-oriented outgrowth. This aligned hydrogel enabled wireless electrical stimulation mediated by magnetoelectric nanochains under magnetic stimulation, thereby activating the voltage-gated ion channel. Consequently, topological and electrical cues in this multifunctional biomimetic hydrogel synergistically enhanced the expression of neural functional proteins, facilitating synapse remodeling and neural regeneration. Predictably, the construction of multifunctional hydrogels based on low-cost and facile synthesis of magnetoelectric nanochains is an emerging patient-friendly and effective therapeutic strategy for neural or other tissue regeneration. STATEMENT OF SIGNIFICANCE: A facile and controllable magnetic strategy is established to manipulate 1D nanomaterial growth, matrix topography, and wireless electrical stimulation of cells. First, the magnetic-assisted interface co-assembly was used to control the length of Fe3O4@BaTiO3 nanochains with enhanced magnetoelectric effect. Then, the motion of the magnetic-induced nanochains guided the orientation of nanofibers in a 3D biomimetic hydrogel matrix. Finally, wireless electrical signals and topological cues in the biomimetic matrix synergistically promoted orderly aligned cell outgrowth and membrane depolarization by Ca2+ influx, thus enhancing nerve cell synaptic plasticity and functional expression. Consequently, this work provides a conceptual strategy from material design to extracellular matrix signal manipulation and synergistic induction of tissue regeneration.

Col1a2-Deleted Mice Have Defective Type I Collagen and Secondary Reactive Cardiac Fibrosis with Altered Hypertrophic Dynamics.

The adult cardiac extracellular matrix (ECM) is largely comprised of type I collagen. In addition to serving as the primary structural support component of the cardiac ECM, type I collagen also provides an organizational platform for other ECM proteins, matricellular proteins, and signaling components that impact cellular stress sensing in vivo. Here we investigated how the content and integrity of type I collagen affect cardiac structure function and response to injury. We generated and characterized Col1a2-/- mice using standard gene targeting. Col1a2-/- mice were viable, although by young adulthood their hearts showed alterations in ECM mechanical properties, as well as an unanticipated activation of cardiac fibroblasts and induction of a progressive fibrotic response. This included augmented TGFβ activity, increases in fibroblast number, and progressive cardiac hypertrophy, with reduced functional performance by 9 months of age. Col1a2-loxP-targeted mice were also generated and crossed with the tamoxifen-inducible Postn-MerCreMer mice to delete the Col1a2 gene in myofibroblasts with pressure overload injury. Interestingly, while germline Col1a2-/- mice showed gradual pathologic hypertrophy and fibrosis with aging, the acute deletion of Col1a2 from activated adult myofibroblasts showed a loss of total collagen deposition with acute cardiac injury and an acute reduction in pressure overload-induce cardiac hypertrophy. However, this reduction in hypertrophy due to myofibroblast-specific Col1a2 deletion was lost after 2 and 6 weeks of pressure overload, as fibrotic deposition accumulated. Defective type I collagen in the heart alters the structural integrity of the ECM and leads to cardiomyopathy in adulthood, with fibroblast expansion, activation, and alternate fibrotic ECM deposition. However, acute inhibition of type I collagen production can have an anti-fibrotic and anti-hypertrophic effect.

Coordination between ECM and cell-cell adhesion regulates the development of islet aggregation, architecture, and functional maturation.

Pancreatic islets are three-dimensional cell aggregates consisting of unique cellular composition, cell-to-cell contacts, and interactions with blood vessels. Cell aggregation is essential for islet endocrine function; however, it remains unclear how developing islets establish aggregation. By combining genetic animal models, imaging tools, and gene expression profiling, we demonstrate that islet aggregation is regulated by extracellular matrix signaling and cell-cell adhesion. Islet endocrine cell-specific inactivation of extracellular matrix receptor integrin β1 disrupted blood vessel interactions but promoted cell-cell adhesion and the formation of larger islets. In contrast, ablation of cell-cell adhesion molecule α-catenin promoted blood vessel interactions yet compromised islet clustering. Simultaneous removal of integrin β1 and α-catenin disrupts islet aggregation and the endocrine cell maturation process, demonstrating that establishment of islet aggregates is essential for functional maturation. Our study provides new insights into understanding the fundamental self-organizing mechanism for islet aggregation, architecture, and functional maturation.