Fibulin Research Articles

EFEMP1 contributes to light-dependent ocular growth in zebrafish.

Myopia (short-sightedness) is the most common ocular disorder. It generally develops after over-exposure to aberrant visual environments, disrupting emmetropization mechanisms that should match eye growth with optical power. A pre-screening of strongly associated myopia-risk genes identified through human genome-wide association studies implicates efemp1 in myopia development, but how this gene impacts ocular growth remains unclear. Here, we modify efemp1 expression specifically in the retina of zebrafish. We found that under normal lighting, efemp1 mutants developed axial myopia, enlarged eyes, reduced spatial vision and altered retinal function. However, under myopia-inducing dark-rearing, compared to control fish, mutants remained emmetropic and showed changes in retinal function. Efemp1 modification changed the expression of efemp1, egr1, tgfb1a, vegfab and rbp3 genes in the eye, and changed the inner retinal distributions of myopia-associated EFEMP1, TIMP2 and MMP2 proteins. Efemp1 modification also impacted dark-rearing-induced responses of vegfab and wnt2b genes and above-mentioned myopia-associated proteins. Together, we provided robust evidence that light-dependent ocular growth is regulated by efemp1.

Identification of extracellular matrix proteins in plasma as a potential biomarker for intervertebral disc degeneration.

Recently, there has been significant focus on extracellular matrix proteolysis due to its importance in the pathological progression of intervertebral disc degeneration (IVDD). The present study investigates the circulating levels of extracellular matrix proteins in the plasma of IVDD and determines their potential relevance as biomarkers in disc degeneration. Global proteomic analysis was performed in the plasma samples of 10 healthy volunteers (HV) and 10 diseased subjects (DS) after depletion of highly abundant proteins such as albumin and IgG. We identified 144 and 135 matrix-associated proteins in plasma samples from healthy volunteers (HV) and patients with disc degeneration (DS), respectively. Among these, 49 of the matrix-associated proteins were identical to the proteins found in intervertebral disc (IVD) tissues retrieved from the in-house library. Applying stringent parameters, we selected 28 proteins, with 26 present in DS and 21 in HV. 19 proteins were found common between the groups, two of which-aggrecan (ACAN) and fibulin 1 (FBLN1) - showed statistically significant differences. Specifically, ACAN was up-regulated and FBLN1 was down-regulated in the DS-plasma. In particular, DS-plasma exhibited specific expression of collagen type 2a1 (COL2A1), native to the nucleus pulposus. The distinct presence of collagen type 2a1 and the elevated expression of aggrecan in IVDD plasma may serve as the basis for the development of a potential biomarker for monitoring the progression of disc degeneration.

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

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

A New Ocular Phenotype Combining Juvenile Glaucoma and Doyne Honeycomb Retinal Dystrophy (Malattia Leventinese) due to a Novel EFEMP1 Pathogenic Variant.

Doyne honeycomb retinal dystrophy (DHRD), also termed malattia leventinese (MLVT), is a dominantly inherited ocular disease characterized by the progressive accumulation of macular and peripapillary drusenoid material beneath the retinal pigment epithelium in the Bruch membrane. In all affected individuals genetically characterized to date, DHRD/MLVT is caused by a single heterozygous p.Arg345Trp missense variant in the EGF-containing fibulin-like extracellular matrix protein 1, EFEMP1. Recently, pathogenic variants in the EFEMP1 gene have also been demonstrated in several families with juvenile or adult-onset hereditary isolated glaucoma. Here, we describe a family featuring a unique phenotype of juvenile glaucoma and DHRD/MLVT caused by a novel EFEMP1 variant. Our results expand both the ocular phenotype associated with EFEMP1 variants and the molecular spectrum causing DHRD by describing the first non-p.Arg345Trp EFEMP1 pathogenic allele.

A Bioinformatics-Based Study on Methylation Alterations of the FBLN1 Gene in Hippocampal Tissue of Alzheimer's Disease Model DKO and DTG Mice.

Alzheimer's disease (AD) is characterized by progressive cognitive decline and late-stage neurobehavioral issues marked by amyloid-beta plaques and Tau protein tangles. This study aims to investigate Fibulin-1(FBLN1) gene expression in the hippocampal tissue of Presenilin-1/Presenilin-2 conditional double-knockout (DKO) and double-transgenic (DTG) mice, using single-cell sequencing and experimental methods to verify abnormal methylation status and correlation with AD. Genomic DNA from DKO and DTG mice was used for genotyping. Reduced Representation Bisulfite Sequencing (RRBS) identified 10 genes with abnormal methylation changes, with protein-protein interaction (PPI) analysis highlighting five core genes, including FBLN1. Single-cell sequencing, RT-PCR, and Western blotting (WB) were used to analyze FBLN1 mRNA and protein levels in the hippocampal tissues of early-stage and mid-stage AD DKO, DTG, and CBAC57 mice. RRBS identified 10 genes with abnormal methylation, with PPI highlighting five core genes. Single-cell sequencing showed significant FBLN1 expression in AD groups. RT-PCR and WB indicated elevated FBLN1 mRNA and protein levels in mid-stage AD DKO and DTG mice compared to CBAC57 mice, with no differences in early-stage AD DKO and CBAC57 mice. RRBS revealed hypomethylation of the FBLN1 gene in mid-stage AD DKO mice. Elevated FBLN1 expression in AD models suggests an age-dependent neurodegenerative mechanism independent of amyloid-beta deposition. This study enhances our understanding of AD's epigenetic mechanisms, which will aid targeted diagnosis, treatment, and prognosis.

Fibulin-2 is an extracellular matrix inhibitor of oligodendrocytes relevant to multiple sclerosis.

Impairment of oligodendrocytes and myelin contributes to neurological disorders including multiple sclerosis (MS), stroke, and Alzheimer's disease. Regeneration of myelin (remyelination) decreases the vulnerability of demyelinated axons, but this repair process commonly fails with disease progression. A contributor to inefficient remyelination is the altered extracellular matrix (ECM) in lesions, which remains to be better defined. We have identified fibulin-2 (FBLN2) as a highly upregulated ECM component in lesions of MS and stroke and in proteome databases of Alzheimer's disease and traumatic brain injury. Focusing on MS, the inhibitory role of FBLN2 was suggested in the experimental autoimmune encephalomyelitis (EAE) model, in which genetic FBLN2 deficiency improved behavioral recovery by promoting the maturation of oligodendrocytes and enhancing remyelination. Mechanistically, when oligodendrocyte progenitors were cultured in differentiation medium, FBLN2 impeded their maturation into oligodendrocytes by engaging the Notch pathway, leading to cell death. Adeno-associated virus deletion of FBLN2 in astrocytes improved oligodendrocyte numbers and functional recovery in EAE and generated new myelin profiles after lysolecithin-induced demyelination. Collectively, our findings implicate FBLN2 as a hitherto unrecognized injury-elevated ECM, and a therapeutic target, that impairs oligodendrocyte maturation and myelin repair.

Mechanism of Fuzheng Huayu Tablets against hepatic fibrosis based on transcriptome and single-cell sequencing

This study aimed to investigate the role of macrophage polarization in the treatment of liver fibrosis by Fuzheng Huayu Tablets(FZHY) through single-cell, transcriptome sequencing and in vitro and in vivo experiments. Liver fibrosis-related datasets, transcriptomic datasets, and single-cell sequencing datasets were obtained from the Gene Expression Omnibus(GEO) database to screen differential genes. Liver fibrosis-related genes were obtained from GeneCards, DisGeNET, NCBI, PharmgKB, TTD and OMIM databases. Macrophage polarization-related genes were obtained from the GeneCards database. The above three gene sets were intersected to construct a protein-protein interaction(PPI) network. Cytoscape software was used to screen core proteins, and the expression pattern of core proteins was visualized by single-cell sequencing. A mouse model of liver fibrosis was constructed using carbon tetrachloride(CCl_4). Hematoxylin-eosin(HE) staining and Masson staining were used to observe the pathological morphology of liver tissues. The expressions of α-smooth muscle actin(α-SMA) and transforming growth factor-β1(TGF-β1) were detected by immunohistochemistry. The levels of alanine aminotransferase(ALT) and aspartate aminotransferase(AST) were detected by colorimetry. The le-vels of inflammatory factors in serum were detected by the enzyme-linked immunosorbent assay(ELISA). Furthermore, the expressions of α-SMA, TGF-β1, cluster of differentiation 86(CD86) and thrombospondin 1(THBS1) in liver tissues were detected by Western blot(WB). Lipopolysaccharide(LPS) was used to stimulate RAW264.7 cells to construct the M1 macrophage polarization model. The cell counting kit-8(CCK-8) method was used to detect cell viability. WB was used to detect the protein expressions of CD86 and THBS1 in cells, and the messenger ribonucleic acid(mRNA) expression levels of tumor necrosis factor-α(TNF-α) and interleukin(IL)-1β by real-time fluorescent quantitative reverse transcription polymerase chain reaction(RT-qPCR). The results showed that a total of 26 potential genes related to the polarization of liver fibrosis macrophages were obtained, and 10 core proteins related to the polarization of liver fibrosis macrophages such as THBS1, lumican(LUM) and fibulin-5(FBLN5) were screened. Single-cell data analysis indicated that THBS1, ranking highest, may be expressed by M1 macrophages. Animal experiments demonstrated that FZHY reduced inflammatory cell infiltration and collagen deposition in CCl_4-induced mouse liver, relieved liver injury and inflammation levels, and inhibited the expressions of α-SMA, TGF-β1, CD86, and THBS1 proteins. Cell experiments revealed that FZHY significantly reduced intracellular expression of CD86 and THBS1 proteins and mRNA levels of TNF-α and IL-1β. In conclusion, FZHY may ameliorate liver fibrosis by inhibiting THBS1 protein expression, suppressing M1 macrophage polarization, and reducing inflammation.

Replication study identified EFEMP1 association with varicose vein predisposition among Indians

BackgroundVaricose vein is a chronic condition that affects the lower extremities of the human body. Several factors have been implicated in the development of this disease, viz age, gender, weight, height and prolonged standing. Recently, genome-wide studies have identified genetic biomarkers that are associated with varicose veins in different ethnic groups. Such genetic studies are lacking in South Asians specifically in Indians where the prevalence of varicose veins is high, and it is important to replicate these variants in the stated population. The study aimed to replicate the association of genetic variants associated with varicose veins in this target population, which were found to be associated with the other ethnic groups.MethodologyThe studied cohort is of the Indian population comprising unrelated 104 varicose veins cases and 448 non-varicose vein controls. The samples were genotyped using the Illumina Global Screening Array. Using the genomic data from UK BioBank and 23andMe studied cohorts; eight genetic variants were selected to replicate in our dataset. The allelic association was performed to identify the effective allele and risk was estimated using odds ratio and p-value as level of significance. Multifactor Dimensionality Reduction was used to estimate the cumulative effect of variants in Indians.ResultVariant rs3791679 of EFEMP1 was found to be associated with varicose veins in Indians. After observing the association of the EFEMP1 with varicose veins, we further ensued to identify all genetic variants within EFEMP1 to uncover the additional variants associated with this trait. Interestingly, we identified six new variants of EFEMP1 gene that have shown association. Moreover, the cumulative effect of all associated variations was estimated and the risk was 2.7 times higher in cases than controls whereas independently their effect ranges from 0.37–1.58.ConclusionThis study identifies EFEMP1 as a potential gene related to the risk of varicose veins in Indians. It also highlights that evaluating the maximum number of variants of a gene rather than focusing solely on replicating single variations offers a more comprehensive and nuanced understanding of the genetic factors contributing to a complex trait like varicose veins.

Stop codon variant in EFEMP1 is associated with primary open-angle glaucoma due to impaired regulation of aqueous humor outflow

It is known that the actin cytoskeleton and its associated cellular interactions in the trabecular meshwork (TM) and juxtacanalicular tissues mainly contribute to the formation of resistance to aqueous outflow of the eye. Fibulin-3, encoded by EFEMP1 gene, has a role in extracellular matrix (ECM) modulation, and interacts with enzymatic ECM regulators, but the effects of fibulin-3 on TM cells has not been explored. Here, we report a stop codon variant (c.T1480C, p.X494Q) of EFEMP1 that co-segregates with primary open angle glaucoma (POAG) in a Chinese pedigree. In the human TM cells, overexpression of wild-type fibulin-3 reduced intracellular actin stress fibers formation and the extracellular fibronectin levels by inhibiting Rho/ROCK signaling. TGFβ1 up-regulated fibulin-3 protein levels in human TM cells by activating Rho/ROCK signaling. In rat eyes, overexpression of wild-type fibulin-3 decreased the intraocular pressure and the fibronectin expression of TM, however, overexpression of mutant fibulin-3 (c.T1480C, p.X494Q) showed opposite effects in cells and rat eyes. Taken together, the EFEMP1 variant may impair the regulatory capacity of fibulin-3 which has a role for modulating the cell contractile activity and ECM synthesis in TM cells, and in turn may maintain normal resistance of aqueous humor outflow. This study contributes to the understanding of the important role of fibulin-3 in TM pathophysiology and provides a new possible POAG therapeutic approach.

Fibulin 1, targeted by microRNA-24-3p, promotes cell proliferation and migration in vascular smooth muscle cells, contributing to the development of atherosclerosis in APOE-/- mice

Extracellular matrix (ECM) and vascular smooth muscle cells (VSMCs) are the main components of atherosclerosis (AS) plaque. VSMCs participate in plaque formation through phenotypic transformation. The complex interplay between ECM and VSMCs plays vital roles in the progression of AS throughout the disease. An in-depth investigation into the functions of ECM-related molecules in VSMC development might contribute to deciphering the complexity of AS pathogenesis. In this study, the roles and molecular mechanisms of the ECM-related molecule Fibulin-1 (FBLN1) in the development of AS and VSMCs were explored using RNA sequencing, bioinformatics analysis, and cell experiments. Furthermore, the expression of FBLN1, as determined by western blot analysis, immunohistochemistry, and real-time quantitative PCR, was significantly increased in AS vascular samples compared to normal vascular samples. Silencing the FBLN1 through AAV viral injection in mice revealed an improvement in AS. Functional analyses revealed that FBLN1 promoted VSMC proliferation, migration, and wound healing. Combined with RNA sequencing and TargetScan7.2 prediction data, 22 microRNAs (miRNAs) were found to have the potential for direct interaction with the FBLN1 3′UTR in VSMCs. Among these 22 miRNAs, it was demonstrated that microRNA-24-3p (miR-24-3p) could negatively regulate FBLN1 expression by directly binding to the FBLN1 3′UTR. Moreover, miR-24-3p inhibited cell proliferation, migration, and wound healing, and suppressed the expression of Ki67, matrix metalloproteinase-2 and −9 (MMP2/9) by targeting FBLN1 in VSMCs. Meanwhile, inhibition of FBLN1 expression could restrain VSMC phenotypic transformation. In conclusion, miR-24-3p inhibited VSMC proliferation and migration by targeting FBLN1. Additionally, multiple miRNAs with the potential to interact with the FBLN1 3′UTR were identified. These findings might deepen our understanding of ECM gene regulatory networks and the complex etiology of AS.

Genetic architecture of anterior abdominal wall hernias

To analyze genome-wide studies devoted to polymorphisms of factors of anterior abdominal wall hernias, to study the association of the most common polymorphism In Russian population. Searching for literature data was carried out in the RSCI and PubMed databases. We enrolled national and foreign reports. The study on Russian population included 577 people. We found 5 genome-wide studies performed by foreign authors. We identified the loci responsible for genetic predisposition to inguinal hernias: WT1, EFEMP1, EBF2 and ADAMTS6. The Japanese scientists revealed an important role of loci TGFB2, RNA5SP214/VGLL2, LOC646588, HMCN2, ATP5F1CP1/CDKN3. In other studies, loci 1q41 (ZC3H11B), 2p16.1 (EFEMP1), 6p22.1 (MHC region), 7q33 (CALD1) and 11p13 (WT1) determined different hernias. The EFEMP1 gene polymorphism was among genes most associated with anterior abdominal wall hernias in all studies. Analysis of this polymorphism In Russian population revealed significant association with anterior abdominal wall hernias. The obtained data on target correction of DNA chains can significantly reduce the incidence of anterior abdominal wall hernias. In turn, this will significantly reduce the cost of surgical treatment and risk of complications with recurrences of hernias. Moreover, identifying the most associated polymorphisms may be valuable to determine the most appropriate surgical treatment.

A Zebrafish Mutant in the Extracellular Matrix Protein Gene efemp1 as a Model for Spinal Osteoarthritis.

Osteoarthritis is a degenerative articular disease affecting mainly aging animals and people. The extracellular matrix protein Efemp1 was previously shown to have higher turn-over and increased secretion in the blood serum, urine, and subchondral bone of knee joints in osteoarthritic patients. Here, we use the zebrafish as a model system to investigate the function of Efemp1 in vertebrate skeletal development and homeostasis. Using in situ hybridization, we show that the efemp1 gene is expressed in the brain, the pharyngeal arches, and in the chordoblasts surrounding the notochord at 48 hours post-fertilization. We generated an efemp1 mutant line, using the CRISPR/Cas9 method, that produces a severely truncated Efemp1 protein. These mutant larvae presented a medially narrower chondrocranium at 5 days, which normalized later at day 10. At age 1.5 years, µCT analysis revealed an increased tissue mineral density and thickness of the vertebral bodies, as well as a decreased distance between individual vertebrae and ruffled borders of the vertebral centra. This novel defect, which has, to our knowledge, never been described before, suggests that the efemp1 mutant represents the first zebrafish model for spinal osteoarthritis.

Remodeling of the Cardiac Extracellular Matrix Proteome During Chronological and Pathological Aging

Impaired extracellular matrix (ECM) remodeling is a hallmark of many chronic inflammatory disorders that can lead to cellular dysfunction, aging, and disease progression. The ECM of the aged heart and its effects on cardiac cells during chronological and pathological aging are poorly understood across species. For this purpose, we first used mass spectrometry-based proteomics to quantitatively characterize age-related remodeling of the left ventricle (LV) of mice and humans during chronological and pathological (Hutchinson-Gilford progeria syndrome (HGPS)) aging. Of the approximately 300 ECM and ECM-associated proteins quantified (named as Matrisome), we identified 13 proteins that were increased during aging, including lactadherin (MFGE8), collagen VI α6 (COL6A6), vitronectin (VTN) and immunoglobulin heavy constant mu (IGHM), whereas fibulin-5 (FBLN5) was decreased in most of the data sets analyzed. We show that lactadherin accumulates with age in large cardiac blood vessels and when immobilized, triggers phosphorylation of several phosphosites of GSK3B, MAPK isoforms 1, 3, and 14, and MTOR kinases in aortic endothelial cells (ECs). In addition, immobilized lactadherin increased the expression of pro-inflammatory markers associated with an aging phenotype. These results extend our knowledge of the LV proteome remodeling induced by chronological and pathological aging in different species (mouse and human). The lactadherin-triggered changes in the proteome and phosphoproteome of ECs suggest a straight link between ECM component remodeling and the aging process of ECs, which may provide an additional layer to prevent cardiac aging.

Whole-exome sequencing uncovers a novel EFEMP2 gene variant (c.C247T) associated with dominant nonsyndromic thoracic aortic aneurysm.

Thoracic aortic aneurysm (TAA) is a multifactorial disorder. Familial TAA, which is more clinically aggressive, is associated with a high risk of lethal dissection or rupture. Genetic evaluation can provide TAA patients with personalized treatment and help in predicting risk to family members. The purpose of this investigation was to report a likely pathogenic variant in the EFEMP2 gene that may contribute to TAA in a family with a documented history of the condition. In the index patient, the causative genetic predisposition was identified using whole-exome sequencing. The potential likely pathogenic effect of the candidate variant was further analyzed through bioinformatics analysis, homology modeling, and molecular docking. The results revealed a likely pathogenic heterozygous variant, c.247C>T p.Arg83Cys, in exon 4 of the EFEMP2 gene (NM_016938), which was predicted to have disease-causing effects by MutationTaster, PROVEAN, SIFT, and CADD (phred score = 27.6). In this study, a likely pathogenic variant in the EFEMP2 gene was identified in an Iranian family with a dominant pattern of autosomal inheritance of TAA. This finding underscores the importance of conducting molecular genetic evaluations in families with nonsyndromic TAA and the significance of early detection of at-risk family members.

The Upregulation of the FBLN1 and HS3ST4 Genes May Represent a Potential Mechanism Driving the Fibrotic Progression in Primary Myelofibrosis and Leading to Adverse Prognosis

Myelofibrosis is a group of diseases characterized by increased proliferation of bone marrow fibrous connective tissue and a decrease in hematopoietic cells, leading to impaired bone marrow hematopoietic function. Myelofibrosis includes primary myelofibrosis（PMF）, myelofibrosis secondary to polycythemia vera（post-PV MF）, and myelofibrosis secondary to essential thrombocythemia（post-ET MF）. Studies suggest that certain genes may be responsible for driving the development of myelofibrosis and causing adverse prognosis. By conducting RNA-Seq analysis, we investigated the differentially expressed genes and their impact on prognosis in primary myelofibrosis and secondary myelofibrosis. Furthermore, we analyzed the potential mechanisms driving the progression of fibrosis. Additionally, we performed a comparative analysis of the clinical features among various types of myelofibrosis. In this study, we performed transcriptome sequencing to analyze gene expression differences in 14 overt-PMF samples, 5 post-ET MF samples, and 3 post-PV MF samples.Functional and pathway analyses were conducted on these differentially expressed genes, and cluster heatmaps were used to visualize their expression patterns.Simultaneously, we performed a comparative analysis of clinical characteristics among 370 overt-PMF patients, 96 post-ET MF patients, and 52 post-PV MF patients.The study revealed that compared to post-PV MF, overt-PMF showed 81 upregulated and 2 downregulated differentially expressed genes, while compared to post-ET MF, overt-PMF displayed 19 upregulated and 3 downregulated differentially expressed genes (Figure a) (Figure b). Based on the similarity of gene expression profiles among the samples, a clustering analysis was performed (Figure c).The results demonstrated that in overt-PMF, the FBLN1 gene was significantly upregulated compared to post-PV MF and was enriched in pathways related to extracellular matrix formation and cell adhesion among the differentially expressed genes (Figure d). Additionally, the HS3ST4 gene was significantly upregulated in overt-PMF compared to post-ET MF and was enriched in pathways related to interleukin-8 generation and regulation of cytokine production involved in inflammatory responses.In the analysis of clinical characteristics among different types of myelofibrosis patients, it was observed that overt-PMF was more prone to transform into acute leukemia compared to post-PV MF, had a higher tendency to develop transfusion dependency (Figure e), and exhibited lower hemoglobin levels and hematocrit at the time of diagnosis (Figure f). Moreover, compared to post-ET MF, overt-PMF had a higher likelihood of transforming into acute leukemia and lower platelet counts at the time of diagnosis. The research findings indicate that the expressions of FBLN1 and HS3ST4 genes are significantly upregulated in overt-PMF, and patients with overt-PMF have a worse prognosis compared to those with post-PV MF and post-ET MF. Previous studies have shown that FBLN1 is involved in extracellular matrix assembly, promoting the formation and stabilization of collagen fibers. It can also interact with integrin receptors and other cell adhesion molecules, participating in cell-extracellular matrix signaling processes. On the other hand, HS3ST4 is involved in processes such as cell adhesion, cell migration, and cell signaling. Based on these findings, it is speculated that the upregulation of FBLN1 and HS3ST4 gene expressions may potentially drive the progression of fibrosis and lead to an adverse prognosis in patients with myelofibrosis. Acknowledgement: This research was funded by the Key R&D Program of Zhejiang, No. 2022C03137; Public Technology Application Research Program of Zhejiang, China, No. LGF21H080003; Zhejiang Medical Association Clinical Medical Research special fund project, No. 2022ZYC-D09. Correspondence to: Dr Jian Huang, Department of Hematology, The First Affiliated Hospital of Zhejiang University School of Medicine. No. 79 Qingchun Road. Hangzhou, Zhejiang, PR China. househuang@zju.edu.cn

Loss of NDUFS1 promotes gastric cancer progression by activating the mitochondrial ROS-HIF1α-FBLN5 signaling pathway

BackgroundRecent studies suggested that NDUFS1 has an important role in human cancers; however, the effects of NDUFS1 on gastric cancer (GC) are still not fully understood.MethodsWe confirmed that NDUFS1 is downregulated in GC cells through western blot immunohistochemistry and bioinformation analysis. The effect of NDUFS1 on GC was studied by CCK-8, colony formation, transwell assay in vitro and Mouse xenograft assay in vivo. Expression and subcellular localization of NDUFS1 and the content of mitochondrial reactive oxygen species (mROS) was observed by confocal reflectance microscopy.ResultsReduced expression of NDUFS1 was found in GC tissues and cell lines. Also, NDUFS1 overexpression inhibited GC cell proliferation, migration, and invasion in vitro as well as growth and metastasis in vivo. Mechanistically, NDUFS1 reduction led to the activation of the mROS-hypoxia-inducible factor 1α (HIF1α) signaling pathway. We further clarified that NDUFS1 reduction upregulated the expression of fibulin 5 (FBLN5), a transcriptional target of HIF1α, through activation of mROS-HIF1α signaling in GC cells.ConclusionsThe results of this study indicate that NDUFS1 downregulation promotes GC progression by activating an mROS-HIF1α-FBLN5 signaling pathway.

Single-cell and spatial heterogeneity landscapes of mature epicardial cells

Tbx18, Wt1, and Tcf21 have been identified as epicardial markers during the early embryonic stage. However, the gene markers of mature epicardial cells remain unclear. Single-cell transcriptomic analysis was performed with the Seurat, Monocle, and CellphoneDB packages in R software with standard procedures. Spatial transcriptomics was performed on chilled Visium Tissue Optimization Slides (10x Genomics) and Visium Spatial Gene Expression Slides (10x Genomics). Spatial transcriptomics analysis was performed with Space Ranger software and R software. Immunofluorescence, whole-mount RNA in situ hybridization and X-gal staining were performed to validate the analysis results. Spatial transcriptomics analysis revealed distinct transcriptional profiles and functions between epicardial tissue and non-epicardial tissue. Several gene markers specific to postnatal epicardial tissue were identified, including Msln, C3, Efemp1, and Upk3b. Single-cell transcriptomic analysis revealed that cardiac cells from wildtype mouse hearts (from embryonic day 9.5 to postnatal day 9) could be categorized into six major cell types, which included epicardial cells. Throughout epicardial development, Wt1, Tbx18, and Upk3b were consistently expressed, whereas genes including Msln, C3, and Efemp1 exhibited increased expression during the mature stages of development. Pseudotime analysis further revealed two epicardial cell fates during maturation. Moreover, Upk3b, Msln, Efemp1, and C3 positive epicardial cells were enriched in extracellular matrix signaling. Our results suggested Upk3b, Efemp1, Msln, C3, and other genes were mature epicardium markers. Extracellular matrix signaling was found to play a critical role in the mature epicardium, thus suggesting potential therapeutic targets for heart regeneration in future clinical practice.

Mutations in EFEMP1 in Patients with Juvenile Open-Angle Glaucoma

Determine the role of the EFEMP1 gene in the pathogenesis of juvenile open-angle glaucoma (JOAG). Prospective case-control PARTICIPANTS: 72 JOAG and 215 POAG patients and 362 controls from Iowa. DNA was tested for coding sequence mutations in the EFEMP1gene using Sanger or whole exome sequencing. No non-synonymous EFEMP1 mutations were detected in JOAG patients and one non-synonymous EFEMP1variant (c.146A>C, p.Asp49Ala) was detected in both POAG patients (n= 2, 1.5%) and controls (n=4, 1.1%) at similar frequencies (p = 0.67). EFEMP1 mutations are not a common cause of glaucoma in our cohort from Iowa.

Genetic variants and haplotypes in fibulin-5 (FBLN5) are associated with pseudoexfoliation glaucoma but not with pseudoexfoliation syndrome.

Pseudoexfoliation (PEX) is a multifactorial age-related disease involving deposition of extracellular proteinaceous aggregates on anterior ocular tissues. The present study aims to identify functional variants in fibulin-5 (FBLN5) as risk factors for the development of PEX. Thirteen tag single-nucleotide polymorphisms (SNPs) in FBLN5 were genotyped using TaqMan SNP genotyping technology to identify association between SNPs of FBLN5 and PEX in an Indian cohort comprising 200 control and 273 PEX patients (169 PEXS and 104 PEXG). Functional analysis of risk variants was done through luciferase reporter assays and electrophoretic mobility shift assay (EMSA) using human lens epithelial cells. Genetic association and risk haplotype analysis showed a significant association of rs17732466:G>A (NC_000014.9:g.91913280G>A) and rs72705342:C>T (NC_000014.9:g.91890855C>T) within FBLN5 as risk factors with the advanced severe stage of the disease, pseudoexfoliation glaucoma (PEXG). Reporter assays showed allele-specific regulatory effect of rs72705342:C>T on gene expression, wherein, construct containing the risk allele showed a significant decrease in the reporter activity compared with the one with protective allele. EMSA further validated higher binding affinity of the risk variant to nuclear protein. In silico analysis predicted binding sites for two transcription factors, GR-α and TFII-I with risk allele at rs72705342:C>T, which were lost in the presence of protective allele. The EMSA showed probable binding of both these proteins to rs72705342. In conclusion, the present study identified the novel association of two genetic variants in FBLN5 with PEXG but not with PEXS, distinguishing between the early and the later forms of PEX. Further, rs72705342:C>T was found to be a functional variant.

Targeted O-glycoproteomics for the development of diagnostic markers for advanced colorectal cancer.

Aberrant glycosylation is a prominent feature of cancer, that can be used as targets to improve the existing cancer biomarkers, and help to assess metastasis risks, and therapeutic effects. We developed a targeted O-glycoproteomics method using serum specimens, and evaluated its utility in identifying advanced colorectal cancer (CRC) markers. To this end, we combined consecutive lectin affinity purification using Maclura pomifera lectin (MPL), jacalin, and Sambucus nigra lectin, which have affinities for the following O-glycans, that have received attention as cancer-related antigens, Tn (GalNAc-Ser/Thr), Sialyl Tn (Siaα2-6GalNAc-Ser/Thr), T (Galβ1-3GalNAc-Ser/Thr), Sialyl T (Siaα2-3Galβ1-GalNAc-Ser/Thr), and di-Sialyl T (Siaα2-3Galβ1-3[Siaα2-6] GalNAc-Ser/Thr), with a unique O-glycoproteomics approach. A total of 2,068 O-glycoforms derived from 265 proteins were identified in healthy individuals and patients with advanced CRC, of which 44 CRC-specific O-glycoforms were extracted. Particularly, five glycoproteins with T, Sialyl T, and di-Sialyl T antigens in specific peptide regions were evaluated quantitatively and statistically. We found that fibulin-2 (FBLN2) (aa330-349)/T antigen (area under the curve [AUC] = 0.92); macrophage colony-stimulating factor 1 (CSF1) (aa370-395)/(T + di-Sialyl T) (AUC = 0.94); macrophage mannose receptor 1 (MRC1) (aa1083-1101 and aa1215-1229)/T (AUC = 0.96 and 0.99); fibrinogen alpha chain (FGA) (aa354-367, aa511-527 and aa559-573)/Sialyl T (AUC = 0.98, 0.90 and 0.94); and complement component C7 (C7) (aa692-701)/di-Sialyl T (AUC = 1.00), can have high diagnostic efficacy to strategically predict advanced CRC groups. Hence, they could be promising markers for detection of advanced CRC, and provide new clinical test indicators along with lectins, such as MPL and jacalin. Our O-glycoproteomics platform provides a novel tool and resource, for researchers and clinicians seeking to better understand and treat advanced CRC.