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1.
Sci Adv ; 10(27): eadk1174, 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38968355

ABSTRACT

During angiogenesis, vascular tip cells guide nascent vascular sprouts to form a vascular network. Apelin, an agonist of the G protein-coupled receptor Aplnr, is enriched in vascular tip cells, and it is hypothesized that vascular-derived Apelin regulates sprouting angiogenesis. We identify an apelin-expressing neural progenitor cell population in the dorsal neural tube. Vascular tip cells exhibit directed elongation and migration toward and along the apelin-expressing neural progenitor cells. Notably, restoration of neural but not vascular apelin expression in apelin mutants remedies the angiogenic defects of mutants. By functional analyses, we show the requirement of Apelin signaling for tip cell behaviors, like filopodia formation and cell elongation. Through genetic interaction studies and analysis of transgenic activity reporters, we identify Apelin signaling as a modulator of phosphoinositide 3-kinase and extracellular signal-regulated kinase signaling in tip cells in vivo. Our results suggest a previously unidentified neurovascular cross-talk mediated by Apelin signaling that is important for tip cell function during sprouting angiogenesis.


Subject(s)
Apelin , Neovascularization, Physiologic , Neural Stem Cells , Signal Transduction , Animals , Apelin/metabolism , Apelin/genetics , Neural Stem Cells/metabolism , Neural Stem Cells/cytology , Zebrafish , Intercellular Signaling Peptides and Proteins/metabolism , Intercellular Signaling Peptides and Proteins/genetics , Cell Movement , Neural Tube/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Chemokines , Zebrafish Proteins
2.
Drug Dev Res ; 85(5): e22222, 2024 Aug.
Article in English | MEDLINE | ID: mdl-39003564

ABSTRACT

Retinoblastoma (RB) is a pediatric malignancy, typically diagnosed at birth or during early childhood. The pathogenesis of RB is marked by the amplification of the Basic Helix-Loop-Helix (BHLH) Transcription Factor MYCN, which serves as a transcriptional regulator capable of binding to Dickkopf 3 (DKK3). However, the precise role of DKK3 in the malignant progression of RB cells caused by MYCN remains elusive. In the present study, the expression of MYCN was either overexpressed or interfered in RB cells. Subsequently, the expression level of DKK3 was assessed through quantitative real-time polymerase chain reaction and western blot analysis. Cell proliferation was evaluated using the Cell Counting Kit-8 assay and 5-ethynyl-2'-deoxyuridine staining, while cell cycle progression and apoptosis were analyzed by flow cytometry and western blot analysis, respectively. Additionally, the expression of proteins involved in the Wnt/ß-catenin/Fra-1/p53 signaling pathway was evaluated via western blot analysis. To gain further insights, Wnt agonists and the P53 inhibitor PFT-α were introduced into exploration. The current investigation revealed a negative correlation between the expression levels of MYCN and DKK3 in RB cells. Additionally, DKK3 overexpression inhibited cell proliferation, promoted cell apoptosis, and arrested cell cycle in RB cells with high expression of MYCN. Moreover, enhanced DKK3 expression inhibited proliferation, promoted cell cycle arrest and apoptosis of RB cells by modulating the wnt/ßcatenin/Fra-1/p53 signaling pathway. Furthermore, in vivo experiments revealed that overexpression of DKK3 inhibits the growth of RB tumors. Collectively, our findings elucidate that MYCN stimulates the Wnt/ß-catenin/Fra-1 pathway by suppressing DKK3 expression, ultimately suppressing p53 activity and contributing to malignant progression of RB.


Subject(s)
Adaptor Proteins, Signal Transducing , Cell Proliferation , N-Myc Proto-Oncogene Protein , Retinoblastoma , Tumor Suppressor Protein p53 , Wnt Signaling Pathway , Humans , N-Myc Proto-Oncogene Protein/genetics , N-Myc Proto-Oncogene Protein/metabolism , Retinoblastoma/metabolism , Retinoblastoma/genetics , Retinoblastoma/pathology , Tumor Suppressor Protein p53/metabolism , Tumor Suppressor Protein p53/genetics , Adaptor Proteins, Signal Transducing/genetics , Adaptor Proteins, Signal Transducing/metabolism , Cell Line, Tumor , Animals , Mice , Apoptosis , Intercellular Signaling Peptides and Proteins/genetics , Intercellular Signaling Peptides and Proteins/metabolism , Mice, Nude , beta Catenin/metabolism
3.
Medicine (Baltimore) ; 103(28): e38913, 2024 Jul 12.
Article in English | MEDLINE | ID: mdl-38996177

ABSTRACT

The objective of this study was to assess the prognostic relevance of Stanniocalcin-2 (STC2) expression, as determined via immunohistochemistry in tumor tissue, in a cohort of 83 patients diagnosed with glioblastoma who underwent maximal safe surgical resection followed by radiotherapy concurrent with adjuvant temozolomide. STC2 expression levels were categorized using a 3-tiered semiquantitative system: negative expression (level 0-), low expression (level 1+), and high expression (levels 2 + and 3+). Patients were categorized into 2 distinct groups according to their STC2 expression levels: negative STC2 (-/+) and positive STC2 (++/+++). The primary outcome measure was the relationship between STC2 expression and progression-free survival (PFS), with overall survival (OS) serving as the secondary endpoint. Kaplan-Meier survival analysis confirmed that patients exhibiting high STC2 expression had significantly shorter OS (8 vs 20 months, P < .001) and PFS (6 vs 18 months, P < .001) than those with low or negative STC2 expression. Multivariate analysis revealed that STC2 expression was an independent prognostic factor for both OS (hazard ratio: 0.4; 95% confidence interval: 0.2-0.8; P < .05) and PFS (hazard ratio: 0.3; 95% confidence interval: 0.2-0.4; P < .05) in patients with glioblastoma. Furthermore, elevated STC2 expression in GBM was correlated with several established aggressive clinicopathological characteristics, including advanced age (≥65 years), low ECOG PS (≥2), and isocitrate dehydrogenase mutation negativity. These findings underscore that heightened STC2 expression within the tumor tissue of GBM patients functions as an adverse prognostic marker, correlating with an elevated risk of progression and reduced OS. Therapeutic interventions targeting the AKT-mTOR, ERK1-2, and mitogen-activated protein kinase pathways as well as immune checkpoint inhibitors and vascular endothelial growth factor blockade, as well as potential forthcoming antibody-drug conjugates targeting the STC2 molecule, have the potential to broaden the scope of combined treatment strategies.


Subject(s)
Biomarkers, Tumor , Brain Neoplasms , Glioblastoma , Glycoproteins , Intercellular Signaling Peptides and Proteins , Humans , Glioblastoma/metabolism , Glioblastoma/mortality , Glioblastoma/genetics , Glioblastoma/pathology , Female , Male , Middle Aged , Biomarkers, Tumor/metabolism , Glycoproteins/metabolism , Prognosis , Aged , Brain Neoplasms/metabolism , Brain Neoplasms/mortality , Brain Neoplasms/genetics , Brain Neoplasms/pathology , Intercellular Signaling Peptides and Proteins/metabolism , Intercellular Signaling Peptides and Proteins/genetics , Adult , Temozolomide/therapeutic use , Kaplan-Meier Estimate , Progression-Free Survival , Retrospective Studies , Antineoplastic Agents, Alkylating/therapeutic use , Immunohistochemistry
4.
Int J Mol Med ; 54(3)2024 Sep.
Article in English | MEDLINE | ID: mdl-38963051

ABSTRACT

Lipid metabolism disorders are a major cause of several chronic metabolic diseases which seriously affect public health. Salusin­α, a vasoactive peptide, has been shown to attenuate lipid metabolism disorders, although its mechanism of action has not been reported. To investigate the effects and potential mechanisms of Salusin­α on lipid metabolism, Salusin­α was overexpressed or knocked down using lentiviral vectors. Hepatocyte steatosis was induced by free fatty acid (FFA) after lentiviral transfection into HepG2 cells. The degree of lipid accumulation was assessed using Oil Red O staining and by measuring several biochemical indices. Subsequently, bioinformatics was used to analyze the signaling pathways that may have been involved in lipid metabolism disorders. Finally, semi­quantitative PCR and western blotting were used to verify the involvement of the liver kinase B1 (LKB1)/AMPK pathway. Compound C, an inhibitor of AMPK, was used to confirm this mechanism's involvement further. The results showed that Salusin­α significantly attenuated lipid accumulation, inflammation and oxidative stress. In addition, Salusin­α increased the levels of LKB1 and AMPK, which inhibited the expression of sterol regulatory element binding protein­1c, fatty acid synthase and acetyl­CoA carboxylase. The addition of Compound C abrogated the Salusin­α­mediated regulation of AMPK on downstream signaling molecules. In summary, overexpression of Salusin­α activated the LKB1/AMPK pathway, which in turn inhibited lipid accumulation in HepG2 cells. This provides insights into the potential mechanism underlying the mechanism by which Salusin­α ameliorates lipid metabolism disorders while identifying a potential therapeutic target.


Subject(s)
AMP-Activated Protein Kinase Kinases , AMP-Activated Protein Kinases , Lipogenesis , Protein Serine-Threonine Kinases , Signal Transduction , Humans , Lipogenesis/genetics , Lipogenesis/drug effects , AMP-Activated Protein Kinases/metabolism , Hep G2 Cells , Protein Serine-Threonine Kinases/metabolism , Protein Serine-Threonine Kinases/genetics , Signal Transduction/drug effects , AMP-Activated Protein Kinase Kinases/genetics , Lipid Metabolism Disorders/metabolism , Lipid Metabolism Disorders/genetics , Lipid Metabolism Disorders/drug therapy , Intercellular Signaling Peptides and Proteins/metabolism , Intercellular Signaling Peptides and Proteins/genetics , Lipid Metabolism/drug effects , Lipid Metabolism/genetics , Sterol Regulatory Element Binding Protein 1/metabolism , Sterol Regulatory Element Binding Protein 1/genetics , Oxidative Stress/drug effects , Gene Expression Regulation/drug effects
5.
Proc Natl Acad Sci U S A ; 121(28): e2408346121, 2024 Jul 09.
Article in English | MEDLINE | ID: mdl-38968117

ABSTRACT

Xenopus embryos provide a favorable material to dissect the sequential steps that lead to dorsal-ventral (D-V) and anterior-posterior (A-P) cell differentiation. Here, we analyze the signaling pathways involved in this process using loss-of-function and gain-of-function approaches. The initial step was provided by Hwa, a transmembrane protein that robustly activates early ß-catenin signaling when microinjected into the ventral side of the embryo leading to complete twinned axes. The following step was the activation of Xenopus Nodal-related growth factors, which could rescue the depletion of ß-catenin and were themselves blocked by the extracellular Nodal antagonists Cerberus-Short and Lefty. During gastrulation, the Spemann-Mangold organizer secretes a cocktail of growth factor antagonists, of which the BMP antagonists Chordin and Noggin could rescue simultaneously D-V and A-P tissues in ß-catenin-depleted embryos. Surprisingly, this rescue occurred in the absence of any ß-catenin transcriptional activity as measured by ß-catenin activated Luciferase reporters. The Wnt antagonist Dickkopf (Dkk1) strongly synergized with the early Hwa signal by inhibiting late Wnt signals. Depletion of Sizzled (Szl), an antagonist of the Tolloid chordinase, was epistatic over the Hwa and Dkk1 synergy. BMP4 mRNA injection blocked Hwa-induced ectopic axes, and Dkk1 inhibited BMP signaling late, but not early, during gastrulation. Several unexpected findings were made, e.g., well-patterned complete embryonic axes are induced by Chordin or Nodal in ß-catenin knockdown embryos, dorsalization by Lithium chloride (LiCl) is mediated by Nodals, Dkk1 exerts its anteriorizing and dorsalizing effects by regulating late BMP signaling, and the Dkk1 phenotype requires Szl.


Subject(s)
Body Patterning , Intercellular Signaling Peptides and Proteins , Signal Transduction , Xenopus Proteins , beta Catenin , Animals , Body Patterning/genetics , Xenopus Proteins/metabolism , Xenopus Proteins/genetics , beta Catenin/metabolism , beta Catenin/genetics , Intercellular Signaling Peptides and Proteins/metabolism , Intercellular Signaling Peptides and Proteins/genetics , Xenopus laevis/embryology , Gene Expression Regulation, Developmental , Gastrulation , Nodal Protein/metabolism , Nodal Protein/genetics , Embryo, Nonmammalian/metabolism , Embryo, Nonmammalian/embryology , Organizers, Embryonic/metabolism , Glycoproteins
6.
Cells ; 13(12)2024 Jun 08.
Article in English | MEDLINE | ID: mdl-38920632

ABSTRACT

Non-coding RNAs (ncRNAs) have emerged as pivotal regulators in cellular biology, dispelling their former perception as 'junk transcripts'. Notably, the DLK1-DIO3 region harbors numerous ncRNAs, including long non-coding RNAs (lncRNAs) and over 50 microRNA genes. While papillary thyroid cancer showcases a pervasive decrease in DLK1-DIO3-derived ncRNA expression, the precise mechanisms driving this alteration remain elusive. We hypothesized that epigenetic alterations underlie shifts in ncRNA expression during thyroid cancer initiation and progression. This study aimed to elucidate the epigenetic mechanisms governing DLK1-DIO3 region expression in this malignancy. We have combined the analysis of DNA methylation by bisulfite sequencing together with that of histone modifications through ChIP-qPCR to gain insights into the epigenetic contribution to thyroid cancer in cell lines representing malignancies with different genetic backgrounds. Our findings characterize the region's epigenetic signature in thyroid cancer, uncovering distinctive DNA methylation patterns, particularly within CpG islands on the lncRNA MEG3-DMR, which potentially account for its downregulation in tumors. Pharmacological intervention targeting DNA methylation combined with histone deacetylation restored ncRNA expression. These results contribute to the understanding of the epigenetic mechanisms controlling the DLK1-DIO3 region in thyroid cancer, highlighting the combined role of DNA methylation and histone marks in regulating the locus' expression.


Subject(s)
Calcium-Binding Proteins , DNA Methylation , Epigenesis, Genetic , Gene Expression Regulation, Neoplastic , Iodide Peroxidase , RNA, Long Noncoding , Thyroid Neoplasms , Humans , DNA Methylation/genetics , Thyroid Neoplasms/genetics , Thyroid Neoplasms/pathology , Thyroid Neoplasms/metabolism , Cell Line, Tumor , Calcium-Binding Proteins/genetics , Calcium-Binding Proteins/metabolism , Iodide Peroxidase/genetics , Iodide Peroxidase/metabolism , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , CpG Islands/genetics , Intercellular Signaling Peptides and Proteins/genetics , Intercellular Signaling Peptides and Proteins/metabolism , Histones/metabolism , Membrane Proteins
7.
Nat Commun ; 15(1): 4976, 2024 Jun 11.
Article in English | MEDLINE | ID: mdl-38862520

ABSTRACT

Twisted gastrulation (TWSG1) is an evolutionarily conserved secreted glycoprotein which controls signaling by Bone Morphogenetic Proteins (BMPs). TWSG1 binds BMPs and their antagonist Chordin to control BMP signaling during embryonic development, kidney regeneration and cancer. We report crystal structures of TWSG1 alone and in complex with a BMP ligand, Growth Differentiation Factor 5. TWSG1 is composed of two distinct, disulfide-rich domains. The TWSG1 N-terminal domain occupies the BMP type 1 receptor binding site on BMPs, whereas the C-terminal domain binds to a Chordin family member. We show that TWSG1 inhibits BMP function in cellular signaling assays and mouse colon organoids. This inhibitory function is abolished in a TWSG1 mutant that cannot bind BMPs. The same mutation in the Drosophila TWSG1 ortholog Tsg fails to mediate BMP gradient formation required for dorsal-ventral axis patterning of the early embryo. Our studies reveal the evolutionarily conserved mechanism of BMP signaling inhibition by TWSG1.


Subject(s)
Bone Morphogenetic Proteins , Signal Transduction , Animals , Bone Morphogenetic Proteins/metabolism , Bone Morphogenetic Proteins/genetics , Mice , Humans , Drosophila Proteins/metabolism , Drosophila Proteins/genetics , Drosophila Proteins/chemistry , Glycoproteins/metabolism , Glycoproteins/genetics , Intercellular Signaling Peptides and Proteins/metabolism , Intercellular Signaling Peptides and Proteins/genetics , Binding Sites , Protein Domains , Protein Binding , Organoids/metabolism , Organoids/embryology , HEK293 Cells , Gastrulation/genetics , Mutation , Crystallography, X-Ray , Drosophila melanogaster/embryology , Drosophila melanogaster/metabolism , Drosophila melanogaster/genetics , Proteins
8.
Int J Biol Sci ; 20(8): 2943-2964, 2024.
Article in English | MEDLINE | ID: mdl-38904030

ABSTRACT

Background: Shear stress-induced Dickkopf-1 (DKK1) secretion by endothelial cells (ECs) promotes EC dysfunction and accelerates atherosclerosis (AS). However, the paracrine role of endothelial DKK1 in modulating adjacent smooth muscle cells (SMCs) in atherosclerosis remains unclear. This study investigated the role of EC-secreted DKK1 in SMC-derived foam cell formation under shear stress, in vitro and in vivo. Methods: Parallel-plate co-culture flow system was used to explore the cellular communication between ECs and SMCs under shear stress in vitro. Endothelium-specific knockout of DKK1 (DKK1ECKO/APOE-/-) and endothelium-specific overexpression of DKK1 (DKK1ECTg) mice were constructed to investigate the role of endothelial DKK1 in atherosclerosis and SMC-derived foam cell formation in vivo. RNA sequencing (RNA-seq) was used to identify the downstream targets of DKK1. Reverse transcription quantitative polymerase chain reaction (RT-qPCR), western blot, coimmunoprecipitation (Co-IP) assays and chromatin immunoprecipitation (ChIP) experiments were conducted to explore the underlying regulatory mechanisms. Results: DKK1 is transcriptionally upregulated in ECs under conditions of low shear stress, but not in co-cultured SMCs. However, DKK1 protein in co-cultured SMCs is increased via uptake of low shear stress-induced endothelial DKK1, thereby promoting lipid uptake and foam cell formation in co-cultured SMCs via the post-translational upregulation of scavenger receptor-A (SR-A) verified in parallel-plate co-culture flow system, DKK1ECKO and DKK1ECTg mice. RNA sequencing revealed that DKK1-induced SR-A upregulation in SMCs is dependent on Ubiquitin-specific Protease 53 (USP53), which bound to SR-A via its USP domain and cysteine at position 41, exerting deubiquitination to maintain the stability of the SR-A protein by removing the K48 ubiquitin chain and preventing proteasomal pathway degradation, thereby mediating the effect of DKK1 on lipid uptake in SMCs. Moreover, DKK1 regulates the transcription of USP53 by facilitating the binding of transcription factor CREB to the USP53 promoter. SMC-specific overexpression of USP53 via adeno-associated virus serotype 2 vectors in DKK1ECKO/APOE-/- mice reversed the alleviation of atherosclerotic plaque burden, SR-A expression and lipid accumulation in SMCs within plaques resulting from DKK1 deficiency. Conclusions: Our findings demonstrate that, endothelial DKK1, induced by pathological low shear stress, acts as an intercellular mediator, promoted the foam cell formation of SMCs. These results suggest that targeted intervention with endothelial DKK1 may confer beneficial effects on atherosclerosis.


Subject(s)
Atherosclerosis , Foam Cells , Intercellular Signaling Peptides and Proteins , Myocytes, Smooth Muscle , Animals , Atherosclerosis/metabolism , Mice , Intercellular Signaling Peptides and Proteins/metabolism , Intercellular Signaling Peptides and Proteins/genetics , Foam Cells/metabolism , Myocytes, Smooth Muscle/metabolism , Endothelial Cells/metabolism , Humans , Ubiquitination , Male , Coculture Techniques , Mice, Knockout , Ubiquitin-Specific Proteases/metabolism , Ubiquitin-Specific Proteases/genetics , Mice, Inbred C57BL
9.
Sci Rep ; 14(1): 12967, 2024 06 05.
Article in English | MEDLINE | ID: mdl-38839844

ABSTRACT

Osteoporosis is a common skeletal disease affecting millions of individuals world-wide, with an increased risk of fracture, and a decreased quality of life. Despite its well-known consequences, the etiology of osteoporosis and optimal treatment methods are not fully understood. Human genetic studies have identified genetic variants within the FMN2/GREM2 locus to be associated with trabecular volumetric bone mineral density (vBMD) and vertebral and forearm fractures, but not with cortical bone parameters. GREM2 is a bone morphogenetic protein (BMP) antagonist. In this study, we employed Grem2-deficient mice to investigate whether GREM2 serves as the plausible causal gene for the fracture signal at the FMN2/GREM2 locus. We observed that Grem2 is moderately expressed in bone tissue and particularly in osteoblasts. Complete Grem2 gene deletion impacted mouse survival and body growth. Partial Grem2 inactivation in Grem2+/- female mice led to increased trabecular BMD of femur and increased trabecular bone mass in tibia due to increased trabecular thickness, with an unchanged cortical thickness, as compared with wildtype littermates. Furthermore, Grem2 inactivation stimulated osteoblast differentiation, as evidenced by higher alkaline phosphatase (Alp), osteocalcin (Bglap), and osterix (Sp7) mRNA expression after BMP-2 stimulation in calvarial osteoblasts and osteoblasts from the long bones of Grem2-/- mice compared to wildtype littermates. These findings suggest that GREM2 is a possible target for novel osteoporotic treatments, to increase trabecular bone mass and prevent osteoporotic fractures.


Subject(s)
Bone Density , Cancellous Bone , Osteoblasts , Animals , Female , Mice , Bone Morphogenetic Protein 2/metabolism , Bone Morphogenetic Protein 2/genetics , Cancellous Bone/metabolism , Cancellous Bone/pathology , Cell Differentiation , Intercellular Signaling Peptides and Proteins/genetics , Intercellular Signaling Peptides and Proteins/metabolism , Mice, Knockout , Osteoblasts/metabolism , Osteogenesis/genetics , Osteoporosis/genetics , Osteoporosis/pathology , Osteoporosis/metabolism
10.
J Exp Med ; 221(8)2024 Aug 05.
Article in English | MEDLINE | ID: mdl-38836810

ABSTRACT

Coxsackievirus A10 (CV-A10) infection, a prominent cause of childhood hand-foot-and-mouth disease (HFMD), frequently manifests with the intriguing phenomenon of onychomadesis, characterized by nail shedding. However, the underlying mechanism is elusive. Here, we found that CV-A10 infection in mice could suppress Wnt/ß-catenin signaling by restraining LDL receptor-related protein 6 (LRP6) phosphorylation and ß-catenin accumulation and lead to onychomadesis. Mechanistically, CV-A10 mimics Dickkopf-related protein 1 (DKK1) to interact with Kringle-containing transmembrane protein 1 (KRM1), the CV-A10 cellular receptor. We further found that Wnt agonist (GSK3ß inhibitor) CHIR99021 can restore nail stem cell differentiation and protect against nail shedding. These findings provide novel insights into the pathogenesis of CV-A10 and related viruses in onychomadesis and guide prognosis assessment and clinical treatment of the disease.


Subject(s)
Intercellular Signaling Peptides and Proteins , Low Density Lipoprotein Receptor-Related Protein-6 , Wnt Signaling Pathway , Animals , Wnt Signaling Pathway/drug effects , Low Density Lipoprotein Receptor-Related Protein-6/metabolism , Low Density Lipoprotein Receptor-Related Protein-6/genetics , Mice , Intercellular Signaling Peptides and Proteins/metabolism , Intercellular Signaling Peptides and Proteins/genetics , Humans , beta Catenin/metabolism , Nail Diseases/metabolism , Nail Diseases/virology , Nail Diseases/pathology , Nails/metabolism , Nails/pathology , Cell Differentiation/drug effects , Mice, Inbred C57BL , Hand, Foot and Mouth Disease/virology , Hand, Foot and Mouth Disease/metabolism , Hand, Foot and Mouth Disease/pathology , Hand, Foot and Mouth Disease/complications , Phosphorylation/drug effects , Coxsackievirus Infections/complications , Coxsackievirus Infections/metabolism , Glycogen Synthase Kinase 3 beta/metabolism , Pyridines/pharmacology , Pyrimidines
11.
Int J Mol Sci ; 25(12)2024 Jun 16.
Article in English | MEDLINE | ID: mdl-38928335

ABSTRACT

Among the myriad of existing tyrosine kinase receptors, the TAM family-abbreviated from Tyro3, Axl, and Mer tyrosine kinase (MerTK)-has been extensively studied with an outstanding contribution from the team of Prof. Greg Lemke. MerTK activity is implicated in a wide variety of functions involving the elimination of apoptotic cells and has recently been linked to cancers, auto-immune diseases, and atherosclerosis/stroke. In the retina, MerTK is required for the circadian phagocytosis of oxidized photoreceptor outer segments by the retinal-pigment epithelial cells, a function crucial for the long-term maintenance of vision. We previously showed that MerTK ligands carry the opposite role in vitro, with Gas6 inhibiting the internalization of photoreceptor outer segments while Protein S acts conversely. Using site-directed mutagenesis and ligand-stimulated phagocytosis assays on transfected cells, we presently demonstrate, for the first time, that Gas6 and Protein S recognize different amino acids on MerTK Ig-like domains. In addition, MerTK's function in retinal-pigment epithelial cells is rhythmic and might thus rely on the respective stoichiometry of both ligands at different times of the day. Accordingly, we show that ligand bioavailability varies during the circadian cycle using RT-qPCR and immunoblots on retinal and retinal-pigment epithelial samples from control and beta5 integrin knockout mice where retinal phagocytosis is arrhythmic. Taken together, our results suggest that Gas6 and Protein S might both contribute to refine the acute regulation of MerTK in time for the daily phagocytic peak.


Subject(s)
Intercellular Signaling Peptides and Proteins , Phagocytosis , Protein S , c-Mer Tyrosine Kinase , Animals , Mice , c-Mer Tyrosine Kinase/metabolism , c-Mer Tyrosine Kinase/genetics , Circadian Rhythm/physiology , Intercellular Signaling Peptides and Proteins/metabolism , Intercellular Signaling Peptides and Proteins/genetics , Ligands , Protein S/metabolism , Receptor Protein-Tyrosine Kinases/metabolism , Receptor Protein-Tyrosine Kinases/genetics , Retina/metabolism , Retinal Pigment Epithelium/metabolism , Retinal Pigment Epithelium/cytology
12.
J Toxicol Sci ; 49(7): 289-299, 2024.
Article in English | MEDLINE | ID: mdl-38945840

ABSTRACT

BACKGROUND: Endothelial barrier dysfunction is critical for the pathogenesis of sepsis-induced acute lung injury (ALI). Lipopolysaccharide (LPS)-stimulated human pulmonary microvascular endothelial cells (HPMECs) are widely used as the cell model of sepsis-associated ALI for exploration of endothelial barrier dysfunction. Dickkopf (DKK) family proteins were reported to mediate endothelial functions in various diseases. The present study explored the effect of Dickkopf-3 (DKK3) on endothelial barrier permeability, angiogenesis, and tight junctions in LPS-stimulated HPMECs. METHODS: RT-qPCR was required for detecting DKK3 and miR-98-3p expression. The angiogenesis of HPMECs was evaluated by tube formation assays. Monolayer permeability of HPMECs was examined by Transwell rhodamine assays. The protein expression of DKK3 and tight junctions in HPMECs was measured via western blotting. Luciferase reporter assay was used to verify the interaction between miR-98-3p and DKK3. RESULTS: LPS treatment inhibited angiogenetic ability while increasing the permeability of HPMECs. DKK3 expression was upregulated while miR-98-3p level was reduced in LPS-treated HPMECs. DKK3 knockdown alleviated HPMEC injury triggered by LPS stimulation. MiR-98-3p targeted DKK3 in HPMECs. Overexpression of miR-98-3p protects HPMECs from the LPS-induced endothelial barrier dysfunction, and the protective effect was reversed by DKK3 overexpression. CONCLUSIONS: MiR-98-3p ameliorates LPS-evoked pulmonary microvascular endothelial barrier dysfunction in sepsis-associated ALI by targeting DKK3.


Subject(s)
Acute Lung Injury , Adaptor Proteins, Signal Transducing , Endothelial Cells , Lipopolysaccharides , MicroRNAs , Sepsis , MicroRNAs/genetics , MicroRNAs/metabolism , Acute Lung Injury/etiology , Acute Lung Injury/genetics , Acute Lung Injury/metabolism , Humans , Sepsis/complications , Sepsis/metabolism , Endothelial Cells/metabolism , Adaptor Proteins, Signal Transducing/genetics , Adaptor Proteins, Signal Transducing/metabolism , Lung/blood supply , Cells, Cultured , Tight Junctions/metabolism , Intercellular Signaling Peptides and Proteins/genetics , Intercellular Signaling Peptides and Proteins/metabolism , Capillary Permeability/drug effects
13.
Fish Shellfish Immunol ; 151: 109708, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38908810

ABSTRACT

Leukocyte-derived chemotaxin-2 (LECT2) is a multifunctional immunoregulator that plays several pivotal roles in the host's defense against pathogens. This study aimed to elucidate the specific functions and mechanisms of LECT2 (CaLECT2) in the northern snakehead (Channa argus) during infections with pathogens such as Nocardia seriolae (N. seriolae). We identified CaLECT2 in the northern snakehead, demonstrating its participation in the immune response to N. seriolae infection. CaLECT2 contains an open reading frame (ORF) of 459 bp, encoding a peptide of 152 amino acids featuring a conserved peptidase M23 domain. The CaLECT2 protein shares 62%-84 % identities with proteins from various other fish species. Transcriptional expression analysis revealed that CaLECT2 was constitutively expressed in all examined tissues, with the highest expression observed in the liver. Following intraperitoneal infection with N. seriolae, CaLECT2 transcription increased in the spleen, trunk kidney, and liver. In vivo challenge experiments showed that injecting recombinant CaLECT2 (rCaLECT2) could protect the snakehead against N. seriolae infection by reducing bacterial load, enhancing serum antibacterial activity and antioxidant capacity, and minimizing tissue damage. Moreover, in vitro analysis indicated that rCaLECT2 significantly enhanced the migration, respiratory burst, and microbicidal activity of the head kidney-derived phagocytes. These findings provide new insights into the role of LECT2 in the antibacterial immunity of fish.


Subject(s)
Fish Diseases , Fish Proteins , Immunity, Innate , Nocardia Infections , Nocardia , Animals , Nocardia Infections/veterinary , Nocardia Infections/immunology , Nocardia/immunology , Fish Diseases/immunology , Fish Proteins/genetics , Fish Proteins/immunology , Immunity, Innate/genetics , Phylogeny , Amino Acid Sequence , Intercellular Signaling Peptides and Proteins/genetics , Intercellular Signaling Peptides and Proteins/immunology , Gene Expression Regulation/immunology , Sequence Alignment/veterinary , Gene Expression Profiling/veterinary , Fishes/immunology , Fishes/genetics , Perciformes/immunology , Perciformes/genetics , Base Sequence
14.
Biochem Biophys Res Commun ; 727: 150277, 2024 Oct 01.
Article in English | MEDLINE | ID: mdl-38936225

ABSTRACT

With the aging of the global demographic, the prevention and treatment of osteoporosis are becoming crucial issues. The gradual loss of self-renewal and osteogenic differentiation capabilities in bone marrow stromal cells (BMSCs) is one of the key factors contributing to osteoporosis. To explore the regulatory mechanisms of BMSCs differentiation, we collected bone marrow cells of femoral heads from patients undergoing total hip arthroplasty for single-cell RNA sequencing analysis. Single-cell RNA sequencing revealed significantly reduced CRIP1 (Cysteine-Rich Intestinal Protein 1) expression and osteogenic capacity in the BMSCs of osteoporosis patients compared to non-osteoporosis group. CRIP1 is a gene that encodes a member of the LIM/double zinc finger protein family, which is involved in the regulation of various cellular processes including cell growth, development, and differentiation. CRIP1 knockdown resulted in decreased alkaline phosphatase activity, mineralization and expression of osteogenic markers, indicating impaired osteogenic differentiation. Conversely, CRIP1 overexpression, both in vitro and in vivo, enhanced osteogenic differentiation and rescued bone mass reduction in ovariectomy-induced osteoporosis mice model. The study further established CRIP1's modulation of osteogenesis through the Wnt signaling pathway, suggesting that targeting CRIP1 could offer a novel approach for osteoporosis treatment by promoting bone formation and preventing bone loss.


Subject(s)
Cell Differentiation , LIM Domain Proteins , Mesenchymal Stem Cells , Osteoblasts , Osteogenesis , Osteoporosis , Wnt Signaling Pathway , Osteogenesis/genetics , Animals , Mesenchymal Stem Cells/metabolism , Mesenchymal Stem Cells/cytology , Cell Differentiation/genetics , LIM Domain Proteins/metabolism , LIM Domain Proteins/genetics , Humans , Osteoblasts/metabolism , Osteoblasts/cytology , Female , Osteoporosis/genetics , Osteoporosis/metabolism , Osteoporosis/pathology , Mice , Mice, Inbred C57BL , Cells, Cultured , Middle Aged , Aged , Intercellular Signaling Peptides and Proteins/metabolism , Intercellular Signaling Peptides and Proteins/genetics , Carrier Proteins
15.
Dev Neurobiol ; 84(3): 203-216, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38830696

ABSTRACT

Formation of the corpus callosum (CC), anterior commissure (AC), and postoptic commissure (POC), connecting the left and right cerebral hemispheres, is crucial for cerebral functioning. Collapsin response mediator protein 2 (CRMP2) has been suggested to be associated with the mechanisms governing this formation, based on knockout studies in mice and knockdown/knockout studies in zebrafish. Previously, we reported two cases of non-synonymous CRMP2 variants with S14R and R565C substitutions. Among the, the R565C substitution (p.R565C) was caused by the novel CRMP2 mutation c.1693C > T, and the patient presented with intellectual disability accompanied by CC hypoplasia. In this study, we demonstrate that crmp2 mRNA could rescue AC and POC formation in crmp2-knockdown zebrafish, whereas the mRNA with the R566C mutation could not. Zebrafish CRMP2 R566C corresponds to human CRMP2 R565C. Further experiments with transfected cultured cells indicated that CRMP2 with the R566C mutation could not bind to kinesin light chain 1 (KLC1). Knockdown of klc1a in zebrafish resulted in defective AC and POC formation, revealing a genetic interaction with crmp2. These findings suggest that the CRMP2 R566C mutant fails to bind to KLC1, preventing axonal elongation and leading to defective AC and POC formation in zebrafish and CC formation defects in humans. Our study highlights the importance of the interaction between CRMP2 and KLC1 in the formation of the forebrain commissures, revealing a novel mechanism associated with CRMP2 mutations underlying human neurodevelopmental abnormalities.


Subject(s)
Intercellular Signaling Peptides and Proteins , Nerve Tissue Proteins , Zebrafish Proteins , Zebrafish , Animals , Intercellular Signaling Peptides and Proteins/metabolism , Intercellular Signaling Peptides and Proteins/genetics , Nerve Tissue Proteins/metabolism , Nerve Tissue Proteins/genetics , Zebrafish Proteins/metabolism , Zebrafish Proteins/genetics , Prosencephalon/metabolism , Kinesins/metabolism , Kinesins/genetics , Corpus Callosum/metabolism , Humans , Animals, Genetically Modified , Embryo, Nonmammalian
16.
Neurogenetics ; 25(3): 193-200, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38847891

ABSTRACT

Most of the heritability in frontotemporal dementia (FTD) is accounted for by autosomal dominant hexanucleotide expansion in the chromosome 9 open reading frame 72 (C9orf72), pathogenic/likely pathogenic variants in progranulin (GRN), and microtubule-associated protein tau (MAPT) genes. Until now, there has been no systematic analysis of these genes in the Serbian population. Herein, we assessed the frequency of the C9orf72 expansion, pathogenic/likely pathogenic variants in GRN and MAPT in a well-characterized group of 472 subjects (FTD, Alzheimer's disease - AD, mild cognitive impairment - MCI, and unspecified dementia - UnD), recruited in the Memory Center, Neurology Clinic, University Clinical Center of Serbia. The C9orf72 repeat expansion was detected in 6.98% of FTD cases (13.46% familial; 2.6% sporadic). In the UnD subgroup, C9orf72 repeat expansions were detected in 4.08% (8% familial) individuals. Pathogenic variants in the GRN were found in 2.85% of familial FTD cases. Interestingly, no MAPT pathogenic/likely pathogenic variants were detected, suggesting possible geographical specificity. Our findings highlight the importance of wider implementation of genetic testing in neurological and psychiatric practice managing patients with cognitive-behavioral and motor symptoms.


Subject(s)
C9orf72 Protein , Frontotemporal Dementia , Progranulins , tau Proteins , Humans , tau Proteins/genetics , C9orf72 Protein/genetics , Progranulins/genetics , Female , Male , Aged , Frontotemporal Dementia/genetics , Middle Aged , Serbia/epidemiology , DNA Repeat Expansion/genetics , Cognitive Dysfunction/genetics , Cognitive Dysfunction/epidemiology , Alzheimer Disease/genetics , Intercellular Signaling Peptides and Proteins/genetics , Aged, 80 and over
17.
Am J Physiol Gastrointest Liver Physiol ; 327(1): G70-G79, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38713614

ABSTRACT

Although impaired regeneration is important in many gastrointestinal diseases including ulcerative colitis (UC), the dynamics of mucosal regeneration in humans are poorly investigated. We have developed a model to study these processes in vivo in humans. Epithelial restitution (ER) and extracellular matrix (ECM) regulation after an experimental injury of the sigmoid colonic mucosa was assessed by repeated high-resolution endoscopic imaging, histological assessment, RNA sequencing, deconvolution analysis, and 16S rDNA sequencing of the injury niche microbiome of 19 patients with UC in remission and 20 control subjects. Human ER had a 48-h lag before induction of regenerative epithelial cells [wound-associated epithelial (WAE) and transit amplifying (TA) cells] along with the increase of fibroblast-derived stem cell growth factor gremlin 1 mRNA (GREM1). However, UC deconvolution data showed rapid induction of inflammatory fibroblasts and upregulation of major structural ECM collagen mRNAs along with tissue inhibitor of metalloproteinase 1 (TIMP1), suggesting increased profibrotic ECM deposition. No change was seen in transforming growth factor ß (TGFß) mRNA, whereas the profibrotic cytokines interleukin 13 (IL13) and IL11 were upregulated in UC, suggesting that human postinjury responses could be TGFß-independent. In conclusion, we found distinct regulatory layers of regeneration in the normal human colon and a potential targetable profibrotic dysregulation in UC that could lead to long-term end-organ failure, i.e., intestinal damage.NEW & NOTEWORTHY The study reveals the regulatory dynamics of epithelial regeneration and extracellular matrix remodeling after experimental injury of the human colon in vivo and shows that human intestinal regeneration is different from data obtained from animals. A lag phase in epithelial restitution is associated with induction of stromal cell-derived epithelial growth factors. Postinjury regeneration is transforming growth factor ß-independent, and we find a profibrotic response in patients with ulcerative colitis despite being in remission.


Subject(s)
Colitis, Ulcerative , Intestinal Mucosa , Signal Transduction , Transforming Growth Factor beta , Humans , Colitis, Ulcerative/metabolism , Colitis, Ulcerative/pathology , Intestinal Mucosa/metabolism , Intestinal Mucosa/pathology , Male , Transforming Growth Factor beta/metabolism , Transforming Growth Factor beta/genetics , Female , Adult , Extracellular Matrix/metabolism , Middle Aged , Regeneration , Fibrosis , Intercellular Signaling Peptides and Proteins/metabolism , Intercellular Signaling Peptides and Proteins/genetics , Epithelial Cells/metabolism , Wound Healing , Colon, Sigmoid/metabolism , Colon, Sigmoid/pathology , Fibroblasts/metabolism
18.
Gynecol Endocrinol ; 40(1): 2353733, 2024 Dec.
Article in English | MEDLINE | ID: mdl-38818662

ABSTRACT

BACKGROUND: Polycystic ovarian syndrome (PCOS) is a prevalent metabolic and endocrine condition in females of reproductive age. This work was to discover the underlying role of Dickkopf 1 (DKK1) and its putative regulating mechanism in P COS. METHODS: Mice recieved dehydroepiandrosterone (DHEA) injection to establish the in vivo P COS model.Hematoxylin and eosin (H&E) staining was performed for histological analysis. RT-qP CR and Western blotting were used to detect gene and protein expression. CCK-8 and flow cytometry assays were applied to detect cell viability and apoptosis. Co-immunoprecipitation (Co-IP) and immunoprecipitation (IP) were applied to assess association between DKK1 and SIRT2. RESULTS: In this work, DKK1 is downregulated in P COS rats. It was revealed that DKK1 knockdown induced apoptosis and suppressed proliferation in KGN cells, whereas DKK1 overexpression had exactly the opposite effects. In addition, DKK1 deactivates the T GF-ß1/SMad3 signaling pathway, thereby controlling KGN cell proliferation and apoptosis. Besides, SIRT2 inhibition reversed the impact of DKK1 overexpression on KGN cell proliferation and apoptosis. Furthermore, SIRT2 downregulated DKK1 expression by deacetylating DKK1 in KGN cells. DISCUSSION: Altogether, we concluded that SIRT2-induced deacetylation of DKK1 triggers T GF-ß1/Smad3 hyperactivation, thereby inhibiting proliferation and promoting apoptosis of KGN cells. The above results indicated that DKK1 might function as a latent target for P COS treatment.


Subject(s)
Intercellular Signaling Peptides and Proteins , Polycystic Ovary Syndrome , Signal Transduction , Sirtuin 2 , Smad3 Protein , Transforming Growth Factor beta1 , Polycystic Ovary Syndrome/metabolism , Polycystic Ovary Syndrome/genetics , Female , Animals , Intercellular Signaling Peptides and Proteins/metabolism , Intercellular Signaling Peptides and Proteins/genetics , Smad3 Protein/metabolism , Smad3 Protein/genetics , Transforming Growth Factor beta1/metabolism , Transforming Growth Factor beta1/genetics , Mice , Sirtuin 2/metabolism , Sirtuin 2/genetics , Rats , Apoptosis , Acetylation , Cell Proliferation , Disease Models, Animal , Humans
19.
J Clin Immunol ; 44(5): 118, 2024 May 17.
Article in English | MEDLINE | ID: mdl-38758417

ABSTRACT

Deficiency of Adenosine Deaminase 2 (DADA2) patients presenting with primary immunodeficiency are at risk of uncontrolled EBV infection and secondary malignancies including EBV-related lymphoproliferative disorders (LPD). This paper describes the first case of EBV related diffuse large B-cell lymphoma in a patient with DADA2 and uncontrolled EBV infection. Consideration should be given to monitoring for EBV viraemia and to preventative EBV specific therapy in DADA2 and patients with at risk primary immunodeficiencies. A type I interferon (IFN) gene signature is associated with DADA2 though its association with immune dysregulation is unclear.


Subject(s)
Adenosine Deaminase , Epstein-Barr Virus Infections , Herpesvirus 4, Human , Lymphoma, Large B-Cell, Diffuse , Humans , Lymphoma, Large B-Cell, Diffuse/etiology , Lymphoma, Large B-Cell, Diffuse/diagnosis , Lymphoma, Large B-Cell, Diffuse/genetics , Epstein-Barr Virus Infections/complications , Epstein-Barr Virus Infections/diagnosis , Adenosine Deaminase/deficiency , Adenosine Deaminase/genetics , Intercellular Signaling Peptides and Proteins/deficiency , Intercellular Signaling Peptides and Proteins/genetics , Male , Female , Hereditary Autoinflammatory Diseases
20.
Cancer Lett ; 592: 216926, 2024 Jun 28.
Article in English | MEDLINE | ID: mdl-38714291

ABSTRACT

Gastric cancer (GC) is one of the most common cancer worldwide. Neural invasion (NI) is considered as the symbiotic interaction between nerves and cancers, which strongly affects the prognosis of GC patients. Small extracellular vesicles (sEVs) play a key role in intercellular communication. However, whether sEVs mediate GC-NI remains unexplored. In this study, sEVs release inhibitor reduces the NI potential of GC cells. Muscarinic receptor M3 on GC-derived sEVs regulates their absorption by neuronal cells. The enrichment of sEV-circVAPA in NI-positive patients' serum is validated by serum high throughput sEV-circRNA sequencing and clinical samples. sEV-circVAPA promotes GC-NI in vitro and in vivo. Mechanistically, sEV-circVAPA decreases SLIT2 transcription by miR-548p/TGIF2 and inhibits SLIT2 translation via binding to eIF4G1, thereby downregulates SLIT2 expression in neuronal cells and finally induces GC-NI. Together, this work identifies the preferential absorption mechanism of GC-derived sEVs by neuronal cells and demonstrates a previously undefined role of GC-derived sEV-circRNA in GC-NI, which provides new insight into sEV-circRNA based diagnostic and therapeutic strategies for NI-positive GC patients.


Subject(s)
Extracellular Vesicles , Intercellular Signaling Peptides and Proteins , Neoplasm Invasiveness , Nerve Tissue Proteins , Neurons , Stomach Neoplasms , Animals , Female , Humans , Male , Mice , Cell Line, Tumor , Cell Proliferation , Extracellular Vesicles/metabolism , Gene Expression Regulation, Neoplastic , Intercellular Signaling Peptides and Proteins/metabolism , Intercellular Signaling Peptides and Proteins/genetics , MicroRNAs/genetics , MicroRNAs/metabolism , Nerve Tissue Proteins/genetics , Nerve Tissue Proteins/metabolism , Neurons/metabolism , Repressor Proteins/genetics , Repressor Proteins/metabolism , Stomach Neoplasms/pathology , Stomach Neoplasms/genetics , Stomach Neoplasms/metabolism , Middle Aged , Mice, Nude , Mice, Inbred BALB C
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