EGF-like Repeats Research Articles

EDIL3 alleviates Mannan-induced psoriatic arthritis by slowing the intracellular glycolysis process in mononuclear-derived dendritic cells.

Psoriatic arthritis (PsA) is an immune-mediated, chronic inflammatory joint disease that commonly occurs as a complication of psoriasis. EGF-like repeats and discoidal I-like domain 3 (EDIL3) is a secreted protein with multiple structural domains and associated with various physiological functions. In this study, we employed a mannan-induced psoriatic arthritis model to investigate the impact of EDIL3 on PsA pathogenesis. Notably, a downregulation of EDIL3 expression was observed in the PsA model, which correlated with increased disease severity. EDIL3 knockout mice exhibited a more severe phenotype of PsA, which was ameliorated upon re-infusion of recombinant EDIL3 protein. The mitigation effect of EDIL3 on PsA depends on its regulation of the activation of monocyte-derived DCs (MoDCs) and T-help 17 cells (Th17). After inhibiting the function of MoDCs and Th17 cells with neutralizing antibodies, the beneficial effects of EDIL3 on PsA were lost. By inducing adenosine monophosphate (AMP)-activated protein kinase (AMPK) phosphorylation and suppressing protein kinase B (AKT) phosphorylation, EDIL3 attenuates intracellular glycolysis in MoDCs stimulated by glucose, thereby impeding their maturation and differentiation. Moreover, it diminishes the differentiation of Th17 cells and decelerates the progression of PsA. In conclusion, our findings elucidate the role and mechanism of EDIL3 in the development of PsA, providing a new target for clinical diagnosis and treatment.

Developmental endothelial locus 1: the present and future of an endogenous factor in vessels.

Developmental Endothelial Locus-1 (DEL-1), also known as EGF-like repeat and discoidin I-like domain-3 (EDIL3), is increasingly recognized for its multifaceted roles in immunoregulation and vascular biology. DEL-1 is a protein that is mainly produced by endothelial cells. It interacts with various integrins to regulate the behavior of immune cells, such as preventing unnecessary recruitment and inflammation. DEL-1 also helps in resolving inflammation by promoting efferocytosis, which is the process of clearing apoptotic cells. Its potential as a therapeutic target in immune-mediated blood disorders, cardiovascular diseases, and cancer metastasis has been spotlighted due to its wide-ranging implications in vascular integrity and pathology. However, there are still unanswered questions about DEL-1's precise functions and mechanisms. This review provides a comprehensive examination of DEL-1's activity across different vascular contexts and explores its potential clinical applications. It underscores the need for further research to resolve existing controversies and establish the therapeutic viability of DEL-1 modulation.

Novel insight into FCSK-congenital disorder of glycosylation through a CRISPR-generated cell model.

FCSK-congenital disorder of glycosylation (FCSK-CDG) is a recently discovered rare autosomal recessive genetic disorder with defective fucosylation due to mutations in the fucokinase encoding gene, FCSK. Despite the essential role of fucokinase in the fucose salvage pathway and severe multisystem manifestations of FCSK-CDG patients, it is not elucidated which cells or which types of fucosylation are affected by its deficiency. In this study, CRISPR/Cas9 was employed to construct an FCSK-CDG cell model and explore the molecular mechanisms of the disease by lectin flow cytometry and real-time PCR analyses. Comparison of cellular fucosylation by lectin flow cytometry in the created CRISPR/Cas9 FCSK knockout and the same unedited cell lines showed no significant change in the amount of cell surface fucosylated glycans, which is consistent with the only documented previous study on different cell types. It suggests a probable effect of this disease on secretory glycoproteins. Investigating O-fucosylation by analysis of the NOTCH3 gene expression as a potential target revealed a significant decrease in the FCSK knockout cells compared with the same unedited ones, proving the effect of fucokinase deficiency on EGF-like repeats O-fucosylation. This study expands insight into the FCSK-CDG molecular mechanism; to the best of our knowledge, it is the first research conducted to reveal a gene whose expression level alters due to this disease.

Role of Mutation of NOTCH1 gene in development of oral squamous cell carcinoma: a narrative review.

Cancer of the oral cavity has numerous types and, among all, oral squamous cell carcinoma represents >90% of all cancers of the oral area. Oral squamous cell carcinoma arises from the squamous lining of the oral cavity. Across the globe, most commonly it develops in the regions of tongue followed by floor of the mouth, and lower lip. Neurogenic locus notch homolog protein 1 gene has its association with oral squamous cell carcinoma and is known to be associated with both oncogenic and tumour suppressor roles. The current narrative review comprised literature published from 2013 to 2023. It was searched on Google Scholar, PubMed and Google databases. Globally, neurogenic locus notch homolog protein 1 mutations are associated with the development of oral squamous cell carcinoma. Most of the mutations are linked to ligand bind epidermal growth factor-like repeat region of extracellular domain of neurogenic locus notch homolog protein 1. Once activated, the pathway is involved in tumour progression and metastasis. The Asians compared to Caucasians are more affected by neurogenic locus notch homolog protein 1 mutations.

Epidermal Growth Factor-Like Repeats and Discoidin I-Like Domains 3 Deficiency Attenuates Dilated Cardiomyopathy by Inhibiting Ubiquitin Specific Peptidase 10 Dependent Smad4 Deubiquitination.

Dilated cardiomyopathy (DCM) is the leading cause of heart failure with a poor prognosis. Recent studies suggest that endothelial to mesenchymal transition (EndMT) may be involved in the pathogenesis and cardiac remodeling during DCM development. EDIL3 (epidermal growth factor-like repeats and discoidin I-like domains 3) is an extracellular matrix glycoprotein that has been reported to promote EndMT in various diseases. However, the roles of EDIL3 in DCM still remain unclear. A mouse model of DCM and human umbilical vein endothelial cells were used to explore the roles and mechanisms of EDIL3 in DCM. The results indicated that EndMT and EDIL3 were activated in DCM mice. EDIL3 deficiency attenuated cardiac dysfunction and remodeling in DCM mice. EDIL3 knockdown alleviated EndMT by inhibiting USP10 (ubiquitin specific peptidase 10) dependent Smad4 deubiquitination invivo and invitro. Recombinant human EDIL3 promoted EndMT via reinforcing deubiquitination of Smad4 in human umbilical vein endothelial cells treated with IL-1β (interleukin 1β) and TGF-β (transforming growth factor beta). Inhibiting USP10 abolished EndMT exacerbated by EDIL3. In addition, recombinant EDIL3 also aggravates doxorubicin-induced EndMT by promoting Smad4 deubiquitination in HUVECs. Taken together, these results indicate that EDIL3 deficiency attenuated EndMT by inhibiting USP10 dependent Smad4 deubiquitination in DCM mice.

Sperm traits and seminal plasma proteome of locally adapted hairy rams subjected to intermittent scrotal insulation

The present study evaluated the effects of heat stress on reproductive parameters of hairy rams. Six animals were subjected to scrotal insulation during four consecutive nights (6 PM – 6 AM). Day (D) 0 was the first day of insulation. Scrotal circumference increased from 30.5 ± 0.3 cm (at pre-insulation) to 31.8 ± 0.4 cm on D4, decreased 3.9 cm on D28, returning to 30.6 ± 0.6 cm on D57. Sperm concentration decreased from 3.7 ± 0.12 ×109 sperm/mL before insulation to 2.6 ± 0.1 ×109 on D23, returning to normal on D57. Sperm motility averaged 75 ± 2.9% before insulation, was undetectable on D23, and became normal on D77. Sperm with normal morphology reached 5.9 ± 2.6% on D35 but recovered (86.8 ± 2.1%) on D91. Sperm DNA integrity decreased from 86.5 ± 4.7% before insulation to 11.1 ± 3.7% on D63, returning to pre-insulation values on D120. Sperm BSP immunostaining was reduced after scrotal insulation. Variations in seminal protein abundances coincided with changes in sperm parameters. Seminal plasma superoxide dismutase, carboxypeptidase Q-precursor and NPC intracellular cholesterol transporter 2 decreased on D18, returning to normal after D28. Albumin, inhibitor of carbonic anhydrase precursor, EGF-like repeat and discoid I-like domain-containing protein 3 and polymeric immunoglobulin receptor increased after insulation. In summary, intermittent scrotal insulation drastically altered ram sperm attributes and seminal proteins, especially those associated with oxidative stress. Knowledge of animal´s response to thermal stress is vital in the scenario of climate changes.

Association of Rare NOTCH3 Variants With Prevalent and Incident Stroke and Dementia in the General Population.

It is uncertain whether rare NOTCH3 variants are associated with stroke and dementia in the general population and whether they lead to alterations in cognitive function. This study aims to determine the associations of rare NOTCH3 variants with prevalent and incident stroke and dementia, as well as cognitive function changes. In the prospective community-based Shunyi Study, a total of 1007 participants were included in the baseline analysis. For the follow-up analysis, 1007 participants were included in the stroke analysis, and 870 participants in the dementia analysis. All participants underwent baseline brain magnetic resonance imaging, carotid ultrasound, and whole exome sequencing. Rare NOTCH3 variants were defined as variants with minor allele frequency <1%. A total of 137 rare NOTCH3 carriers were enrolled in the baseline study. At baseline, rare NOTCH3 variant carriers had higher rates of stroke (8.8% versus 5.6%) and dementia (2.9% versus 0.8%) compared with noncarriers. After adjustment for associated risk factors, the epidermal growth factor-like repeats (EGFr)-involving rare NOTCH3 variants were associated with a higher risk of prevalent stroke (odds ratio [OR], 2.697 [95% CI, 1.266-5.745]; P=0.040) and dementia (OR, 8.498 [95% CI, 1.727-41.812]; P=0.032). After 5 years of follow-up, we did not find that the rare NOTCH3 variants increased the risk of incident stroke and dementia. There was no statistical difference in the change in longitudinal cognitive scale scores. Rare NOTCH3 EGFr-involving variants are genetic risk factors for stroke and dementia in the general Chinese population.

In vivo evidence for GDP-fucose transport in the absence of transporter SLC35C1 and putative transporter SLC35C2

Slc35c1 encodes an antiporter that transports GDP-fucose into the Golgi and returns GMP to the cytoplasm. The closely related gene Slc35c2 encodes a putative GDP-fucose transporter and promotes Notch fucosylation and Notch signaling in cultured cells. Here, we show that HEK293T cells lacking SLC35C1 transferred reduced amounts of O-fucose to secreted epidermal growth factor-like (EGF) repeats from NOTCH1 or secreted thrombospondin type I repeats (TSRs) from thrombospondin 1. However, cells lacking SLC35C2 did not exhibit reduced fucosylation of these EGF repeats or TSRs. To investigate SLC35C2 functions in vivo, WW6 embryonic stem cells were targeted for Slc35c2. Slc35c2[-/-] mice were viable and fertile and exhibited no evidence of defective Notch signaling during skeletal or T cell development. By contrast, mice with inactivated Slc35c1 exhibited perinatal lethality and marked skeletal defects in late embryogenesis, typical of defective Notch signaling. Compound Slc35c1[-/-]Slc35c2[-/-] mutants were indistinguishable in skeletal phenotype from Slc35c1[-/-] embryos and neonates. Double mutants did not exhibit the exacerbated skeletal defects predicted if SLC35C2 was functionally important for Notch signaling in vivo. In addition, NOTCH1 immunoprecipitated from Slc35c1[-/-]Slc35c2[-/-] neonatal lung carried fucose detected by binding of Aleuria aurantia lectin. Given that the absence of both SLC35C1, a known GDP-fucose transporter, and SLC35C2, a putative GDP-fucose transporter, did not lead to afucosylated NOTCH1 nor to the severe Notch signaling defects and embryonic lethality expected if all GDP-fucose transport were abrogated, at least one more mechanism of GDP-fucose transport into the secretory pathway must exist in mammals.

EOGT enables residual Notch signaling in mouse intestinal cells lacking POFUT1

Notch signaling determines cell fates in mouse intestine. Notch receptors contain multiple epidermal growth factor-like (EGF) repeats modified by O-glycans that regulate Notch signaling. Conditional deletion of protein O-fucosyltransferase 1 (Pofut1) substantially reduces Notch signaling and markedly perturbs lineage development in mouse intestine. However, mice with inactivated Pofut1 are viable, whereas complete elimination of Notch signaling in intestine is lethal. Here we investigate whether residual Notch signaling enabled by EGF-domain-specific O-linked N-acetylglucosamine transferase (Eogt) permits mice conditionally lacking Pofut1 in intestine to survive. Mice globally lacking Eogt alone were grossly unaffected in intestinal development. In contrast, mice lacking both Eogt and Pofut1 died at ~ 28 days after birth with greater loss of body weight, a greater increase in the number of goblet and Paneth cells, and greater downregulation of the Notch target gene Hes1, compared to Pofut1 deletion alone. These data reveal that both O-fucose and O-GlcNAc glycans are fundamental to Notch signaling in the intestine and provide new insights into roles for O-glycans in regulating Notch ligand binding. Finally, EOGT and O-GlcNAc glycans provide residual Notch signaling and support viability in mice lacking Pofut1 in the intestine.

EDIL3 is a potential prognostic biomarker that correlates with immune infiltrates in gastric cancer.

EDIL3, which contains epidermal growth factor-like repeats and discoidin I-like domains, is a secretory protein that plays an important role in embryonic development and various illnesses. However, the biological function of EDIL3 in gastric cancer (GC) is still unclear. The objective of this research was to explore the role and potential mechanism of EDIL3 in GC. In this study, we used the GEPIA, HPA, MethSurv, SMART, STRING, GeneMANIA, LinkedOmics TIMER, TIMER2.0, TISIDB, and RNAactDrug databases to comprehensively analyze the roles of EDIL3 in GC. To validate the in silico findings, EDIL3 expression was measured in our collected GC tissues. Meanwhile, several in vitro experiments were performed to test the function of EDIL3 in GC. We found that EDIL3 was highly expressed in GC and associated with adverse clinical features. In vitro assays revealed that EDIL3 promoted the proliferation, migration, and invasion of GC cells. The functions of EDIL3 and co-expression genes were significantly associated with extracellular structure organization and matrix receptor interaction. EDIL3 expression was positively associated with numerous tumor-infiltrating immune cells and their biomarkers. This study determined that EDIL3 may function as an oncogene and is associated with immune infiltration in GC. EDIL3 could be used as a potential therapeutic target for GC.

Overexpression of ASPH protein predicts poor outcomes in retroperitoneal liposarcoma patients.

Overexpression of ASPH protein predicts poor outcomes in retroperitoneal liposarcoma patients.

Identification of Eimeria tenella sporozoite immunodominant mimotopes by random phage-display peptide libraries-a proof of concept study.

Coccidiosis, caused by parasites of numerous Eimeria species, has long been recognized as an economically significant disease in the chicken industry worldwide. The rise of anti-coccidian resistance has driven a search for other parasite management techniques. Recombinant antigen vaccination presents a highly feasible alternative. Properly identifying antigens that might trigger a potent immune response is one of the major obstacles to creating a viable genetically modified vaccine. This study evaluated a reverse immunology approach for the identification of B-cell epitopes. Antisera from rabbits and hens inoculated with whole-sporozoites of E. tenella were used to identify Western blot antigens. The rabbit IgG fraction from the anti-sporozoite serum exhibited the highest reactogenicity; consequently, it was purified and utilized to screen two random Phage-display peptide libraries (12 mer and c7c mer). After three panning rounds, 20 clones from each library were randomly selected, their nucleotide sequences acquired, and their reactivity to anti-sporozoite E. tenella serum assessed. The selected peptide clones inferred amino acid sequences matched numerous E. tenella proteins. The extracellular domain of the epidermal growth factor-like (EGF-like) repeats, and the thrombospondin type-I (TSP-1) repeats of E. tenella micronemal protein 4 (EtMIC4) matched with the c7c mer selected clones CNTGSPYEC (2/20) and CMSTGLSSC (1/20) respectively. The clone CSISSLTHC that matched with a conserved hypothetical protein of E. tenella was widely selected (3/20). Selected clones from the 12-mer phage display library AGHTTQFNSKTT (7/20), GPNSAFWAGSER (2/20) and HFAYWWNGVRGP (8/20) showed similarities with a cullin homolog, elongation factor-2 and beta-dynein chain a putative E. tenella protein, respectively. Four immunodominant clones were previously selected and used to immunize rabbits. By ELISA and Western blot, all rabbit anti-clone serums detected E. tenella native antigens. Thus, selected phagotopes contained recombinant E. tenella antigen peptides. Using antibodies against E. tenella sporozoites, this study demonstrated the feasibility of screening Phage-display random peptide libraries for true immunotopes. In addition, this study looked at an approach for finding novel candidates that could be used as an E. tenella recombinant epitope-based vaccine.

Autosomal Recessive NOTCH3-Related Leukodystrophy in Two Siblings and Review of the Literature

BackgroundNOTCH3, a large type I transmembrane receptor expressed on arterial smooth muscle cells and capillary pericytes, features a diverse extracellular domain with 34 epidermal growth factor-like repeats. It exhibits distinct phenotypes due to variant zygosity and type; missense mutations cause CADASIL with cerebral vasculopathy, while null mutations lead to severe congenital manifestations. MethodsThis report describes two cases with homozygous loss- of- function variants in NOTCH3 along with their clinical manifestations. ResultsThese patients presented with a severe congenital phenotype, including eye misalignment, visual impairment, epilepsy, global developmental delay, and subsequent development of pyramidal signs. Biallelic nonsense variants were discovered in both the cases (NM_000435.3:c.2203 C > T (p. [Arg735Ter]). Livedo reticularis was not reported in our cases, although it was present in previously reported patients. Autosomal recessive NOTCH3-related leukodystrophy is usually caused by biallelic null mutations in NOTCH3. ConclusionsThe phenotype of biallelic null variants is associated with a more severe phenotype than the dominantly inherited form of the disease.

Two NOTCH1 O-fucose sites have opposing functions in mouse retinal angiogenesis.

Previous in vitro studies demonstrated that Fringe glycosylation of the NOTCH1 extracellular domain at O-fucose residues in Epidermal Growth Factor-like Repeats (EGFs) 6 and 8 is a significant contributor to suppression of NOTCH1 activation by JAG1 or enhancement of NOTCH1 activation by DLL1, respectively. In this study, we sought to evaluate the significance of these glycosylation sites in a mammalian model by generating 2 C57BL/6J mouse lines carrying NOTCH1 point mutations, which eliminate O-fucosylation and Fringe activity at EGFs 6 (T232V) or 8 (T311V). We assessed changes to morphology during retinal angiogenesis, a process in which expression of Notch1, Jag1, Dll4, Lfng, Mfng, and Rfng genes coordinate cell-fate decisions to grow vessel networks. In the EGF6 O-fucose mutant (6f/6f) retinas, we observed reduced vessel density and branching, suggesting that this mutant is a Notch1 hypermorph. This finding agrees with prior cell-based studies showing that the 6f mutation increased JAG1 activation of NOTCH1 during co-expression with inhibitory Fringes. Although we predicted that the EGF8 O-fucose mutant (8f/8f) would not complete embryonic development due to the direct involvement of the O-fucose in engaging ligand, the 8f/8f mice were viable and fertile. In the 8f/8f retina, we measured increased vessel density consistent with established Notch1 hypomorphs. Overall, our data support the importance of NOTCH1 O-fucose residues for pathway function and confirms that single O-glycan sites are rich in signaling instructions for mammalian development.

A novel scavenger receptor (EcSRECII) as a lipopolysaccharide recognition molecule involved in regulating NF-κB activation through extracellular EGF-like cysteine-rich repeat domains with lysosomes in Epinephelus coioides

Scavenger receptors (SRs), as multifunctional pattern recognition receptors, play an important role in innate immunity in mammals, however, their function in fish is limited. Herein, scavenger receptor F2 in Epinephelus coioides (EcSRECII) induced an innate immune response to LPS in GS cells. EcSRECII markedly enhanced LPS-induced NF-κB and IFN-β signaling pathways, whereas knockdown of EcSRECII significantly inhibited LPS-induced NF-κB and IFN-β promoter activation. Interestingly, only retain of epidermal growth factor (EGF)/EGF-like domain in EcSRECII resulted in a punctate cytoplasmic distribution, while the C-terminal domain exhibited a distinct cytoskeletal cytoplasmic distribution. Moreover, devoid of this EGF/EGF-like domain fragment more sharply impaired its ability to activate EcSRECII-induced NF-κB activation than deletion of the C-terminal domain region, but both domains significantly induced IFN-β promoter activation. Full-length EcSRECII and the deletion mutant of C-terminal domain could partly colocalize with lysosomes by LPS derived from V. parahaemolyticus (V.p. LPS) in GS cells, but there was no similar distribution in the deletion mutant of EGF/EGF-like domain. This finding firstly suggested that the N-terminal EGF/EGF-like domain was necessary for the NF-κB signaling pathway to trigger resistance to vibrio infection and its functional exertion may be associated with lysosomes, thus providing insights into the regulation of resistance to vibrio infection in teleosts.

EDIL3 and VEGF Synergistically Affect Angiogenesis in Endothelial Cells.

Angiogenesis is one of the histologically predominant characteristics of psoriasis. Vascular endothelial growth factor (VEGF) and epidermal growth factor-like repeats and discoidin I-like domains 3 (EDIL3) have critical effects on angiogenesis. Both these proteins are vital proangiogenic factors in tumor occurrence and progression; however, the relationship between EDIL3 and VEGF with psoriasis remains unclear. We aimed to elucidate the role of EDIL3 and VEGF and the involved mechanisms in psoriasis-associated angiogenesis. EDIL3 and VEGF expression in cutaneous tissue was determined by immunohistochemical assay. The effects of EDIL3 on VEGF, VEGFR2, and the growth, migration, and tube formation of human umbilical vein endothelial cells (HUVECs) were analyzed by Western blotting assay, cell counting kit-8 assay, Transwell assay, and Matrigel tube formation assay. EDIL3 and VEGF levels in psoriatic lesions significantly increased as compared to those in normal individuals and showed a positive relationship with the Psoriasis Area and Severity Index. The downregulation of EDIL3 decreased VEGF and VEGFR2 expression in HUVECs. Moreover, the decreased expression of EDIL3 and VEGF reduced the growth, invasion, and tube formation abilities of HUVECs, while EDIL3 resistance to VEGF and VEGFR2 was restored by using the EDIL3 recombinant protein. These results suggest that psoriasis is also characterized by EDIL3 and VEGF-mediated angiogenesis. Thus, EDIL3 and VEGF could serve as novel targets for treating psoriasis.

A Rare Mutation Associated with Cerebral Arteriopathy with Subcortical Infarct and Leukoencephalopathy (CADASIL) (P2-5.002)

<h3>Objective:</h3> To report a rare cause of CADASIL with a point mutation in exon 5 of NOTCH 3 gene causing a non-cysteine change and its implication. <h3>Background:</h3> CADASIL is a rare genetic non-amyloid arteriopathy primarily affecting small brain vessels. Its prevalence in population is 2 to 5/100,000, but may be underestimated and underdiagnosed. Although there is over 200 different NOTCH-3 mutations described worldwide, 95% of them are missense mutation in the exons 2–24, which leads to a gain or loss of a cysteine residue in one of 34 epidermal growth factor-like repeat (EGFr) domains of the NOTCH3 protein. Non-cysteine mutations are rare and their role is not well determined. <h3>Design/Methods:</h3> Case report <h3>Results:</h3> 58-year-old man with a three-year progressive cognitive decline, history of headaches, fatigue, and generalized weakness was admitted to the neurology wards for worsening weakness and increased need for assistance in daily life. Neurological exam was significant for mild left hemiparesis. MoCA score was 19/30. Brain MRI showed one subacute and numerous chronic lacunar ischemic strokes including in the corpus callosum, also seen on previous outpatient MRIs. These changes had been attributed to demyelinating disease by the outpatient physician. An extensive workup including autoimmune was unrevealing. Classical leukoencephalopathy was not present, but hyperintensities in the temporal lobe raised concern for CADASIL. DNA sequencing revealed a non-cysteine mutation with c.754 G&gt;A transition in exon 5 of NOTCH 3 gene resulting in a substitution of Valine to Methionine (V252M). This is the second case of this mutation reported in the literature. Non-cysteine mutation may affect NOTCH-3 signaling output and possibly lead to a milder leukoencephalopathy and extensive involvement of corpus callosum with lacunar infarctions resembling demyelinating disease. <h3>Conclusions:</h3> CADASIL with a point mutation in exon 5 of NOTCH 3 gene causing a non-cysteine change may present with milder disease and not classical MRI changes. <b>Disclosure:</b> Dr. Delpirou Nouh has nothing to disclose. Dr. Mahmoud has nothing to disclose. Juliane Chainakul has nothing to disclose. Robert Hamilton has nothing to disclose. Dr. Sidorov has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Allergan. Dr. Sidorov has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for BioHaven .

SCUBE-1 as a novel predictor of thromboembolic event

SCUBE-1 is a newly identified, secreted cell surface protein that is determined during early embryogenesis. This protein consists of cascading EGF-like repeats following the N-terminal signal peptide sequence, a spacer region, cysteine-rich repeat motifs, and a CUB domain at the C-terminus. These molecules are stored in alpha granules in inactivated platelets, translocated to the platelet surface after activation by thrombin, secreted as small soluble fragments, and incorporated into the thrombus.

A new model of Notch signalling: Control of Notch receptor cis-inhibition via Notch ligand dimers

All tissue development and replenishment relies upon the breaking of symmetries leading to the morphological and operational differentiation of progenitor cells into more specialized cells. One of the main engines driving this process is the Notch signal transduction pathway, a ubiquitous signalling system found in the vast majority of metazoan cell types characterized to date. Broadly speaking, Notch receptor activity is governed by a balance between two processes: 1) intercellular Notch transactivation triggered via interactions between receptors and ligands expressed in neighbouring cells; 2) intracellular cis inhibition caused by ligands binding to receptors within the same cell. Additionally, recent reports have also unveiled evidence of cis activation. Whilst context-dependent Notch receptor clustering has been hypothesized, to date, Notch signalling has been assumed to involve an interplay between receptor and ligand monomers. In this study, we demonstrate biochemically, through a mutational analysis of DLL4, both in vitro and in tissue culture cells, that Notch ligands can efficiently self-associate. We found that the membrane proximal EGF-like repeat of DLL4 was necessary and sufficient to promote oligomerization/dimerization. Mechanistically, our experimental evidence supports the view that DLL4 ligand dimerization is specifically required for cis-inhibition of Notch receptor activity. To further substantiate these findings, we have adapted and extended existing ordinary differential equation-based models of Notch signalling to take account of the ligand dimerization-dependent cis-inhibition reported here. Our new model faithfully recapitulates our experimental data and improves predictions based upon published data. Collectively, our work favours a model in which net output following Notch receptor/ligand binding results from ligand monomer-driven Notch receptor transactivation (and cis activation) counterposed by ligand dimer-mediated cis-inhibition.

Establishment of NCHi009-A, an iPSC line from a patient with hypoplastic left heart syndrome (HLHS) carrying a heterozygous NOTCH1 mutation

Hypoplastic left heart syndrome (HLHS) is a congenital heart malformation clinically characterized by an underdeveloped left ventricle, mitral or aortic valve stenosis or atresia, and narrowed ascending aorta. Although genetic etiology of HLHS is heterogenous, recurrent NOTCH1 variants have been associated with this defect. We report generation of an iPSC line derived from a female with HLHS with a heterozygous missense NOTCH1 (c.2058G > A; p.Gly661Ser) mutation within the conserved EGF-like repeat 17. This iPSC line exhibited typical cellular morphology, normal karyotype, high expression of pluripotent markers, and trilineage differentiation potential; and can be leveraged to dissect the complex NOTCH1-mediated HLHS disease mechanism.