Estrogen receptor ß2 (ERß2)-mediated upregulation of hsa_circ_0000732 promotes tumor progression via sponging microRNA-1184 in triple-negative breast cancer (TNBC).

BACKGROUND: The role of estrogen receptor ß (ERß) in the pathogenesis and development of breast cancer (BC) is controversial, and it is currently considered to play contradictory roles in different phenotypes. ERß2 is thought to promote the BC process, but its role in triple-negative breast cancer (TNBC) has not been reported. METHODS: In this study, we collected tumor tissues from 15 patients with TNBC and obtained a variety of TNBC cell lines as research objects. The plasmid vectors and RNA interference techniques were used to change the level of target genes in cells, quantitative PCR and Western Blots were used to detect gene expression levels, CCK-8 and EdU assay were used to detect cell growth, and Transwell was used to detect cell migration and invasion. Dual-luciferase gene reports and RNA immunoprecipitation (RIP) were used to verify gene targeting relationships. RESULTS: ERß2 was up-regulated in TNBC tissues and promoted the growth, migration, and invasion of TNBC cells. ERß2 regulated hsa_circ_0000732 expression by binding to SCARF1 promoter. Knockdown of hsa_circ_0000732 inhibited TNBC cell proliferation, migration, and invasion by upregulating miR-1184. CONCLUSION: Our present study found that ERß2 is upregulated in some TNBC cells and promotes TNBC cell growth, migration and invasion by regulating hsa_circ_0000732 targeting miR-1184. The special role of ERß2 in TNBC may be the breakthrough of a targeted treatment strategy for TNBC.

SCARF1-Induced Efferocytosis Plays an Immunomodulatory Role in Humans, and Autoantibodies Targeting SCARF1 Are Produced in Patients with Systemic Lupus Erythematosus.

Deficiency in the clearance of cellular debris is a major pathogenic factor in the emergence of autoimmune diseases. We previously demonstrated that mice deficient for scavenger receptor class F member 1 (SCARF1) develop a lupus-like autoimmune disease with symptoms similar to human systemic lupus erythematosus (SLE), including a pronounced accumulation of apoptotic cells (ACs). Therefore, we hypothesized that SCARF1 will be important for clearance of ACs and maintenance of self-tolerance in humans, and that dysregulation of this process could contribute to SLE. In this article, we show that SCARF1 is highly expressed on phagocytic cells, where it functions as an efferocytosis receptor. In healthy individuals, we discovered that engagement of SCARF1 by ACs on BDCA1+ dendritic cells initiates an IL-10 anti-inflammatory response mediated by the phosphorylation of STAT1 and STAT3. Unexpectedly, there was no significant difference in SCARF1 expression in samples of patients with SLE compared with healthy donor samples. However, we detected anti-SCARF1 autoantibodies in 26% of patients with SLE, which was associated with dsDNA Ab positivity. Furthermore, our data show a direct correlation of the levels of anti-SCARF1 in the serum and defects in the removal of ACs. Depletion of Ig restores efferocytosis in SLE serum, suggesting that defects in the removal of ACs are partially mediated by SCARF1 pathogenic autoantibodies. Our data demonstrate that human SCARF1 is an AC receptor in dendritic cells and plays a role in maintaining tolerance and homeostasis.

Integration of genetic, transcriptomic, and clinical data provides insight into 16p11.2 and 22q11.2 CNV genes.

BACKGROUND: Deletions and duplications of the multigenic 16p11.2 and 22q11.2 copy number variant (CNV) regions are associated with brain-related disorders including schizophrenia, intellectual disability, obesity, bipolar disorder, and autism spectrum disorder (ASD). The contribution of individual CNV genes to each of these identified phenotypes is unknown, as well as the contribution of these CNV genes to other potentially subtler health implications for carriers. Hypothesizing that DNA copy number exerts most effects via impacts on RNA expression, we attempted a novel in silico fine-mapping approach in non-CNV carriers using both GWAS and biobank data. METHODS: We first asked whether gene expression level in any individual gene in the CNV region alters risk for a known CNV-associated behavioral phenotype(s). Using transcriptomic imputation, we performed association testing for CNV genes within large genotyped cohorts for schizophrenia, IQ, BMI, bipolar disorder, and ASD. Second, we used a biobank containing electronic health data to compare the medical phenome of CNV carriers to controls within 700,000 individuals in order to investigate the full spectrum of health effects of the CNVs. Third, we used genotypes for over 48,000 individuals within the biobank to perform phenome-wide association studies between imputed expressions of individual 16p11.2 and 22q11.2 genes and over 1500 health traits. RESULTS: Using large genotyped cohorts, we found individual genes within 16p11.2 associated with schizophrenia (TMEM219, INO80E, YPEL3), BMI (TMEM219, SPN, TAOK2, INO80E), and IQ (SPN), using conditional analysis to identify upregulation of INO80E as the driver of schizophrenia, and downregulation of SPN and INO80E as increasing BMI. We identified both novel and previously observed over-represented traits within the electronic health records of 16p11.2 and 22q11.2 CNV carriers. In the phenome-wide association study, we found seventeen significant gene-trait pairs, including psychosis (NPIPB11, SLX1B) and mood disorders (SCARF2), and overall enrichment of mental traits. CONCLUSIONS: Our results demonstrate how integration of genetic and clinical data aids in understanding CNV gene function and implicates pleiotropy and multigenicity in CNV biology.

Insights into the ligand binding specificity of SREC-II (scavenger receptor expressed by endothelial cells).

SREC-II (scavenger receptor expressed by endothelial cells II) is a membrane protein encoded by the SCARF2 gene, with high homology to class F scavenger receptor SR-F1, but no known scavenging function. We produced the extracellular domain of SREC-II in a recombinant form and investigated its capacity to interact with common scavenger receptor ligands, including acetylated low-density lipoprotein (AcLDL) and maleylated or acetylated BSA (MalBSA or AcBSA). Whereas no binding was observed for AcLDL, SREC-II ectodomain interacted strongly with MalBSA and bound with high affinity to AcBSA, a property shared with the SR-F1 ectodomain. SREC-II ectodomain also interacted with two SR-F1-specific ligands, complement C1q and calreticulin, with affinities in the 100 nm range. We proceeded to generate a stable CHO cell line overexpressing full-length SREC-II; binding of MalBSA to these cells was significantly increased compared with nontransfected CHO cells. In contrast, no increase in binding could be detected for C1q and calreticulin. We show for the first time that SREC-II has the capacity to interact with the common scavenger receptor ligand MalBSA. In addition, our data highlight similarities and differences in the ligand binding properties of SREC-II in soluble form and at the cell surface, and show that endogenous protein ligands of the ectodomain of SREC-II, such as C1q and calreticulin, are shared with the corresponding domain of SR-F1.

The Role of SREC-â in Innate Immunity to Aspergillus fumigatus Keratitis.

Purpose: To determine the role of scavenger receptor expressed by endothelial cell-1 (SREC-Ⅰ) in vitro and in a mouse model of Aspergillus fumigatus keratitis. Methods: SREC-Ⅰ mRNA and protein expression were tested in both normal and A fumigatus stimulated human corneal epithelial cells (HCECs). Immunofluorescence was used to detect SREC-Ⅰ expression in human corneas with or without A fumigatus infection. HCECs were incubated with SREC-Ⅰ small interfering RNA, then the mRNA levels of LOX-1, IL-1ß, and TNF-α were detected after A fumigatus stimulation. A mouse fungal keratitis (FK) model was established and SREC-Ⅰ mRNA and protein expression were detected by RT-PCR, Western blot and immunofluorescence. The severity of FK was evaluated by clinical score. CLCX1, LOX-1, IL-1ß, and TNF-α mRNA expression levels were tested before and after anti-SREC-Ⅰ treatment. Results: SREC-Ⅰ expressed in normal and A fumigatus treated HCECs and human corneal epithelium. In vitro experiment showed that SREC-Ⅰ mRNA and protein levels were significantly increased after A fumigatus stimulation. SREC-Ⅰ small interfering RNA treatment inhibited the expressions of LOX-1, IL-1ß, and TNF-α in HCECs. The expressions of CLCX1, LOX-1, IL-1ß, and TNF-α were elevated in mice with A fumigatus keratitis, which could be decreased by SREC-Ⅰ-neutralizing antibody treatment. Conclusions: SREC-Ⅰ is a key mediator in inflammatory response induced by A fumigatus keratitis. SREC-Ⅰ blockade could be a potential therapeutic approach for FK.

Further delineation of van den Ende-Gupta syndrome: Genetic heterogeneity and overlap with congenital heart defects and skeletal malformations syndrome.

Van den Ende-Gupta syndrome (VDEGS) is a rare autosomal recessive condition characterized by distinctive facial and skeletal features, and in most affected persons, by biallelic pathogenic variants in SCARF2. We review the type and frequency of the clinical features in 36 reported individuals with features of VDEGS, 15 (42%) of whom had known pathogenic variants in SCARF2, 6 (16%) with negative SCARF2 testing, and 15 (42%) not tested. We also report three new individuals with pathogenic variants in SCARF2 and clinical features of VDEGS. Of the six persons without known pathogenic variants in SCARF2, three remain unsolved despite extensive genetic testing. Three were found to have pathogenic ABL1 variants using whole exome sequencing (WES) or whole genome sequencing (WGS). Their phenotype was consistent with the congenital heart disease and skeletal malformations syndrome (CHDSKM), which has been associated with ABL1 variants. Of the three unsolved cases, two were brothers who underwent WGS and targeted long-range sequencing of both SCARF2 and ABL1, and the third person who underwent WES and RNA sequencing for SCARF2. Because these affected individuals with classical features of VDEGS lacked a detectable pathogenic SCARF2 variant, genetic heterogeneity is likely. Our study shows the importance of performing genetic testing on individuals with the VDEGS "phenotype," either as a targeted gene analysis (SCARF2, ABL1) or WES/WGS. Additionally, individuals with the combination of arachnodactyly and blepharophimosis should undergo echocardiography while awaiting results of molecular testing due to the overlapping physical features of VDEGS and CHDSKM.

SCARF1 promotes M2 polarization of Kupffer cells via calcium-dependent PI3K-AKT-STAT3 signalling to improve liver transplantation.

OBJECTIVES: This study aimed to investigate the protective effect of SCARF1 on acute rejection (AR), phagocytic clearance of Kupffer cells (KCs), M2 polarization and the exact mechanism underlying these processes. METHODS: AAV was transfected into the portal vein of rats, and AR and immune tolerance (IT) models of liver transplantation were established. Liver tissue and blood samples were collected. The level of SCARF1 was detected via WB and immunohistochemical staining. Pathological changes in liver tissue were detected using HE staining. Apoptotic cells were detected using TUNEL staining. KC polarization was assessed via immunohistochemical staining. Primary KCs were isolated and co-cultured with apoptotic T lymphocytes. Phagocytosis of apoptotic cells and polarization of KCs were both detected using immunofluorescence. Calcium concentration was determined using immunofluorescence and a fluorescence microplate reader. The levels of PI3K, p-AKT and P-STAT3 were assessed via WB and immunofluorescence. RESULTS: Compared to the IT group, the level of SCARF1 was significantly decreased in the AR group. Overexpression of SCARF1 in KCs improved AR and liver function markers. Enhanced phagocytosis mediated by SCARF1 is beneficial for improving the apoptotic clearance of AR and promoting M2 polarization of KCs. SCARF1-mediated enhancement of phagocytosis promotes increased calcium concentration in KCs, thus further activating the PI3K-AKT-STAT3 signalling pathway. CONCLUSIONS: SCARF1 promotes the M2 polarization of KCs by promoting phagocytosis through the calcium-dependent PI3K-AKT-STAT3 signalling pathway.

A blood RNA transcript signature for TB exposure in household contacts.

BACKGROUND: Current tools for diagnosing latent TB infection (LTBI) detect immunological memory of past exposure but are unable to determine whether exposure is recent. We sought to identify a whole-blood transcriptome signature of recent TB exposure. METHODS: We studied household contacts of TB patients; healthy volunteers without recent history of TB exposure; and patients with active TB. We performed whole-blood RNA sequencing (in all), an interferon gamma release assay (IGRA; in contacts and healthy controls) and PET/MRI lung scans (in contacts only). We evaluated differentially-expressed genes in household contacts (log2 fold change ≥1 versus healthy controls; false-discovery rate < 0.05); compared these to differentially-expressed genes seen in the active TB group; and assessed the association of a composite gene expression score to independent exposure/treatment/immunological variables. RESULTS: There were 186 differentially-expressed genes in household contacts (n = 26, age 22-66, 46% male) compared with healthy controls (n = 5, age 29-38, 100% male). Of these genes, 141 (76%) were also differentially expressed in active TB (n = 14, age 27-69, 71% male). The exposure signature included genes from inflammatory response, type I interferon signalling and neutrophil-mediated immunity pathways; and genes such as BATF2 and SCARF1 known to be associated with incipient TB. The composite gene-expression score was higher in IGRA-positive contacts (P = 0.04) but not related to time from exposure, isoniazid prophylaxis, or abnormalities on PET/MRI (all P > 0.19). CONCLUSIONS: Transcriptomics can detect TB exposure and, with further development, may be an approach of value for epidemiological research and targeting public health interventions.

Type F scavenger receptor expressed by endothelial cells (SREC)-II from Epinephelus coioides is a potential pathogen recognition receptor in the immune response to Vibrio parahaemolyticus infection.

Scavenger receptors play a central role in defending against infectious diseases in mammals. However, the function of SRECII remains unknown in teleost fish. In this study, type F scavenger receptor expressed by endothelial cells-II (SRECII) cDNA sequence was first identified from Epinephelus coioides, named EcSRECII, which contained an N-terminal signal peptide, eight EGF/EGF-like cysteine-rich motifs and a C-terminal low-complexity region. The gene location maps revealed that EcSRECII has the conservation of synteny among selected species. Subcellular localization showed that EcSRECII was mainly located in the cytoplasm in HEK293T cells and GS cells. In healthy E. coioides, EcSRECII mRNA was highly expressed in spleen, skin, gill, thymus and head kidney. The relative EcSRECII mRNA expression after Vibrio parahaemolyticus infection was significantly up-regulated at 12 h in spleen, head kidney and thymus, but downregulated at 1 d in skin and reduced at 3 d and 1 w in spleen. Furthermore, overexpression of EcSRECII activated NF-κB and IFN-ß signaling pathway in vitro. Taken together, these results indicated that EcSRECII could be as the potential pathogen recognition receptor for involving in bacterial infection by regulating innate immunity responses in E. coioides.

Results of next-generation sequencing gene panel diagnostics including copy-number variation analysis in 810 patients suspected of heritable thoracic aortic disorders.

Simultaneous analysis of multiple genes using next-generation sequencing (NGS) technology has become widely available. Copy-number variations (CNVs) in disease-associated genes have emerged as a cause for several hereditary disorders. CNVs are, however, not routinely detected using NGS analysis. The aim of this study was to assess the diagnostic yield and the prevalence of CNVs using our panel of Hereditary Thoracic Aortic Disease (H-TAD)-associated genes. Eight hundred ten patients suspected of H-TAD were analyzed by targeted NGS analysis of 21 H-TAD associated genes. In addition, the eXome hidden Markov model (XHMM; an algorithm to identify CNVs in targeted NGS data) was used to detect CNVs in these genes. A pathogenic or likely pathogenic variant was found in 66 of 810 patients (8.1%). Of these 66 pathogenic or likely pathogenic variants, six (9.1%) were CNVs not detectable by routine NGS analysis. These CNVs were four intragenic (multi-)exon deletions in MYLK, TGFB2, SMAD3, and PRKG1, respectively. In addition, a large duplication including NOTCH1 and a large deletion encompassing SCARF2 were detected. As confirmed by additional analyses, both CNVs indicated larger chromosomal abnormalities, which could explain the phenotype in both patients. Given the clinical relevance of the identification of a genetic cause, CNV analysis using a method such as XHMM should be incorporated into the clinical diagnostic care for H-TAD patients.

Inclusion of joint laxity, recurrent patellar dislocation, and short distal ulnae as a feature of Van Den Ende-Gupta syndrome: a case report.

BACKGROUND: Van Den Ende-Gupta Syndrome (VDEGS) is an extremely rare autosomal recessive syndrome with less than 20 reported families (approximately 40 patients) in the worldwide literature. CASE PRESENTATION: We have assessed one consanguineous Saudi family with typical features of VDEGS. Two siblings were affected with almost identical features; including blepharophimosis, arachnodactyly, flexion contractures of the elbows, camptodactyly, slender ribs, hooked lateral clavicular ends, and bilateral radial head dislocations. Both patients had several unusual features; including joint laxity, flat feet, recurrent patellar dislocations, and bilateral short distal ulnae. Full sequencing of SCARF2 revealed a homozygous mutation c.773G > A (p. Cys258Tyr) in both affected children. The parents (both with no abnormalities) were heterozygous for the same mutation. CONCLUSION: Joint laxity, recurrent patellar dislocations, and short distal ulnae should be included as part of the clinical spectrum of VDEGS.

Diagnosis of Van den Ende-Gupta syndrome: Approach to the Marden-Walker-like spectrum of disorders.

Marden-Walker syndrome is challenging to diagnose, as there is significant overlap with other multi-system congenital contracture syndromes including Beals congenital contractural arachnodactyly, D4ST1-Deficient Ehlers-Danlos syndrome (adducted thumb-clubfoot syndrome), Schwartz-Jampel syndrome, Freeman-Sheldon syndrome, Cerebro-oculo-facio-skeletal syndrome, and Van den Ende-Gupta syndrome. We discuss this differential diagnosis in the context of a boy from a consanguineous union with Van den Ende-Gupta syndrome, a diagnosis initially confused by the atypical presence of intellectual disability. SNP microarray and whole exome sequencing identified a homozygous frameshift mutation (p.L870V) in SCARF2 and predicted damaging mutations in several genes, most notably DGCR2 (p.P75L) and NCAM2 (p.S147G), both possible candidates for this child's intellectual disability. We review distinguishing features for each Marden-Walker-like syndrome and propose a clinical algorithm for diagnosis among this spectrum of disorders. © 2016 Wiley Periodicals, Inc.

Molecular Characterization of Three Canine Models of Human Rare Bone Diseases: Caffey, van den Ende-Gupta, and Raine Syndromes.

One to two percent of all children are born with a developmental disorder requiring pediatric hospital admissions. For many such syndromes, the molecular pathogenesis remains poorly characterized. Parallel developmental disorders in other species could provide complementary models for human rare diseases by uncovering new candidate genes, improving the understanding of the molecular mechanisms and opening possibilities for therapeutic trials. We performed various experiments, e.g. combined genome-wide association and next generation sequencing, to investigate the clinico-pathological features and genetic causes of three developmental syndromes in dogs, including craniomandibular osteopathy (CMO), a previously undescribed skeletal syndrome, and dental hypomineralization, for which we identified pathogenic variants in the canine SLC37A2 (truncating splicing enhancer variant), SCARF2 (truncating 2-bp deletion) and FAM20C (missense variant) genes, respectively. CMO is a clinical equivalent to an infantile cortical hyperostosis (Caffey disease), for which SLC37A2 is a new candidate gene. SLC37A2 is a poorly characterized member of a glucose-phosphate transporter family without previous disease associations. It is expressed in many tissues, including cells of the macrophage lineage, e.g. osteoclasts, and suggests a disease mechanism, in which an impaired glucose homeostasis in osteoclasts compromises their function in the developing bone, leading to hyperostosis. Mutations in SCARF2 and FAM20C have been associated with the human van den Ende-Gupta and Raine syndromes that include numerous features similar to the affected dogs. Given the growing interest in the molecular characterization and treatment of human rare diseases, our study presents three novel physiologically relevant models for further research and therapy approaches, while providing the molecular identity for the canine conditions.

The SREC-I and SREC-II associated with epidermal growth factor in scavenger receptor family are the potential regulative transmembrane receptors in Larimichthys crocea.

In innate immunity, the regulation of the immunologic gene expression plays a vital role in defense against pathogenic threat. The class F scavenger receptors (SCARFs), a kind of crucial immunologic type I transmembrane receptors, mainly involve in the signal transmission and eliminating pathogens in host immune system. In this study, the SREC-I and SREC-II of SCARFs in Larimichthys crocea (designated as LycSREC1 and LycSREC2 respectively) were first identified, the potential genetic locus relationships with other species were depicted and the features of gene expression after Vibrio alginolyticus stimulation were tested. The results demonstrated that the complete ORF sequences of two candidates were 3024 bp and 2832 bp (KM884873 and KM884874) respectively including some important domains and motifs, such as EGF/EGF-like domains, TRAF2-binding consensus motif, generic motif and atipical motif. The gene location maps and genetic locus interpreted that the DNA sequences of LycSREC1 and LycSREC2 were 7603 bp and 4883 bp, and some locus had changed compared with human being, but three more crucial genetic locus were conservative among ten species. Furthermore, quantitative real-time PCR (qRT-PCR) analysis indicated that the highest mRNA expression of LycSREC1 and LycSREC2 were both in liver among eight detected tissues, and their expression were up-regulated by V. alginolyticus stimulation. All these findings would contribute to better understanding the biologic function of SCARFs in defending against pathogenic bacteria challenge and further exploring the innate immune of sciaenidae fish.

Scavenger receptor SREC-I promotes double stranded RNA-mediated TLR3 activation in human monocytes.

Scavenger receptor associated with endothelial cells (SREC-I) was previously shown to be expressed by immune cells and to play a role in CD8(+)-mediated T cell immunity. SREC-I was also shown to modulate the function of Toll like receptors with essential roles in innate immunity. Here we have shown that SREC-I enhanced double stranded RNA (dsRNA)-mediated Toll like receptor-3 (TLR3) activation. Viral double stranded RNA (dsRNA) was demonstrated to be a pathogen associated molecular pattern (PAMP) signaling viral infection. We found that in human monocyte/macrophage THP1 cells as well as murine bone marrow derived macrophages SREC-I led to elevated responses to the dsRNA-like molecule polyinosine-polycytidylic acid (Poly I:C) and enhanced production of inflammatory cytokines. Our data also showed that intracellular/endocytic TLR3 could directly interact with SREC-I in the presence of Poly I:C. The internalized ligand, along with TLR3 and SREC-I localized in endosomes within macrophages and in HEK293 cells engineered to express TLR3 and SREC-I. SREC-I also stimulated dsRNA-mediated TLR3 activation of signaling through the NFκß, MAP kinase and interferon regulatory factor 3 (IRF3) pathways leading to expression of cytokines, most notably interleukin-8 and interferon-ß. We therefore hypothesized that SREC-I could be a receptor capable of internalizing Poly I:C, boosting TLR3 mediated inflammatory signaling and stimulating cytokine production in macrophages.

Hsp90-peptide complexes stimulate antigen presentation through the class II pathway after binding scavenger receptor SREC-I.

Molecular chaperones such as heat shock protein 90 (Hsp90) have been shown to form complexes with tumor antigens and can be used to prepare anticancer vaccines largely due to this property. Earlier studies had suggested that mice immunized with a molecular chaperone-based vaccine derived from tumors became immune to further vaccination and that both CD8(+) and CD4(+) T cells were activated by the chaperone vaccine in a manner dependent on scavenger receptor SREC-I. Here we have investigated mechanisms whereby SREC-I might facilitate uptake of Hsp90-conjugated peptides by APC into the MHC class II pathway for presentation to CD4(+) T cells. Our studies showed that antigenic peptides associated with Hsp90 were taken up into the class II pathway by a mechanism dependent on SREC-I binding and internalization and presented to CD4(+) T cells. In addition our studies showed that SREC-I could associate with MHC class II molecules on the cell surface and in intracellular endosomes, suggesting a mechanism involving facilitated uptake of peptides into the MHC class II pathway. These studies in addition to our earlier findings showed SREC-I to play a primary role in chaperone-associated antigen uptake both through cross priming of MHC class I molecules and entry into the class II pathway.

Sclerocornea in a patient with van den Ende-Gupta syndrome homozygous for a SCARF2 microdeletion.

Van den Ende-Gupta Syndrome (VDEGS) is an autosomal recessive disorder characterized by blepharophimosis, distinctive nose, hypoplastic maxilla, and skeletal abnormalities. Using homozygosity mapping in four VDEGS patients from three consanguineous families, Anastacio et al. [Anastacio et al. (2010); Am J Hum Genet 87:553-559] identified homozygous mutations in SCARF2, located at 22q11.2. Bedeschi et al. [2010] described a VDEGS patient with sclerocornea and cataracts with compound heterozygosity for the common 22q11.2 microdeletion and a hemizygous SCARF2 mutation. Because sclerocornea had been described in DiGeorge-velo-cardio-facial syndrome but not in VDEGS, they suggested that the ocular abnormalities were caused by the 22q11.2 microdeletion. We report on a 23-year-old male who presented with bilateral sclerocornea and the VDGEGS phenotype who was subsequently found to be homozygous for a 17 bp deletion in exon 4 of SCARF2. The occurrence of bilateral sclerocornea in our patient together with that of Bedeschi et al., suggests that the full VDEGS phenotype may include sclerocornea resulting from homozygosity or compound heterozygosity for loss of function variants in SCARF2.

The scavenger receptor SCARF1 mediates the clearance of apoptotic cells and prevents autoimmunity.

The clearance of apoptotic cells is critical for the control of tissue homeostasis; however, the full range of receptors on phagocytes responsible for the recognition of apoptotic cells remains to be identified. Here we found that dendritic cells (DCs), macrophages and endothelial cells used the scavenger receptor SCARF1 to recognize and engulf apoptotic cells via the complement component C1q. Loss of SCARF1 impaired the uptake of apoptotic cells. Consequently, in SCARF1-deficient mice, dying cells accumulated in tissues, which led to a lupus-like disease, with the spontaneous generation of autoantibodies to DNA-containing antigens, activation of cells of the immune system, dermatitis and nephritis. The discovery of such interactions of SCARF1 with C1q and apoptotic cells provides insight into the molecular mechanisms involved in the maintenance of tolerance and prevention of autoimmune disease.

SR-A and SREC-I are Kupffer and endothelial cell receptors for helper-dependent adenoviral vectors.

Helper-dependent adenoviral (HDAd) vectors can mediate long-term, high-level transgene expression from transduced hepatocytes with no chronic toxicity. However, a toxic acute response with potentially lethal consequences has hindered their clinical applications. Liver sinusoidal endothelial cells (LSECs) and Kupffer cells are major barriers to efficient hepatocyte transduction. Understanding the mechanisms of adenoviral vector uptake by non-parenchymal cells may allow the development of strategies aimed at overcoming these important barriers and to achieve preferential hepatocyte gene transfer with reduced toxicity. Scavenger receptors on Kupffer cells bind adenoviral particles and remove them from the circulation, thus preventing hepatocyte transduction. In the present study, we show that HDAd particles interact in vitro and in vivo with scavenger receptor-A (SR-A) and with scavenger receptor expressed on endothelial cells-I (SREC-I) and we exploited this knowledge to increase the efficiency of hepatocyte transduction by HDAd vectors in vivo through blocking of SR-A and SREC-I with specific fragments antigen-binding (Fabs).