Extracellular Matrix Protein 1 Gene Research Articles

Citri Reticulatae Pericarpium-Reynoutria japonica Houtt. herb pair suppresses breast cancer liver metastasis by targeting ECM1-mediated cholesterol biosynthesis pathway

BackgroundLiver metastasis is a frequent event in breast cancer that causes low survival rate and poor prognosis. Citri Reticulatae Pericarpium-Reynoutria japonica Houtt. (CR), a traditional Chinese herb pair, is used for the treatment of breast cancer liver metastasis or cholesterol gallstone disease in clinics. PurposeThis study attempted to investigate the potential therapeutic target and mechanism of CR herb pair on breast cancer liver metastasis. MethodsThe anti-metastatic and cholesterol-lowering activities of CR extract were evaluated in triple-negative breast cancer (TNBC) cell lines and an experimental liver metastasis model. The role of extracellular matrix protein 1 (ECM1) in the cholesterol biosynthesis pathway was determined by the knockdown and overexpression of ECM1 gene of TNBC cells. Changes in the gene and protein expression levels of ECM1 and the cholesterol biosynthesis pathway after CR treatment were detected in vitro and in vivo by real-time PCR and Western blot. ResultsThe invasive and metastatic potentials and hypercholesterol levels of TNBC cells were positively associated with ECM1 expression. ECM1 knockdown reduced tumor cholesterol levels via downregulating cholesterol biosynthesis genes, including ACAT2, HMGCS1, HMGCR, MVK, and MVD, whereas ECM1 overexpression elicited the opposite effects. CR herb pair exerts the potential therapeutic effects on TNBC liver metastasis, which is partially mediated by disrupting ECM1-activated cholesterol biosynthesis process in TNBC cells. ConclusionThis study reveals that ECM1 is a novel target for the activation of cholesterol biosynthesis to promote TNBC liver metastasis occurrence. CR herb pair, an ECM1 inhibitor, maybe be considered to serve as an adjuvant therapeutic drug for liver metastasis in clinical practice.

Wentilactone A Reverses the NF-κB/ECM1 Signaling-Induced Cisplatin Resistance through Inhibition of IKK/IκB in Ovarian Cancer Cells.

Wentilactone A (WA) is a tetranorditerpenoid isolated from marine algae. We previously found that WA inhibited cancer cell proliferation with little toxicity. In this study, we show that high expression of extracellular matrix protein-1 (ECM1) promotes cancer cell cisplatin resistance, and the secreted ECM1 activates normal fibroblasts (NFs) to transform cells with characteristics of cancer-associated fibroblasts (CAFs). Transcription of the ECM1 gene is regulated largely by NF-κB through EP881C/T-EP266C binding sites. WA supresses the phosphorylation of NF-κB through inhibition of the upstream IKK/IκB phoshorylation to block the expression of ECM1, which reverses the cisplatin-induced activation of NF-κB/ECM1. On the contrary, cisplatin facilitates phosphorylation of NF-κB to enhance the expression of ECM1. These results highlight ECM1 as a potential target for treatment of cisplatin-resistant cancers associated with the ECM1 activated signaling. In addition, WA reverses cisplatin resistance by targeting both tumor cells and the tumor microenvironment through IKK/IκB/NF-κB signaling to reduce the expression of the ECM1 protein.

Synthesized Drug from Medicinal Plant phytochemicals Effectively Targets ECM1 Gene Mutations in Ulcerative Colitis

: Ulcerative colitis (UC); an inflammatory bowel disease primarily affects the mucosa of the colon. Depending on its mode of appearance, it can affect either the entire colon or even the distal rectum. UC can manifest in both genders and every generation, but most generally appear in people between the ages of 15 and 30. The extracellular matrix protein-1 (ECM1) gene is an important candidate, mutations leading to tissue damage in patients with ECM1 single-nucleotide polymorphisms are likely to intensify tissue damage caused by Metalloproteinase9 resulting in UC. In this analysis, approval for the synthesis of Chemical Compound was obtained from the scientific committee of the Department of Traditional Chinese Medicine, Qilu Hospital, China. Several derivatives used as UC therapy were selected to build the pharmacophore model, using a ligand-based pharmacophore modeling approach and virtual screenings were done for the identification of suitable drug compounds. The selected compound was then synthesized in-vitro and validated using the molecular docking technique. The synthesized compound fulfills all the characteristics of the non-toxic existence of other drug-likeness laws. The specific interactive amino acids found in the docked complex are arginine (ARG):47, lysine (LYS):54, phenylalanine (PHE):141, aspargine (ASN):51, serine (SER):219, histadine (HIS):144, PHE:214, valine(VAL):220, tyrosine(TYR):145, and TYR:284. The interaction of the synthesized compound with mutated TYR:284 of ECM1 confirmed the viability and safety of a drug molecule as a medication in Ulcerative Colitis care. In the future, its validity can be explored in the laboratory and this synthesized compound can be used as a medication target in clinical studies against TYR:284 mutation in the ECM1 gene.

ECM1 is an essential factor for the determination of M1 macrophage polarization in inflammatory bowel disease in response to LPS stimulation

Abstract Inflammatory bowel disease (IBD) comprises chronic relapsing disorders of the gastrointestinal tract characterized pathologically by intestinal inflammation and epithelial injury. Here, we uncover a new function of extracellular matrix protein 1 (ECM1) in promoting the pathogenesis of human and mouse IBD. ECM1 was highly expressed in macrophages, particularly tissue-infiltrated macrophages under inflammatory conditions, and ECM1 expression was significantly induced during IBD progression. The macrophage-specific knockout of ECM1 resulted in increased arginase 1 (ARG1) expression and impaired polarization into the M1 macrophage phenotype following LPS treatment. A mechanistic study showed that ECM1 can regulate M1 macrophage polarization through the GM-CSF/STAT5 signalling pathway. Pathological changes in mice with dextran sodium sulphate-induced IBD were alleviated by the specific knockout of the ECM1 gene in macrophages. Taken together, our findings show that ECM1 has an important function in promoting M1 macrophage polarization, which is critical for controlling inflammation and tissue repair in the intestine.

ECM1 is an essential factor for the determination of M1 macrophage polarization in IBD in response to LPS stimulation

Inflammatory bowel disease (IBD) comprises chronic relapsing disorders of the gastrointestinal tract characterized pathologically by intestinal inflammation and epithelial injury. Here, we uncover a function of extracellular matrix protein 1 (ECM1) in promoting the pathogenesis of human and mouse IBD. ECM1 was highly expressed in macrophages, particularly tissue-infiltrated macrophages under inflammatory conditions, and ECM1 expression was significantly induced during IBD progression. The macrophage-specific knockout of ECM1 resulted in increased arginase 1 (ARG1) expression and impaired polarization into the M1 macrophage phenotype after lipopolysaccharide (LPS) treatment. A mechanistic study showed that ECM1 can regulate M1 macrophage polarization through the granulocyte-macrophage colony-stimulating factor/STAT5 signaling pathway. Pathological changes in mice with dextran sodium sulfate-induced IBD were alleviated by the specific knockout of the ECM1 gene in macrophages. Taken together, our findings show that ECM1 has an important function in promoting M1 macrophage polarization, which is critical for controlling inflammation and tissue repair in the intestine.

MiR-92a antagonized the facilitation effect of extracellular matrix protein 1 in GC metastasis through targeting its 3′UTR region

MicroRNAs were known to play very important roles in human diseases, and have attracted great interests of research scientists in medicine, toxicology and functional foods. Gastric carcinoma (GC) remains one of the most common and lethal types of malignancy worldwide. However, the molecular mechanism of GC and the role of microRNAs in GC development remain unclear. The expression of extracellular matrix protein 1 (ECM1) is up-regulated in many cancer types, but its functional role is inconstant. In the present study, we aimed to investigate the correlation between GC development and ECM1 expression, along with its regulation by microRNAs. Immunohistochemical results showed that ECM1 was up-regulated in GC tissues and ECM1 expression level was negatively correlated with the prognosis of GC. ECM1 was found to promote gastric cancer cell metastasis in cell migration assays by facilitating the expression of proteins involved in epithelial-mesenchymal transition (EMT). MiR-92a was recognized for the first time to suppress the migration of human GC cells by directly targeting to the 3′UTR of ECM1 gene in a dual-luciferase reporter assay. These results highlighted the antagonistic roles of ECM1 and miR-92a in GC development, which may serve as a new target for gastric cancer.

Extracellular Matrix Protein 1 Gene Mutation in Turkish Patients with Lipoid Proteinosis.

Background:Lipoid proteinosis (LP) is a rare autosomal recessive genodermatosis characterized by mucocutaneous lesions and hoarseness of voice that develop in early childhood. LP is caused by mutation in the extracellular matrix protein 1 (ECM1) gene, which is located on 1q21.2.Aims:This study aimed to present the profile of ECM1 gene mutations and to identify possible novel mutations specific to Turkey.Materials and Methods:The ECM1 gene mutations of 19 LP patients from five families were evaluated using DNA isolated from peripheral blood samples. All ten exons in the ECM1 gene region were amplified by polymerase chain reaction (PCR). The PCR products were analyzed using a DNA sequencing analyzer. The results of DNA sequencing were analyzed with bioinformatics methods.Results:of the 19 LP patients evaluated in our study, we detected defects in exon 6 (c.507delT, 658T>G), exon 9 (157C>T, 727C>T), and exon 10 (c.93_94delGCinsTT) of the ECM1 gene.Conclusions:Our results indicate that defects in exons 6, 9, and 10 of the ECM1 gene were responsible for LP in our country. The identification of these pathogenic mutations is valuable because it facilitates early diagnosis and genetic counseling.

Lipoid proteinosis and epilepsy: Molecular analysis

Aim: Lipoid proteinosis (LP) is also known as Urbach-Wiethe disease which is a rare autosomal recessive disorder characterized by intracellular accumulation of hyaline material in skin and mucosae. LP has typical neurological, dermatological and radiological findings. The pathogenesis of disease is unknown. In literature several cases have been reported up to date. Mutations in extracellular matrix protein 1 (ECM1) gene have been found to cause the disease. We evaluated the molecular features of a family diagnosed with LP and evaluate the known and novel mutations of LP. Material and Methods: Genomic DNA was extracted from peripheral blood of the patients and family members including clinically normal parents and two siblings of the two affected subjects by using a commercial DNA extraction kit. Polymerase chain reaction was performed for all 10 exons of ECM1 gene by using the primers defined. Results: All of the exons of the ECM1 gene were sequenced and this revealed a 2-bp deletion in exon 7 of the ECM1 gene in both patients and both parents. Patients have the homozygous 2-bp deletions (c735del TG) and the parents and two healthy siblings showed heterozygous 2-bp deletion. Conclusions: Our patients found to be homozygous for the deletion in ECM1 gene. In order to understand the molecular pathology of the disease in detail, further functional analysis of the mutations should be performed.

Pathogenetic mechanism of lipoid proteinosis caused by mutation of the extracellular matrix protein 1 gene.

Lipoid proteinosis (LP) is a rare form of dermatosis with autosomal recessive inheritance. The present study hypothesized that an extracellular matrix protein 1 (ECM1) gene mutation forms the pathological basis of LP. The association between ECM1 mutation and LP; however, requires further investigation and was thus investigated in the present study. Injury skin tissue samples from patients with LP were collected, along with venous blood samples for genomic DNA extraction. Immunohistochemical staining was performed. Polymerase chain reaction (PCR) was then used to obtain an ECM1 gene fragment, which was sequenced and compared with healthy individuals. Histopathological examination revealed that all included patients fitted the features of LP and PCR amplification of the ECM1 gene in all patients obtained positive results. Patients with LP in the present study exhibited point mutations in the ECM1 gene, including one homozygous mutation (C220G) as previously reported, and one novel homozygous mutation c.508insCTG and two heterozygous mutations (C220G/P.R481X and c507delT/c.l473delT). LP is correlated with ECM1 gene mutation.

Extracellular matrix protein 1 gene rs3737240 single nucleotide polymorphism is associated with ulcerative colitis in Turkish patients.

Ulcerative colitis (UC) and Crohn's disease are chronic inflammatory diseases. Genetic, immunologic, and microbial factors play an important role in their pathogenesis. Extracellular matrix protein 1 (ECM1), a gene related to mucosal barrier function, has been shown to be associated with UC. This study aims to determine the relationship between ECM1 gene rs3737240 single nucleotide polymorphism (SNP) and UC in a group of Turkish patients. Ninety-four UC patients and 120 healthy controls were enrolled in the study. ECM1 gene rs3737240 SNP genotyping was performed using the polymerase chain reaction-restriction fragment length polymorphism method. TT genotype was significantly more common in UC patients than in the healthy control group [p=0.034; odds ratio (OR) 2.34; 95% confidence interval (CI) 1.04-5.25]. The presence of C allele significantly lowered the UC risk (p=0.034; OR 0.42; 95% CI 0.19-0.95). TT genotype was significantly associated with azathioprine use in UC patients (p=0.037; OR 3.0; 95% CI 1.04-8.65). The C allele significantly reduced the probability of azathioprine use in UC patients (p=0.037; OR 0.33 CI 95% 0.11-0.96). No relation was found between rs3737240 SNP genotype and the phenotypical characteristics of UC patients. The TT genotype of ECM1 gene rs3737240 SNP significantly increased susceptibility for UC and azathioprine use in UC patients in a Turkish population.

ECM1 promotes migration and invasion of hepatocellular carcinoma by inducing epithelial-mesenchymal transition

BackgroundExtracellular matrix protein 1 (ECM1) is a glycoprotein involved in many biologic processes. To determine the expression of ECM1 in hepatocellular carcinoma (HCC), and to study the role of ECM1 in inducing epithelia-mesenchymal transition (EMT) to analyze the effect of ECM1 on the migration and invasion of HCC cells.MethodsThe expression of ECM1 in HCC specimens was examined by immunohistochemistry staining, and the correlations were analyzed between the expression of ECM1 and the clinicopathological data. The ECM1 expression plasmid was transfected into Bel-7402 cells to induce exogenous overexpression of ECM1 protein. The changes of the expression of ECM1, EMT-related protein (E-cadherin, Vimentin), in Bel-7402 cells were detected by Western blot after transfection of ECM1; the wound healing and invasion assay in vitro were used to determine the role of ECM1 gene transfection on the ability of migration and invasive potential of Bel-7402 cells.ResultsImmumohistochemistry staining method displayed the ECM1 expression was positively associated with vascular invasion, TNM stage, and poor prognosis. A significant positive correlation was found between the expressions of ECM1 and Vimentin. After ECM1 overexpression, Western blot exhibited that the expression of E-cadherin was down-regulated and Vimentin expression was up-regulated in Bel-7402 cells; the wound healing and invasion assay showed that the migration and invasion potentials of Bel-7402 cells were significantly enhanced.ConclusionsECM1, which displayed a high expression in HCC specimens, was closely associated with clinicopathologic data and may promote migration and invasion of HCC cells by inducing EMT.Electronic supplementary materialThe online version of this article (doi:10.1186/s12957-016-0952-z) contains supplementary material, which is available to authorized users.

Association between genetic variants of EGF-containing fibulin-like extracellular matrix protein1 gene and sporadic breast cancer in a Chinese Han population.

Genetic susceptibility of breast cancer has been shown to be modulated by inheritance of polymorphic genes. EGF-containing fibulin-like extracellular matrix protein 1 (EFEMP1) gene played an important role in many tumors, including lung cancer, hepatic carcinoma, and prostate cancer. In addition, it was importantly downexpressed in breast cancer. The present research aimed to assess the association between genetic variations of EFEMP1 and breast cancer risk. The authors genotyped 11 common tagging SNPs with an array platform including 960 cases and 972 cancer-free controls of Chinese women, according to the HapMap database based on the pairwise linkage disequilibrium (LD) r² threshold of 0.8, minor allele frequency of 0.05. Three SNPs were significant associated with breast cancer (rs3791679, p = 0.016, OR = 1.21, 95% CI = 1.04-1.41; rs1346786, p = 0.005, OR = 1.31, 95% CI = 1.08 -1.59; rs727878, p = 0.002, OR = 1.29, 95%CI = 1.10-1.51). Multivariate logistic regression analysis revealed that, compared with wild-type carriers in a dominant model, a significantly increased breast cancer risk was associated with the three identified risk SNPs. Among the selected tagging SNPs, three haplotype blocks were identified, and the results of haplotype analysis were consistent with the single-locus analysis. The haplotype 'GG' in block 1 and haplotype 'AG' in block 2 were significantly associated with breast cancer, and had a 54% and 28% increased breast cancer risk respectively, compared with their corresponding noncarriers. The present results suggested that the polymorphisms of EFEMP1 gene were associated with breast cancer and might contribute to the susceptibility of the progression of breast cancer in Chinese Han women. Individuals with the risk alleles might increase the risk of breast cancer.

Clinical investigation and mutation analysis of ECM1 gene in a family with lipoid proteinosis

Objective To report a family with lipoid proteinosis (LP) from Shandong province and to analyze mutations in the extracellular matrix protein 1 (ECM1) gene in this family.Methods Eight members in a threegeneration family with LP were clinically investigated,and two patients were identified to suffer from LP,including the proband (Ⅲ 1) and her mother (Ⅱ 2).Both of the patients presented with papules on the palpebral margin,short and thick lingual frenum,and hoarseness.Indirect laryngoscopy showed infiltrating and thickening of the vocal cord.Pathological examination of lesions on the palpebral margin and laryngeal mucosa revealed deposits of hyaline-like material in the dermis,which was strongly positive for periodic acid-Schiff (PAS) staining and resistant to diastase digestion.The pathological diagnosis was LP.Blood samples were collected from all the family members and 100 ethnically matched,unrelated and unaffected Chinese human controls followed by DNA extraction.PCR and sequencing were performed to detect the ECM1 gene,and nested PCR followed by agarose gel electrophoresis to analyze mutations in the coding region of the ECM1 gene.Results Both of the two patients were compound heterozygotes.Three missense mutations,incluing p.P169T,p.A44T and p.R392W,were found in the ECM1 gene of the affected mother,with p.P169T in one allele and p.A44T as well as p.R392W in the other.The girl patient inheried the missence mutation p.P169T from her mother and a synonymous mutation c.879G ＞ A from her father (Ⅱ 1).Nested PCR showed that the c.978G ＞ A mutation generated a splice-acceptor site AG,which leaded to a splicing defect.Conclusion A novel synonymous splice-acceptor site mutation c.879G ＞ A in the ECM1 gene is identified in the family with LP. Key words: Lipoid proteinosis of Urbach and Wiethe; Extracellular matrix proteins; Mutation

N-Glycosylation of extracellular matrix protein 1 (ECM1) regulates its secretion, which is unrelated to lipoid proteinosis

Extracellular matrix protein 1 (ECM1) is expressed in a wide variety of tissues and plays important roles in extracellular matrix formation. Additionally, ECM1 gene mutations cause lipoid proteinosis (LP), a rare skin condition of genetic origin. However, an effective therapeutic approach of LP is not established. Here, we showed that ECM1 gene mutation observed in LP patients significantly suppresses its secretion. As ECM1 has three putative N-glycosylation sites and most of mutated ECM1 observed in LP patients are defective in these N-glycosylation sites, we investigated the correlation between LP and N-glycosylation of ECM1. We identified that the Asn354 and Asn444 residues in ECM1 were N-glycosylated by mass spectrometry analysis. In addition, an N-linked glycan at Asn354 negatively regulated secretion of ECM1, contrary to LP patient-derived mutants. These results indicate that the defect of N-glycosylation in ECM1 is not involved in the aberration of secretion of LP-derived mutated ECM1.

The Extracellular Matrix Protein 1 (ECM1) in Skin Biology: An Update for the Pleiotropic Action

Extracellular matrix protein 1 (ECM1) is a secreted glycoprotein that plays a pivotal role in the structural and homeostatic biology of the skin, particularly in angiogenesis, reconstitution of basement membrane, proliferation and differentiation of epidermal keratinocytes and dermal fibroblasts, and malignant transformation. This rationale is substantiated by loss-of-function mutations in the ECM1 gene in an autosomal recessive genodermatosis lipoid proteinosis and circulating IgG autoantibodies to this molecule in a humoral autoimmune condition lichen sclerosus, both of which are counterpart disease conditions sharing comparable skin pathology. In the recent decade, considerable progress has been made in determining the in vivo function of ECM1 in animal model studies. Furthermore, underlying insights arose for the genetic predisposition in inflammatory bowel disease ulcerative colitis, acquisition of immune tolerance and allergic responses via particular T cell subsets such as CD4+CD25+ regulatory T cells and Th2 cells, regeneration of certain organs, and clinical advantages for diagnostic and prognostic significance in various cancers. Following our latest review in 2009, we now update the most recent evidences for the pleiotropic action of ECM1 in skin research, and also highlight the novel pathogenic relevance of this molecule in a variety of human disorders.

Lipoid proteinosis with bilateral amygdalae calcifications, headache, and cognitive impairments

Lipoid proteinosis (LP) is a systemic autosomal recessive disorder caused by mutations in the ECM1 (extracellular matrix protein 1) gene1 and is occasionally associated with cognitive impairment, headache, and temporal lobe epilepsy.2 A 37-year-old woman with characteristic cutaneous lesions (figure 1), bilateral cataracts, and lens subluxation was evaluated for diffuse cognitive impairment and headache. Neuroimaging revealed bilateral amygdaloid calcifications typical for LP (figure 2). Sequencing the ECM1 gene identified homozygosity for a splice-site mutation, c.195 + 1G > C in intron 1. This case illustrates the various clinical manifestations of LP (none suggestive of amygdala involvement), which should be considered in the differential diagnosis of cerebral calcifications.

A novel missense mutation of the ECM1 gene in a Chinese patient with lipoid proteinosis

Lipoid proteinosis (LP), is caused by loss-of-function mutations in the gene for extracellular matrix protein 1 (ECM1), and has been mapped to chromosome 1q21. We report the case of a 49-year-old Chinese woman with LP, who presented with a hoarse voice, easily damaged skin with poor wound healing, lesions and scarring on the skin, and bead-like papules around the eyelids. On physical examination, yellowish deposits were seen on the soft palate, with thickening of the vocal cords. The coding region of ECM1 was amplified and sequenced, and a novel homozygous single-nucleotide substitution, c.1429T>C, was found in exon 9, which converts cysteine to arginine, designated p.C477R. This mutation was not founded in 100 unrelated normal genomic DNA sequences. In conclusion, this is a novel mutation in the ECM1 gene, which is the underlying cause of LP in this patient.

English

  A number of mutations in extracellular matrix protein 1 (ECM1) that is a glycoprotein and expressed in skin and other tissues are reported to cause a rare, autosomal recessive disorder called lipoid proteinosis (LP). The peculiar manifestation of LP is hoarseness of voice caused by laryngeal infiltration in infancy. Skin and mucous membrane changes clinically become apparent, and the disease typically follows a slowly progressive, yet often benign, course. About 300 cases of LP have been reported, but occurrence in siblings is rare. In this study, two siblings (18 and 24-year-old) of a Pakistani family were reported to have LP. This study presents two brothers with scaly itchy lesions on whole body, hoarse voice and macroglossia. Their deceased father had similar clinical manifestations but mother, younger brother and sister were unaffected. Blood from affected and clinically unaffected family members were collected with informed consent. The ECM1 gene containing 10 exons were amplified and sequenced. Both patients showed non-pathogenic missense and silent mutations in exon 6 and 8. In exon 6, a nucleotide C was substituted to T (C®T) at codon 2, in patient 1. This non-pathogenic missense mutation causes appearance of amino acid cysteine instead of arginine that is part of normal ECM1 protein. In patient 2, polymorphism of nucleotide C to T (C/T) was observed observed in exion 6 that may lead to the appearance of cysteine and/or arginine in the resulting gene product. In exon 8, a nucleotide G was substituted to A (G®A) at codon 53, in patient 1. This substitution leads to a silent mutation asserine is coded by both forms of codon. In patient 2, polymorphism of nucleotide G to A (G/A) was observed in exion 8 that do not cause any change in the coded amino acid. These findings represent a set of missense and silent mutations supporting an unusual function of ECM1 protein, broadening the spectrum of disease-linked mutations in rare cases of LP.   Key words: Lipoid proteinosis, extracellular matrix protein 1 (ECM1), missense, silent mutation, single nucleotide polymorphism, exons 6 and 8, genodermatosis.

Homozygous frame shift mutation in ECM1 gene in two siblings with lipoid proteinosis

The extracellular matrix protein 1 (ECM1) is a glycoprotein, expressed in skin and other tissues. Loss-of-function mutation in ECM1 causes a rare autosomal recessive disorder called lipoid proteinosis. Lipoid proteinosis is presented by varying degrees of skin scars, beaded papules along the eyelid margins, variable signs of hoarseness of voice and respiratory disorders. More than 250 cases of this disorder have been described in the literature, but occurrence of lipoid proteinosis in siblings is very rare. This study was designed to investigate the possible mutation causing lipoid proteinosis in a Pakistani family and to elaborate the scope of possible genetic changes, causing the genodermatosis in Pakistan. In this study, two siblings (12 and 9-years sisters) were presented with scaly itchy lesions on whole body, hoarse voice and macroglossia. Their deceased father had similar clinical manifestations but mother and younger brother were unaffected. Blood samples from clinically affected and unaffected family members were collected with informed consent. The coding region of ECM1 gene containing 10 exons were amplified and sequenced. Both the affected siblings were shown to have homozygous frame shift mutation by deletion of the nucleotide T at 507, codon 169, exon 6. This resulted in a frame shift from codon 169 and appearance of a premature stop codon at 177, causing formation of a mutated protein (176 amino acids) instead of normal ECM1 protein (540 amino acids). A case of homozygous 62-bp insertion in ECM1 gene causing lipoid proteinosis has been reported in another Pakistani family. The current study presents a homozygous frame shift mutation supporting an unusual function of ECM1 protein and broadens the spectrum of disease-linked mutations in this rare case of genodermatosis in this region.

Phospholipid Scramblase 1 Is Secreted by a Lipid Raft-dependent Pathway and Interacts with the Extracellular Matrix Protein 1 in the Dermal Epidermal Junction Zone of Human Skin

We examined the interaction of ECM1 (extracellular matrix protein 1) using yeast two-hybrid screening and identified the type II transmembrane protein, PLSCR1 (phospholipid scramblase 1), as a binding partner. This interaction was then confirmed by in vitro and in vivo co-immunoprecipitation experiments, and additional pull-down experiments with GST-tagged ECM1a fragments localized this interaction to occur within the tandem repeat region of ECM1a. Furthermore, immunohistochemical staining revealed a partial overlap of ECM1 and PLSCR1 in human skin at the basal epidermal cell layer. Moreover, in human skin equivalents, both proteins are expressed at the basal membrane in a dermal fibroblast-dependent manner. Next, immunogold electron microscopy of ultrathin human skin sections showed that ECM1 and PLSCR1 co-localize in the extracellular matrix, and using antibodies against ECM1 or PLSCR1 cross-linked to magnetic immunobeads, we were able to demonstrate PLSCR1-ECM1 interaction in human skin extracts. Furthermore, whereas ECM1 is secreted by the endoplasmic/Golgi-dependent pathway, PLSCR1 release from HaCaT keratinocytes occurs via a lipid raft-dependent mechanism, and is deposited in the extracellular matrix. In summary, we here demonstrate that PLSCR1 interacts with the tandem repeat region of ECM1a in the dermal epidermal junction zone of human skin and provide for the first time experimental evidence that PLSCR1 is secreted by an unconventional secretion pathway. These data suggest that PLSCR1 is a multifunctional protein that can function both inside and outside of the cell and together with ECM1 may play a regulatory role in human skin.