Transforming Growth Factor Beta-induced Gene Research Articles

Investigation of the roles of TGFβ1, CUG2, TGFBI genes, and thiol-disulfide balance on prostate cancer and metastasis

Abstract Objectives Transforming growth factor-beta (TGFβ1) is involved in tumorigenesis and metastasis. It provides this effect both by disrupting the thiol-disulfide balance and through the cancer-upregulated gene (CUG2) and transforming growth factor beta-induced (TGFBI) genes in the signaling pathway. In this study, the roles of TGFβ1 and related genes, as well as thiol-disulfide balance, in the formation of prostate cancer and metastasis were investigated. Methods Tissue samples were taken from 33 benign prostatic hyperplasia (BPH) and 35 prostate cancer (PC) patients to determine the Gleason score and metastasis. TGFβ1, CUG2, and TGFBI gene expression levels were measured by RT-PCR. Serum prostate specific antigen (PSA) levels were measured in patients, and PSA density (PSAD) was calculated. Total thiol and native thiol measurements in serum were performed spectrophotometrically, and disulfide was calculated. Results In patients with prostate cancer and metastases, PSA and PSAD levels were high, while total thiol and native thiol were significantly lower (p<0.05). TGFβ1, CUG2 and TGFBI gene expression levels were higher in patients with prostate cancer and metastases and were negatively correlated with total thiol and native thiol (p<0.001). Conclusions As a result of our study, we determined that the increase in TGFβ1, CUG 2 and TGFBI in prostate cancer plays an important role in cancer formation and metastasis by disrupting the thiol-disulfide balance.

Association of transforming growth factor beta induced mutations with congenital and juvenile onset open angle glaucoma

AbstractPurpose: To investigate the molecular basis of congenital glaucoma in a family with GAPO (growth retardation, alopecia, pseudoanodontia, and progressive optic atrophy) syndrome.Methods: We report ocular features of three girls with GAPO syndrome born of consanguineous marriage in a multi‐ generation consanguineous family. The proband (4 year old girl) and her younger sibling (1 year old girl) were operated for bilateral congenital glaucoma in both eyes. The elder sibling (10 year old female) had features of GAPO syndrome but did not manifest features of glaucoma.Results: A genetic evaluation using whole exome sequencing revealed a homozygous ANTXR1 mutation in all 3 affected siblings with GAPO. No other mutations were detected in the genes associated with glaucoma. A rare missense mutation in Transforming Growth Factor Beta Induced (TGFBI) gene was shared in the two siblings with congenital glaucoma and GAPO syndrome. We then looked for the presence of TGFBI gene mutations in another cohort of 54 unrelated patients with early onset glaucoma (before 25 years of age) in whom Whole exome sequencing was previously done and no known glaucoma mutations were detected. We found three TGFBI mutations present in three unrelated juvenile onset open angle glaucoma (JOAG) patients, one of whom also had an associated corneal granular dystrophy. None of these patients had any other mutations associated with known genes for glaucoma.Conclusions: Mutations in TGFBI gene could have a role in the pathogenesis of congenital and juvenile onset open angle glaucoma.

Torin 1 alleviates impairment of TFEB-mediated lysosomal biogenesis and autophagy in TGFBI (p.G623_H626del)-linked Thiel-Behnke corneal dystrophy

ABSTRACT Thiel-Behnke corneal dystrophy (TBCD) is an epithelial-stromal TGFBI dystrophy caused by mutations in the TGFBI (transforming growth factor beta induced) gene, though the underlying mechanisms and pathogenesis of TBCD are still obscure. The study identifies a novel mutation in the TGFBI gene (p.Gly623_His626del) in a TBCD pedigree. Characteristics of the typical vacuole formation, irregular corneal epithelial thickening and thinning, deposition of eosinophilic substances beneath the epithelium, and involvement of the anterior stroma were observed in this pedigree via transmission electron microscopy (TEM) and histological staining. Tgfbi-p.Gly623_Tyr626del mouse models of TBCD were subsequently generated via CRISPR/Cas9 technology, and the above characteristics were further verified via TEM and histological staining. Lysosomal dysfunction and downregulation of differential expression protein CTSD (cathepsin D) were observed using LysoTracker Green DND-26 and proteomic analysis, respectively. Hence, lysosomal dysfunction probably leads to autophagic flux obstruction in TBCD; this was supported by enhanced LC3-II and SQSTM1 levels and decreased CTSD. TFEB (transcription factor EB) was prominently decreased in TBCD corneal fibroblasts and administration of ATP-competitive MTOR inhibitor torin 1 reversed this decline, resulting in the degradation of accumulated mut-TGFBI (mutant TGFBI protein) via the ameliorative lysosomal function and autophagic flux owing to elevated TFEB activity as measured by western blot, confocal microscopy, and flow cytometry. Transfected HEK 293 cells overexpressing human full-length WT-TGFBI and mut-TGFBI were generated to further verify the results obtained in human corneal fibroblasts. Amelioration of lysosome dysfunction may therefore have therapeutic efficacy in the treatment of TBCD. Abbreviations AS-OCT: anterior segment optical coherence tomography; ATP: adenosine triphosphate; Cas9: CRISPR-associated protein 9; CLEAR: coordinated lysosomal expression and regulation; CRISPR: clustered regularly interspaced short palindromic repeats; CTSB: cathepsin B; CTSD: cathepsin D; CTSF: cathepsin F; CTSL: cathepsin L; DNA: deoxyribonucleic acid; ECM: extracellular matrix; Fas1: fasciclin 1; FC: flow cytometry; GAPDH: glyceraldeyde-3-phosphate dehydrogenase; GCD2: granular corneal dystrophy type 2; HE: hematoxylin and eosin; LAMP2: lysosomal-associated membrane protein; MT: mutation type; MTOR: mechanistic target of rapamycin kinase; MTORC1: MTOR complex 1; mut-TGFBI: mutant TGFBI protein; SD: standard deviation; TBCD: Thiel-Behnke corneal dystrophy; TEM: transmission electron microscopy; TFEB: transcription factor EB; TGFBI: transforming growth factor beta induced; WT: wild type

Genotypic Homogeneity in Distinctive Transforming Growth Factor-Beta Induced (TGFBI) Protein Phenotypes.

Background: To evaluate the distribution of the transforming growth factor-beta induced (TGFBI) corneal dystrophies in a multi-ethnic population in Singapore, and to present the different phenotypes with the same genotype. Methods: This study included 32 patients. Slit lamp biomicroscopy was performed for each patient to determine the disease phenotype. Genomic DNA was extracted from the blood samples and the 17 exons of the TGFBI gene were amplified by PCR and sequenced bi-directionally for genotype analysis. Results: Regarding phenotypes, the study patients comprised 11 (34.4%; 8 with R555W and 3 with R124H mutation) patients with granular corneal dystrophy type 1 (GCD1), 6 (18.8%; 5 with R124H and 1 with R124C mutation) patients with GCD2, 13 (40.6%; 7 with R124C, 2 with H626R, 2 with L550P, 1 with A620D and 1 with H572R) patients with lattice corneal dystrophy (LCD) and 2 (6.3%; 1 with R124L and 1 with R124C) patients with Reis–Bückler corneal dystrophy. Regarding genotype, R124H mutation was associated with GCD2 (5 cases; 62.5%) and GCD1 (3 cases; 37.5%). R124C mutation was associated with LCD (7 cases; 87.5%) and GCD2 (1 case; 12.5%). All the 8 cases (100%) of R555W mutation were associated with GCD1. Conclusions: Although the association between genotype and phenotype was good in most cases (65.7%; 21 of 32 patients), genotype/phenotype discrepancy was observed in a significant number.

In vivo Imaging of Reis-Bücklers and Thiel-Behnke Corneal Dystrophies Using Anterior Segment Optical Coherence Tomography.

PurposeTo investigate in vivo corneal changes of genetically confirmed Reis–Bücklers corneal dystrophy (RBCD) and Thiel–Behnke corneal dystrophy (TBCD) using anterior segment optical coherence tomography (AS-OCT).DesignA single-center, prospective, comparative case series.MethodsSeven patients from 3 pedigrees (3 males, 4 females) with RBCD [Arg124Leu (R124L) heterozygous missense mutation of human transforming growth factor beta-induced (TGFBI) gene] and 4 patients from 3 pedigrees (3 males, 1 female) with TBCD [Arg555Gln (R555Q) heterozygous missense mutation of TGFBI gene] were examined. Six patients with RBCD and three patients with TBCD exhibited recurrence after corneal surgery including penetrating keratoplasty, phototherapeutic keratectomy, and electrolysis. All patients were examined by slit-lamp biomicroscopy followed by AS-OCT. Selected AS-OCT images of the cornea were evaluated qualitatively for changes in shape and degree of light reflection of corneal deposits.ResultsSlit-lamp biomicroscopy showed characteristic irregular gray opacities in Bowman’s layer in each dystrophy: a geographic pattern in RBCD and a honeycomb pattern in TBCD. In each dystrophy, distinct characteristic deposits were observed by AS-OCT as a banding lesion in Bowman’s layer and its adjacent epithelium/stroma. In RBCD, the banding lesion was highly reflective and sharply margined at the stroma. In contrast, deposits in TBCD in the same layer showed a saw-tooth pattern toward the epithelium and poorly margined at the stroma.ConclusionAS-OCT is able to clearly identify characteristic in vivo corneal microstructural changes associated with RBCD and TBCD. As a result, in vivo differentiation of RBCD and TBCD can be achieved.

Investigation of TGFBI (transforming growth factor beta-induced) Gene Mutations in Families with Granular Corneal Dystrophy Type 1 in the Konya Region.

Objectives:Granular corneal dystrophies (GCD) are characterized by small, discrete, sharp-edged, grayish-white opacities in the corneal stroma. Among the genes responsible for the development of GCD, the most strongly related gene is transforming growth factor beta-induced (TGFBI), located in the 5q31.1 locus. Studies show that R124H in exon 4 and R555W in exon 12 are hot-spot mutations in the TGFBI gene that lead to GCD development. In this study, we aimed to investigate these two hot-spot mutations in exons 4 and 12 of the TGFBI gene and other possible mutations in the same regions, which code important functional regions of the protein, in Turkish families with GCD1 and to determine the relationship between the mutations and disease and related phenotypes.Materials and Methods:The study included, 16 individuals diagnosed with GCD type 1 (GCD1), 11 of these patients’ healthy relatives, and 28 unrelated healthy individuals. DNA was obtained from peripheral blood samples taken from each individual and polymerase chain reaction was used to amplify target gene regions. Genotyping studies were done by sequence analysis.Results:The R124S mutation in exon 4 of TGFBI was not detected in the patients or healthy individuals in our study. However, all individuals diagnosed as having GCD1 were found to be heterozygous carriers of the R555W mutation in exon 12 of TGFBI. This mutation was not detected in healthy family members or control individuals unrelated to these families. In addition, we detected the silent mutation F540F in exon 12 and c.32924 G>A substitution in an intronic region of the gene in a few patients and healthy individuals.Conclusion:Our study strongly supports the association of GCD1 with R555W mutation in exon 12 region of the TGFBI gene, as reported in the literature.

Involvement of the JNK signaling in granular corneal dystrophy by modulating TGF-β-induced TGFBI expression and corneal fibroblast apoptosis.

Granular corneal dystrophy (GCD) is featured by corneal deposits of transforming growth factor beta-induced gene (TGFBI) mediated by the TGF-β (transforming growth factor-β)/Smad signaling. However, the roles of c-Jun amino-terminal kinase (JNK) pathway in GCD pathogenesis remains unexplored, which was investigated in this study. JNK signaling activation and inhibition in primary corneal fibroblasts were obtained by treatments with anisomycin and SP600125, respectively. Protein abundance and phosphorylation were detected by immunoblotting. Cell viability and apoptosis were analyzed by CCK-8 and flow cytometry respectively. TGFBI deposit and autophagy progression were assessed by immunofluorescence. The results found that JNK1 expression and phosphorylation were greatly increased in corneal tissues from GCD2 patients. JNK signaling activation impaired the viability and promoted apoptosis and autophagy processes in primary corneal fibroblasts, along with Smad2/3 phosphorylation, TGFBI accumulation and Bcl-2 suppression. Autophagy related proteins, such as ATG5 (autophagy related 5), ATG12 (autophagy related 12) and LC3B (microtubule-associated protein 1 light chain 3 beta), were also increased in anisomycin or TGF-β1 treated corneal fibroblasts. However, SP600125 effectively reversed the above effect induced by TGF-β1 treatment in corneal fibroblasts, including the TGF-β-induced autophagy progression. The results suggested that JNK signaling was activated in GCD2 corneal tissues, and it mediated the TGF-β-induced TGFBI protein accumulation and apoptosis of corneal fibroblasts during GCD2 pathogenesis.

Transforming growth factor beta-induced p.(L558P) variant is associated with autosomal dominant lattice corneal dystrophy type IV in a large cohort of Spanish patients.

Rare transforming growth factor beta-induced (TGFBI) gene variants are involved in autosomal dominant corneal dystrophies (CDs) with heterogeneous clinical features. The purpose of this study was to analyse TGFBI gene variants and genotype-phenotype correlations in a cohort affected by atypical stromal CD. Retrospective cohort study (from May 2014 to September 2017). Thirty-five individuals from 10 unrelated South European families presenting atypical lattice CD (LCD) were included. Corneal phenotypes were assessed by slit-lamp examination and optical coherence tomography (OCT). Contrast sensitivity was measured under mesopic conditions. Genomic DNA was obtained from blood samples, and all 17 TGFBI exons were screened for variants by Sanger sequencing. p.(L558P) variant of TGFBI gene. The p.(L558P) variant was identified in 22 members of the 10 families diagnosed with atypical LCD, characterized by late-onset and absence of recurrent erosion syndrome. OCT revealed punctiform deposits in the deep-mid stroma and normal anterior stroma. This variant was demonstrated to be transmitted with the disease according to autosomal dominant inheritance in most families. To the best of our knowledge, we describe a detailed clinical characterization of the largest CD cohort carrying the TGFBI p.(L558P) variant. We propose that the atypical phenotype of this recently reported alteration can be classified as a form of LCD type IV. The results show that OCT and anterior-posterior analysis of the stromal location of the opacities, along with a genetic analysis of TGFBI, are required to ensure accurate diagnosis and management of CDs.

Cornea guttata associated with special phenotypic variants of granular corneal dystrophy type 2 in a Chinese family.

The aim of this study was to analyze the relevant gene mutations in a Chinese family with special phenotypic variants of granular corneal dystrophy type 2 with cornea guttata. A total of 11 individuals from the affected family underwent complete ophthalmic examination. Genomic DNA was extracted from peripheral leukocytes of affected and unaffected family members. High-throughput sequencing was performed to screen for mutations in 290 genes associated with inherited ophthalmic diseases. Results were validated by bidirectional Sanger sequencing. An Arg124His (R124H) mutation of the transforming growth factor beta-induced gene was identified in three members of the affected family: the proband (II-1), his mother (I-2), and his son (III-1). The eyes of the proband and his mother had bilateral superficial whitish ring patches with clear centers occupying their central corneas and appeared to be discoid or ring shaped. In addition, specular microscopic examination showed the presence of dark, round bodies. In vivo confocal microscopy showed some hyporeflective round images (cornea guttata), containing occasionally central highlight, in the proband, his mother, and one of his elder sisters. We report, for the first time, atypical granular corneal dystrophy type 2 with cornea guttata associated with a single R124H mutation in a Chinese family. Our findings emphasize that genotyping is essential for the accurate diagnosis and classification of granular corneal dystrophy type 2.

Identification of a Heterozygous Mutation in the TGFBI Gene in a Hui-Chinese Family with Corneal Dystrophy.

Background/Aims Corneal dystrophies (CDs) belong to a group of hereditary heterogeneous corneal diseases which result in visual impairment due to the progressive accumulation of deposits in different corneal layers. So far, mutations in several genes have been responsible for various CDs. The purpose of this study is to identify gene mutations in a three-generation Hui-Chinese family associated with granular corneal dystrophy type I (GCD1). Methods A three-generation Hui-Chinese pedigree with GCD1 was recruited for this study. Slit-lamp biomicroscopy, optical coherence tomography, and confocal microscopy were performed to determine the clinical features of available members. Whole exome sequencing was performed on two patients to screen for potential disease-causing variants in the family. Sanger sequencing was used to test the variant in the family members. Results Clinical examinations demonstrated bilaterally abundant multiple grayish-white opacities in the basal epithelial and superficial stroma layers of corneas of the two patients. Whole exome sequencing revealed that a heterozygous missense mutation (c.1663C > T, p.Arg555Trp) in the transforming growth factor beta-induced gene (TGFBI) was shared by the two patients, and it cosegregated with this disease in the family confirmed by Sanger sequencing. Conclusions The results suggested that the heterozygous TGFBI c.1663C > T (p.Arg555Trp) mutation was responsible for GCD1 in the Hui-Chinese family, which should be of great help in genetic counseling for this family.

Analysis of TGFBI Gene Mutations in Three Chinese Families with Corneal Dystrophy.

Objective To identify the types of TGFBI (transforming growth factor, beta-induced) gene mutations in three Chinese families with Reis–Bücklers corneal dystrophy (RBCD), lattice corneal dystrophy type I (LCDI), or Avellino corneal dystrophy (ACD) and to investigate the relationship between the phenotypes and genotypes of corneal dystrophy. Methods Peripheral blood was collected from 24 patients and 76 phenotypically normal members in three Chinese families as well as from 100 healthy controls. Genomic DNA was extracted. All 17 exons of the TGFBI gene, and the exon-intron junctions were examined by polymerase chain reaction (PCR) and direct DNA sequencing to identify and analyse gene mutations. In addition, all members of the three families were subjected to detailed clinical examinations. Results The heterozygous c.371G > T (p.R124L) mutation was detected in exon 4 of the TGFBI gene in nine patients from the family with RBCD. In contrast, this mutation was not found in the phenotypically normal members of the family. The heterozygous c.370C > T (p.R124C) mutation was found in exon 4 of the TGFBI gene in 11 patients from the family with LCDI. This mutation was not found in the phenotypically normal members of the family. The heterozygous c.371G > A (p.R124H) mutation was detected in exon 4 of the TGFBI gene in four patients from the family with ACD. Again, this mutation was not found in the phenotypically normal members of the family. The TGFBI gene mutations cosegregated with the disease phenotypes in the three families and exhibited an autosomal dominant mode of inheritance. No TGFBI gene mutations were detected in the 100 healthy controls. Conclusion There is a high degree of correlation between the phenotypes and genotypes of TGFBI-linked corneal dystrophies. R124 represents a mutational hotspot in the TGFBI gene. Gene mutation analysis provides a reliable basis for the definitive diagnosis of corneal dystrophy.

TGFBI Expressed by Bone Marrow Niche Cells and Hematopoietic Stem and Progenitor Cells Regulates Hematopoiesis.

The interactions of hematopoietic stem and progenitor cells (HSPCs) with extracellular matrix (ECM) components and cells from the bone marrow (BM) microenvironment control their homeostasis. Regenerative BM conditions can induce expression of the ECM protein transforming growth factor beta-induced gene H3 (TGFBI or BIGH3) in murine HSPCs. In this study, we examined how increased or reduced TGFBI expression in human HSPCs and BM mesenchymal stromal cells (MSCs) affects HSPC maintenance, differentiation, and migration. HSPCs that overexpressed TGFBI showed accelerated megakaryopoiesis, whereas granulocyte differentiation and proliferation of granulocyte, erythrocyte, and monocyte cultures were reduced. In addition, both upregulation and downregulation of TGFBI expression impaired HSPC colony-forming capacity of HSPCs. Interestingly, the colony-forming capacity of HSPCs with reduced TGFBI levels was increased after long-term co-culture with MSCs, as measured by long-term culture-colony forming cell (LTC-CFC) formation. Moreover, TGFBI downregulation in HSPCs resulted in increased cobblestone area-forming cell (CAFC) frequency, a measure for hematopoietic stem cell (HSC) capacity. Concordantly, TGFBI upregulation in HSPCs resulted in a decrease of CAFC and LTC-CFC frequency. These results indicate that reduced TGFBI levels in HSPCs enhanced HSC maintenance, but only in the presence of MSCs. In addition, reduced levels of TGFBI in MSCs affected MSC/HSPC interaction, as observed by an increased migration of HSPCs under the stromal layer. In conclusion, tight regulation of TGFBI expression in the BM niche is essential for balanced HSPC proliferation and differentiation.

Two mutations in the transforming growth factor beta-induced gene associated with familial Lattice corneal dystrophy.

To report a phenotypic variant pedigree of lattice corneal dystrophy (LCD) associated with two mutations, R124C and A546D, in the transforming growth factor beta-induced gene (TGFBI). A detailed ocular examination was taken for all participants of a LCD family. Peripheral blood leukocytes from each participant were extracted to obtain the DNA. Polymerase chain reaction (PCR) of all seventeen exons of TGFBI gene was performed. The products were sequenced and analyzed. Histological examination was carried out after a penetrating keratoplasty from the right eye of proband. Genetic analysis showed that the proband and all 6 affected individuals harbored both a heterozygous CGC to TGC mutation at codon 124 and a heterozygous GCC to GAC mutation at codon 546 of TGFBI. None of the 100 control subjects and unaffected family members was positive for these two mutations. Ocular examination displayed multiple refractile lattice-like opacities in anterior stroma of the central cornea and small granular deposits in the peripheral cornea. The deposits were stained positively with Congo red indicating be amyloid in nature and situated mainly in the anterior and middle stroma. We observed a novel LCD family which carried two pathogenic mutations (R124C and A546D) in the TGFBI gene. The phenotypic features were apparently different from those associated with corresponding single mutations. The result reveals that although the definite mutation is the most important genetic cause of the disease, some different modifier alleles may influence the phenotype.

TGFBI Gene Mutation Analysis in Chinese Families with Corneal Dystrophies.

To identify transforming growth factor beta-induced (TGFBI) gene mutations in four Chinese families affected by corneal dystrophies. In this study, three families (21 patients and 18 normal relatives), respectively, with Reis-Bücklers corneal dystrophy (RBCD), classic lattice corneal dystrophy (LCDI), and variant LCD (LCDI/IIIA) were assessed. All subjects underwent a complete ophthalmological evaluation, including biomicroscopic inspection and dilated fundus examination. As a control, 100 individuals without corneal disease were selected from the general population. Polymerase chain reaction (PCR) and direct sequencing were used to screen for mutations in TGFBI. For the three families, a single heterozygous c.371G>T (R124L) point mutation was found in exon 4 of TGFBI in 14 affected members with RBCD, a single heterozygous c.370C>T (R124C) point mutation was found in exon 4 of TGFBI in four affected members with LCDI, and a single heterozygous c.1877A>G (H626R) point mutation was found in exon 14 of TGFBI in four affected members with LCDI/IIIA. TGFBI gene mutation had not been detected in the unaffected members and 100 normal controls. TGFBI gene mutations were present in all three Chinese families with corneal dystrophy, and our study further verified the relationship between phenotype and genotype of corneal dystrophy.

Uncovering the profile of mutations of transforming growth factor beta-induced gene in Chinese corneal dystrophy patients.

To uncover the mutations profile of transforming growth factor beta-induced (TGFBI) gene in Chinese corneal dystrophy patients and further investigate the characteristics of genotype-phenotype correlations. Forty-two subjects (6 unrelated families including 15 patients and 8 unaffected members, and 19 sporadic patients) of Chinese origin were subjected to phenotypic and genotypic characterization. The corneal phenotypes of patients were documented by slit lamp photography. Mutation screening of the coding regions of TGFBI was performed by direct sequencing. We detected four corneal dystrophy types. The most frequent phenotypes were granular corneal dystrophy (GCD) (including 3 families and 8 sporadic patients) and lattice corneal dystrophy (LCD) (including 2 families and 9 sporadic patients). The next phenotypes were corneal dystrophy of Bowman layer (CDB) (1 family and 1 sporadic patient) and epithelial basement membrane dystrophy (EBMD) (1 sporadic patient). Six distinct mutations responsible for TGFBI corneal dystrophies were identified in 30 individuals with corneal dystrophies. Those were, p.R124H mutation in 1 family and 2 sporadic patients with GCD, p.R555W mutation in 2 families and 3 sporadic patients with GCD, p.R124C mutation in 2 families and 7 sporadic patients with LCD, p.A620D mutation in 1 sporadic patient with LCD, p.H626R mutation in 1 sporadic patient with LCD, and p.R555Q in 1 family and 1 sporadic patient with CDB. No mutation was detected in the remaining 3 atypical GCD patients and 1 EBMD patient. GCD and LCD are the most frequent phenotypes in Chinese population. R555W was the most common mutation for GCD; R124C was the most common mutation for LCD. Our findings extend the mutational spectrum of TFGBI, and this is the extensively delineated TGFBI mutation profile associated with the various corneal dystrophies in the Chinese population.

Abstract P6-02-03: TGF-b1-inducible protein BIGH3 (transforming growth factor beta-induced gene human clone 3): A new mechanism inducing breast cancer cell apoptosis

Abstract Cancer development and progression is a complex process involving tumor cell mechanisms as well as tumor-host cell interactions. Using autocrine and paracrine mechanisms the cytokine TGF-b1 can influence cancer progression, in part through promoting the synthesis and secretion of extracellular matrix molecules. TGF-β1 strongly upregulates the gene TGFBI, which encodes a secretory protein named BIGH3. BIGH3 is an extracellular matrix, adhesion-class proapoptotic protein characterized by four fasciclin-1 (FAS1)-like domains, a cysteine-rich region and several different integrin-binding sequences. The C-terminus of BIGH3 encodes the integrin-binding peptides EPDIM and RGD. These sequences, and the integrin α3β1, have been implicated as important components of BIGH3-induced apoptosis. Breast cancer cells express the integrin α3β1, which is reported to play various roles including signaling, invasion and metastasis. Breast cancer cells and tumor-host cells express BIGH3 protein, which is expected to accumulate in the presence of TGF-β1. The above findings highlight the molecules TGF-β1 and α3β1 in tumor progression and are the basis for our hypothesis that BIGH3 protein itself is sufficient to induce an increase in breast cancer cell apoptosis. In order to test this hypothesis we utilized human breast cancer MCF-7 cells, human recombinant BIGH3 and TUNEL assays. Here, we show for the first time that exogenous human recombinant BIGH3 in cancer cell growth medium evokes a statistically significant increase in breast cancer cell apoptosis. A concentration curve shows that there is a direct relationship between the quantity of BIGH3 in the cells’ milieu and the number of cells undergoing apoptosis. This finding is consistent with receptor-ligand binding and indicates that BIGH3 is a potential target for breast cancer treatment. Importantly, in-house developed anti-BIGH3 antibody completely blocked apoptosis when compared to apoptotic cells in negative control conditions. Stimulation of BIGH3 gene expression in breast cancer cells, and providing exogenous BIGH3 to breast cancer cells, are expected to diminish breast cancer progression. Along this line, BIGH3 may be valuable as an agent for neoadjuvant or adjuvant therapy for human breast cancer patients. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-02-03.

Individual phenotypic variances in a family with Avellino corneal dystrophy

BackgroundAvellino corneal dystrophy (ACD) is an autosomal dominant disorder, characterized by the presence of deposits in the anterior stroma, and results from a specific mutation (R124H) in the transforming growth factor beta-induced gene (TGFBI). This report presents corneal dystrophy of the Bowman layer as a rare phenotypic appearance of ACD and a high intra-familial variability of phenotype in patients with ACD.Case presentationA 56 year-old Caucasian woman with recurrent corneal erosions was diagnosed with corneal dystrophy of the Bowman layer after a clinical examination. Optical coherence tomography of the anterior segment (AS-OCT) mainly demonstrated deposits in the Bowman layer and a few deposits in the superficial stroma. Her son, a 36 year-old man, has a typical clinical presentation of ACD with all the deposits arranged in stromal layers. In his case, the opacities resemble snowflakes between the granular deposits, and AS-OCT shows large, snowflake-like deposits in the superficial and deep stroma without accumulation in the Bowman layer. Genetic screening in both cases shows the heterozygous R124H mutation in the TGFBI gene.ConclusionThe clinical finding of the granular-lattice corneal dystrophy in which deposits are located in the Bowman layer may be an atypical presentation of ACD. This paper demonstrates a high degree of variability in the quantity and form of deposits between ACD heterozygotes. This is the first description of Avellino corneal dystrophy in the Balkans and in Serbia.

Modified classification method of corneal dystrophy at the molecular level

Corneal dystrophy represents a group of inherited corneal diseases with progressive accumulation of deposits in different layers of cornea,resulting in loss of corneal transparency and visual impairment,or even blindness.Initial classification of corneal dystrophy was upon involved cornea layer,and it is insufficient for some multi-layer lesion.With the current progress in molecular genetics,researchers proposed a new classifying way based on genetic information of corneal dystrophy.A revised classification has been recommended by the International Committee for Classification of Corneal Dystrophies (IC3D).The clinical manifestation,histological and genetic basis of the disease are integrated in the classification system,so it is regarded as to be more scientific and reasonable.Recent years,our laboratory performed genetic screen on some Chinese pedigrees with corneal dystrophy,mainly focusing on the corneal dystrophy-associated genes such as human transforming growth factor beta induced (TGFBI) gene,which reveals the relationship of the different mutations on TGFBI gene with clinical phenotypes.Our studies further indicated that the corneal dystrophy classification method based on molecular level is a more scientific and practicable method.Some updated information on the clinical phenotypes and molecular aspects of corneal dystrophy were provided here aimed to offer the aid to the differential diagnosis and management of these diseases. Key words: Corneal dystrophy/classification; International Committee for Classification of Corneal Dystrophies; Transforming growth factor beta induced gene

Targeted Disruption of TGFBI in Mice Reveals Its Role in Regulating Bone Mass and Bone Size through Periosteal Bone Formation

Transforming growth factor-beta induced (TGFBI) and periostin are two closely related proteins in structure as well as in function. A previous study found that periostin positively regulates bone size. Here, we hypothesize that TGFBI has a similar function in bone development. To test this hypothesis, we employed TGFBI-deficient mice, which were generated by targeted disruption of the TGFBI gene. We bred these mice with C57BL/6J mice to generate homozygous TGFBI-deficient (TGFBI(-/-)) mice and homozygous wild-type littermates. All mice were raised to 12 weeks of age. Bone mass parameters were determined by PIXImus and micro-CT, bone strength parameters by three-point bending, and bone formation and resorption parameters by histomorphometry. We found that targeted disruption of TGFBI led to reduced body size, bone mass, bone size, and bone strength. This indicates that, like periostin, TGFBI also positively regulates bone size and that changes in bone size affect bone strength. Furthermore, there was also a significant decrease in periosteal, but not endosteal, bone formation rate of cortical bone in TGFBI(-/-) mice, suggesting that the observed effect of TGFBI on bone mass and bone size was largely caused by the effect of TGFBI on periosteal bone formation.

Construction of eukaryotic plasmid expressing human TGFBI and its influence on human corneal epithelial cells.

To detect the expression of transforming growth factor beta-induced gene (TGFBI) protein in human corneal tissue and overexpress it in the human corneal epithelial cells in order to discuss the function of TGFBI in the pathogenesis of corneal dystrophy. Immunohistochemistry (IHC) was used to detect the expression of TGFBI in the human cornea tissue. TGFBI cDNA was obtained by reverse transcription-PCR from human corneal total RNA extracted from cornea transplant donor and cloned into pCMV-N-HA vector. The recombinant pCMV-N-HA-TGFBI plasmid transfected human corneal epithelial cells. Forty-eight hours later, mRNA and proteins were harvested from cells for real-time PCR analysis and western blot assay respectively. IHC indicated TGFBI mainly exist below the human corneal epithelium layer. Transfection of recombinant pCMV-N-HA-TGFBI into human corneal epithelial cells resulted in effective expression of TGFBI, as shown by increased mRNA level detected by real-time PCR as well as increased protein level detected by Western blot. Meanwhile the result of real-time PCR and Western blot shown the expression of MMP1, MMP3 (matrix metalloproteinases MMP) increased while the expressin of TIMP1 (tissue inhibitors of matrix metalloproteinases TIMP) decreased. TGFBI mainly exists below the corneal epithelial layer, recombinant eukaryotic expression vector harboring human TGFBI cDNA was obtained and efficiently overexpressed in human corneal epithelial cells. Meanwhile the TGFBI overexpression in human corneal epithelial cells result in MMP1, MMP3 increasing and TIMP1 decreasing. The result might be helpful for studying the function and role of TGFBI in pathogenesis of corneal dystrophy.