transforming-growth-factor-beta and Amyloidosis

In 1997, a group of hereditary corneal dystrophies was related to mutations in the TGFBI (BIGH3) gene. Within this group, some corneal dystrophies present particular biochemical features in that they are characterized by corneal amyloid deposition. Contrary to clinical and genetic knowledge, the biochemical characteristics of the encoded protein (Big-h3) and the mechanisms of its amyloid conversion remain unclear. We review the current knowledge on the Big-h3 protein and focus on the behavior of the codon 124 region. We discuss this protein's mechanisms of amyloid conversion from our results and previous reports as well as from other types of amyloidosis. These data provide a better understanding of the putative processes leading to the phenotypic variations linked with their respective codon 124 mutation.

Topics: Amino Acid Sequence; Amyloidosis; Base Sequence; Codon; Corneal Diseases; Extracellular Matrix Proteins; Eye Proteins; Humans; Molecular Sequence Data; Mutation; Transforming Growth Factor beta

Despite its identification as a key checkpoint regulator of microglial activation in Alzheimer's disease, the overarching role of CX3CR1 signaling in modulating mechanisms of Aβ driven neurodegeneration, including accumulation of hyperphosphorylated tau is not well understood.. Accumulation of soluble and insoluble Aβ species, microglial activation, synaptic dysregulation, and neurodegeneration is investigated in 4- and 6-month old 5xFAD;Cx3cr1. Disease progression in 5xFAD;Cx3cr1. Cx3cr1 deficiency impairs microglial uptake and degradation of fibrillar Aβ, thereby triggering increased accumulation of neurotoxic Aβ species. Furthermore, loss of Cx3cr1 results in microglial dysfunction typified by dampened TGFβ-signaling, increased oxidative stress responses and dysregulated pro-inflammatory activation. Our results indicate that Aβ-driven microglial dysfunction in Cx3cr1

Topics: Alzheimer Disease; Amyloidogenic Proteins; Amyloidosis; Animals; Cognitive Dysfunction; CX3C Chemokine Receptor 1; Mice; Neurons; Plaque, Amyloid; Transforming Growth Factor beta

To investigate the possible mutations in the carbohydrate sulfotransferase 6 (CHST6) gene of 2 unrelated cases of macular corneal dystrophy (MCD) and to report atypical stromal deposits in one of them.. Corneal tissues were stained with antisulfated keratan sulfate (KS), antitransforming growth factor beta 1-induced protein (TGFBIp), thioflavin-T, alcian blue, and Masson trichrome. Sequencing was performed to identify potential mutations in the CHST6 gene and the fourth and twelfth exons of the TGFBI gene.. Alcian blue staining revealed the presence of multiple subepithelial and intrastromal mucopolysaccharide deposits, confirming the diagnosis of MCD in both cases. Immunofluorescence staining in case 1 revealed the presence of sulfated KS only in the keratocytes and select endothelial cells, consistent with MCD type IA. Preferential expression of sulfated KS was observed in keratocytes and extracellular stromal matrix in case 2, consistent with MCD type II. Atypical subepithelial and superficial stromal deposits were observed in case 1, which stained positively with alcian blue, eosin, Masson trichrome, and thioflavin-T indicating the presence of hyaline and amyloid materials. CHST6 gene sequencing revealed 2 heterozygous mutations in case 1 (a p.Arg211Gln and a novel mutation of p.Arg177Gly) and a novel homozygous mutation of p.Pro186Arg in case 2. No mutations were found in exons 4 or 12 of the TGFBI gene in case 1.. Secondary hyalinosis and amyloidosis occur in a case of MCD type IA with a novel p.Arg177Gly mutation in CHST6. A novel p.Pro186Arg mutation in CHST6 is associated with MCD type II in an African American.

Topics: Adult; Alcian Blue; Amyloidogenic Proteins; Amyloidosis; Carbohydrate Sulfotransferases; Coloring Agents; Corneal Dystrophies, Hereditary; Corneal Stroma; DNA Mutational Analysis; Extracellular Matrix Proteins; Female; Humans; Keratoplasty, Penetrating; Male; Point Mutation; Polymerase Chain Reaction; Staining and Labeling; Sulfotransferases; Transforming Growth Factor beta

An atypical case of late-onset lattice corneal dystrophy is described in a 61-year-old man without a family history of eye disease. Mutational analysis of the TGFBI gene excluded any pathogenic sequence variants. However, 2 years later, renal impairment and nephrotic syndrome were diagnosed, resulting in a diagnosis of systemic heavy-chain amyloidosis.. Slit-lamp examination, corneal photography, and in vivo confocal microscopy were performed. General systemic evaluation included blood and urine assessment, bone marrow and renal biopsies, and cardiologic evaluation. A DNA sample underwent initial mutational analysis of TGFBI and, subsequently, gelsolin. The renal biopsy sample was subject to direct protein sequencing by mass spectrometry.. A bilateral, atypical, fine, midperipheral lattice corneal dystrophy with minor central subepithelial scarring was clinically characterized. Subsequently, abnormal renal functions with proteinuria, IgG lambda paraproteinemia, extensive deposition of amyloid in renal glomeruli, and increased plasma cells in bone marrow were identified. No pathogenic sequence mutations were identified in TGFBI or the gelsolin genes. Direct protein sequencing by mass spectrometry showed amyloid to be heavy-chain deposition rather than the more usual light-chain deposition.. Atypical midperipheral lattice corneal dystrophy presenting with adult onset and negative family history should arouse suspicion for an association with paraproteinemias or amyloidosis. Exclusion of TGFBI mutations should alert the clinician to the possibility of potentially life-threatening conditions, with referral for careful systemic evaluation.

Topics: Amyloid; Amyloidosis; Antineoplastic Combined Chemotherapy Protocols; Boronic Acids; Bortezomib; Corneal Dystrophies, Hereditary; Dexamethasone; DNA Mutational Analysis; Extracellular Matrix Proteins; Gelsolin; Glucocorticoids; Humans; Immunoglobulin Heavy Chains; Male; Mass Spectrometry; Melphalan; Microscopy, Confocal; Middle Aged; Mutation; Nephrotic Syndrome; Paraproteinemias; Pyrazines; Sequence Analysis, Protein; Transforming Growth Factor beta

Specific components of transforming growth factor-beta-induced protein (TGFBIp) responsible for amyloid deposits in lattice corneal dystrophy (LCD) have not been delineated. LCD has been associated with various TGFBIp mutations such as R124C, L518P, and L527R. Using recombinant TGFBIp, this study was undertaken to identify TGFBIp components potentially contributing to the protein deposits in LCD.. Recombinant wild-type (WT) TGFBIp and four mutants (R124C, R124H, L518P, and L527R) were generated in HEK293FT cells. WT and mutant TGFBIp were collected from crude cell lysates or purified from culture media. Immunoblot analyses were performed with four different anti-TGFBIp antibodies raised against various regions of TGFBIp.. Consistent with the authors' previous findings, purified recombinant proteins are more prone to polymerize than crude cell lysates. As expected, all monomers and polymers of TGFBIp WT and mutants were detected by these antibodies. However, the authors noted WT and TGFBIp mutants showed differential reactivities with these antibodies. A 47-kDa band was detected in purified 2-tag proteins of L518P by all four antibodies. A unique 43-kDa band was detected in both 1-tag cell lysates and purified proteins of R124C by the authors' custom-made antibody (KE50) and a commercial anti-TGFBIp.. Based on its universal reactivity with various antibodies, the authors surmise that the 47-kDa protein is a ubiquitous TGFBIp fragment derived from the N-terminus of the L518P mutant. The fact that the 43-kDa protein fragment was present primarily in R124C and R124H but not in WT implicates its potential role in the protein deposits of LCD.

Topics: Amyloidosis; Corneal Dystrophies, Hereditary; Electrophoresis, Polyacrylamide Gel; Extracellular Matrix Proteins; HEK293 Cells; Humans; Immunoblotting; Molecular Weight; Peptide Fragments; Polymerase Chain Reaction; Recombinant Proteins; Transforming Growth Factor beta

To report a novel mutation in TGFBI (GenBank NM_000358), p.Met619Lys, associated with a variant of combined granular-lattice corneal dystrophy.. Slitlamp examination and DNA collection from the proband and affected and unaffected relatives. All 17 exons of TGFBI were amplified and sequenced in the proband. Exon 14 was amplified and sequenced in the proband's family members and in 100 controls. Histopathologic examination of the excised corneal buttons from the proband and 3 family members was also performed.. Affected individuals demonstrated an age-dependent phenotype, with the progression from central subepithelial needlelike deposits in younger individuals to polymorphic anterior stromal opacities in older family members. Screening of TGFBI in the proband demonstrated a novel mutation, p.Met619Lys, which was also present in all affected family members. Histopathologic examination revealed stromal deposits that stained with the Congo red and Masson trichrome stains as well as an antibody to the protein product of TGFBI.. We present a unique corneal dystrophy phenotype associated with the novel p.Met619Lys mutation in TGFBI. Clinical Relevance The atypical and variable phenotype and the demonstration of both hyaline and amyloid stromal deposits indicate that neither clinical nor histopathologic features may be relied on to accurately diagnose and classify the corneal dystrophies.

Topics: Adult; Aged; Amyloid; Amyloidosis; Corneal Dystrophies, Hereditary; Corneal Stroma; DNA Mutational Analysis; Exons; Extracellular Matrix Proteins; Female; Gene Amplification; Genetic Variation; Humans; Male; Middle Aged; Mutation, Missense; Pedigree; Phenotype; Polymerase Chain Reaction; Sequence Analysis, DNA; Transforming Growth Factor beta

To identify mutations in the Transforming Growth Factor Beta Induced (TGFBI) gene in Hungarian patients with corneal dystrophy and to characterize histological features of their corneal buttons excised during penetrating keratoplasty.. Exons of TGFBI were sequenced in 38 members of 15 unrelated families with corneal dystrophy and exon 12 was also sequenced in 100 healthy controls from the same population. Immunohistological analysis of available corneal buttons excised during penetrating keratoplasty was also performed.. Molecular genetic analysis revealed a heterozygous R124C mutation in 18 patients with lattice type I dystrophy. A R555W heterozygous mutation was detected in five patients with granular Groenouw type I corneal dystrophy and a R555Q heterozygous mutation was found in four patients clinically diagnosed with Reis-Bücklers (one patient) and Thiel-Behnke (three patients) dystrophy. Three patients with "atypical granular" dystrophy later diagnosed as Avellino dystrophy were heterozygous for the R124H mutation. A novel heterozygous mutation (T1640C) causing a F547S amino acid exchange was detected in a patient with polymorphic corneal amyloidosis. Immunohistochemistry showed the presence of BIGH3 protein deposits in all examined corneal buttons. Electron microscopy confirmed the presence of amyloid fibrils in the case of the novel mutation.. Our results indicate that molecular genetic analysis is required to confirm the diagnosis of corneal dystrophies. We report the first cases of Avellino dystrophy from Central-Eastern Europe. We conclude that the novel F547S mutation causes polymorphic corneal amyloidosis since no other mutations were detected in the TGFBI gene of this patient and the novel mutation could not be found in healthy controls.

Topics: Amino Acid Substitution; Amyloidosis; Base Sequence; Cornea; Corneal Dystrophies, Hereditary; Extracellular Matrix Proteins; Heterozygote; Humans; Hungary; Keratoplasty, Penetrating; Middle Aged; Mutation; Phenylalanine; Serine; Transforming Growth Factor beta

Amyloid is found in several corneal dystrophies, including distinct lattice corneal dystrophies (LCD) and Avellino corneal dystrophy. Recently, point mutations in the transforming growth factor-beta-induced gene (TGFBI) encoding for keratoepithelin (KE) have been demonstrated in these corneal disease entities. We intended to investigate if KE was also a component of the rarely seen secondary corneal amyloid deposits.. Immunohistochemical staining with a polyclonal antibody against KE was performed on formalin-fixed paraffin-embedded tissue of five corneal buttons with secondary amyloid obtained after keratoplasty. Secondary amyloidosis was due to Fuchs endothelial dystrophy (FED) with bullous keratopathy and/or recurrent erosions in all cases. The diagnosis had been established by light microscopy using Congo red staining. Two cases of LCD type I served as positive controls and three corneas with FED and one with keratoconus without amyloid served as negative controls.. All corneas with secondary amyloidosis as well as LCD type I revealed positive staining in the respective amyloid deposits. KE was localized in the subepithelial pannus and in the anterior stroma in the corneas with secondary amyloidosis. In the specimens with LCD type I it was distributed in the amyloid deposits located in the anterior and mid-stroma. Staining for KE showed a granular appearance in all cases. The intensity of staining was variable among the specimens.. KE is found not only in primary amyloid deposits of hereditary corneal dystrophies, but also in secondary amyloidosis of the cornea of diverse ethiologies.

Topics: Adult; Aged; Aged, 80 and over; Amyloid; Amyloidosis; Corneal Diseases; Extracellular Matrix Proteins; Female; Humans; Immunohistochemistry; Keratoplasty, Penetrating; Male; Middle Aged; Transforming Growth Factor beta

To report a case of stellate and branching linear corneal stromal amyloid deposits secondary to trichiasis and the use of molecular genetic analysis to exclude lattice corneal dystrophy.. Case report and review of the literature. A 30-year-old man with a history of chronic ocular irritation was found to have distichiasis, epiblepharon, and unilateral corneal amyloidosis indistinguishable from lattice corneal dystrophy. Screening of the TGFBI gene was performed to rule out a previously reported mutation associated with lattice corneal dystrophy.. A corneal biopsy performed before presentation to the authors confirmed the presence of corneal amyloidosis. Screening of exons 4, 11, 12, and 14 in the TGFBI gene identified 2 previously reported polymorphisms, Leu472Leu and Phe540Phe, but no other coding region changes.. Corneal stromal amyloidosis clinically resembling lattice corneal dystrophy may be associated with trichiasis. The exclusion of a TGFBI-associated corneal dystrophy in this case, leaving trichiasis as the most likely cause of the corneal amyloid deposition, demonstrates the utility of molecular genetic analysis in confirming or refuting a presumptive clinical diagnosis.

Topics: Adult; Amyloidosis; Corneal Diseases; Corneal Stroma; Exons; Extracellular Matrix Proteins; Eyelashes; Eyelid Diseases; Hair Diseases; Humans; Male; Polymorphism, Single Nucleotide; Transforming Growth Factor beta

To determine the genetic basis for lattice corneal dystrophy (LCD) in an extensively studied family.. Ten affected family members were examined clinically, and three individuals were studied with in vivo confocal microscopy and optical coherence tomography (OCT). Corneal tissues from eight affected family members were examined histopathologically. The status of the transforming growth factor beta-induced gene (TGFBI) gene was determined in each consenting family member (six affected, seven nonaffected) by amplifying, sequencing, and analyzing exons 4 and 12 of TGFBI for mutations. All exons from the entire coding region of TGFBI of one affected person were analyzed for mutations.. Slit lamp biomicroscopy disclosed the clinical features of LCD in both eyes of affected individuals. In vivo confocal microscopy confirmed the presence of deposits as bright lesions within the corneal stroma. OCT revealed increased reflectivity within the corneal stroma. The corneal stroma in persons undergoing penetrating keratoplasty contained amyloid. Affected members of the family were found to have two heterozygous single-nucleotide mutations in exon 12 of the TGFBI gene (C1637A and C1652A) leading to predicted amino acid substitutions in the encoded TGFbeta-induced protein (A546D and P551Q). Mutations were not detected in exon 4. In addition, an inconsequential single-nucleotide polymorphism T1620C (F540F) was found in some affected and nonaffected family members.. Two mutations in the TGFBI gene (A546D and P551Q) cosegregated with LCD in an extensively studied family that lacked the R124C mutation that frequently accompanies this form of corneal amyloidosis.

Topics: Adult; Age of Onset; Aged; Amino Acid Substitution; Amyloid; Amyloidosis; Corneal Dystrophies, Hereditary; Corneal Stroma; Exons; Extracellular Matrix Proteins; Female; Humans; Male; Microscopy, Confocal; Middle Aged; Pedigree; Point Mutation; Polymorphism, Single Nucleotide; Tomography, Optical Coherence; Transforming Growth Factor beta

To characterize the clinicopathologic phenotype as well as the molecular genetic basis of an autosomal dominant form of corneal amyloidosis.. Clinicopathologic and molecular genetic study of a family with a form of corneal amyloidosis.. Forty-nine individuals from one family were studied.. The medical records of affected family members were reviewed, and corneal tissue from those who had undergone penetrating keratoplasty (PK) was examined. Several family members were examined clinically, and corneas were photographed. Deoxyribonucleic acid from blood or buccal swabs was extracted from each consenting family member to determine the status of their transforming growth factor beta-induced (TGFBI) gene. The coding region of the TGFBI gene was analyzed for mutations in the proband's DNA, and compared with the nucleotide sequences of normal individuals. This was performed by amplifying and sequencing all exons of the TGFBI gene. In all other family members, only exons 4, 8, 11, and 12 of the gene were amplified, sequenced, and analyzed for mutations.. Clinicopathologic manifestations in relation to mutational status of the TGFBI gene.. Slit-lamp biomicroscopy revealed bilateral multiple polymorphic, polygonal, refractile, chipped ice-appearing gray and white opacities. There were also occasional deep filamentous lines that did not form a distinct lattice pattern. Corneal tissue of affected individuals who underwent PK contained widespread deposits of amyloid within the corneal stroma, particularly in the deep central stroma. Twelve members of the family were found to have a heterozygous single mutation in the TGFBI gene leading to a predicted amino acid substitution of aspartic acid for alanine (A546D). Nine of these individuals had ophthalmologist-documented corneal disease. The remaining 3, who were 11, 14, and 15 years old, were asymptomatic. In addition, 4 inconsequential polymorphisms with the nucleotide changes 387 G/A (R129R), 981 G/A (V327V), 1416 T/C (L472L), and 1620 C/T (F540F) were found.. A distinct, progressive form of corneal amyloidosis with an autosomal dominant mode of inheritance is characterized clinically by the presence of refractile polymorphic corneal opacities. We have designated this entity, which is caused by an A546D mutation in the TGFBI gene, polymorphic corneal amyloidosis.

Topics: Adolescent; Adult; Aged; Amyloidosis; Child; Corneal Diseases; Corneal Opacity; DNA Mutational Analysis; Extracellular Matrix Proteins; Female; Genes, Dominant; Humans; Keratoplasty, Penetrating; Male; Middle Aged; Mutation, Missense; Pedigree; Polymerase Chain Reaction; Reoperation; Transforming Growth Factor beta

To report a phenotypic variant of lattice corneal dystrophy associated with two missense changes, Ala546Asp and Pro551Gln, in the transforming growth factor-beta-induced gene (TGFBI).. Experimental study.. Genomic DNA was obtained from the proband as well as affected and unaffected family members. Exons 4, 11, 12, and 14 of the TGFBI gene were amplified and sequenced. Additionally, a corneal button excised from the proband was examined by light and transmission electron microscopy. Haplotype analysis was performed on the proband's family and members of a previously identified pedigree with the same TGFBI gene missense changes.. Bilateral, symmetric, radially arranged, branching refractile lines within and surrounding an area of central anterior stromal haze were noted in the proband. Multiple polymorphic, refractile deposits were noted in the mid and posterior stroma in both the proband and her daughter. Light and electron microscopic analyses demonstrated amyloid and excluded the presence of deposits characteristic of granular corneal dystrophy. Screening of TGFBI exon 12 in the proband and her affected daughter revealed two missense changes, Ala546Asp and Pro551Gln (both absent in 250 control chromosomes). Haplotype analysis suggested that the mutations in this family and in a previously identified pedigree reflect a founder effect, rather than an independent occurrence.. We present a phenotypic variant of lattice corneal dystrophy associated with the Ala546Asp and Pro551Gln missense changes in exon 12 of the TGFBI gene. A common ancestor appears to account for the missense mutations observed in this pedigree and in a previously reported family.

Topics: Adult; Alanine; Amyloid; Amyloidosis; Aspartic Acid; Cornea; Corneal Dystrophies, Hereditary; DNA Mutational Analysis; Exons; Extracellular Matrix Proteins; Female; Glutamine; Haplotypes; Humans; Mutation, Missense; Pedigree; Proline; Transforming Growth Factor beta

Topics: Adult; Amyloid; Amyloidosis; Corneal Dystrophies, Hereditary; Corneal Transplantation; DNA Mutational Analysis; Exons; Extracellular Matrix Proteins; Female; Humans; Neoplasm Proteins; Polymerase Chain Reaction; Transforming Growth Factor beta

To assess the morphologic differences of three types of lattice corneal dystrophies (LCDs) from histologic, immunohistochemical, and ultrastructural studies.. Corneas from three patients, one LCD1, one His626Arg-LCD, and one LCD3A were processed for Congo red, betaig-h3(541-564) antibodies immunostaining, and electron transmission microscopy studies. Control tissues were submitted to identical analyses and consisted of one cornea from a patient not having LCD and one skin biopsy from the patient suffering from LCD1.. The three corneas displayed birefringent congophilic deposits under polarized light, confirming their amyloid nature. The deposits differed regarding their shape and location in each of the corneas. A strong immunoreactivity for betaig-h3 was shown in the LCD1 and His626Arg-LCD deposits, which was faint for the LCD3A deposits. Ultrastructural analysis confirmed the dissimilarity of the deposits among the different types of LCD. No amyloid deposits were observed in the skin from the LCD1 patient, whereas immunostaining showed the presence of high amounts of betaig-h3.. Our results show that betaig-h3 is involved in amyloid deposition in all the LCDs included in the study (LCD1, His626Arg-LCD, and LCD3A). These three forms of LCD, clinically different, were also distinguishable histologically, confirming that they belong to distinctive groups of LCDs. The absence of amyloid deposition in skin from the LCD1 patient supports cornea-specific amyloid formation. In light of the present clinical, histologic, and ultrastructural data, His626Arg and related LCDs constitute a separate group of LCD that could be considered as of intermediate type on clinical grounds.

Topics: Aged; Amyloid; Amyloidosis; Congo Red; Cornea; Corneal Dystrophies, Hereditary; Extracellular Matrix Proteins; Female; Humans; Immunoenzyme Techniques; Male; Middle Aged; Neoplasm Proteins; Staining and Labeling; Transforming Growth Factor beta

To report two Japanese patients who were clinically diagnosed with late-onset and sporadic lattice corneal dystrophy (LCD) in whom a Leu527Arg mutation in the TGFBI gene was found.. Molecular genetic analysis was performed on DNA extracted from peripheral leukocytes from the patients. Exons 4, 11, and 12 of the TGFBI gene were amplified by polymerase chain reaction and directly sequenced. Histopathologic study was performed on the corneal tissue obtained during deep lamellar keratoplasty (DLK) from one of the patients.. Patient 1 was a 74-year-old man who noticed a visual disturbance at the age of 72 years. Deep stromal opacities with nodular deposits and thick lattice lines were observed only in the right cornea, and DLK was performed. Patient 2 was an 82-year-old man who had LCD (similar in appearance to that in patient 1) in both eyes without visual disturbance. Neither of the patients had a family history of corneal problems and had no episode of corneal erosion. A heterozygous single base-pair transition (CTG to CGG, leucine to arginin) was detected in codon 527 of the TGFBI gene in both patients. No mutation was found in codons 124, 501, 518, 546, or 555. Histopathologically, relatively large amyloid deposits in the deep corneal stroma and ribbons of amyloid deposits just beneath the Bowman's layer were observed in the corneal tissue of patient 1.. Clinical features and pathologic findings of the late-onset form of LCD with an L527R mutation in the TGFBI gene were made clear.

Topics: Aged; Aged, 80 and over; Amyloidosis; Arginine; Codon; Corneal Dystrophies, Hereditary; DNA Mutational Analysis; Extracellular Matrix Proteins; Humans; Leucine; Male; Neoplasm Proteins; Point Mutation; Polymerase Chain Reaction; Transforming Growth Factor beta

Advanced glycation end product-modified beta2-microglobulin (AGE-beta2m) is an important component of dialysis-related amyloidosis (DRA). Its presence induces monocyte chemotaxis and the release of the proinflammatory cytokines through macrophage activation. Transforming growth factor-beta (TGF-beta) is a multifunctional cytokine that also has chemotactic activity for monocytes at very low (0.1 to 10 pg/mL) concentrations and inhibits proinflammatory cytokine production of macrophages. In this study, we investigated the role of TGF-beta in the pathogenesis of DRA.. We performed an immunohistochemical study of DRA tissues (8 cases) to confirm the existence of TGF-betas and their receptors; we also performed a chemotaxis assay of human monocytes as well as enzyme-linked immunosorbent assay (ELISA) of TGF-beta1, tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and interleukin-1 receptor antagonist (IL-1Ra) in the supernatant of human monocyte-derived macrophage cell culture under varying conditions of incubation with TGF-beta1, AGE-beta2m, and TGF-beta1 antibody additions.. There was positive staining for TGF-betas (types 1, 2, and 3) and their receptors (types I, II, and III) in infiltrated macrophages (CD68+), synovial lining cell, as well as vascular walls around amyloid deposition. AGE-beta2m also induced TGF-beta1 production by macrophages in a dose-dependent manner (410 +/- 80 pg/mL at 12.5 microg/mL, 621 +/- 62 pg/mL at 25 microg/mL, and 776 +/- 62 pg/mL at 50 microg/mL of AGE-beta2m). AGE-beta2m induced significant TNF-alpha and IL-1Ra production by macrophage. The addition of exogenous TGF-beta1 (0.1 to 10 ng/mL) decreased AGE-beta2m-induced TNF-alpha production and increased IL-1Ra production in a dose-dependent fashion. IL-1beta production was not effected by any experimental conditions. In chemotaxis assay, anti-TGF-beta1 antibody (0.1 to 10 microg/mL) attenuated AGE-beta2m-induced monocyte chemotaxis.. These results provide the first evidence to our knowledge for the presence of TGF-beta in DRA tissue, as well as the stimulatory action of AGE-beta2m on tissue macrophages. In turn, TGF-beta suppresses the proinflammatory activation of macrophages, suggesting a dual role for TGF-beta in the inflammatory process of DRA. These observations may provide a pathophysiologic link between TGF-beta and DRA.

Topics: Aged; Amyloidosis; beta 2-Microglobulin; Cells, Cultured; Chemotaxis; Chronic Disease; Female; Glycation End Products, Advanced; Humans; Interleukin 1 Receptor Antagonist Protein; Kidney Failure, Chronic; Macrophages; Male; Middle Aged; Monocytes; Receptors, Transforming Growth Factor beta; Renal Dialysis; Sialoglycoproteins; Synovial Membrane; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

To characterize the betaig-h3 gene defect in a French family affected with lattice corneal dystrophy type IIIA (LCDIIIA).. Histologic examination was performed from corneal buttons of two patients. Genomic DNA was extracted from leukocytes, and exons of the betaig-h3 gene were amplified by polymerase chain reaction to be directly sequenced.. Numerous deposits were evident in the stroma and beneath the Bowman membrane, which had all the features of amyloid deposits. Analysis of exon 12 revealed a heterozygous G to A transition on codon 546.. In contrast to Japanese patients, these French patients affected with LCDIIIA carry a distinct mutation of the betaig-h3 gene (A546T instead of P501T). Therefore, it is unclear whether different mutations could result in the same dystrophy or whether we are dealing with clinical heterogeneity of LCDIIIA.

Topics: Adult; Amyloidosis; Corneal Dystrophies, Hereditary; Corneal Stroma; DNA; Exons; Extracellular Matrix Proteins; Female; France; Humans; Male; Middle Aged; Neoplasm Proteins; Pedigree; Point Mutation; Polymerase Chain Reaction; Transforming Growth Factor beta

To report a Japanese family diagnosed clinically as having lattice corneal dystrophy type I (LCDI) in which a Leu518Pro mutation in the betaig-h3 gene and not the R124C mutation reported previously was found.. Molecular genetic analysis was performed on DNA extracted from peripheral leucocytes from four members (three affected and one unaffected) of a family. Exon 4 of the betaig-h3 gene was amplified by PCR and directly sequenced. Histopathological study was performed on the corneal tissue from the proband obtained during deep lamellar keratoplasty.. All the affected members were clinically diagnosed as having LCDI, and the pedigree indicated an autosomal dominant inheritance. A heterozygous single base pair transition (CTG to CCG, leucine to proline) was detected in codon 518 of the betaig-h3 gene in the three affected members, and not in the unaffected member. No mutation was found in codon 124. Amyloid deposits were observed between the collagen bundles of the corneal stroma and were seen to extend deep into the stroma.. The Leu518Pro mutated betaig-h3 forms amyloidogeneic intermediates which precipitate in the cornea and gives rise to a clinical appearance of LCDI.

Topics: Adolescent; Adult; Amyloidosis; Corneal Dystrophies, Hereditary; Extracellular Matrix Proteins; Female; Humans; Male; Neoplasm Proteins; Pedigree; Point Mutation; Transforming Growth Factor beta

To discover if beta ig-h3 is mutated in gelatinous drop-like corneal dystrophy, as has been suggested.. Genomic DNA was isolated from unrelated individuals with lattice corneal dystrophy type I (n = 3), Avellino corneal dystrophy (n = 3), and gelatinous drop-like corneal dystrophy (n = 3) and used as a template for polymerase chain reaction to amplify all exons in beta ig-h3. The polymerase chain reaction product was then sequenced.. Beta ig-h3 is mutated in lattice corneal dystrophy type I (Arg124Cys) and Avellino corneal dystrophy (Arg124His). In gelatinous drop-like corneal dystrophy, on the other hand, no mutation was detected in the entire coding region of beta ig-h3 (all 17 exons).. Unlike the amyloidotic corneal dystrophies lattice type I and Avellino, gelatinous drop-like corneal dystrophy is not likely to be caused by a mutation in beta ig-h3.

Topics: Amyloidosis; Cornea; Corneal Dystrophies, Hereditary; DNA Mutational Analysis; Exons; Extracellular Matrix Proteins; Humans; Mutation; Neoplasm Proteins; Polymerase Chain Reaction; Transforming Growth Factor beta

We have shown in vitro AL-amyloid formation by human mesangial cells (HMCs). AL-amyloid formation may require lysosomal processing of the light chains (LCs) by HMCs for amyloidogenesis to occur. Chloroquine inhibits lysosomal activity. TGF-beta mediates extracellular matrix formation in many glomerulopathies. Thrombospondin (TSP) has been proposed as a mediator of cell proliferation and a marker of early fibrosis. We investigated amyloid formation by HMCs exposed to AL-LCs in the absence of amyloid enhancing factor (AEF). The effects of TGF-beta, TSP and chloroquine on in vitro amyloid formation were studied. HMCs were incubated with two AL-LCs, a light chain deposition disease (LCDD)-LC, or one of two tubulopathic LCs (T-LCs). Additional cells were treated with an AL-LC and chloroquine, TGF-beta, or TSP. Amyloid formation was evaluated microscopically using hematoxylin and eosin, Congo red and Thioflavin-T stains, as well as ultrastructurally. Amyloid was formed only when HMCs were incubated with AL-LCs. Addition of TSP significantly enhanced amyloid formation. In contrast, exogenous TGF-beta and chloroquine significantly attenuated amyloid formation. These findings show that some AL-LCs do not require AEF for amyloidogenesis to occur, and that chloroquine, TGF-beta and sTSP modulate in vitro AL-amyloidosis.

Topics: Amyloid; Amyloidosis; Cells, Cultured; Chloroquine; Glomerular Mesangium; Humans; Immunoglobulin Light Chains; Kidney Diseases; Kidney Tubules; Thrombospondins; Transforming Growth Factor beta

Deposition of amyoid-beta peptide in the central nervous system is a hallmark of Alzheimer's disease and a possible cause of neurodegeneration. The factors that initiate or promote deposition of amyloid-beta peptide are not known. The transforming growth factor TGF-beta1 plays a central role in the response of the brain to injury, and increased TGF-beta1 has been found in the central nervous system of patients with Alzheimer's disease. Here we report that TGF-beta1 induces amyloid-beta deposition in cerebral blood vessels and meninges of aged transgenic mice overexpressing this cytokine from astrocytes. Co-expression of TGF-beta1 in transgenic mice overexpressing amyloid-precursor protein, which develop Alzheimer's like pathology, accelerated the deposition of amyloid-beta peptide. More TGF-beta1 messenger RNA was present in post-mortem brain tissue of Alzheimer's patients than in controls, the levels correlating strongly with amyloid-beta deposition in the damaged cerebral blood vessels of patients with cerebral amyloid angiopathy. These results indicate that overexpression of TGF-beta1 may initiate or promote amyloidogenesis in Alzheimer's disease and in experimental models and so may be a risk factor for developing Alzheimer's disease.

Topics: Aged; Aging; Alzheimer Disease; Amyloid beta-Peptides; Amyloidosis; Animals; Astrocytes; Benzothiazoles; Brain; Cerebral Amyloid Angiopathy; Humans; Mice; Mice, Inbred BALB C; Mice, Transgenic; Thiazoles; Transforming Growth Factor beta