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Biomedical subjects

K Miyazono

Publications and source records attributed to K Miyazono.

At least 127 records · Page 7Linked to original sources
PubMed1997

Expression of tetra-spans transmembrane family (CD9, CD37, CD53, CD63, CD81 and CD82) in normal and neoplastic human keratinocytes: an association of CD9 with alpha 3 beta 1 integrin.

Tetra-spans transmembrane family (TSTF) members (CD9, CD37, CD53, CD63, CD81 and CD82) have potent effects on cell growth, motility and adhesion in various cells. However, little is known about their expression in human skin. Using immunohistological techniques, we have studied the localization of all six members of TSTF in normal and carcinomatous human keratinocytes. CD9, CD81 and CD82 were expressed in the entire living layers of the epidermis. Their staining pattern was quite similar, and was mainly intercellular with occasional intracellular immunoreactivity. CD53 expression was confined to the intercellular spaces of the upper spinous or granular layer in the normal epidermis. No clear-cut expression of CD63 could be detected in the epidermis. CD37 was not detected at all. Cultured human keratinocytes also expressed CD9, CD81 and CD82 at the surface membrane of cell-cell boundaries. Expression of CD37 and CD53 was negative in cultured keratinocytes, while CD63 was clearly localized in the cytoplasmic lysosomes. An immunoprecipitation assay revealed that alpha 3 beta 1 integrin is molecularly associated with CD9. The expression of CD9, CD81 and CD82 was markedly down-regulated in basal cell carcinoma but not in Bowen's disease. The abundant and differential expression of TSTF molecules and the selective association of CD9 with alpha 3 beta 1 integrin suggest that the TSTF molecules may be involved in the regulation of epidermal differentiation and integrity in vivo.

Antigens, CD↗
PubMed1996

Phosphorylation of Ser165 in TGF-beta type I receptor modulates TGF-beta1-induced cellular responses.

Transforming growth factor-beta (TGF-beta) signals via an oligomeric complex of two serine/threonine kinase receptors denoted TGF-beta type I receptor (TbetaR-I) and type II receptor (TbetaR-II). We investigated the in vivo phosphorylation sites in TbetaR-I and TbetaR-II after complex formation. Phosphorylation of TbetaR-II was observed at residues in the C-terminus (Ser549 and Ser551) and at residues in the juxtamembrane domain (Ser223, Ser226 and Ser227). TGF-beta1 induced in vivo phosphorylation of serine and threonine residues in the juxtamembrane domain of TbetaR-I in a region rich in glycine, serine and threonine residues (GS domain; Thr185, Thr186, Ser187, Ser189 and Ser191), and more N-terminal of this region (Ser165). Phosphorylation in the GS domain has been shown previously to be involved in activation of the TbetaR-I kinase. We show here that phosphorylation of TbetaR-I at Ser165 is involved in modulation of TGF-beta1 signaling. Mutations of Ser165 in TbetaR-I led to an increase in TGF-beta1-mediated growth inhibition and extracellular matrix formation, but, in contrast, to decreased TGF-beta1-induced apoptosis. A transcriptional activation signal was not affected. Mutations of Ser165 changed the phosphorylation pattern of TbetaR-I. These observations suggest that TGF-beta receptor signaling specificity is modulated by phosphorylation of Ser165 of TbetaR-I.

Amino Acid Sequence↗
PubMed1996

Characterization of the interaction of FKBP12 with the transforming growth factor-beta type I receptor in vivo.

The type I transforming growth factor-beta receptor (TbetaR-I) is the efferent component of the receptor complex, which presumably phosphorylates intracellular targets. FKBP12, a binding protein for FK506 and rapamycin, is shown to associate with the cytoplasmic region of TbetaR-I in vitro. In this report, we investigated the interaction of FKBP12 with TbetaR-I in vivo. FKBP12 interacts with TbetaR-I in mammalian cells as well as in yeast. Ligand addition does not affect the interaction, and both constitutively active and kinase-negative mutants of TbetaR-I bind FKBP12. FKBP12 dissociates from TbetaR-I in the presence of a high concentration of FK506. The juxtamembrane region of TbetaR-I, containing the major phosphorylation sites by the type II receptor, is required for the interaction. One of the deletion mutants in this region, which was shown to mediate transcriptional response, does not bind FKBP12, suggesting that FKBP12 is not directly involved in TGF-beta signaling. Furthermore TbetaR-I does not phosphorylate FKBP12 in vitro. FKBP12 may not be a direct substrate of TbetaR-I but possibly modulates the TbetaR-I function through its interaction with the regulatory domain of the kinase.

Activin Receptors, Type I↗
PubMed1996

Identification of type I and type II serine/threonine kinase receptors for growth/differentiation factor-5.

Growth/differentiation factor-5 (GDF-5) is a member of the bone morphogenetic protein (BMP) family, which plays an important role in bone development in vivo. Mutations in the GDF-5 gene result in brachypodism in mice and Hunter-Thompson type chondrodysplasia in human. BMPs transduce their effects through binding to two different types of serine/threonine kinase receptors, type I and type II. However, binding abilities appear to be different among the members of the BMP family. BMP-4 binds to two different type I receptors, BMP receptors type IA (BMPR-IA) and type IB (BMPR-IB), and a type II receptor, BMP receptor type II (BMPR-II). In addition to these receptors, osteogenic protein-1 (OP-1, also known as BMP-7) binds to activin type I receptor (ActR-I) as well as activin type II receptors (ActR-II and ActR-IIB). Here we investigate the binding and signaling properties of GDF-5 through type I and type II receptors. GDF-5 induced alkaline phosphatase activity in a rat osteoprogenitor-like cell line, ROB-C26. 125I-GDF-5 bound to BMPR-IB and BMPR-II but not to BMPR-IA in ROB-C26 cells and other nontransfected cell lines. Analysis using COS-1 cells transfected with the receptor cDNAs revealed that GDF-5 bound to BMPR-IB but not to the other type I receptors when expressed alone. When COS-1 cells were transfected with type II receptor cDNAs, GDF-5 bound to ActR-II, ActR-IIB, and BMPR-II but not to transforming growth factor-beta type II receptor. In the presence of type II receptors, GDF-5 bound to different sets of type I receptors, but the binding was most efficient to BMPR-IB compared with the other type I receptors. Moreover, a transcriptional activation signal was efficiently transduced by BMPR-IB in the presence of BMPR-II or ActR-II after stimulation by GDF-5. These results suggest that BMPR-IB mediates certain signals for GDF-5 after forming the heteromeric complex with BMPR-II or ActR-II.

Alkaline Phosphatase↗
PubMed1996

Identification of important regions in the cytoplasmic juxtamembrane domain of type I receptor that separate signaling pathways of transforming growth factor-beta.

Proteins in the transforming growth factor-beta (TGF-beta) superfamily exert their effects by forming heteromeric complexes of their type I and type II serine/threonine kinase receptors. The type I and type II receptors form distinct subgroups in the serine/threonine kinase receptor family based on the sequences of the kinase domains and the presence of a highly conserved region called the GS domain (or type I box) located just N-terminal to the kinase domain in the type I receptors. Recent studies have revealed that upon TGF-beta binding several serine and threonine residues in the GS domain of TGF-beta type I receptor (T beta R-I) are phosphorylated by TGF-beta type II receptor (T beta R-II) and that the phosphorylation of GS domain is essential for TGF-beta signaling. Here we investigated the role of cytoplasmic juxtamembrane region located between the transmembrane domain and the GS domain of T beta R-I by mutational analyses using mutant mink lung epithelial cells, which lack endogenous T beta R-I. Upon transfection, wild-type T beta R-I restored the TGF-beta signals for growth inhibition and production of plasminogen activator inhibitor-1 (PAI-1) and fibronectin. A deletion mutant, T beta R-I/JD1(delta 150-181), which lacks the juxtamembrane region preceding the GS domain, bound TGF-beta in concert with T beta R-II and transduced a signal leading to production of PAI-I but not growth inhibition. Recombinant receptors with mutations that change serine 172 to alanine (S172A) or threonine 176 to valine (T176V) were similar to wild-type T beta R-I in their abilities to bind TGF-beta, formed complexes with T beta R-II, and transduced a signal for PAI-1 and fibronectin. Similar to T beta R-I/JD1 (delta 150-181), however, these missence mutant receptors were impaired to mediate a growth inhibitory signal. These observations indicate that serine 172 and threonine 176 of T beta R-I are dispensable for extracellular matrix protein production but essential to the growth inhibition by TGF-beta.

Amino Acid Sequence↗
PubMed1996

Effect of transforming growth factor-beta and platelet-derived growth factor-BB on articular cartilage in rats.

The short-term and long-term effects on the growth zone in articular cartilage of transforming growth factor-beta 1 and platelet-derived growth factor-BB injected intraarticularly into the knee joint of growing rats were investigated. The changes induced by five injections of 0.5 micrograms of transforming growth factor-beta 1 included a rapid decrease in the size and number of hypertrophic cells and an enhanced subchondral bone formation. The changes were most marked in the patella but were also apparent in the tibia and femur. The proliferating cells became swollen and lost their normal organization. From the seventh day of the experiment to about 3 weeks, the matrix stained intensely with safranin O for proteoglycans. The alterations induced by transforming growth factor-beta also included synovial fibroplasia and synovitis, consisting predominantly of mononuclear cells. Localised necroses in the cartilage sometimes appeared after 21 days. In long-term studies, destroyed cartilage was found in three of six rats and partial ossification of the joint cartilage was found in two after 90 and 180 days. Ossicles developed in the tendons in all six patellae. Injection of platelet-derived growth factor-BB resulted in an early and transitory minor increase in the osteogenic activity in the zone between cartilage and red bone marrow and later produced an ossicle in one of four tendons. None of the other changes noted after injection of transforming growth factor was observed.

Animals↗
PubMed1996

Differential localization of TGF-beta-precursor isotypes in psoriatic human skin.

Transforming growth factor-beta (TGF-beta) can act as a multi-functional regulator of both cell growth and differentiation. Three isoforms of TGF-betas, namely TGF-beta 1 TGF-beta 2 and TGF-beta 3, have been identified in human tissues. Previously we reported the expression of TGF-beta isoforms in normal human skin. However little is known about the role of TGF-beta isoforms in the pathogenesis of psoriasis. Using the TGF-beta precursor-specific antibodies to strengthen the specificity, we studied the immunohistochemical distribution of TGF-betas 1-3 in psoriatic skin. TGF-beta 2, which was found in the intercellular space of all the layers of the epidermis in normal human skin, was decreased in the psoriatic epidermis. The intensity of immunoreactivity has the tendency to decrease in the lower epidermis rather than in the upper epidermis of the transitional lesion. In contrast, TGF-beta 3 was present in the subepidermal area of the psoriatic skin as in the normal human skin. TGF-beta 1 was observed in neither epidermis nor dermis in both normal and psoriatic skin. Since TGF-beta is a potent growth inhibitor for human keratinocytes, the decrease of TGF-beta 2 in the epidermis of psoriatic skin may contribute to epidermal hyperplasia, a hallmark of psoriasis.

Humans↗
PubMed1996

Active complex formation of type I and type II activin and TGF beta receptors in vivo as studied by overexpression in zebrafish embryos.

We have investigated the involvement of activin receptors and TGF beta type I receptor in zebrafish development. Overexpression of either full-length or a truncated form of mouse ActR-IIA interferes with the development. Different splice variants of mouse ActR-IIB have distinct effects; ActR-IIB4 induces abnormal embryos, whereas ActR-IIB2 does not. Activin and TGF beta type I receptors can induce axis duplications. Co-expression of ActR-IA or ActR-IB with the type II activin receptors results in a synergistic increase of the frequency of axis duplication. Moreover, ActR-IIB2 is synergistic with ActR-IA and ActR-IB, demonstrating that ActR-IIB2 can interact with the zebrafish ligand. Overexpression of TGF beta R-I with ActR-IIA or ActR IIB4 results in a synergistic increase in frequency of abnormal embryos, whereas in combination with ActR-IIB2 no such increase occurs.

Activins↗
PubMed1996

Signaling via hetero-oligomeric complexes of type I and type II serine/threonine kinase receptors.

Members of the transforming growth factor-beta (TGF-beta) superfamily have been found to signal by inducing the formation of hetero-oligomeric complexes of different type I and type II serine/threonine kinase receptors. Recent data indicate that binding of TGF-beta to its constitutively active type II receptor recruits the type I receptor into the complex; the type I receptor is thereafter phosphorylated and activated, processes which are necessary and sufficient for most TGF-beta mediated responses. Recent genetic analyses of Drosophila also indicate a strict requirement for both type I and type II receptors in decapentaplegic signaling in vivo.

Activin Receptors, Type I↗
PubMed1996

Bone morphogenetic protein type IB receptor is progressively expressed in malignant glioma tumours.

The distribution of bone morphogenetic protein (BMP) type I receptors and the activin type I receptor (ActR-I) was investigated in 16 cases of human glioma and five cases of non-tumourous gliosis tissue by immunohistochemical technique. Both BMP type IA (BMPR-IA) and the type IB (BMPR-IB) receptors were detected in human glioma cells. A significant increase in BMPR-IB in tumour cells was observed in malignant glioma compared with both low-grade astrocytomas (n=16, P<0.005) and gliosis (n=13, P<0.001). However, enhancement of BMPR-IA staining was moderate and ActR-I staining was only weakly expressed in the malignant glioma tumours. Osteogenic protein (OP)-1/BMP-7, which is known to bind BMPR-IA, BMPR-IB and ActR-I, was expressed in nervous tissue and was also detected in anaplastic areas of malignant glioma. In contrast to the tissue materials, BMPR-IA was expressed to a stronger degree than BMPR-IB in human glioma cell lines; the growth of these cells was suppressed by OP-1. These results suggest the presence of BMP receptors and a functional role for BMPs in malignant glioma.

Activin Receptors↗
PubMed1996

Characterization of ficolins as novel elastin-binding proteins and molecular cloning of human ficolin-1.

A novel elastin-binding protein, EBP-37, was recently identified and purified from human plasma. Its partial amino acid sequences showed significant homology to porcine ficolins, which were originally purified from porcine uterus membranes as multimeric proteins with fibrinogen- and collagen-like domains. Here we report the presence of ficolins in an elastin-binding fraction of porcine plasma and the direct binding of recombinant porcine ficolin-alpha to elastin. In addition, a cDNA encoding a human counterpart of porcine ficolins that is composed of 319 amino acids and is different from EBP-37 was cloned and named human ficolin-1. Northern blotting of various human tissues revealed that human ficolin-1 mRNA is highly expressed in peripheral blood leukocytes. These data suggested that there are at least two kinds of ficolin-related proteins in both pig and human, and they may function as plasma proteins with elastin-binding activities.

Amino Acid Sequence↗
PubMed1996

Distribution of transforming growth factor-beta and its receptors in gastric carcinoma tissue.

The distribution of the three mammalian isoforms of transforming growth factor (TGF)-beta (TGF-beta 1, -beta 2, and -beta 3) as well as their signaling receptors, TGF-beta type I and type II receptors (T beta R-I and T beta R-II, respectively), in gastric carcinoma tissue was examined by immunohistochemistry using specific antibodies. Tissue specimens were obtained from 25 cases of gastric carcinoma, which were classified into two groups according to Lauren's classification, i.e. 15 cases of diffuse carcinoma and 10 cases of intestinal carcinoma. In normal gastric mucosa apart from carcinoma nests, all of TGF-beta 1, -beta 2, -beta 3, T beta R-I and T beta R-II were clearly demonstrated in fundic glands. In sharp contrast, none of them was detectable in surface mucous cells. In carcinoma cells, strong staining for TGF-beta 1, -beta 2 and -beta 3 was obtained only in diffuse-type carcinoma. In particular, carcinoma cells scattered as single cells or small nests had a tendency to show strong staining for TGF-betas. The receptors tended to be distributed concomitantly with the ligands, and diffuse-type carcinoma showed stronger receptor staining than intestinal-type carcinoma. In cancer stroma, TGF-betas and receptors were detected in both diffuse and intestinal types, but the area with positive staining was wider and more dispersed in diffuse-type carcinoma than in intestinal carcinoma. These results suggest that TGF-beta may contribute in part to the variety of histogenesis and mode of progression of gastric carcinoma.

Adenocarcinoma↗
PubMed1996

[Transforming growth factor-beta and its receptors].

Transforming growth factor-beta (TGF-beta) is a family of multifunctional proteins that inhibit the growth of most cell types, and these proteins induce the deposition of extracellular matrix. TGF-beta inhibits the growth and migration of endothelial cells in vitro, but induces angiogenesis in vivo. TGF-beta belongs to a larger superfamily known as the TGF-beta superfamily, which includes activins and bone morphogenetic proteins. TGF-beta is produced as latent high molecular weight complexes from producer cells and is then activated by plasmin or thrombospondin. Latent TGF-beta binding protein (LTBP) is a component of the latent TGF-beta complex produced from platelets and many other cell types; LTBP plays an important role for the interaction of the latent TGF-beta complex with extracellular matrix components. TGF-beta binds several cell surface receptors, including type III receptor (betaglycan), endoglin, type II receptor and type I receptor. The type III receptor and endoglin are indirectly involved in the signal transduction. The Type II and type I receptors have intracellular serine/threonine kinase domains. They form a heteromeric complex after ligand binding and are most important for signal transduction; the type II receptor transactivates the type I receptor, which transduces various signals.

Animals↗
PubMed1996

Loss of expression of transforming growth factor beta type I and type II receptors correlates with tumor grade in human prostate cancer tissues.

Transforming growth factor beta1 (TGF-beta1) is a potential regulator of prostate cancer cell growth that signals through a heteromeric complex composed of type I and type II receptors. In the present study, an attempt was made to establish a correlation between expression of TGF-beta receptors and tumor grade in archival human prostate cancer tissues. To this end, immunohistochemical studies for TGF-beta receptors were carried out on 32 cases of human prostate cancer and 8 samples of benign human prostate. In both benign and malignant human prostate tissues, immunoreactivity for both type I and type II receptors was detected predominantly in epithelial cells. In addition, there was an inverse correlation between the loss of expression of TGF-beta1 type I and type II receptors and the tumor grade. Of the 32 prostate cancer cases screened, staining was completely absent in four samples for type II receptor (P < 0.05) and eight samples for type I receptor (P < 0.025). In contrast, all eight samples of benign prostate tissues investigated in this study showed strong staining for both type I and type II receptors. These results, taken together, indicate that human prostate cancer cells frequently have loss of expression of TGF-beta type I and/or type II receptors. Furthermore, these observations provide a potential mechanism for prostate cancer cells to escape the growth-inhibitory effect of TGF-beta.

Activin Receptors, Type I↗
PubMed1995

Efficient association of an amino-terminally extended form of human latent transforming growth factor-beta binding protein with the extracellular matrix.

Latent transforming growth factor-beta (TGF-beta) binding protein-1 (LTBP-1) is a component of the high molecular weight latent TGF-beta complex found in various cells, including human platelets. LTBP-1 is observed as different molecular sizes in different cell types, probably due to proteolytic processing and alternative splicing. We here report a novel form of human LTBP-1, which is longer in its NH2-terminal part (LTBP-1L). Northern hybridization analysis revealed that the LTBP-1L is derived from a 7.0-kilobase mRNA, whereas the originally reported shorter form (LTBP-1S) is derived from a 5.2-kilobase mRNA. Transfection of cDNA for LTBP-1L and -1S in COS cells revealed that LTBP-1L bound more efficiently to the extracellular matrix than did LTBP-1S. These results suggest that the different splice forms of LTBP-1 mediate different localization patterns of the latent TGF-beta complexes in vivo.

Amino Acid Sequence↗
PubMed1995

Interaction of the transforming growth factor-beta type I receptor with farnesyl-protein transferase-alpha.

Transforming growth factor-beta 1 (TGF-beta 1) is the prototype of a large family of molecules that regulate a variety of biological processes. The type I (T beta R-I) and type II (T beta R-II) receptors for TGF-beta 1 are transmembrane serine/threonine kinases, forming a heteromeric signaling complex. Recent studies have shown that T beta R-II is a constitutively active kinase and phosphorylates T beta R-I upon ligand binding, suggesting that T beta R-I is the effector subunit of the receptor complex, which transduces signals to intracellular targets. This model has been further confirmed by the identification of constitutively active T beta R-I that mediates TGF-beta 1-specific cellular responses in the absence of ligand and T beta R-II. To investigate signaling by TGF-beta 1, we have sought to isolate proteins that interact with the cytoplasmic region of T beta R-I. One of the proteins identified was the alpha subunit of farnesyl-protein transferase (FT alpha) that modifies a series of peptides including Ras. T beta R-I specifically interacts with FT alpha in the yeast two-hybrid system. Glutathione S-transferase-T beta R-I fusion proteins bind FT alpha translated in vitro. T beta R-I also phosphorylates FT alpha. We further show that the constitutively active T beta R-I interacted with FT alpha very strongly whereas an inactive form of T beta R-I did not. These results suggest that FT alpha may be one of the substrates of the activated T beta R-I kinase.

Activin Receptors, Type I↗
PubMed1995

Cloning and characterization of a human type II receptor for bone morphogenetic proteins.

Bone morphogenetic proteins (BMPs) are members of the transforming growth factor beta superfamily. Several members of this family have been shown to transduce their signals through binding to type I and type II serine-(threonine) kinase receptors. Here we report the cDNA cloning and characterization of a human type II receptor for BMPs (BMPR-II), which is distantly related to DAF-4, a BMP type II receptor from Caenorhabditis elegans. In transfected COS-1 cells, osteogenic protein (OP)-1/BMP-7, and less efficiently BMP-4, bound to BMPR-II. BMPR-II bound ligands only weakly alone, but the binding was facilitated by the presence of previously identified type I receptors for BMPs. Binding of OP-1/BMP-7 to BMPR-II was also observed in nontransfected cell lines. Moreover, a transcriptional activation signal was transduced by BMPR-II in the presence of type I receptors after stimulation by OP-1/BMP-7.

Amino Acid Sequence↗