Vascular Health Research Group（VHRG） ジャーナルクラブミーティング
文献 1 miRNA-206によるTIMP3のdownregulation
Liu H, Chen SE, Jin B, Carson JA, Niu A, Durham W, Lai JY, Li YP. TIMP3: a physiological regulator of adult myogenesis. J Cell Sci. 2010 Sep 1;123(Pt 17):2914-21.
Abstract
Myogenic differentiation in adult muscle is normally suppressed and can be activated by myogenic cues in a subset of activated satellite cells. The switch mechanism that turns myogenesis on and off is not defined. In the present study, we demonstrate that tissue inhibitor of metalloproteinase 3 (TIMP3), the endogenous inhibitor of TNFalpha-converting enzyme (TACE), acts as an on-off switch for myogenic differentiation by regulating autocrine TNFalpha release. We observed that constitutively expressed TIMP3 is transiently downregulated in the satellite cells of regenerating mouse hindlimb muscles and differentiating C2C12 myoblasts. In C2C12 myoblasts, perturbing TIMP3 downregulation by overexpressing TIMP3 blocks TNFalpha release, p38 MAPK activation, myogenic gene expression and myotube formation. TNFalpha supplementation at a physiological concentration rescues myoblast differentiation. Similarly, in the regenerating soleus, overexpression of TIMP3 impairs release of TNFalpha and myogenic gene expression, and delays the formation of new fibers. In addition, downregulation of TIMP3 is mediated by the myogenesis-promoting microRNA miR-206. Thus, TIMP3 is a physiological regulator of myogenic differentiation.
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Muscle regeneration entails the activation, proliferation and differentiation of mononucleated satellite cells (muscle stem cells) that are associated with muscle fibers. Myogenic differentiation is a carefully controlled process that is normally suppressed until it is activated at an appropriate time in a subset of proliferating satellite cells. The remaining satellite cell pool stays undifferentiated and serves as the reserve for future regeneration events (Charge and Rudnicki, 2004). Although myogenic gene expression requires the reactivation of the myogenic program involving the expression of such transcription factors as Pax7, Myf5, MyoD, myogenin, MRF4 and MEF2, it is clear now that epigenetic regulations also have a pivotal role in mediating myogenesis in regenerating muscle (Guasconi and Puri, 2009).
Before myogenic gene expression, the SWI/SNF chromatin-remodeling complex first has to be activated to allow access of myogenic transcription factors to the muscle-specific gene promoters. Activation of the SWI/SNF chromatin-remodeling complex is mediated by coordinated activation of both p38 MAPK and AKT (Serra et al., 2007). Blockade of either kinase abolishes myogenesis (Cuenda and Cohen, 1999; de Angelis et al., 2005; Jiang et al., 1999; Perdiguero et al., 2007; Puri et al., 2000; Wu et al., 2000; Zetser et al., 1999). It has been known for sometime that myogenic activation of AKT is induced by IGF-I (Lawlor et al., 2000; Rommel et al., 2001; Tureckova et al., 2001). However, the signaling mechanism of myogenic activation of p38, particularly in adult muscle, emerged only recently. It was demonstrated in adult muscle that myogenic activation of p38 requires TNFα-receptor-mediated signaling (Chen et al., 2005). In addition, authors showed that in response to diverse myogenic cues, myoblasts release autocrine TNFα, which is crucial to myogenic activation of the MKK6–p38 pathway and ensuing myogenesis (Chen et al., 2007; Zhan et al., 2007). Moreover, TNFα-converting enzyme (TACE, also known as ADAM17), the disintegrin metalloproteinase (Black, 2002) that cleaves plasma membrane-anchored pro-TNFα (26 kDa) to release free TNFα (17 kDa), is rate limiting for myogenic activation of p38 (Zhan et al., 2007). These findings revealed a new signaling paradigm through which myogenic cues are transduced to activate myogenic gene expression via the activation of p38. In this study, they address the question of how myogenic cues stimulate TACE release of TNFα.
TACE activity is normally repressed by its physiological inhibitor tissue inhibitor of metalloproteinase 3 (TIMP3). TIMP3 is a member of the tissue inhibitor of metalloproteinase family that uniquely inhibits TACE (Amour et al., 1998). As a transmembrane protein, TACE is structurally related to the matrix metalloproteinases (MMPs) (Black, 2002). TIMP3 appears to inhibit TACE in the same way the TIMPs inhibit MMPs: by chelating the extracellular active-site zinc with its N-terminus (Gomis-Ruth et al., 1997; Lee et al., 2005). TIMP3 is the only one of four TIMPs that binds to the extracellular matrix (Mohammed et al., 2003) and possesses an amino acid sequence (PFG) necessary for inhibiting TACE (Lee et al., 2005). TIMP3 suppresses inflammation (Black, 2004; Smookler et al., 2006) and impedes cell migration (van der Laan et al., 2003). These effects of TIMP3 could be attributed to its inhibition of TACE release of TNFα, which mediates inflammation (Tracey and Cerami, 1992) and stimulates the chemotactic response (Torrente et al., 2003). Because TIMP3 is constitutively expressed in muscle cells of mice (Leco et al., 1994) and humans (Apte et al., 1994), this article hypothesized that it has a physiological role in suppressing myogenesis as an inhibitor of TACE, and that it has to be downregulated in response to myogenic cues to allow TACE release of autocrine TNFα and the ensuing activation of p38-dependent myogenesis. This study demonstrates that TIMP3 is downregulated in regenerating mouse muscle, particularly, myogenic progenitor cells (MPCs). Furthermore, downregulation of TIMP3 is required for release of TNFα, activation of p38 and ensuing myogenesis. This article also demonstrate that the downregulation of TIMP3 is mediated by microRNA-206 (miR-206).
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Specific primer sets for mouse Timp3：Forward: 5′-AAGGTACTAGAAACAGACTCCTCCAG-3′, and Reverse: 5′-TTGATACAGGACAAGAACTTGAGTG-3′
Duplexes of miR-1 and miR-206 microRNA : from Dharmacon
As with miR-1, miR-206 is induced in differentiating myoblasts (Rao et al., 2006) and regenerating muscle (Yuasa et al., 2008) by the muscle regulatory factors (MRFs) MyoD and Myf5 (Rosenberg et al., 2006; Sweetman et al., 2008); and has a crucial role in the promotion of myogenesis (Chen et al., 2006; Kim et al., 2006). However, the mechanism through which miR-206 promotes myogenesis is just emerging, despite the fact that miR-206 is predicted to target a long list of genes which includes Timp3 (McCarthy, 2008). This article indicates that miR-206 is the primary microRNA that downregulates TIMP3 expression during myogenesis. TIMP3 downregulation is part of the intrinsic myogenic program that activates myogenesis. In addition, a mechanism for miR-206 promotion of myogenesis is that miR-206 promotes myogenesis by serving as an upstream signal for myogenic activation of p38, a key mediator of cell cycle exit (Perdiguero et al., 2007), chromatin remodeling (Simone et al., 2004) and the activation of myogenic gene expression (de Angelis et al., 2005; Lluis et al., 2005; Wu et al., 2000).
文献2 TIMP3による糸球体・尿細管障害
Kassiri Z, Oudit GY, Kandalam V, Awad A, Wang X, Ziou X, Maeda N, Herzenberg AM, Scholey JW. Loss of TIMP3 enhances interstitial nephritis and fibrosis. J Am Soc Nephrol. 2009 Jun;20(6):1223-35.
Abstract
The balance of matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) determines the integrity of the extracellular matrix. TIMP3 is the most highly expressed tissue inhibitor of metalloproteinase (TIMP) in the kidney, but its function in renal disease is incompletely understood. In this study, TIMP3-/- mice demonstrated an age-dependent chronic tubulointerstitial fibrosis. After unilateral ureteral obstruction (UUO), young TIMP3-/- mice exhibited increased renal injury (tubular atrophy, cortical and medullary thinning, and vascular damage) compared with wild-type mice. In addition, TIMP3-/- mice had greater interstitial fibrosis; increased synthesis and deposition of type I collagen; increased activation of fibroblasts; enhanced apoptosis; and greater activation of MMP2, but not MMP9, after UUO. TIMP3 deficiency also led to accelerated processing of TNFalpha, demonstrated by significantly higher TACE activity and greater soluble TNFalpha levels by 3 d after UUO. The additional deletion of TNFalpha markedly reduced inflammation, apoptosis, and induction of a number of MMPs. Moreover, inhibition of MMPs in TIMP3-/-/TNFalpha-/- mice further abrogated postobstructive injury and prevented tubulointerestitial fibrosis. In humans, TIMP3 expression increased in the renal arteries and proximal tubules of subjects with diabetic nephropathy or chronic allograft nephropathy. Taken together, these results provide evidence that TIMP3 is an important mediator of kidney injury, and regulating its activity may have therapeutic benefit for patients with kidney disease.
文献3 TNFα-mediated epithelial barrier disruption
Fréour T, Jarry A, Bach-Ngohou K, Dejoie T, Bou-Hanna C, Denis MG, Mosnier JF, Laboisse CL, Masson D. TACE inhibition amplifies TNF-alpha-mediated colonic epithelial barrier disruption. Int J Mol Med. 2009 Jan;23(1):41-8.
Abstract
Inflammatory bowel diseases (IBD) are characterized by tumor necrosis factor alpha (TNF-alpha)-mediated epithelial barrier disruption. TNF-alpha production and the bioavailability of its receptors on the cell surface are regulated by TACE (TNF-alpha converting enzyme), a pleiotropic metalloprotease also known as ADAM17, and its specific inhibitor TIMP3. We therefore examined ADAM17 and TIMP3 expression in human intestinal epithelial cells (IEC) using immunohistochemistry on tissue microarrays and real-time PCR on preparations of IEC isolated from human normal and IBD colon. The effects of TACE inhibition by TIMP3 or a pharmacological inhibitor were assessed in inflammatory conditions on a TIMP3-deficient colonic cell line HT29-Cl.16E. Both TACE and TIMP3 were found to be constitutively expressed by intestinal epithelial cells in the normal and inflammatory human intestinal barrier. In the TIMP3-deficient cell line, the addition of recombinant human TIMP3 or of Tapi-2, a pharmacological ADAM17 inhibitor, i) sensitized the cells to TNF-alpha-mediated hyperpermeability, ii) down-regulated tight junction-associated protein expression and iii) inhibited TNFRI shedding. In conclusion, our data showed that TACE and TIMP3 were co-expressed in the human intestinal barrier and that TACE inhibition, either physiologically or pharmacologically, amplified TNF-alpha-mediated hyperpermeability. TIMP3 could thus play a major role in inflammatory conditions by creating an autocrine effect leading to amplified epithelial barrier hyperpermeability.
文献4 Psoriasis-like inflammatory skin disease in sepsis
Guinea-Viniegra J, Zenz R, Scheuch H, Hnisz D, Holcmann M, Bakiri L, Schonthaler HB, Sibilia M, Wagner EF. TNFalpha shedding and epidermal inflammation are controlled by Jun proteins. Genes Dev. 2009 Nov 15;23(22):2663-74.
Abstract
Inducible epidermal deletion of JunB and c-Jun in adult mice causes a psoriasis-like inflammatory skin disease. Increased levels of the proinflammatory cytokine TNFalpha play a major role in this phenotype. Here we define the underlying molecular mechanism using genetic mouse models. We show that Jun proteins control TNFalpha shedding in the epidermis by direct transcriptional activation of tissue inhibitor of metalloproteinase-3 (TIMP-3), an inhibitor of the TNFalpha-converting enzyme (TACE). TIMP-3 is down-regulated and TACE activity is specifically increased, leading to massive, cell-autonomous TNFalpha shedding upon loss of both JunB and c-Jun. Consequently, a prominent TNFalpha-dependent cytokine cascade is initiated in the epidermis, inducing severe skin inflammation and perinatal death of newborns from exhaustion of energy reservoirs such as glycogen and lipids. Importantly, this metabolic "cachectic" phenotype can be genetically rescued in a TNFR1-deficient background or by epidermis-specific re-expression of TIMP-3. These findings reveal that Jun proteins are essential physiological regulators of TNFalpha shedding by controlling the TIMP-3/TACE pathway. This novel mechanism describing how Jun proteins control skin inflammation offers potential targets for the treatment of skin pathologies associated with increased TNFalpha levels.
文献5
Tsakadze NL, Sithu SD, Sen U, English WR, Murphy G, D'Souza SE. Tumor necrosis factor-alpha-converting enzyme (TACE/ADAM-17/CD156q) mediates the ectodomain cleavage of intercellular adhesion molecule-1 (ICAM-1). J Biol Chem. 2006 Feb 10;281(6):3157-64.
Abstract
Ectodomain shedding has emerged as an important regulatory step in the function of transmembrane proteins. Intercellular adhesion molecule-1 (ICAM-1), an adhesion receptor that mediates inflammatory and immune responses, undergoes shedding in the presence of inflammatory mediators and phorbol 12-myristate 13-acetate (PMA). The shedding of ICAM-1 in ICAM-1-transfected 293 cells upon PMA stimulation and in endothelial cells upon tumor necrosis factor-alpha stimulation was blocked by metalloproteinase inhibitors, whereas serine protease inhibitors were ineffective. p-Aminophenylmercuric acetate, a mercuric compound that is known to activate matrix metalloproteinases, up-regulated ICAM-1 shedding. TIMP-3 (but not TIMP-1 or -2) effectively blocked cleavage. This profile suggests the involvement of the ADAM family of proteases in the cleavage of ICAM-1. The introduction of enzymatically active tumor necrosis factor-alpha-converting enzyme (TACE) into ICAM-1-expressing cells up-regulated cleavage. Small interfering RNA directed against TACE blocked ICAM-1 cleavage. ICAM-1 transfected into TACE-/- fibroblasts did not show increased shedding over constitutive levels in the presence of PMA, whereas cleavage did occur in ICAM-1-transfected TACE+/+ cells. These results indicate that ICAM-1 shedding is mediated by TACE. Blocking the shedding of ICAM-1 altered the cell adhesive function, as ICAM-1-mediated cell adhesion was up-regulated in the presence of TACE small interfering RNA and TIMP-3, but not TIMP-1. However, cleavage was found to occur at multiple sites within the stalk domain of ICAM-1, and numerous point mutations within the region did not affect cleavage, indicating that TACE-mediated cleavage of ICAM-1 may not be sequence-specific.
文献6
Federici M, Hribal ML, Menghini R, Kanno H, Marchetti V, Porzio O, Sunnarborg SW, Rizza S, Serino M, Cunsolo V, Lauro D, Mauriello A, Smookler DS, Sbraccia P, Sesti G, Lee DC, Khokha R, Accili D, Lauro R. Timp3 deficiency in insulin receptor-haploinsufficient mice promotes diabetes and vascular inflammation via increased TNF-alpha. J Clin Invest. 2005 Dec;115(12):3494-505.
Abstract
Activation of inflammatory pathways may contribute to the beginning and the progression of both atherosclerosis and type 2 diabetes. Here we report a novel interaction between insulin action and control of inflammation, resulting in glucose intolerance and vascular inflammation and amenable to therapeutic modulation. In insulin receptor heterozygous (Insr+/-) mice, we identified the deficiency of tissue inhibitor of metalloproteinase 3 (Timp3, an inhibitor of both TNF-alpha-converting enzyme [TACE] and MMPs) as a common bond between glucose intolerance and vascular inflammation. Among Insr+/- mice, those that develop diabetes have reduced Timp3 and increased TACE activity. Unchecked TACE activity causes an increase in levels of soluble TNF-alpha, which subsequently promotes diabetes and vascular inflammation. Double heterozygous Insr+/-Timp3+/- mice develop mild hyperglycemia and hyperinsulinemia at 3 months and overt glucose intolerance and hyperinsulinemia at 6 months. A therapeutic role for Timp3/TACE modulation is supported by the observation that pharmacological inhibition of TACE led to marked reduction of hyperglycemia and vascular inflammation in Insr+/- diabetic mice, as well as by the observation of increased insulin sensitivity in Tace+/- mice compared with WT mice. Our results suggest that an interplay between reduced insulin action and unchecked TACE activity promotes diabetes and vascular inflammation.
文献7 Preadipocyte factor 1 (Pref-1) & TIMP3-TACE in the preadipocytes
Wang Y, Sul HS. Ectodomain shedding of preadipocyte factor 1 (Pref-1) by tumor necrosis factor alpha converting enzyme (TACE) and inhibition of adipocyte differentiation. Mol Cell Biol. 2006 Jul;26(14):5421-35.
Abstract
Preadipocyte factor 1 (Pref-1), an epidermal growth factor repeat containing transmembrane protein found in the preadipocytes, inhibits adipocyte differentiation in vitro and in vivo. Here, we examined the processing of membrane form of Pref-1A to release the 50-kDa soluble form that inhibits adipocyte differentiation. The ectodomain cleavage of Pref-1 is markedly enhanced by phorbol 12-myristate 13-acetate in a dose- and time-dependent manner. The basal and stimulated cleavage is inhibited by the broad metalloproteinase inhibitor GM6001, a fact that suggests that cleavage of membrane Pref-1A is dependent on a metalloproteinase. Next, we showed that release of soluble Pref-1A is inhibited by TAPI-0 and by a tissue inhibitor of metalloproteinase-3, TIMP-3, that can inhibit tumor necrosis factor alpha converting enzyme (TACE), but not by TIMP-1 or TIMP-2. On the other hand, overexpression of TACE increases Pref-1 cleavage to produce the 50-kDa soluble form. Furthermore, this cleavage was not detected in cells with TACE mutation or with TACE small interfering RNA. TACE-mediated shedding of Pref-1 ectodomain inhibits adipocyte differentiation of 3T3-L1 cells and in Pref-1-null mouse embryo fibroblasts transduced with Pref-1A. Identification of TACE as the major protease responsible for conversion of membrane-bound Pref-1 to the biologically active diffusible form provides a new insight into Pref-1 function in adipocyte differentiation.
文献8
Dada LA, Sznajder JI. Mitochondrial Ca²+ and ROS take center stage to orchestrate TNF-α-mediated inflammatory responses. J Clin Invest. 2011 May 2;121(5):1683-5.
Abstract
Proinflammatory stimuli induce inflammation that may progress to sepsis or chronic inflammatory disease. The cytokine TNF-α is an important endotoxin-induced inflammatory glycoprotein produced predominantly by macrophages and lymphocytes. TNF-α plays a major role in initiating signaling pathways and pathophysiological responses after engaging TNF receptors. In this issue of JCI, Rowlands et al. demonstrate that in lung microvessels, soluble TNF-α (sTNF-α) promotes the shedding of the TNF-α receptor 1 ectodomain via increased mitochondrial Ca²+ that leads to release of mitochondrial ROS. Shedding mediated by TNF-α-converting enzyme (TACE) results in an unattached TNF receptor, which participates in the scavenging of sTNF-α, thus limiting the propagation of the inflammatory response. These findings suggest that mitochondrial Ca²+, ROS, and TACE might be therapeutically targeted for treating pulmonary endothelial inflammation.
文献9 Erica MartinのLungにおけるTIMP3研究
Martin EL, Sheikh TA, Leco KJ, Lewis JF, Veldhuizen RA. Contribution of alveolar macrophages to the response of the TIMP-3 null lung during a septic insult. Am J Physiol Lung Cell Mol Physiol. 2007 Sep;293(3):L779-89.
Abstract
Mice deficient in tissue inhibitor of metalloproteinase-3 (TIMP-3) develop an emphysema-like phenotype involving increased pulmonary compliance, tissue degradation, and matrix metalloproteinase (MMP) activity. After a septic insult, they develop a further increase in compliance that is thought to be a result of heightened metalloproteinase activity produced by the alveolar macrophage, potentially modeling an emphysemic exacerbation. Therefore, we hypothesized that TIMP-3 null mice lacking alveolar macrophages would not be susceptible to the altered lung function associated with a septic insult. TIMP-3 null and wild-type (WT) mice were depleted of alveolar macrophages before the induction of a septic insult and assessed for alteration in lung mechanics, alveolar structure, metalloproteinase levels, and inflammation. The results showed that TIMP-3 null mice lacking alveolar macrophages were protected from sepsis-induced alterations in lung mechanics, particularly pulmonary compliance, a finding that was supported by changes in alveolar structure. Additionally, changes in lung mechanics involved primarily peripheral tissue vs. central airways as determined using the flexiVent system. From investigation into possible molecules that could cause these alterations, it was found that although several proteases and inflammatory mediators were increased during the septic response, only MMP-7 was attenuated after macrophage depletion. In conclusion, the alveolar macrophage is essential for the TIMP-3 null sepsis-induced compliance alterations. This response may be mediated in part by MMP-7 activity but occurs independently of inflammatory cytokine and/or chemokine concentrations.
次回 VHRG10月予定：'Do'nt eat me'シグナルとニッチ理論 プレゼンテータ 松田直之
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