Yuya Tsurutani

CCN3 Inhibits Neointimal Hyperplasia Through Modulation of Smooth Muscle Cell Growth and Migration

Objective—CCN3 belongs to the CCN family, which constitutes multifunctional secreted proteins that act as matrix cellular regulators. We investigated the pathophysiological roles of CCN3 in the vessels. Methods and Results—We examined the effects of CCN3 on the proliferation and migration of rat vascular smooth muscle cells (VSMC). CCN3 knockout mice were created, and vascular phenotypes and neointimal hyperplasia induced by photochemically induced thrombosis were investigated. CCN3 suppressed the VSMC proliferation induced by fetal bovine serum. The neutralizing antibody for transforming growth factor-&bgr; did not affect the growth inhibitory effect of CCN3. Moreover, CCN3 enhanced the mRNA expression of cyclin-dependent kinase inhibitors, p21 and p15. Gamma secretase inhibitor, an inhibitor of Notch signaling, partially inhibited the enhanced expression of p21 induced by CCN3. CCN3 also inhibited the VSMC migration. Finally, the histopathologic evaluation of the arteries 21 days after the endothelial injury revealed a 6-fold enhancement of neointimal thickening in the null mice compared with the wild-type mice. Conclusion—CCN3 suppresses neointimal thickening through the inhibition of VSMC migration and proliferation. Our findings indicate the involvement of CCN3 in vascular homeostasis, especially on injury, and the potential usefulness of this molecule in the modulation of atherosclerotic vascular disease.

The roles of transforming growth factor-β and Smad3 signaling in adipocyte differentiation and obesity.

We aimed at elucidating the roles of transforming growth factor (TGF)-β and Smad3 signaling in adipocyte differentiation (adipogenesis) and in the pathogenesis of obesity. TGF-β/Smad3 signaling in white adipose tissue (WAT) was determined in genetically obese (ob/ob) mice. The effect of TGF-β on adipogenesis was evaluated in mouse embryonic fibroblasts (MEF) isolated both from WT controls and Smad3 KO mice by Oil red-O staining and gene expression analysis. Phenotypic analyses of high-fat diet (HFD)-induced obesity in Smad3 KO mice compared to WT controls were performed. TGF-β/Smad3 signaling was elevated in WAT from ob/ob mice compared to the controls. TGF-β significantly inhibited adipogenesis in MEF, but the inhibitory effects of TGF-β on adipogenesis were partially abolished in MEF from Smad3 KO mice. TGF-β inhibited adipogenesis independent from the Wnt and β-catenin pathway. Smad3 KO mice were protected against HFD-induced insulin resistance. The size of adipocytes from Smad3 KO mice on the HFD was significantly smaller compared to the controls. In conclusion, the TGF-β/Smad3 signaling pathway plays key roles not only in adipogenesis but also in development of insulin resistance.

JMJD1A is a signal-sensing scaffold that regulates acute chromatin dynamics via SWI/SNF association for thermogenesis

Histone 3 lysine 9 (H3K9) demethylase JMJD1A regulates β-adrenergic-induced systemic metabolism and body weight control. Here we show that JMJD1A is phosphorylated at S265 by protein kinase A (PKA), and this is pivotal to activate the β1-adrenergic receptor gene (Adrb1) and downstream targets including Ucp1 in brown adipocytes (BATs). Phosphorylation of JMJD1A by PKA increases its interaction with the SWI/SNF nucleosome remodelling complex and DNA-bound PPARγ. This complex confers β-adrenergic-induced rapid JMJD1A recruitment to target sites and facilitates long-range chromatin interactions and target gene activation. This rapid gene induction is dependent on S265 phosphorylation but not on demethylation activity. Our results show that JMJD1A has two important roles in regulating hormone-stimulated chromatin dynamics that modulate thermogenesis in BATs. In one role, JMJD1A is recruited to target sites and functions as a cAMP-responsive scaffold that facilitates long-range chromatin interactions, and in the second role, JMJD1A demethylates H3K9 di-methylation.

Halofuginone prevents extracellular matrix deposition in diabetic nephropathy

Transforming growth factor-beta (TGF-beta) is known to promote the accumulation of extracellular matrix (ECM) and the development of diabetic nephropathy. Halofuginone, an analog of febrifugine, has been shown to block TGF-beta(1) signaling and subsequent type I collagen production. Here, the inhibitory effect of halofuginone on diabetic nephropathy was examined. Halofuginone suppressed Smad2 phosphorylation induced by TGF-beta(1) in cultured mesangial cells. In addition, the expression of TGF-beta type 2 receptor decreased by halofuginone. Halofuginone showed an inhibitory effect on type I collagen and fibronectin expression promoted by TGF-beta(1). An in vivo experiment using db/db mice confirmed the ability of halofuginone to suppress mesangial expansion and fibronectin overexpression in the kidneys. Moreover, an analysis of urinary 8-OHdG level and dihydroethidium fluorescence revealed that halofuginone reduced oxidative stress in the glomerulus of db/db mice. These data indicate that halofuginone prevents ECM deposition and decreases oxidative stress, thereby suppressing the progression of diabetic nephropathy.

The FBXL10/KDM2B Scaffolding Protein Associates with Novel Polycomb Repressive Complex-1 to Regulate Adipogenesis

Background: Polycomb repressive complex PRC1 is an epigenetic regulator of cellular differentiation. However, its function during adipogenesis is unknown. Results: FBXL10/KDM2B recruited noncanonical PRC1 complex in F-box and LRR motifs dependent on cell cycle-related genes and Pparg genes and repressed 3T3-L1 adipogenesis. Conclusion: Noncanonical PRC1 complex containing FBXL10/KDM2B regulates adipogenesis. Significance: Our findings revealed a novel epigenetic mechanism of adipogenesis. Polycomb repressive complex 1 (PRC1) plays an essential role in the epigenetic repression of gene expression during development and cellular differentiation via multiple effector mechanisms, including ubiquitination of H2A and chromatin compaction. However, whether it regulates the stepwise progression of adipogenesis is unknown. Here, we show that FBXL10/KDM2B is an anti-adipogenic factor that is up-regulated during the early phase of 3T3-L1 preadipocyte differentiation and in adipose tissue in a diet-induced model of obesity. Interestingly, inhibition of adipogenesis does not require the JmjC demethylase domain of FBXL10, but it does require the F-box and leucine-rich repeat domains, which we show recruit a noncanonical polycomb repressive complex 1 (PRC1) containing RING1B, SKP1, PCGF1, and BCOR. Knockdown of either RING1B or SKP1 prevented FBXL10-mediated repression of 3T3-L1 preadipocyte differentiation indicating that PRC1 formation mediates the inhibitory effect of FBXL10 on adipogenesis. Using ChIP-seq, we show that FBXL10 recruits RING1B to key specific genomic loci surrounding the key cell cycle and the adipogenic genes Cdk1, Uhrf1, Pparg1, and Pparg2 to repress adipogenesis. These results suggest that FBXL10 represses adipogenesis by targeting a noncanonical PRC1 complex to repress key genes (e.g. Pparg) that control conversion of pluripotent cells into the adipogenic lineage.

PPARβ/δ activation of CD300a controls intestinal immunity

Macrophages are important for maintaining intestinal immune homeostasis. Here, we show that PPARβ/δ (peroxisome proliferator-activated receptor β/δ) directly regulates CD300a in macrophages that express the immunoreceptor tyrosine based-inhibitory motif (ITIM)-containing receptor. In mice lacking CD300a, high-fat diet (HFD) causes chronic intestinal inflammation with low numbers of intestinal lymph capillaries and dramatically expanded mesenteric lymph nodes. As a result, these mice exhibit triglyceride malabsorption and reduced body weight gain on HFD. Peritoneal macrophages from Cd300a−/− mice on HFD are classically M1 activated. Activation of toll-like receptor 4 (TLR4)/MyD88 signaling by lipopolysaccharide (LPS) results in prolonged IL-6 secretion in Cd300a−/− macrophages. Bone marrow transplantation confirmed that the phenotype originates from CD300a deficiency in leucocytes. These results identify CD300a-mediated inhibitory signaling in macrophages as a critical regulator of intestinal immune homeostasis.

An Angiotensin II Type 1 Receptor Blocker Prevents Renal Injury via Inhibition of the Notch Pathway in Ins2 Akita Diabetic Mice

Recently, it has been reported that the Notch pathway is involved in the pathogenesis of diabetic nephropathy. In this study, we investigated the activation of the Notch pathway in Ins2 Akita diabetic mouse (Akita mouse) and the effects of telmisartan, an angiotensin II type1 receptor blocker, on the Notch pathway. The intracellular domain of Notch1 (ICN1) is proteolytically cleaved from the cell plasma membrane in the course of Notch activation. The expression of ICN1 and its ligand, Jagged1, were increased in the glomeruli of Akita mice, especially in the podocytes. Administration of telmisartan significantly ameliorated the expression of ICN1 and Jagged1. Telmisartan inhibited the angiotensin II-induced increased expression of transforming growth factor β and vascular endothelial growth factor A which could directly activate the Notch signaling pathway in cultured podocytes. Our results indicate that the telmisartan prevents diabetic nephropathy through the inhibition of the Notch pathway.

Primary lung cancer associated with Werner syndrome.

A 52‐year‐old man with Werner Syndrome (WS) was admitted to our hospital for the treatment of skin ulcers on his thighs. Routine chest radiography revealed an abnormal shadow in the left upper lung field. Computed tomography (CT) revealed a poorly demarcated homogeneous mass (diameter, 4 cm) in the S1 + 2 lung area; no pleural effusion was observed. CT‐guided percutaneous needle biopsy revealed the presence of an adenocarcinoma. Other imaging studies did not reveal any lymph‐node involvement or presence of metastatic lesions. The patient was diagnosed with stage IB adenocarcinoma (T2N0M0), and a left upper lobectomy was successfully carried out; postoperative wound healing was steady and uneventful, with no obvious ulcer formation. Primary lung cancers very rarely develop in patients with WS; non‐epithelial tumors are usually observed in such patients. Patients with WS usually develop severe skin problems, such as refractory skin ulcers in the extremities; however, our patient did not develop any skin‐related complications after surgery. As the expected lifespan of patients with WS is increasing, we need to pay attention not only to the rare non‐epithelial malignancy, but also cancer. Further, the expected short lifespan of patients with WS, as well as the possibility of skin‐related problems after surgery, should not be considered while deciding whether to take the option of surgery in the case of malignancy. Geriatr Gerontol Int 2010; 10: 319–323.

A novel podocyte gene, semaphorin 3G, protects glomerular podocyte from lipopolysaccharide-induced inflammation

Kidney diseases including diabetic nephropathy have become huge medical problems, although its precise mechanisms are still far from understood. In order to increase our knowledge about the patho-physiology of kidney, we have previously identified >300 kidney glomerulus-enriched transcripts through large-scale sequencing and microarray profiling of the mouse glomerular transcriptome. One of the glomerulus-specific transcripts identified was semaphorin 3G (Sema3G) which belongs to the semaphorin family. The aim of this study was to analyze both the in vivo and in vitro functions of Sema3G in the kidney. Sema3G was expressed in glomerular podocytes. Although Sema3G knockout mice did not show obvious glomerular defects, ultrastructural analyses revealed partially aberrant podocyte foot processes structures. When these mice were injected with lipopolysaccharide to induce acute inflammation or streptozotocin to induce diabetes, the lack of Sema3G resulted in increased albuminuria. The lack of Sema3G in podocytes also enhanced the expression of inflammatory cytokines including chemokine ligand 2 and interleukin 6. On the other hand, the presence of Sema3G attenuated their expression through the inhibition of lipopolysaccharide-induced Toll like receptor 4 signaling. Taken together, our results surmise that the Sema3G protein is secreted by podocytes and protects podocytes from inflammatory kidney diseases and diabetic nephropathy.

18F-deoxyglucose positron emission tomography computed tomography as a useful diagnostic tool in an elderly patient with suspected but atypical polymyalgia rheumatica: A case report: PMR patient with atypical symptoms

ated with eosinophilia and rearrangement of PDGFRA, PDGFRB, and FGFR1: a review. Int J Lab Hematol 2013 (Oct); 35: 491–500. 3 Gotlib J. World Health Organization-defined eosinophilic disorders: 2014 update on diagnosis, risk stratification, and management. Am J Hematol 2014 (Mar); 89: 325–337. 4 Sada A, Katayama Y, Yamamoto K et al. A multicenter analysis of the FIP1L1-alphaPDGFR fusion gene in Japanese idiopathic hypereosinophilic syndrome: an aberrant splicing skipping the alphaPDGFR exon 12. Ann Hematol 2007; 86: 855–863. 5 Baccarani M, Cilloni D, Rondoni M et al. The efficacy of imatinib mesylate in patients with FIP1L1-PDGFRalphapositive hypereosinophilic syndrome. Results of a multicenter prospective study. Haematologica 2007 (Sep); 92: 1173–1179. 6 Legrand F, Renneville A, Macintyre E et al. The spectrum of FIP1L1-PDGFRA-associated chronic eosinophilic leukemia: new Insights based on a survey of 44 cases. Medicine (Baltimore) 2013 (Aug); 92: e1–e9. 7 Helbig G, Stella-Hołowiecka B, Majewski M et al. A single weekly dose of imatinib is sufficient to induce and maintain remission of chronic eosinophilic leukaemia in FIP1L1PDGFRA-expressing patients. Br J Haematol 2008 (Apr); 141: 200–204. 8 Nemoto T, Saito Y, Tokuhira M et al. Acute-onset eosinophilic leukemia associated with tumor lysis syndrome after imatinib and steroid pulse therapy. Rinsho Ketsueki 2010 (May); 51: 326–331. (Abstract in English.)