Article: Transition of pathophysiological significance of plasminogen activator inhibitor-From a chief player in antiinflammation, antifibrinolysis to that in the development of insulin resistance.[show abstract] [hide abstract]
ABSTRACT: In the early phase of research, plasminogen activator inhibitor (PAI) was regarded as a negative regulator of fibrinolytic system, but the later study clarified that the changes in PAI level is closely related to risk factors of various pathologic processes of the lifestyle-related diseases. It is accepted that PAI-1 is a risk factor of the cardiovascular event in lifestyle-related diseases by recent researches analyzing the detailed function of PAI-1. In this review paper, we described the transition of pathophysiological significance of PAI based on many research papers especially from ours, which clarified the mechanism on protein expression of PAI, especially PAI-1.Pathophysiology 07/2009; 17(2):109-18.
Masanori Sunagawa[show abstract] [hide abstract]
ABSTRACT: Proliferation of vascular smooth muscle (VSM) cells is a crucial step for developing vascular diseases such as atherosclerosis, hypertension and vascular restenosis after angioplasty. Proliferation of VSM cells is regulated by many intracellular signals: second messengers (e.g. Ca(2+), phosphatydylinositol, cAMP/cGMP), protein kinases and transcription factors. Although Ca(2+) regulation of cell proliferation is very important, there is rarely any informative review paper about the topic. Increase in cytosolic intracellular Ca(2+) concentration ([Ca(2+)](i)) due to Ca(2+) entry is necessary for proliferation of VSM cells. Elevation of [Ca(2+)](i) is needed for both cell cycle progressions at G(1)/S phase and the cell division in M phase. Intracellular Ca(2+) is regulated by the balance between Ca(2+)-elevating machinery such as Ca(2+) influx through voltage-dependent Ca(2+) channels (VDCC), Ca(2+) release from stored Ca(2+) in sarcoplasmic reticulum and Ca(2+)-lowering machinery such as Ca(2+) transport ATPases. In this review paper, we focus on the role of VDCC in the regulation of cell proliferation, especially in VSM cells. We also described significant roles of VDCC in pathophysiological conditions such as atherosclerosis, stroke and renal dysfunction.Pathophysiology 07/2009; 17(2):101-8.
Article: RNAi targeting embryonic myosin heavy chain isoform inhibited bound thrombin-induced migration of vascular smooth muscle cells.[show abstract] [hide abstract]
ABSTRACT: To investigate the effect of bound thrombin, a complex of alpha-thrombin with fibrin fragments derived from clots, on proliferation and migration of cultured rabbit vascular smooth muscle cells, cell proliferation was measured by WST-1 reagent and migration was evaluated by counting migrated cells through pores of cell culture insert (8 mum size) after 48-hour treatment with bound thrombin (10 U/ml). To examine the role of an embryonic myosin heavy chain isoform (SMemb) in these effects by bound thrombin, the cells were subsequently treated for 48 h with an siRNA expression vector (ORF-2/pSilencer) directed against the open reading frame of SMemb mRNA. SMemb and plasminogen activator inhibitor-1 mRNA expressions were measured by Northern blot analysis. Bound thrombin significantly increased SMemb mRNA expression by 1.4 +/- 0.01-fold and significantly increased plasminogen activator inhibitor-1 mRNA expression by 2.65 +/- 0.69-fold (p < 0.01 vs. PBS treatment for each), which were abolished by treatment with ORF-2/pSilencer. Although bound thrombin had no effect on cell proliferation, bound thrombin significantly increased migration by 1.93 +/- 0.20-fold (p < 0.05). ORF-2/pSilencer treatment significantly reduced the bound thrombin-stimulated migration activity by 1.28 +/- 0.15-fold (p < 0.05). Thus, SMemb plays an important role in bound thrombin-induced cell migration activity of cultured vascular smooth muscle cells.Journal of Vascular Research 06/2008; 46(1):55-63. · 2.65 Impact Factor
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ABSTRACT: The habutobin cDNA was cloned from total RNA extracted from venom glands of Trimeresurus flavoviridis (the habu snake). The conceptual translation of 1539 bp of habutobin cDNA consists of 236 amino acids and its molecular weight is 25.7 kDa. Histidine (His)-tagged recombinant habutobin fusion protein, pET-r-habutobin and AcNPV-r-habutobin, was purified by bacterial system and baculoviral system, respectively. After refolding pET-r-habutobin, there were two protein bands at about 32 kDa and 65 kDa, indicating that habutobin might be produced as a monomer protein and processed to form two concatenated protein. Purified AcNPV-r-habutobin dose-dependently increased fibrin forming activity and inhibited collagen-induced aggregation of rabbit washed platelets. Thus, AcNPV-r-habutobin produced by baculoviral system is very useful for study on structure-function relationship, which is necessary for developing an antithrombotic drug from habutobin.Biochemical and Biophysical Research Communications 12/2007; 362(4):899-904. · 2.48 Impact Factor
Article: Inhibition of IgE-mediated phosphorylation of FcepsilonRIgamma protein by antiallergic drugs in rat basophilic leukemia (RBL-2H3) cells: a novel action of antiallergic drugs.[show abstract] [hide abstract]
ABSTRACT: We examined the effect of antiallergic drugs, azelastine and epinastine, on the expression of FcepsilonRIalpha, beta, and gamma chains and phosphorylation of the gamma chains in rat basophilic leukemia (RBL-2H3) cells. The cells were cultured for 24 h with IgE treatment in the presence of azelastine or epinastine at the concentration of 10(-5) M. The FcepsilonRIalpha mRNA expression was determined by northern blot analysis. The protein level of FcepsilonRI expressed on the plasma membrane was examined following IgE treatment by immunoprecipitation with anti-IgE light chain, followed by western blot analysis with anti-gamma chain of FcR. Azelastine and epinastine had no effect on the FcepsilonRIalpha, beta and gamma mRNA levels. Although the amount of gamma chain assembled into IgE-bound FcepsilonRI was not changed by treatment with azelastine nor epinastine, phosphorylation levels of gamma chains of IgE-bound FcepsilonRI were inhibited by azelastine. The inhibitory effect of azelastine on the IgE-mediated expression of FcepsilonRIgamma protein is not due to their inhibition of mRNA and protein expression, but due to abrogating phosphorylation of the gamma chains, which is important for initiation of FcepsilonRI signaling cascade elicited by IgE interaction.International Immunopharmacology 08/2007; 7(7):994-1002. · 2.38 Impact Factor