yes / Background/purpose Coronary heart disease is the leading cause of morbidity in patients with type 2 diabetes mellitus (T2DM), frequently resulting in a requirement for coronary revascularization using the internal mammary artery (IMA) or saphenous vein (SV). Patency rates of SV grafts are inferior to IMA and further impaired by T2DM whilst IMA patencies appear similar in both populations. Smooth muscle cells (SMC) play a pivotal role in graft integration; we therefore examined the phenotype and proliferative function of IMA- and SV-SMC isolated from non-diabetic (ND) patients or those diagnosed with T2DM. Methods/materials SMC were cultured from fragments of SV or IMA. Morphology was analyzed under light microscopy (spread cell area measurements) and confocal microscopy (F-actin staining). Proliferation was analyzed by cell counting. Levels of RhoA mRNA, protein and activity were measured by real-time RT-PCR, western blotting and G-LISA respectively. Results IMA-SMC from T2DM and ND patients were indistinguishable in both morphology and function. By comparison, SV-SMC from T2DM patients exhibited significantly larger spread cell areas (1.5-fold increase, P < 0.05), truncated F-actin fibers and reduced proliferation (33% reduction, P < 0.05). Furthermore, lower expression and activity of RhoA were observed in SV-SMC of T2DM patients (37% reduction in expression, P < 0.05 and 43% reduction in activity, P < 0.01). Conclusions IMA-SMC appear impervious to phenotypic modulation by T2DM. In contrast, SV-SMC from T2DM patients exhibit phenotypic and functional changes accompanied by reduced RhoA activity. These aberrancies may be epigenetic in nature, compromising SMC plasticity and SV graft adaptation in T2DM patients.

Yes / Cardiovascular disease is a leading cause of morbidity and mortality. Smooth muscle cells (SMC) comprising the vascular wall can switch phenotypes from contractile to synthetic, which can promote the development of aberrant remodelling and intimal hyperplasia (IH). MicroRNA‐21 (miR‐21) is a short, non‐coding RNA that has been implicated in cardiovascular diseases including proliferative vascular disease and ischaemic heart disease. However, its involvement in the complex development of atherosclerosis has yet to be ascertained. Smooth muscle cells (SMC) were isolated from human saphenous veins (SV). miR‐21 was over‐expressed and the impact of this on morphology, proliferation, gene and protein expression related to synthetic SMC phenotypes monitored. Over‐expression of miR‐21 increased the spread cell area and proliferative capacity of SV‐SMC and expression of MMP‐1, whilst reducing RECK protein, indicating a switch to the synthetic phenotype. Furthermore, platelet‐derived growth factor BB (PDGF‐BB; a growth factor implicated in vasculoproliferative conditions) was able to induce miR‐21 expression via the PI3K and ERK signalling pathways. This study has revealed a mechanism whereby PDGF‐BB induces expression of miR‐21 in SV‐SMC, subsequently driving conversion to a synthetic SMC phenotype, propagating the development of IH. Thus, these signaling pathways may be attractive therapeutic targets to minimise progression of the disease. / King Saud University; College of Medicine , Riyadh, Saudi Arabia

Yes / (1) Abdominal aortic aneurysm (AAA) is a silent, progressive disease with significant mortality from rupture. Whilst screening programmes are now able to detect this pathology early in its development, no therapeutic intervention has yet been identified to halt or retard aortic expansion. The inability to obtain aortic tissue from humans at early stages has created a necessity for laboratory models, yet it is essential to create a timeline of events from EARLY to END stage AAA progression. (2) We used a previously validated ex vivo porcine bioreactor model pre-treated with protease enzyme to create "aneurysm" tissue. Mechanical properties, histological changes in the intact vessel wall, and phenotype/function of vascular smooth muscle cells (SMC) cultured from the same vessels were investigated. (3) The principal finding was significant hyperproliferation of SMC from EARLY stage vessels, but without obvious histological or SMC aberrancies. END stage tissue exhibited histological loss of α-smooth muscle actin and elastin; mechanical impairment; and, in SMC, multiple indications of senescence. (4) Aortic SMC may offer a therapeutic target for intervention, although detailed studies incorporating intervening time points between EARLY and END stage are required. Such investigations may reveal mechanisms of SMC dysfunction in AAA development and hence a therapeutic window during which SMC differentiation could be preserved or reinstated. / This research was funded in part by The Leeds Teaching Hospitals Charitable Foundation (R11/8002). E.R.C. was supported by a PhD studentship from the Engineering and Physical Sciences Research Council (EPSRC; EP/F500513/1). R.J.H. was the recipient of an Intercalated Batchelor of Science Degree in Science award from the Royal College of Surgeons of England. M.A.B.(FS/18/12/33270 and FS/12/54/29671), K.I.B. (FS/12/26/29395), and K.J.G. (FS/11/91/29090) were supported by BHF Clinical Research Training Fellowships.

Yes / Coronary microvascular dysfunction (CMD) is an under-diagnosed condition characterized by functional alteration of the small coronary arterioles and the cardiac capillary bed. The vessels do not dilate appropriately in response to changes in cardiac oxygen demand, leading to chest pain and symptoms of angina. These blood vessels contain two major cell types: the endothelial cells, which line the blood vessels and detect changes in oxygen demand, and smooth muscle cells (SMC) which respond to these changes by contracting or relaxing to provide an optimal blood supply to the cardiac tissue. Many CMD studies have focused on the endothelial cells as these cells secrete vasorelaxants and vasoconstrictors. However, comparably fewer studies have examined SMC despite their functional role in contracting and relaxing. A variety of health conditions and lifestyle choices, such as diabetes, hypertension and cigarette smoking, can promote the development of both CMD and macrovascular coronary artery disease; a condition where SMC have been studied extensively. This review article will consider the influence of CMD on SMC phenotype. It will discuss the structural, cellular and molecular changes in CMD, and will summarise how co-morbidities can have differing effects on micro- and macro-vascular SMC phenotype and function, which complicates the development of new therapeutic avenues for CMD.

京都大学 / 新制・論文博士 / 博士(医学) / 乙第13515号 / 論医博第2265号 / 新制||医||1061(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 湊谷 謙司, 教授 石見 拓, 教授 江木 盛時 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM

No description available.

No description available.

京都大学 / 新制・課程博士 / 博士(医学) / 甲第23802号 / 医博第4848号 / 新制||医||1058(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 永井 洋士, 教授 羽賀 博典, 教授 木村 剛 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

The underlying cause of all vascular proliferative diseases is injury-induced activation of vascular endothelium and vascular smooth muscle cells (VSMC). Activated VSMC proliferate, than migrate from the arterial media to the intima, contributing to neointima formation. Activated immune cells, vascular cells, and their endogenous regulators mediate this complex process. One integral regulator of VSMC activation is allograft inflammatory factor-1 (AIF-1). AIF-1 is a cytoplasmic scaffold protein, expressed constitutively in lymphoid cells and induced in VSMC by injury. Stable over expression of AIF-1 increases VSMC proliferation and migration in vitro, causes increased injury-induced neointima formation, and increases Rac1 and p38 MAP Kinase activity. Recent studies show a correlation between VSMC expression of AIF-1 and atherosclerosis development. We hypothesize that VSMC over expression of AIF-1 contributes to atherosclerosis development by increasing activity of inflammatory signaling molecules, and that inhibiting VSMC AIF-1 expression will decrease injury-induced neointima formation. Rat carotid arteries transfected with AIF-1 si RNA adenovirus after balloon angioplasty developed significantly less neointima compared to controls. AIF-1 si RNA transfected VSMC proliferated significantly less than AIF-1 or GFP transfected VSMC, while AIF-1 si RNA transfection did not attenuate AIF-1-mediated migration. p38 inhibition showed that AIF-1-mediated proliferation is dependent on p38 activation while AIF-1-mediated migration is not. AIF-1 transgenic mice fed a high fat diet showed significantly more atherosclerotic lesions than WT littermates. Boyden Chamber assays showed OxLDL treatment increases VSMC migration but does not effect AIF-1-mediated migration. Expression of migration and inflammatory responsive genes in AIF-1 and XGal transfected VSMC after OxLDL treatment at various time points were examined. MMP-2 and -9 expression did not change. ICAM-1 and VCAM-1 expression increased in both groups. AIF-1 VSMC showed significantly higher ICAM-1 expression at baseline and early time points and elevated, but not significantly higher VCAM-1 expression at early time points. Western blots showed increased activation of NF-kB in AIF-1 transfected VSMC at baseline and 30 minutes after OxLDL stimulation compared to XGal transfected VSMC. Expression of the scavenger receptor receptors CD36 and SRA(I) expression increased after lipid treatment in AIF-1 and XGal transfected groups. AIF-1 VSMC showed sustained expression of both receptors after 16 hours of treatment compared to XGal VSMC, which showed decreased expression at that time point. CXCL16/PSOX expression increased with treatment, but differences in expression patterns were not seen between cell groups. Analysis showed significantly more OxLDL was taken up by AIF-1 VSMC compared to XGal VSMC. These data show that AIF-1 expression in VSMC is tightly linked to the vascular response to injury and development of vascular disease. Although AIF-1-mediated migration is not p38 dependent, AIF-1 may contribute to increased VSMC migration in part by upregulating NF- kB downstream effectors through increased NF-kB activity. AIF-1 may also speed the progression of atherosclerosis by increasing scavenger receptor expression and thereby increasing OxLDL uptake and foam cell formation. Although more study is required to fully elucidate the molecular mechanisms leading to AIF-1 mediated VSMC activation, these data have further established AIF-1 as an integral regulator of the VSMC response to injury. / Molecular and Cellular Physiology

O quadro de resistência à insulina em humanos está fortemente relacionado ao acumulo de lipídeos intracelulares, a inatividade física e ao aumento de espécies reativas de oxigênio (ERO). O objetivo deste estudo foi verificar se o aumento na oferta de nutrientes incluindo glicose e ácido graxo palmítico pode alterar o potencial de membrana mitocondrial, a respiração, a produção de espécies reativas de oxigênio e a resposta a insulina em células do tecido muscular. Nossos resultados mostram que a exposição de células musculares a elevada disponibilidade de substratos resultou em diminuição do potencial de membrana mitocondrial, e aumento da respiração no estado IV e da expressão do RNAm da proteína desacopladora mitocondrial UCP-3. Mostrando a existência de um mecanismo de desacoplamento intrínseco em células do músculo esquelético ativado em situações de elevada oferta de nutrientes. Nessas condições observamos redução do acoplamento e da eficiência termodinâmica mitocondrial. Interessantemente, essa capacidade de desacoplamento parece ser perdida cronicamente como indicado pelos nossos resultados de consumo de oxigênio no período de 48h favorecendo uma menor atividade mitocondrial, aumento de EROs e redução da razão GSH/GSSG. Imagens de microscopia eletrônica em cultura primária e expressão gênica do PGC1-, um reconhecido gene regulador da biogênese mitocondrial, não demonstraram diferença entre controle e tratamento com palmitato. O ácido palmito resultou na redução da fosforilação de Akt, bem como, na captação de glicose estimulada por insulina. Nossos achados, portanto, sugerem que uma redução do acoplamento termodinâmico mitocondrial e do sistema antioxidante, juntamente com aumento do peróxido de hidrogênio, estão fortemente relacionados a redução da resposta a insulina. Deste modo, nosso estudo sugere um papel importante da mitocôndria na resposta a insulina. / The insulin resistance in human framework is strongly related to the accumulation of intracellular lipids, physical inactivity and increased reactive oxygen species (ROS). The aim of this study was to determine whether the increase in nutrient supply including glucose and palmitic fatty acid can change the mitochondrial membrane potential, respiration, production of reactive oxygen species and the insulin response in muscle tissue cells. Our results show that exposure of muscle cells to high availability of the substrate resulted in decreased mitochondrial membrane potential, in increased respiration in the state IV and mRNA expression of mitochondrial uncoupling protein UCP-3. Showing the existence of an intrinsic uncoupling mechanism of skeletal muscle cells activated in situations of high supply of nutrients. However, under these conditions we observed a reduction of the coupling and mitochondrial thermodynamic efficiency. Interestingly, this decoupling capacity was chronically lost as indicated by our results in the 48 hours period favoring a lower mitochondrial activity, increase of ROS and reduced GSH / GSSG ratio. Images from electron microscopy and gene expression of PGC1-, a recognized regulatory gene of mitochondrial biogenesis, showed no difference between control and treatment with palmitate. The palm acid resulted in reduced phosphorylation of Akt, as well as glucose uptake stimulated by insulin. Our findings thus suggest that a reduction in mitochondrial antioxidant and thermodynamic coupling system, along with increase in the hydrogen peroxide, are closely related to reducing insulin response. Thus, our findings suggest a role of mitochondria in insulin response.