Objective-To study matrix metalloproteinase 2 (MMP-2) effects on transforming growth factor-␤1 (TGF-␤1) activation status and downstream signaling during arterial aging. Methods and Results-Western blotting and immunostaining showed that latent and activated TGF-␤1 are markedly increased within the aorta of aged Fisher 344 cross-bred Brown Norway (30 months of age) rats compared with adult (8 months of age) rats. Aortic TGF-␤1-type II receptor (T␤RII), its downstream molecules p-similar to mad-mother against decapentaplegic (SMAD)2/3 and SMAD4, fibronectin, and collagen also increased with age. Moreover, TGF-␤1 staining is colocalized with that of activated MMP-2 within the aged arterial wall and vascular smooth muscle cell (VSMC) in vitro, and this physical association was confirmed by coimmunoprecipitation. Incubation of young aortic rings ex vivo or VSMCs in vitro with activated MMP-2 enhanced active TGF-␤1, collagen, and fibronectin expression to the level of untreated old counterparts, and this effect was abolished via inhibitors of MMP-2. Interestingly, in old untreated rings or VSMCs, the increased TGF-␤1, fibronectin, and collagen were also substantially reduced by inhibition of MMP-2. Conclusions-Active TGF-␤1, its receptor, and receptor-mediated signaling increase within the aortic wall with aging.TGF-␤1 activation is dependent, in part at least, by a concomitant age-associated increase in MMP-2 activity. Thus, MMP-2-activated TGF-␤1, and subsequently T␤RII signaling, is a novel molecular mechanism for arterial aging.

Increased angiotensin II (Ang II), matrix metalloproteinase type II (MMP2), and sympathetic activity accompany age-associated arterial remodeling. To analyze this relationship, we infused a low subpressor dose of Ang II into young (8 months old) rats. This increased carotid arterial MMP2 transcription, translation, and activation, as well as transforming growth factor-␤1 activity and collagen deposition. A higher Ang II concentration, which increased arterial pressure to that of old (30 months old) untreated rats, produced carotid media thickening and intima infiltration by vascular smooth muscle cells (VSMCs). Ex vivo, Ang II increased MMP2 activity in carotid rings from young rats to that of untreated old rats. Ang II also increased the ability of early passage VSMCs from young rats to invade a synthetic basement membrane, similar to that of untreated VSMCs from old rats. The MMP inhibitor GM6001 and the AT 1 receptor antagonist Losartan inhibited these effects. The ␣-adrenoreceptor agonist phenylephrine increased arterial Ang II protein, causing MMP2 activation and intima and media thickening. Exposure of young VSMCs to phenylephrine in vitro increased Ang II protein and MMP2 activity to the levels of old VSMCs; Losartan abolished these effects. Thus, Ang II-induced effects on MMP2, transforming growth factor-␤1, collagen, and VSMCs are central to the arterial remodeling that accompanies advancing age. (Am J Pathol 2005,

Among post-menopausal women, a higher testosterone/estradiol ratio was associated with an elevated risk for incident CVD, CHD, and HF events, higher levels of testosterone associated with increased CVD and CHD, whereas higher estradiol levels were associated with a lower CHD risk. Sex hormone levels after menopause are associated with women's increased CVD risk later in life.

MHO participants had a higher prevalence of subclinical coronary atherosclerosis than metabolically-healthy normal-weight participants, which supports the idea that MHO is not a harmless condition. This association, however, was mediated by metabolic risk factors at levels below those considered abnormal, which suggests that the label of metabolically healthy for obese subjects may be an artifact of the cutoff levels used in the definition of metabolic health.

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Objective-With age, rat arterial walls thicken and vascular smooth muscle cells (VSMCs) exhibit enhanced migration and proliferation. Monocyte chemotactic protein-1 (MCP-1) affects these VSMC properties in vitro. Because arterial angiotensin II, which induces MCP-1 expression, increases with age, we hypothesized that aortic MCP-1 and its receptor CCR2 are also upregulated and affect VSMC properties. Methods and Results-Both MCP-1 and CCR2 mRNAs and proteins increased in old (30-month) versus young (8-month) F344ϫBN rat aortas in vivo. Cellular MCP-1 and CCR2 staining colocalized with that of ␣-smooth muscle actin in the thickened aortas of old rats and were expressed by early-passage VSMCs isolated from old aortas, which, relative to young VSMCs, exhibited increased invasion, and the age difference was abolished by vCCI, an inhibitor of CCR2 signaling. MCP-1 treatment of young VSMCs induced migration and increased their ability to invade a synthetic basement membrane. The MCP-1-dependent VSMC invasiveness was blocked by vCCI. After MCP-1 treatment, migration and invasion capacities of VSMCs from young aortas no longer differed from those of VSMCs isolated from older rats. Key Words: chemokines Ⅲ aging Ⅲ aorta Ⅲ vascular smooth muscle cells Ⅲ invasion A ging is the major risk factor for the development of atherosclerosis and hypertension, which have an important impact on Western society because they lead to myocardial infarction, stroke, and heart failure. 1-3 Arterial remodeling accompanies advancing age in all species, from rodents to nonhuman primates to humans, and the mechanisms involved in this remodeling likely confer on aging the status of the major risk factor for vascular diseases. 1,2 Specific facets of age-associated remodeling include luminal dilation, thickening of the intimal and medial layers with cellular and extracellular matrix reorganization, increased stiffness, and endothelial dysfunction. 4 -6 Studies from our laboratory and others have shown that diffuse intimal thickening with aging is characterized by accumulation of fibronectin, collagen, and vascular smooth muscle cells (VSMCs), with an increase in matrix metalloproteinase (MMP)-2 and angiotensin II (Ang II) expression. [7][8][9][10][11] In addition, the expression of aortic intracellular adhesion molecule and transforming growth factor-␤1 markedly increases with age, and these molecules localize to MMP-2-staining positive areas. 12 Arterial aging is also characterized by an increase in NAD(P)H oxidase activity and reactive oxygen species production and a reduction in nitric oxide (NO) bioavailability. [13][14][15][16] In addition, increased arterial levels of proinflammatory cytokines, such as tumor necrosis factor-␣ and interleukin-6, among others, accompany aging. [17][18][19][20] Structural and biochemical changes that occur within large arteries with aging are accompanied by a shift of the VSMC phenotype from the "contractile" to the "synthetic" state, characterized by an increased proliferative and migratory responsiveness to...

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The risk of nonalcoholic fatty liver disease (NAFLD) among obese individuals without obesity-related metabolic abnormalities, a condition referred to as metabolically healthy obese (MHO), is largely unexplored. Therefore, we examined the association between body mass index (BMI) categories and the development of NAFLD in a large cohort of metabolically healthy men and women. METHODS:A cohort study was conducted in 77,425 men and women free of NAFLD and metabolic abnormalities at baseline, who were followed-up annually or biennially for an average of 4.5 years. Being metabolically healthy was defi ned as not having any metabolic syndrome component and having a homeostasis model assessment of insulin resistance <2.5. The presence of fatty liver was determined using ultrasound. RESULTS:During 348,193.5 person-years of follow-up, 10,340 participants developed NAFLD (incidence rate, 29.7 per 1,000 person-years). The multivariable adjusted hazard ratios (95% confi dence intervals) for incident NAFLD comparing overweight and obese with normal-weight participants were 2.15 (2.06-2.26) and 3.55 (3.37-3.74), respectively. In detailed dose-response analyses, increasing baseline BMI showed a strong and approximately linear relationship with the incidence of NAFLD, with no threshold at no risk. This association was present in both men and women, although it was stronger in women ( P for interaction <0.001), and it was evident in all clinically relevant subgroups evaluated, including participants with low infl ammation status. CONCLUSIONS:In a large cohort of strictly defi ned metabolically healthy men and women, overweight and obesity were strongly and progressively associated with an increased incidence of NAFLD, suggesting that the obese phenotype per se , regardless of metabolic abnormalities, can increase the risk of NAFLD. Am J Gastroenterol 2016; 111:1133-1140 doi: 10.1038/ajg.2016 Specifi cally, it is unclear whether obesity is a risk factor for NALFD in subjects who do not have any of the metabolic abnormalities associated with excess adiposity, a group oft en described as metabolically healthy obese (MHO) ( 11,12 ). Th e health implications of . Only one study has evaluated the association of MHO with NAFLD ( 16 ). In this study, MHO subjects had an increased prevalence of NAFLD compared with metabolically healthy non-obese subjects, but the cross-sectional design of this study limited its ability to establish a temporal relation between obesity and NAFLD.No cohort study has evaluated the role of MHO as a determinant of incident NAFLD among subjects free of NAFLD at baseline. Th erefore, we examined the association between body mass index (BMI) categories and the development of NAFLD in a large cohort of metabolically healthy men and women who participated in a health screening examination program. METHODS Study populationTh e Kangbuk Samsung Health Study is a cohort study of men and women 18 years of age or older who underwent a comprehensive annual or biennial health examination at the clinics of the Kangbuk Samsu...