Cytokine responses during chronic denervation

BACKGROUND: The aim of the present study was to examine inflammatory responses during Wallerian degeneration in rat peripheral nerve when the regrowth of axons was prevented by suturing. METHODS: Transected rat sciatic nerve was sutured and ligated to prevent reinnervation. The samples were collected from the left sciatic nerve distally and proximally from the point of transection. The endoneurium was separated from the surrounding epi- and perineurium to examine the expression of cytokines in both of these compartments. Macrophage invasion into endoneurium was investigated and Schwann cell proliferation was followed as well as the expression of cytokines IL-1β, IL-10, IFN-γ and TNF-α mRNA. The samples were collected from 1 day up to 5 weeks after the primary operation. RESULTS: At days 1 to 3 after injury in the epi-/perineurium of the proximal and distal stump, a marked expression of the pro-inflammatory cytokines TNF-α and IL-1β and of the anti-inflammatory cytokine IL-10 was observed. Concurrently, numerous macrophages started to gather into the epineurium of both proximal and distal stumps. At day 7 the number of macrophages decreased in the perineurium and increased markedly in the endoneurium of both stumps. At this time point marked expression of TNF-α and IFN-γ mRNA was observed in the endo- and epi-/perineurium of the proximal stump. At day 14 a marked increase in the expression of IL-1β could be noted in the proximal stump epi-/perineurium and in the distal stump endoneurium. At that time point many macrophages were observed in the longitudinally sectioned epineurium of the proximal 2 area as well as in the cross-section slides from the distal stump. At day 35 TNF-α, IL-1β and IL-10 mRNA appeared abundantly in the proximal epi-/perineurium together with macrophages. CONCLUSION: The present studies show that even during chronic denervation there is a cyclic expression pattern for the studied cytokines. Contrary to the previous findings on reinnervating nerves the studied cytokines show increased expression up to 35 days. The high expressions of pro-inflammatory and anti-inflammatory cytokines in the proximal epi-/perineurial area at day 35 may be involved in the formation of fibrosis due to irreversible nerve injury and thus may have relevance to the formation of traumatic neuroma

Temporal profiles of age-dependent changes in cytokine mRNA expression and glial cell activation after status epilepticus in postnatal rat hippocampus

<p>Abstract</p> <p>Background</p> <p>Status epilepticus (SE) is proposed to lead to an age-dependent acute activation of a repertoire of inflammatory processes, which may contribute to neuronal damage in the hippocampus. The extent and temporal profiles of activation of these processes are well known in the adult brain, but less so in the developing brain. We have now further elucidated to what extent inflammation is activated by SE by investigating the acute expression of several cytokines and subacute glial reactivity in the postnatal rat hippocampus.</p> <p>Methods</p> <p>SE was induced by an intraperitoneal (i.p.) injection of kainic acid (KA) in 9- and 21-day-old (P9 and P21) rats. The mRNA expression of interleukin-1 beta (IL-1β), tumor necrosis factor-alpha (TNF-α), interleukin-10 (IL-10), matrix metalloproteinase-9 (MMP-9), glial-derived neurotrophic factor (GDNF), interferon gamma (IFN-γ), and transforming growth factor-beta 1 (TGF-β1) were measured from 4 h up to 3 days after KA injection with real-time quantitative PCR (qPCR). IL-1β protein expression was studied with ELISA, GFAP expression with western blotting, and microglial and astrocyte morphology with immunohistochemistry 3 days after SE.</p> <p>Results</p> <p>SE increased mRNA expression of IL-1β, TNF-α and IL-10 mRNA in hippocampus of both P9 and P21 rats, their induction being more rapid and pronounced in P21 than in P9 rats. MMP-9 expression was augmented similarly in both age groups and GDNF expression augmented only in P21 rats, whereas neither IFN-γ nor TGF-β1 expression was induced in either age group. Microglia and astrocytes exhibited activated morphology in the hippocampus of P21 rats, but not in P9 rats 3 d after SE. Microglial activation was most pronounced in the CA1 region and also detected in the basomedial amygdala.</p> <p>Conclusion</p> <p>Our results suggest that SE provokes an age-specific cytokine expression in the acute phase, and age-specific glial cell activation in the subacute phase as verified now in the postnatal rat hippocampus. In the juvenile hippocampus, transient increases in cytokine mRNA expression after SE, in contrast to prolonged glial reactivity and region-specific microglial activity after SE, suggest that the inflammatory response is changed from a fulminant and general initial phase to a more moderate and specific subacute response.</p

Childhood Psychosocial Environment and Adult Cardiac Health : A Causal Mediation Approach

Introduction: This study used causal mediation analysis to assess the life-course associations of a favorable childhood psychosocial environment with left ventricular mass and diastolic function in adulthood and the extent to which adult health behaviors mediate these associations. Methods: The sample included 880 participants (56% women) from the Young Finns Study with data on the childhood environment from 1980, adult health behaviors (smoking, physical activity, diet, and BMI) from 2001 and an echocardiographic assessment of the left ventricular mass (g/m(2.7)) and diastolic function (E/e' ratio; higher values indicating a lower diastolic function) from 2011. The associations of the childhood environment with the left ventricular mass and E/e' ratio and mediation pathways through health behaviors were assessed using marginal structural models that were controlled for age, sex, and time-dependent confounding by adult socioeconomic position (measured as educational attainment) via inverse probability weighting. The data were analyzed in 2018-2019. Results: The mean age in 2011 was 41 (range 34-49) years. Those above versus below the median childhood score had a 1.28 g/m(2.7) lower left ventricular mass (95% CI = -2.63, 0.07) and a 0.18 lower E/e' ratio (95% CI = -0.39, 0.03). There was no evidence for indirect effects from childhood environments to left ventricular outcomes through adult health behaviors after controlling for time-dependent confounding by the adult socioeconomic position (indirect effect beta = -0.30, 95% CI = -1.22, 0.63 for left ventricular mass; beta = -0.04, 95% CI = -0.18, 0.11 for E/e' ratio). The results after multiple imputation were similar. Conclusions: A favorable childhood environment is associated with more optimal cardiac structure and function in adulthood. After accounting for socioeconomic positions, adult health behaviors explain little of the associations. (C) 2019 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.Peer reviewe

Determinants of left ventricular diastolic function-The Cardiovascular Risk in Young Finns Study

Decreased left ventricular (LV) diastolic function is associated with increased all-cause mortality and risk for a heart failure. The determinants of LV diastolic function have been mainly studied in elderly populations; however, the origin of LV heart failure may relate to the lifestyle factors acquired during the life course. Therefore, we examined biochemical, physiological, and lifestyle determinants of LV diastolic function in 34-49-year-old participants of the Cardiovascular Risk in Young Finns Study (Young Finns Study). In 2011, clinical examination and echocardiography were performed for 1928 participants (880 men and 1048 women; aged 34-49 years). LV diastolic function was primarily defined using E/e-ratio (population mean 4.8, range 2.1-9.0). In a multivariate model, systolic blood pressure (P <0.005), female sex (P <0.005), age (P <0.005), waist circumference (P = 0.024), smoking (P = 0.028), serum alanine aminotransferase (P = 0.032) were directly associated with E/e-ratio, while an inverse association was found for height (P <0.005). Additionally, a higher E/e-ratio was found in participants with concentric hypertrophy compared to normal cardiac geometry (P <0.005). Other indicators of the LV diastolic function including E/A-ratio and left atrial volume index showed similarly strong associations with systolic blood pressure and age. In conclusion, we identified systolic blood pressure, waist circumference and smoking as modifiable determinants of the LV diastolic function in the 34-49-year-old participants of the Young Finns Study.Peer reviewe

Ideal cardiovascular health in childhood-Longitudinal associations with cardiac structure and function : The Special Turku Coronary Risk Factor Intervention Project (STRIP) and the Cardiovascular Risk in Young Finns Study (YFS)

Background: Ideal cardiovascular health (CVH), defined by the American Heart Association, is associated with incident cardiovascular disease in adults. However, association of the ideal CVH in childhood with current and future cardiac structure and function has not been studied. Methods and results: The sample comprised 827 children participating in the longitudinal Special Turku Coronary Risk Factor Intervention Project (STRIP) and The Cardiovascular Risk in Young Finns Study (YFS). In STRIP, complete data on the seven ideal CVH metrics and left ventricular (LV) mass measured with echocardiography were available at the age of 15 (n= 321), 17 (n= 309) and 19 (n= 283) years. In YFS, the cohort comprised children aged 12-18 years (n = 506) with complete ideal CVH metrics data from childhood and 25 years later in adulthood, and echocardiography performed in adulthood. In STRIP, ideal CVH score was inversely associated with LV mass during childhood (P = 0.036). In YFS, childhood ideal CVH score was inversely associated with LV mass, LV end-diastolic volume, E/e' ratio, and left atrium end-systolic volume in adulthood (all P <0.01). In addition, improvement of the ideal CVH score between childhood and adulthood was inversely associated with LV mass, LV end-diastolic volume, E/e' ratio, and left atrium end-systolic volume (all P Conclusions: Childhood ideal CVH score has a long-lasting effect on cardiac structure and function, and the association is evident already in childhood. Our findings support targeting the ideal CVHmetrics as part of primordial prevention of cardiovascular diseases. (C) 2016 Elsevier Ireland Ltd. All rights reserved.Peer reviewe

Subtle increases in heart size persist into adulthood in growth restricted babies: the Cardiovascular Risk in Young Finns Study

BACKGROUND AND OBJECTIVES: Impaired fetal growth is associated with increased cardiovascular morbidity and mortality in adulthood. We sought to determine whether adults born with intrauterine growth restriction have primary maladaptive changes in cardiac structure. METHODS: Study participants were adults (34-49 years) who attended the 31-year follow-up of the Cardiovascular Risk in Young Finns Study (longitudinal cohort). Transthoracic echocardiograms and demographic and cardiovascular risk surveys were completed for 157 adults born small for gestational age (SGA, birth weight <10th population centile) and 627 born average for gestational age (average for gestational age (AGA), birth weight 50th-90th population centile). RESULTS: Those born growth restricted had subtly enlarged hearts with indexed left ventricular (LV) end-systolic and end-diastolic diameters slightly greater in the SGA individuals than the AGA group (LVESD 18.7 mm/m(2) SGA vs 18.1 mm/m(2) AGA, p<0.01; LVEDD 27.5 mm/m(2) SGA vs 26.6 mm/m(2) AGA, p<0.01); LV base-to-apex length (47.4 mm/m(2) SGA vs 46.0 mm/m(2) AGA, p<0.01); LV basal diameter (26.4 mm/m(2) SGA vs 25.7 mm/m(2) AGA, p<0.01); and right ventricular base-to-apex length (40.1 mm/m(2) SGA vs 39.2 mm/m(2) AGA, p=0.02). LV stroke volume was greater in those born AGA (74.5 mL SGA vs 78.8 mL AGA, p<0.01), with no significant difference in cardiac output (5 L/min SGA vs 5.2 L/min AGA, p=0.06), heart rate, diastolic indices or sphericity index. CONCLUSIONS: Adults born SGA have some statistically significant but subtle changes in cardiac structure and function, which are less marked than have been described in childhood, and are unlikely to play a pathogenic role in their elevated cardiovascular risk

Influence of early-life body mass index and systolic blood pressure on left ventricle in adulthood - the Cardiovascular Risk in Young Finns Study

BackgroundIncreased left ventricular mass (LVM) predicts cardiovascular events and mortality. The objective of this study was to determine whether early-life exposures to body mass index (BMI) and systolic blood pressure (SPB) affects the left ventricular structure in adulthood.MethodsWe used longitudinal data from a 31-year follow-up to examine the associations between early-life (between ages 6-18) BMI and SPB on LVM in an adult population (N = 1864, aged 34-49). The burden of early-life BMI and SBP was defined as area under the curve.ResultsAfter accounting for contemporary adult determinants of LVM, early-life BMI burden associated significantly with LVM (3.61 g/SD increase in early-life BMI; [1.94 - 5.28], p 25 kg/m2) associated with 4.7% (2.5-6.9%, p 30kg/m2) resulted in a 21% (17.3-32.9%, p ConclusionsHigh BMI in early-life confers a sustained effect on LVM and the risk for eccentric hypertrophy independently of adulthood risk factors.</p

Cardiovascular risk factors in childhood and left ventricular diastolic function in adulthood

BACKGROUND AND OBJECTIVES: Cardiovascular risk factors, such as obesity, blood pressure, and physical inactivity, have been identified as modifiable determinants of left ventricular (LV) diastolic function in adulthood. However, the links between childhood cardiovascular risk factor burden and adulthood LV diastolic function are unknown. To address this lack of knowledge, we aimed to identify childhood risk factors associated with LV diastolic function in the participants of the Cardiovascular Risk in Young Finns Study. METHODS: Study participants (N = 1871; 45.9% men; aged 34-49 years) were examined repeatedly between the years 1980 and 2011. We determined the cumulative risk exposure in childhood (age 6-18 years) as the area under the curve for systolic blood pressure, adiposity (defined by using skinfold and waist circumference measurements), physical activity, serum insulin, triglycerides, total cholesterol, and high- and low-density lipoprotein cholesterols. Adulthood LV diastolic function was defined by using E/é ratio. RESULTS: Elevated systolic blood pressure and increased adiposity in childhood were associated with worse adulthood LV diastolic function, whereas higher physical activity level in childhood was associated with better adulthood LV diastolic function (P,.001 for all). The associations of childhood adiposity and physical activity with adulthood LV diastolic function remained significant (both P,.05) but were diluted when the analyses were adjusted for adulthood systolic blood pressure, adiposity, and physical activity. The association between childhood systolic blood pressure and adult LV diastolic function was diluted to nonsignificant (P =.56). CONCLUSIONS: Adiposity status and the level of physical activity in childhood are independently associated with LV diastolic function in adulthood.Peer reviewe

Vimentin regulates Notch signaling strength and arterial remodeling in response to hemodynamic stress

The intermediate filament (IF) cytoskeleton has been proposed to regulate morphogenic processes by integrating the cell fate signaling machinery with mechanical cues. Signaling between endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) through the Notch pathway regulates arterial remodeling in response to changes in blood flow. Here we show that the IF-protein vimentin regulates Notch signaling strength and arterial remodeling in response to hemodynamic forces. Vimentin is important for Notch transactivation by ECs and vimentin knockout mice (VimKO) display disrupted VSMC differentiation and adverse remodeling in aortic explants and in vivo. Shear stress increases Jagged1 levels and Notch activation in a vimentin-dependent manner. Shear stress induces phosphorylation of vimentin at serine 38 and phosphorylated vimentin interacts with Jagged1 and increases Notch activation potential. Reduced Jagged1-Notch transactivation strength disrupts lateral signal induction through the arterial wall leading to adverse remodeling. Taken together we demonstrate that vimentin forms a central part of a mechanochemical transduction pathway that regulates multilayer communication and structural homeostasis of the arterial wall