Doctoral Thesis
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Background: A large body of research indicates that the cognitions individuals have
about their own age and aging, so called self-perceptions of aging (SPA), predict health and
wellbeing in later life. However, much less is known about associations of SPA with
developmental correlates such as personality. Some initial studies have found cross-sectional
and longitudinal associations of the Big Five traits (openness to experience,
conscientiousness, extraversion, agreeableness, and neuroticism) with SPA. Building on these
findings, this thesis aimed at advancing knowledge on associations of personality with SPA.
To this end, cross-sectional associations of the meta-traits of agency, i.e., a focus on the self,
and communion, i.e., a focus on others, with SPA were examined in study 1, and longitudinal
associations of agentic and communal personal values with SPA were examined in study 2.
Study 3 aimed at expanding findings of previous studies on associations of SPA with selfreported
physical function to an objective indicator of physical function, namely, gait pattern.
In all studies, SPA were treated as a multidimensional construct comprising gains and losses.
Methods: Study 1 was based on data of 154 adults aged 75 and older that were
recruited in hospital. Data was collected one month after recruitment. In regression analyses,
associations of agentic and communal traits with SPA beyond health were examined. Study 2
was based on data of 6,089 adults aged 40 and older enrolled in the German Ageing Survey
(DEAS). Multiple regression analyses were used to test whether personal value priority
predicted change in SPA over three years beyond age stereotypes. For study 3, latent profile
analysis was employed to detect gait patterns based on data of 150 adults aged 70 and older
collected via an automated walkway at participants’ regular speed and individual maximum
speed. In a next step, associations of SPA with gait patterns beyond personality traits were
investigated in binary logistic regressions.
Results: Agentic and communal personality traits were associated with gain-, but not
loss-related SPA when controlling for health (study 1). In study 2, the value priority of
openness to change (self-direction, stimulation) predicted more gain-related SPA three years
later, while the value priority of conservation (tradition, security) was negatively associated
with gain-related SPA. The value priority of self-enhancement (achievement, power) was
associated with more loss-related SPA three years later. Finally, the value priority of selftranscendence
(universalism, benevolence), i.e. a concern for the well-being of others, was
associated with more gain- and less loss-related SPA at follow-up. In study 3, latent profile
analyses distinguished two groups with different gait patterns in both gait speed conditions.
One group exhibited a slower and less well-coordinated gait pattern, which reflected
functional limitations. The other group exhibited a faster and well-coordinated gait pattern,
which reflected better physical function. More loss-, but not gain-related SPA were associated
with higher likelihood to exhibit a functionally limited gait pattern at regular speed.
Conversely, gain- but not loss-related SPA were associated with higher likelihood to exhibit a
fit gait pattern at individual maximum speed.
Conclusion: Results of this thesis have three main implications for research on SPA.
First, agency and communion may constitute useful dimensions for further investigating SPA
domains, as both were associated with SPA in study 1. Second, findings of study 2 point to
the role of motivation for SPA that needs to be further explored. Third, findings of study 3
indicate that SPA are not only associated with self-reported, but also objectively measured
physical function, which stresses the importance of SPA for health in later life. As a practical
implication, the findings presented here suggest that interventions on SPA should consider
participants’ personality, both on the level of traits and values.
Aging is a risk factor for stroke. Animal models of stroke have been widely used to study the pathophysiology of ischemic stroke, which in turn helped to develop numerous therapeutic strategies. Despite the considerable success of therapeutic strategies in animal models of ischemic stroke, almost all of them have been proved to be unsuccessful in the clinical trials. One of explanation is that data obtained from young animals may not fully resemble the effects of ischemic stroke in aged animals or elder patients, causing the discrepancy between animal experiments and clinical trials. To investigate these differences with regard to age, pathway specific gene arrays were used to identify and isolate differentially expressed genes in periinfarct following focal cerebral ischemia. The results from this study showed a persistent up-regulation of pro-apoptotic and inflammatory-related genes up to 14 days post stroke, a 50% reduction in the number of transcriptionally active stem cell-related genes and a decreased expression of genes with anti-oxidative capacity in aged rats. Also, it was observed that at day 3 post-stroke, the contralateral, healthy hemisphere of young rats is much more active at transcriptional level than that of the aged rats, especially at the level of stem cell- and hypoxia signaling associated genes. Next, protein levels between young and aged post-stroke rats in periinfarct were compared using proteomic tools. Among others, AnxA3 was identified as differentially regulated protein, but the expression of AnxA3 has no significant changes in periinfarct between these two age groups at day 3 and 14. Different from periinfarct, a strong upregulation of AnxA3 at day 3 in young rats plus a strengthened increase of AnxA3 at day 14 in aged rats using immunohistochemical quantification indicated a delayed microglial accumulation in infarct core of aged rats, suggesting that quick activation of microglia in infarct core of young rats might be beneficial for recovery. Colocalization with established microglial marker demonstrated that AnxA3 as a novel microglial marker is implicated in the microglial responses to the focal cerebral ischemia. In addition, it was found that AnxA3 positive microglial cells incorporated more proliferating cell marker BrdU. Third, the expression, localization and function of several transport proteins were investigated in young rats following focal ischemic stroke. P-gp staining was detected in endothelial cells of desintegrated capillaries and by day 14 in newly generated blood vessels. There was no significant difference, however, in the Mdr1a mRNA amount in the periinfarct region compared to the contralateral site. For Bcrp, a significant mRNA up-regulation was observed from day 3 to 14. This up-regulation was followed by the protein as confirmed by quantitative immunohistochemistry. Oatp2, located in the vascular endothelium, was also up-regulated at day 14. For Mrp5, an up-regulation was observed in neurons in the periinfarct region (day 14). In conclusion, reduced transcriptional activity in the healthy, contralateral sensorimotor cortex in conjunction with an early up-regulation of proapoptotic genes and a decreased expression of genes with anti-oxidative capacity in the ipsilateral sensorimotor cortex of aged rats, plus the delayed up-regulation of AnxA3 positive microglial cells in infarct core may contribute to diminished recovery in post-stroke old rats. In addition, it was demonstrated in this study that after stroke the transport proteins were up-regulated with a maximum at day 14, a time point that coincides with behavioral recuperation. The study further suggests Bcrp as a pronounced marker for the regenerative process and a possible functional role of Mrp5 in surviving neurons. This study provided several evidences for the different responses of young and aged rats using a focal ischemic stroke model. Understanding the effect of age is crucial for the development of relevant therapeutic drugs.