DOI 10.1515/hmbci-2013-0064 Horm Mol Biol Clin Invest 2013; 16(1): 1–2
Preface
Special issue on hormones and ageing Dear Readers, Hormones play a major role in our entire development, are essential for many features – not only for reproduction – but are also major regulators of our homeostasis and wellbeing. They are also likely to influence our ageing process. With this issue we would like to shed some light into the involvement of hormones in the ageing process. Ageing can be defined as a reduction of intracellular and intercellular pathway capacity by increasing time, and thus, ageing results in reducing cellular and organ function by time. On the other hand, reducing cellular and organ function by time leads to the ageing phenotype. Reproduction-based ageing is suggested to play a role in many organisms. Beyond that, however, a reduction of many hormone actions by age are known in humans, including the decline of steroids, thyroid hormones, vitamin D and insulin action. Accordingly, the existence of an endocrine ageing needs to be postulated among other age-associated hypotheses. This includes the ageing of the axis of hypothalamus – pituitary – hormone secretory organs, the insulin pathway, menopausal-associated changes in homone levels and action as well as hormonally controlled oxidative stress and inflammation with their associated age-dependent diseases. Also, the endocrine ageing theory offers the interesting possibility to differentiate between the genders in the ageing process. In order to analyse the role of hormones, it is important not only to detect the hormone levels but to analyse functionally the action of hormones and their receptors by age. This includes age-dependent changes of hormone transport, uptake and intracellular hormoneinduced pathways and hormone metabolism, which may change by age. As a result, similar levels of hormones may mediate a changed or reduced age-dependent functional action. Therefore, the endocrine ageing theory should target the incorporation of functional changes in the actions and downstream changes of hormones in the elderly. One central question is whether hormone actions reduced by age can be compensated by hormone treatments and hormone replacement therapies. In line with this question, it is important to investigate whether the change of hormone action by time can be shifted to a beneficial level so that endocrine ageing can be counteracted by endogenous or exogenous factors to reduce morbidity,
also in a gender-specific manner, and to improve the quality of life of the elderly. With this special issue we address topics of hormonal regulation of oxidative stress including gender differences, caloric restriction, insulin resistance, hormone replacement therapies including melatonin therapy options, hormesis and vitagens. The topics also critically address hormone replacement therapies with natural products, gender differences in mitochondrial function, role of oestrogens in oxidative stress, age-associated diabetes, insulin resistance, melatonin therapy options, as well as an organ ageing exemplified by the skin as a major organ and indicator of ageing. An age-dependent abrupt decline of oestrogens and progestin levels occur in female menopause, an event which is induced by a cut-off point in ovarian function. In contrast, males exhibit a mild decline in sexual hormones at older ages and remain fertile, although with a reduced potency. Interestingly, gender differences in the mitochondrial redox system by age are also reported in this issue. The important topic of plant-derived alternatives for hormone replacement therapy is addressed, reviewing in a critical manner our knowledge of the last years including selective oestrogen receptor modulators. The skin, the largest human tissue, is presented as a model system for human organ ageing, because it responds to both endogenous and exogenous factors. The skin is attributed to several theories of ageing, including endocrine ageing, stem cell exhaustion, immunological alterations and cellular senescence. The skin responds by changes of skin functions and morphology to exogenous factors, including photo-damage (e.g., UV light), smoking, and wound healing processes. Certain genetic predispositions, such as progeria syndromes, are also mirrored in skin ageing. In addition, premature skin ageing is observed in insulin growth factor age-related decline. Diabetes type 2, an age-related disease, associated with metabolism, the redox system, caloric restriction (CR) and the insulin pathway, is addressed in association with melatonin therapy. Interesting new findings may improve age-dependent morbidity in future. Moreover, potential beneficial hormetic dose-responses of caloric restriction mimetics, including natural products, and the role of the heat shock proteins, the sirtuin family and the thioredoxin system on longevity processes, are reviewed. We wish you a pleasant and informative reading.
2 Baniahmad et al.: Special issue on hormones and ageing Aria Baniahmad Institute of Human Genetics, Jena University Hospital, Kollegiengasse 10, Jena, Germany, E-mail: [email protected] Jesus A.F. Tresguerres Laboratory of Experimental Endocrinology, Department of Physiology, School of Medicine, Complutense University, 28040 Madrid, Spain
Christos C. Zouboulis Departments of Dermatology, Venereology, Allergology and Immunology, Dessau Medical Center, Auenweg 38, 06847 Dessau, Germany
Copyright of Hormone Molecular Biology & Clinical Investigation is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
Preface
Special issue on hormones and ageing Dear Readers, Hormones play a major role in our entire development, are essential for many features – not only for reproduction – but are also major regulators of our homeostasis and wellbeing. They are also likely to influence our ageing process. With this issue we would like to shed some light into the involvement of hormones in the ageing process. Ageing can be defined as a reduction of intracellular and intercellular pathway capacity by increasing time, and thus, ageing results in reducing cellular and organ function by time. On the other hand, reducing cellular and organ function by time leads to the ageing phenotype. Reproduction-based ageing is suggested to play a role in many organisms. Beyond that, however, a reduction of many hormone actions by age are known in humans, including the decline of steroids, thyroid hormones, vitamin D and insulin action. Accordingly, the existence of an endocrine ageing needs to be postulated among other age-associated hypotheses. This includes the ageing of the axis of hypothalamus – pituitary – hormone secretory organs, the insulin pathway, menopausal-associated changes in homone levels and action as well as hormonally controlled oxidative stress and inflammation with their associated age-dependent diseases. Also, the endocrine ageing theory offers the interesting possibility to differentiate between the genders in the ageing process. In order to analyse the role of hormones, it is important not only to detect the hormone levels but to analyse functionally the action of hormones and their receptors by age. This includes age-dependent changes of hormone transport, uptake and intracellular hormoneinduced pathways and hormone metabolism, which may change by age. As a result, similar levels of hormones may mediate a changed or reduced age-dependent functional action. Therefore, the endocrine ageing theory should target the incorporation of functional changes in the actions and downstream changes of hormones in the elderly. One central question is whether hormone actions reduced by age can be compensated by hormone treatments and hormone replacement therapies. In line with this question, it is important to investigate whether the change of hormone action by time can be shifted to a beneficial level so that endocrine ageing can be counteracted by endogenous or exogenous factors to reduce morbidity,
also in a gender-specific manner, and to improve the quality of life of the elderly. With this special issue we address topics of hormonal regulation of oxidative stress including gender differences, caloric restriction, insulin resistance, hormone replacement therapies including melatonin therapy options, hormesis and vitagens. The topics also critically address hormone replacement therapies with natural products, gender differences in mitochondrial function, role of oestrogens in oxidative stress, age-associated diabetes, insulin resistance, melatonin therapy options, as well as an organ ageing exemplified by the skin as a major organ and indicator of ageing. An age-dependent abrupt decline of oestrogens and progestin levels occur in female menopause, an event which is induced by a cut-off point in ovarian function. In contrast, males exhibit a mild decline in sexual hormones at older ages and remain fertile, although with a reduced potency. Interestingly, gender differences in the mitochondrial redox system by age are also reported in this issue. The important topic of plant-derived alternatives for hormone replacement therapy is addressed, reviewing in a critical manner our knowledge of the last years including selective oestrogen receptor modulators. The skin, the largest human tissue, is presented as a model system for human organ ageing, because it responds to both endogenous and exogenous factors. The skin is attributed to several theories of ageing, including endocrine ageing, stem cell exhaustion, immunological alterations and cellular senescence. The skin responds by changes of skin functions and morphology to exogenous factors, including photo-damage (e.g., UV light), smoking, and wound healing processes. Certain genetic predispositions, such as progeria syndromes, are also mirrored in skin ageing. In addition, premature skin ageing is observed in insulin growth factor age-related decline. Diabetes type 2, an age-related disease, associated with metabolism, the redox system, caloric restriction (CR) and the insulin pathway, is addressed in association with melatonin therapy. Interesting new findings may improve age-dependent morbidity in future. Moreover, potential beneficial hormetic dose-responses of caloric restriction mimetics, including natural products, and the role of the heat shock proteins, the sirtuin family and the thioredoxin system on longevity processes, are reviewed. We wish you a pleasant and informative reading.
2 Baniahmad et al.: Special issue on hormones and ageing Aria Baniahmad Institute of Human Genetics, Jena University Hospital, Kollegiengasse 10, Jena, Germany, E-mail: [email protected] Jesus A.F. Tresguerres Laboratory of Experimental Endocrinology, Department of Physiology, School of Medicine, Complutense University, 28040 Madrid, Spain
Christos C. Zouboulis Departments of Dermatology, Venereology, Allergology and Immunology, Dessau Medical Center, Auenweg 38, 06847 Dessau, Germany
Copyright of Hormone Molecular Biology & Clinical Investigation is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
