Seasonal reproduction and gonadal function: A focus on humans starting from animal studies

Author(s):  
Ester Beltran-Frutos ◽  
Livio Casarini ◽  
Daniele Santi ◽  
Giulia Brigante

Abstract Photoperiod impacts reproduction in many species of mammals. Mating occurs at specific seasons to achieve reproductive advantages, such as optimization of offspring survival. Light is the main regulator of these changes during the photoperiod. Seasonally breeding mammals detect and transduce light signals through extraocular photoreceptor, regulating downstream melatonin-dependent peripheral circadian events. In rodents, hormonal reduction and gonadal atrophy occur quickly, and consensually with short-day periods. It remains unclear whether photoperiod influences human reproduction. Seasonal fluctuations of sex hormones have been described in humans, although they seem to not imply adaptative seasonal pattern in human gonads. This review discusses current knowledge about seasonal changes in the gonadal function of vertebrates, including humans. The photoperiod-dependent regulation of hypothalamic–pituitary-gonadal axis, as well as morphological and functional changes of the gonads are evaluated herein. Endocrine and morphological variations of reproductive functions, in response to photoperiod, are of interest as they may reflect the nature of past population selection for adaptative mechanisms that occurred during evolution.

2020 ◽  
Vol 20 (4) ◽  
pp. 247-258 ◽  
Author(s):  
Hajra Takala ◽  
Qiwei Yang ◽  
Ahmed M. Abd El Razek ◽  
Mohamed Ali ◽  
Ayman Al-Hendy

Lifestyle factors, such as alcohol intake, have placed a substantial burden on public health. Alcohol consumption is increasing globally due to several factors including easy accessibility of this addictive substance besides its legal status and social acceptability. In the US, alcohol is the third leading preventable cause of death (after tobacco, poor diet and physical inactivity) with an estimated 88,000 people dying from alcohol-related causes annually, representing 1 in 10 deaths among working adults. Furthermore, the economic burden of excess drinking costs the US around $249 billion ($191.1 billion related to binge drinking). Although men likely drink more than women do, women are at much higher risk for alcohol-related problems. Alcohol use is also considered to be one of the most common non-communicable diseases, which affects reproductive health. This review article summarizes the current knowledge about alcohol-related pathogenesis of uterine fibroids (UFs) and highlights the molecular mechanisms that contribute to the development of UFs in response to alcohol consumption. Additionally, the effect of alcohol on the levels of various factors that are involved in UFs pathogenesis, such as steroid hormones, growth factors and cytokines, are summarized in this review. Animal studies of deleterious alcohol effect and future directions are discussed as well.


2020 ◽  
Vol 20 ◽  
Author(s):  
Nur Najmi Mohamad Anuar ◽  
Nurul Iman Natasya Zulkafali ◽  
Azizah Ugusman

: Matrix metalloproteinases (MMPs) are a group of zinc-dependent metallo-endopeptidase that are responsible towards the degradation, repair and remodelling of extracellular matrix components. MMPs play an important role in maintaining a normal physiological function and preventing diseases such as cancer and cardiovascular diseases. Natural products derived from plants have been used as traditional medicine for centuries. Its active compounds, such as catechin, resveratrol and quercetin, are suggested to play an important role as MMPs inhibitors, thereby opening new insights into their applications in many fields, such as pharmaceutical, cosmetic and food industries. This review summarises the current knowledge on plant-derived natural products with MMP-modulating activities. Most of the reviewed plant-derived products exhibit an inhibitory activity on MMPs. Amongst MMPs, MMP-2 and MMP-9 are the most studied. The expression of MMPs is inhibited through respective signalling pathways, such as MAPK, NF-κB and PI3 kinase pathways, which contribute to the reduction in cancer cell behaviours, such as proliferation and migration. Most studies have employed in vitro models, but a limited number of animal studies and clinical trials have been conducted. Even though plant-derived products show promising results in modulating MMPs, more in vivo studies and clinical trials are needed to support their therapeutic applications in the future.


Antioxidants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 33
Author(s):  
Chien-Ning Hsu ◽  
You-Lin Tain

The “developmental origins of health and disease” theory indicates that many adult-onset diseases can originate in the earliest stages of life. The developing kidney has emerged as being particularly vulnerable to adverse in utero conditions leading to morphological and functional changes, namely renal programming. Emerging evidence indicates oxidative stress, an imbalance between reactive oxygen/nitrogen species (ROS/RNS) and antioxidant systems, plays a pathogenetic role in the developmental programming of kidney disease. Conversely, perinatal use of antioxidants has been implemented to reverse programming processes and prevent adult-onset diseases. We have termed this reprogramming. The focus of this review is twofold: (1) To summarize the current knowledge on oxidative stress implicated in renal programming and kidney disease of developmental origins; and (2) to provide an overview of reprogramming effects of perinatal antioxidant therapy on renal programming and how this may prevent adult-onset kidney disease. Although early-life oxidative stress is implicated in mediating renal programming and adverse offspring renal outcomes, and animal models provide promising results to allow perinatal antioxidants applied as potential reprogramming interventions, it is still awaiting clinical translation. This presents exciting new challenges and areas for future research.


Author(s):  
Analia Lorena Tomat ◽  
Francisco Javier Salazar

AbstractA substantial body of epidemiological and experimental evidence suggests that a poor fetal and neonatal environment may “program” susceptibility in the offspring to later development of cardiovascular, renal and metabolic diseases.This review focuses on current knowledge from the available literature regarding the mechanisms linking an adverse developmental environment with an increased risk for cardiovascular, renal and metabolic diseases in adult life. Moreover, this review highlights important sex-dependent differences in the adaptation to developmental insults.Developmental programming of several diseases is secondary to changes in different mechanisms inducing important alterations in the normal development of several organs that lead to significant changes in birth weight. The different diseases occurring as a consequence of an adverse environment during development are secondary to morphological and functional cardiovascular and renal changes, to epigenetic changes and to an activation of several hormonal and regulatory systems, such as angiotensin II, sympathetic activity, nitric oxide, COX2-derived metabolites, oxidative stress and inflammation. The important sex-dependent differences in the developmental programming of diseases seem to be partly secondary to the effects of sex hormones. Recent studies have shown that the progression of these diseases is accelerated during aging in both sexes.The cardiovascular, renal and metabolic diseases during adult life that occur as a consequence of several insults during fetal and postnatal periods are secondary to multiple structural and functional changes. Future studies are needed in order to prevent the origin and reduce the incidence and consequences of developmental programmed diseases.


2014 ◽  
Vol 94 (4) ◽  
pp. 1027-1076 ◽  
Author(s):  
M. A. Hanson ◽  
P. D. Gluckman

Extensive experimental animal studies and epidemiological observations have shown that environmental influences during early development affect the risk of later pathophysiological processes associated with chronic, especially noncommunicable, disease (NCD). This field is recognized as the developmental origins of health and disease (DOHaD). We discuss the extent to which DOHaD represents the result of the physiological processes of developmental plasticity, which may have potential adverse consequences in terms of NCD risk later, or whether it is the manifestation of pathophysiological processes acting in early life but only becoming apparent as disease later. We argue that the evidence suggests the former, through the operation of conditioning processes induced across the normal range of developmental environments, and we summarize current knowledge of the physiological processes involved. The adaptive pathway to later risk accords with current concepts in evolutionary developmental biology, especially those concerning parental effects. Outside the normal range, effects on development can result in nonadaptive processes, and we review their underlying mechanisms and consequences. New concepts concerning the underlying epigenetic and other mechanisms involved in both disruptive and nondisruptive pathways to disease are reviewed, including the evidence for transgenerational passage of risk from both maternal and paternal lines. These concepts have wider implications for understanding the causes and possible prevention of NCDs such as type 2 diabetes and cardiovascular disease, for broader social policy and for the increasing attention paid in public health to the lifecourse approach to NCD prevention.


Author(s):  
Jip Gudden ◽  
Alejandro Arias Vasquez ◽  
Mirjam Bloemendaal

The importance of diet and the gut-brain axis for brain health and cognitive function is increasingly acknowledged. Dietary interventions are tested for their potential to prevent and/or treat brain disorders. Intermittent fasting (IF), the abstinence or strong limitation of calories for 12 to 48 hours, alternated with periods of regular food intake, has shown promising results on neurobiological health in animal models. In this review article, we discuss the potential benefits of IF on cognitive function and the possible effects on the prevention and progress of brain-related disorders in animals and humans. We do so by summarizing the effects of IF which - through metabolic, cellular and circadian mechanisms - lead to anatomical and functional changes in the brain. Our review shows that there is no clear evidence of a positive short-term effect of IF on cognition in healthy subjects. Clinical studies show benefits of IF for epilepsy, Alzheimer’s disease and multiple sclerosis on disease symptoms and progress. Findings from animal studies show mechanisms by which Parkinson’s disease, ischaemic stroke, autism spectrum disorder and mood- and anxiety disorders could benefit from IF. Future research should disentangle whether positive effects of IF hold true regardless of age or the presence of obesity. Also, variations in fasting patterns, total caloric intake and intake of specific nutrients may be relevant components of IF success. Longitudinal studies and Randomized Clinical Trials (RCTs) will provide a window into the long-term effects of IF on the development and progress of brain-related diseases.


2020 ◽  
Vol 21 (14) ◽  
pp. 5097
Author(s):  
Aleksandar Arsenijevic ◽  
Bojana Stojanovic ◽  
Jelena Milovanovic ◽  
Dragana Arsenijevic ◽  
Nebojsa Arsenijevic ◽  
...  

Primary biliary cholangitis (PBC) is a chronic inflammatory autoimmune liver disease characterized by inflammation and damage of small bile ducts. The NLRP3 inflammasome is a multimeric complex of proteins that after activation with various stimuli initiates an inflammatory process. Increasing data obtained from animal studies implicate the role of NLRP3 inflammasome in the pathogenesis of various diseases. Galectin-3 is a β-galactoside-binding lectin that plays important roles in various biological processes including cell proliferation, differentiation, transformation and apoptosis, pre-mRNA splicing, inflammation, fibrosis and host defense. The multilineage immune response at various stages of PBC development includes the involvement of Gal-3 in the pathogenesis of this disease. The role of Galectin-3 in the specific binding to NLRP3, and inflammasome activation in models of primary biliary cholangitis has been recently described. This review provides a brief pathogenesis of PBC and discusses the current knowledge about the role of Gal-3 in NLRP3 activation and PBC development.


2020 ◽  
Vol 10 (s1) ◽  
pp. S21-S27
Author(s):  
Jay L. Alberts ◽  
Anson B. Rosenfeldt

Over the past two decades, aerobic exercise has emerged as a mainstream recommendation to aid in treating Parkinson’s disease (PD). Despite the acknowledgement of the benefits of exercise for people with PD (PwPD), frequently, exercise recommendations lack specificity in terms of frequency, intensity and duration. Additionally, conflating physical activity with exercise has contributed to providing vague exercise recommendations to PwPD. Therefore, the beneficial effects of exercise may not be fully realized in PwPD. Data provided by animal studies and select human trials indicate aerobic exercise may facilitate structural and functional changes in the brain. Recently, several large human clinical trials have been completed and collectively support the use of aerobic exercise, specifically high-intensity aerobic exercise, in improving PD motor symptoms. Data from these and other studies provide the basis to include aerobic exercise as an integral component in treating PD. Based on positive clinical findings and trials, it is advised that PwPD perform aerobic exercise in the following dose: 3x/week, 30–40-minute main exercise set, 60–80% of heart rate reserve or 70–85% of heart rate max. In lieu of heart rate, individuals can achieve an intensity of 14–17 on a 20-point RPE scale. Ongoing clinical trials, SPARX3 and CYCLE-II, have potential to further develop patient-specific exercise recommendations through prognostic modeling.


2003 ◽  
Vol 31 (1_suppl) ◽  
pp. 123-127 ◽  
Author(s):  
U. Zühlke ◽  
G. Weinbauer

The common marmoset, Callithrix jacchus, is the smallest nonhuman primate commonly used in biomedical research. Marmoset characteristics and propensities have enabled them to be used in a wide range of research as a model of human disease, physiology, drug metabolism, general toxicology, and reproductive biology. This paper provides a general overview of the marmoset with special emphasis on the benefits and disadvantages of this species as a model for inclusion in preclinical drug development programmes. In view of its small size in comparison with other nonrodent species marmosets have become of value for toxicology studies with biotechnology products where compound supply is limited. In general toxicology studies, marmosets have been successfully used to meet regulatory endpoints also for specific investigatory purposes. The widespread use of this species has allowed extensive background information to become available and a summary of the most frequently measured parameters are presented. Marmosets apparently represent an interesting animal model for comparative research on primate reproductive physiology. However, several basic aspects of reproductive processes exhibit cardinal discrepancies to those described for macaques and human. Thus, from the viewpoint of reproductive toxicology, the relevance of the marmoset primate model for human reproduction remains unclear to date and further research is obviously needed. Given our current knowledge of marmoset reproductive features, the use of this animal model cannot be recommended for reproductive toxicology assessment.


2002 ◽  
Vol 4 (1) ◽  
pp. 5-15 ◽  
Author(s):  
Beverly B. Childress ◽  
Joyce K. Stechmiller

Chronic wounds mainly affect elderly individuals and persons with comorbid diseases due to a compromised immune status. An age-related decline in immune function deters proper healing of wounds in an orderly and timely manner. Thus, older adults with 1 or more concomitant illnesses are more likely to experience and suffer from a nonhealing wound, which may drastically decrease their quality of life and financial resources. Novel therapies in wound care management rely heavily on our current knowledge of wound healing physiology. It is well established that normal wound healing occurs sequentially and is strictly regulated by pro-inflammatory cytokines and growth factors. A multitude of commercial products such as growth factors are available; however, their effectiveness in healing chronic wounds has yet to be proven. Recently, investigators have implicated nitric oxide (NO) in the exertion of regulatory forces on various cellular activities of the inflammatory and proliferative phases of wound healing. Gene therapy in animal studies has shown promising results and is furthering our understanding of impaired wound healing. The purpose of this article is to review the literature on NO and its role in wound healing. A discussion of the physiology of normal healing and the pathophysiology of chronic wounds is provided.


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