Brown adipose tissue and alzheimer's disease.

Alzheimer's disease (AD), the most common type of senile dementia, is a chronic neurodegenerative disease characterized by cognitive dysfunction and behavioral disability. The two histopathological hallmarks in this disease are the extraneuronal accumulation of amyloid-ß (Aß) and the intraneuronal deposition of neurofibrillary tangles (NFTs). Despite this, central and peripheral metabolic dysfunction, such as abnormal brain signaling, insulin resistance, inflammation, and impaired glucose utilization, have been indicated to be correlated with AD. There is solid evidence that the age-associated thermoregulatory deficit induces diverse metabolic changes associated with AD development. Brown adipose tissue (BAT) has been known as a thermoregulatory organ particularly vital during infancy. However, in recent years, BAT has been accepted as an endocrine organ, being involved in various functions that prevent AD, such as regulating energy metabolism, secreting hormones, improving insulin sensitivity, and increasing glucose utilization in adult humans. This review focuses on the mechanisms of BAT activation and the effect of aging on BAT production and signaling. Specifically, the evidence demonstrating the effect of BAT on pathological mechanisms influencing the development of AD, including insulin pathway, thermoregulation, and other hormonal pathways, are reviewed in this article.

Regenerative Medicine Perspectives in Polycystic Ovary Syndrome.

Polycystic ovary syndrome (PCOS) is the most common gynecologic endocrine disorder in women between the ages of 15 and 40, with uncertain etiology. It is mostly presented with hyperandrogenism and insulin resistance along with a variety of comorbidities that significantly reduce a patient's quality of life. Many disturbed metabolic pathways are correlated with PCOS. Moreover, it is evident that there is a strong genetic factor for PCOS. Indeed, several altered gene expressions have been found in PCOS subjects, but the exact genetic origins are still unclear. The major treatment options such as pharmacological treatments are to improve the symptoms. In addition, surgical procedures (Bariatric surgery and assisted reproductive technologies) can be used to treat some of the patient's complications and reduce their severity. Generally, using pharmacological agents for a long period of time can increase the risk of adverse effects. Moreover, surgical options may have high-risk consequences. Herein, there is an undeniable need for a different multidisciplinary approach to PCOS. Regenerative medicine with the help of stem cells can develop a worthy alternative approach for the treatment of PCOS. Furthermore, animal models can provide valuable knowledge of genetic alterations and metabolic pathway disturbances in PCOS. They can also be used for testing novel treatments in pre-clinical stages. Therein, the current knowledge of PCOS and investigation about the potential role of regenerative medicine in developing new and more efficient treatments for PCOS are summarized here.

Opportunities and Challenges in Stem Cell Aging.

Studying aging, as a physiological process that can cause various pathological phenotypes, has attracted lots of attention due to its increasing burden and prevalence. Therefore, understanding its mechanism to find novel therapeutic alternatives for age-related disorders such as neurodegenerative and cardiovascular diseases is essential. Stem cell senescence plays an important role in aging. In the context of the underlying pathways, mitochondrial dysfunction, epigenetic and genetic alterations, and other mechanisms have been studied and as a consequence, several rejuvenation strategies targeting these mechanisms like pharmaceutical interventions, genetic modification, and cellular reprogramming have been proposed. On the other hand, since stem cells have great potential for disease modeling, they have been useful for representing aging and its associated disorders. Accordingly, the main mechanisms of senescence in stem cells and promising ways of rejuvenation, along with some examples of stem cell models for aging are introduced and discussed. This review aims to prepare a comprehensive summary of the findings by focusing on the most recent ones to shine a light on this area of research.

Zebrafish for Personalized Regenerative Medicine; A More Predictive Humanized Model of Endocrine Disease.

Regenerative medicine is a multidisciplinary field that aims to determine different factors and develop various methods to regenerate impaired tissues, organs, and cells in the disease and impairment conditions. When treatment procedures are specified according to the individual's information, the leading role of personalized regenerative medicine will be revealed in developing more effective therapies. In this concept, endocrine disorders can be considered as potential candidates for regenerative medicine application. Diabetes mellitus as a worldwide prevalent endocrine disease causes different damages such as blood vessel damages, pancreatic damages, and impaired wound healing. Therefore, a global effort has been devoted to diabetes mellitus investigations. Hereupon, the preclinical study is a fundamental step. Up to now, several species of animals have been modeled to identify the mechanism of multiple diseases. However, more recent researches have been demonstrated that animal models with the ability of tissue regeneration are more suitable choices for regenerative medicine studies in endocrine disorders, typically diabetes mellitus. Accordingly, zebrafish has been introduced as a model that possesses the capacity to regenerate different organs and tissues. Especially, fine regeneration in zebrafish has been broadly investigated in the regenerative medicine field. In addition, zebrafish is a suitable model for studying a variety of different situations. For instance, it has been used for developmental studies because of the special characteristics of its larva. In this review, we discuss the features of zebrafish that make it a desirable animal model, the advantages of zebrafish and recent research that shows zebrafish is a promising animal model for personalized regenerative diseases. Ultimately, we conclude that as a newly introduced model, zebrafish can have a leading role in regeneration studies of endocrine diseases and provide a good perception of underlying mechanisms.