DNA Damage Responses, the Trump Card of Stem Cells in the Survival Game.

Stem cells, as a group of undifferentiated cells, are enriched with self-renewal and high proliferative capacity, which have attracted the attention of many researchers as a promising approach in the treatment of many diseases over the past years. However, from the cellular and molecular point of view, the DNA repair system is one of the biggest challenges in achieving therapeutic goals through stem cell technology. DNA repair mechanisms are an advantage for stem cells that are constantly multiplying to deal with various types of DNA damage. However, this mechanism can be considered a trump card in the game of cell survival and treatment resistance in cancer stem cells, which can hinder the curability of various types of cancer. Therefore, getting a deep insight into the DNA repair system can bring researchers one step closer to achieving major therapeutic goals. The remarkable thing about the DNA repair system is that this system is not only under the control of genetic factors, but also under the control of epigenetic factors. Therefore, it is necessary to investigate the role of the DNA repair system in maintaining the survival of cancer stem cells from both aspects.

Application of Biocompatible Scaffolds in Stem-Cell-Based Dental Tissue Engineering.

Tissue engineering as an important field in regenerative medicine is a promising therapeutic approach to replace or regenerate injured tissues. It consists of three vital steps including the selection of suitable cells, formation of 3d scaffolds, and adding growth factors. Mesenchymal stem cells (MSCs) and embryonic stem cells (ESCs) are mentioned as two main sources for this approach that have been used for the treatment of various types of disorders. However, the main focus of literature in the field of dental tissue engineering is on utilizing MSCs. On the other hand, biocompatible scaffolds play a notable role in this regenerative process which is mentioned to be harmless with acceptable osteoinductivity. Their ability in inhibiting inflammatory responses also makes them powerful tools. Indeed, stem cell functions should be supported by biomaterials acting as scaffolds incorporated with biological signals. Naturally derived polymeric scaffolds and synthetically engineered polymeric/ceramic scaffolds are two main types of scaffolds regarding their materials that are defined further in this review. Various strategies of tissue bioengineering can affect the regeneration of dentin-pulp complex, periodontium regeneration, and whole teeth bioengineering. In this regard, in vivo/ex vivo experimental models have been developed recently in order to perform preclinical studies of dental tissue engineering which make it more transferable to be used for clinic uses. This review summarizes dental tissue engineering through its different components. Also, strategies of tissue bioengineering and experimental models are introduced in order to provide a perspective of the potential roles of dental tissue engineering to be used for clinical aims.

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.

Effect of Processed Honey and Royal Jelly on Cancer-Related Fatigue: A Double-Blind Randomized Clinical Trial.

BACKGROUND: Cancer-related fatigue (CRF) is experienced by 50% to 90% of cancer patients and can severely affect their quality of life and functional capacity. Several randomized trials have recommended various ways to alleviate the symptoms of CRF with or without recourse to medications. OBJECTIVE: The aim of this study is to evaluate the effectiveness of processed honey and royal jelly on the symptoms of CRF in cancer patients who are undergoing hormone therapy, chemotherapy, chemo-radiation, or radiotherapy. METHODS: Fifty-two participants from the patients who visited the oncology clinic of Shohada-e-Tajrish hospital in Tehran (Iran) between May 2013 and August 2014 were selected and divided into two groups. The study group (26 patients) received processed honey and royal jelly, while the control group received pure honey. Both groups were instructed to consume their 5mL supplement twice daily for 4 weeks. Both groups were assessed at the beginning of the study, after 2 weeks, and then at the end of 4 weeks of treatment. Fatigue was measured using a visual analogue fatigue scale (VAFS) and fatigue severity scale (FSS). The results were compared between the two arms of study, and equality of probability distributions was assessed using a Kolmogorov-Smirnov test. RESULTS: The mean age of the 52 patients was 54.84. After two and four weeks of treatment with processed honey and royal jelly, VAFS and FSS due to treatment was better in the study group than in the control group, and the differences were statistically significant (p<0.001, p<0.001, respectively). CONCLUSION: To the best of our knowledge, our study provided support for the use of processed honey and royal jelly to ameliorate CRF. The positive results of this study warrant further studies in this field. CLINICAL TRIAL REGISTRATION: The study was registered in the Iranian Clinical Trial Registry Center (http://www.irct.ir) with the registration code: IRCT2015081423426N1. FUNDING: The authors received no financial support for the research, authorship, and/or publication of this article.