A new guest playing with bone and fat

Melatonin regulates mesenchymal stem cell differentiation: a review

Among the numerous functions of melatonin, the control of survival and differentiation of mesenchymal stem cells (MSCs) has been recently proposed. MSCs are a heterogeneous population of multipotent elements resident in tissues such as bone marrow, muscle, and adipose tissue, which are primarily involved in developmental and regeneration processes, gaining thus increasing interest for tissue repair and restoration therapeutic protocols. Receptor-dependent and receptor-independent responses to melatonin are suggested to occur in these cells. These involve antioxidant or redox-dependent functions of this indolamine as well as secondary effects resulting from autocrine and paracrine responses. Inflammatory cytokines and adipokines, proangiogenic/mitogenic stimuli, and other mediators that influence the differentiation processes may affect the survival and functional integrity of these mesenchymal precursor cells. In this scenario, melatonin seems to regulate signaling pathways that drive commitment and differentiation of MSC into osteogenic, chondrogenic, adipogenic, or myogenic lineages. Common pathways suggested to be involved as master regulators of these processes are the Wnt/β-catenin pathway, the MAPKs and the, TGF-β signaling. In this respect melatonin emerges a novel and potential modulator of MSC lineage commitment and adipogenic differentiation. These and other aspects of the physiological and pharmacological effects of melatonin as regulator of MSC are discussed in this review.

Melatonin as a potential therapeutic agent in psychiatric illness

The aim of this review was to summarize the potential use of melatonin in the treatment of mental disorders, specifically bipolar disorders, depression, and schizophrenia. To date, melatonin has been most commonly used in psychiatry because of its hypnotic, rhythm resynchronizing, and antioxidant actions. Here, we examine other properties of the melatonin including its anti-inflammatory, antinociceptive, anxiolytic, and drug detoxification actions as well as its protective effects against neural loss. The brain is an intricate sensory and motor organ which receives information from both the external and internal environments. It transduces information into complex chemical and electrical signals which are transmitted throughout the central nervous system (CNS) and the organism. The pathogenesis of mental disorders remains ambiguous and neuroinflammation has been proposed as a causative agent. We consider the potential contributions of melatonin as therapeutic agent in CNS and during neuroinflammation in mental disorders.