Band 5, Heft 3

Transposable elements (TEs) make up a large proportion of mammalian genomes and are a strong evolutionary force capable of rewiring regulatory networks and causing genome rearrangements. Additionally, there are many eukaryotic epigenetic defense mechanisms able to transcriptionally silence TEs. Furthermore, small RNA molecules that target TE DNA sequences often mediate these epigenetic defense mechanisms. As a result, epigenetic marks associated with TE silencing can be reestablished after epigenetic reprogramming – an event during the mammalian life cycle that results in widespread loss of parental epigenetic marks. Furthermore, targeted epigenetic marks associated with TE silencing may have an impact on nearby gene expression. Therefore, TEs may have driven species evolution via their ability to heritably alter the epigenetic regulation of gene expression in mammals.

Neuroglobin (Ngb), a monomeric hexacoordinated heme protein of 17 kDa, was identified in 2000 in the nervous system. Accumulative evidence has proved that Ngb is an endogenous neuroprotective molecule against ischemic/hypoxic insults and oxidative stresses, and in most ischemic conditions, Ngb is up-regulated. The underlying mechanisms, however, are not fully clarified. Here we review the recent experimental findings, mainly focusing on the mechanisms of Ngb’s protection and induction during ischemic/hypoxic conditions, the roles of Ngb in astrocytes and tumors, as well as Ngb’s function in neurite outgrowth.

The first Jumonji gene was cloned in 1995 by Takeuchi et al. [Takeuchi T, Yamazaki Y, Katoh-Fukui Y, Tsuchiya R, Kondo S, Motoyama J, Higashinakagawa T. Gene trap capture of a novel mouse gene, jumonji, required for neural tube formation. Genes Dev 1995; 9: 1211–22.]. Several genes sharing similar biological features have since been discovered, and are currently grouped into the JMJ family. Interestingly, their deregulation has been associated with cardiac disease, obesity, neurological disorders and cancer. One of the mechanisms underlying their function is gene expression modulation via histone post-translational modifications (PTMs). Increasing evidence of Jumonji deregulation in tumours such as colon, prostate, haematological and breast cancer is continually emerging, hence the need to acquire a better understanding. The Genesapiens.org database of patient arrays allows target expression levels to be investigated in a wide range of cancers, corroborating and extending the role of the JMJ family. Here, we provide an overview of the expression profile and regulation of JMJ family members in cancer, examining the most recent literature in the light of analyses drawn from this database.

Over 80 years has passed since the discovery of substance P (SP), and a variety of peptides of the tachykinin (TK) family have been found and investigated. SP, neurokinin A (NKA), and neurokinin B (NKB) are representative peptides in mammalian species. SP and NKA are major excitatory neurotransmitters in the peripheral nervous system, while NKB is primarily involved in the central nervous system (CNS). Moreover, TK peptides play roles not only as neurotransmitters but also as local factors and are involved in almost all aspects of the regulation of physiological functions and pathophysiological processes. The role of SP as a mediator of pain processing and inflammation in peripheral tissues in coordination with transient receptor potential channels is well established, while novel aspects of TKs in relation to hematopoiesis, venous thromboembolism, tendinopathy, and taste perception have been clarified. In the CNS, the NKB signaling system in the hypothalamus has been shown to play a crucial role in the regulation of gonadotropin hormone secretion and the onset of puberty, and molecular biological studies have elucidated novel prophylaxic activities of TKs against neurogenic movement disorders based on their molecular structure. This review provides an overview of the novel aspects of TKs reported around the world in the last 5 years, with particular focus on nociception, inflammation, hemopoiesis, gonadotropin secretion, and CNS diseases.

Daily rhythms of light/darkness, activity/rest and feeding/fasting are important in human physiology and their disruption (for example by frequent changes between day and night shifts) increases the risk of disease. Many of the diseases found to be associated with such disrupted circadian lifestyles, including cancer, cardiovascular diseases, metabolic disorders and neurological diseases, depend on pathological de-regulation of angiogenesis, suggesting that disrupting the circadian clock will impair the physiological regulation of angiogenesis leading to development and progression of these diseases. Today there is little known regarding circadian regulation of pathological angiogenesis but there is some evidence that supports both direct and indirect regulation of angiogenic factors by the cellular circadian clock machinery, as well as by circulating circadian factors, important for coordinating circadian rhythms in the organism. Through highlighting recent advances both in pre-clinical and clinical research on various diseases including cancer, cardiovascular disorders and obesity, we will here present an overview of the available knowledge on the importance of circadian regulation of angiogenesis and discuss how the circadian clock may provide alternative targets for pro- or anti-angiogenic therapy in the future.

Aggregation of transthyretin (TTR), a plasma-binding protein for thyroxine and retinol-binding protein, is the cause of several amyloid diseases. Disease-associated mutations are well known, but wild-type TTR is, to a lesser extent, also amyloidogenic. Monomerization, not oligomer formation as in several other depository diseases, is the rate-limiting step in TTR aggregation, and stabilization of the natively tetrameric form can inhibit amyloid formation. Modifications on Cys10, as well as interactions with native ligands in plasma, were early found to influence the equilibrium between tetrameric and monomeric TTR by dissociating or stabilizing the tetramer. Following these discoveries, synthetic ligands for pharmacological prevention of TTR aggregation could be developed. In this article, we outline how the different types of TTR interactions and its microheterogeneity in plasma are related to its propensity to form amyloid fibrils. We conclude that plasma constituents and dietary components may act as natural TTR stabilizers whose mechanisms of action provide cues for the amelioration of TTR amyloid disease.