Spontaneous and Experimentally Induced Pathologies in the Naked Mole Rat (Heterocephalus glaber)

The naked mole rat (Heterocephalus glaber, Rüppell, 1842) is a unique eusocial rodent with unusually long lifespan. Therefore, the study of spontaneous and experimentally induced pathologies in these animals is one of the most important tasks of gerontology. Various infections, noninfectious pathologies (including age-dependent changes), and tumors have been described in the naked mole rat. The most frequent pathologies are traumas (bite wounds), purulent and septic complications of traumatic injuries, renal tubular calcinosis, chronic progressive nephropathy, hepatic hemosiderosis, testicular interstitial cell hyperplasia, calcinosis cutis, cardiomyopathy, and dysbiosis-related infectious lesions of the digestive system. However, the summarized data on pathology (including tumor incidence) and on the causes of mortality are insufficient. There are only few publications about the results of experiments where pathologies were induced in the naked mole rat. All these problems could be subjects for promising future studies without which adequate studies on mechanisms providing the long lifespan of the naked mole rat are impossible, as well as the elucidation of causes of tumor resistance of this species.

Age-associated murine cardiac lesions are attenuated by the mitochondria-targeted antioxidant SkQ1

Age-related changes in mammalian hearts often result in cardiac hypertrophy and fibrosis that are preceded by inflammatory infiltration. In this paper, we show that lifelong treatment of BALB/c and C57BL/6 mice with the mitochondria-targeted antioxidant SkQ1 retards senescence-associated myocardial disease (cardiomyopathy), cardiac hypertrophy, and diffuse myocardial fibrosis. To investigate the molecular basis of the action of SkQ1, we have applied DNA microarray analysis. The global gene expression profile in heart tissues was not significantly affected by administration of SkQ1. However, we found some small but statistically significant modifications of the pathways related to cell-to-cell contact, adhesion, and leukocyte infiltration. Probably, SkQ1-induced decrease in leukocyte and mesenchymal cell adhesion and/or infiltration lead to a reduction in age-related inflammation and subsequent fibrosis. The data indicate a causative role of mitochondrial reactive oxygen species in cardiovascular aging and imply that SkQ1 has potential as a drug against age-related cardiac dysfunction.

[Characteristics of the reparative regeneration of fins in the polypterid fish (Polypteridae, Actinopterygii)]

Epimorphic regeneration of fins was studied in different ray-finned fishes (Actinopterygii), but species representing the phylogenetically basal lineages of the taxon have remained outside the attention of researchers. Information on the regenerative abilities of these groups is important both for understanding the evolutionary origins of the epimorphic regeneration phenomenon and for assessing the universality of regenerative potencies in Actinopterygii. Addressing this problem, we studied for the first time fin regeneration in two members of the archaic family Polypteridae: the ropefish (Erpetoichthys calabaricus) and the Senegal bichir (Polypterus senegalus). Along with the ability to regenerate the bony rays of fins, widespread among Actinopterygii, polypterids show the ability to effectively regenerate the endoskeleton and musculature of their fins. This unusual feature allows us to suggest polypterids as new model organisms for the study of the mechanisms of vertebrate limb regeneration.