Vol 8, No 6 (2018)

The data on the molecular mechanisms of normal and pathological apoptosis are summarized. Three phases of apoptosis are distinguished: signal, effector, and degradation. The signal phase includes the extrinsic (caspase-dependent) and extrinsic (mitochondrial) pathways. Molecular markers of extrinsic and extrinsic apoptotic pathways play an important role in the diagnostics and treatment of immune, bronchopulmonary, excretory, and cardiovascular system pathologies, oncology, and senescence. This review considers the initiator caspases-8 and -9 and the effector caspase-3 as the molecular markers of the caspase-dependent apoptosis. The main molecular markers of the mitochondrial (or caspase-independent) apoptosis are p53, p21, and p16 proteins, which respond to DNA damage and are involved in cellular senescence, as well as chaperon prohibitin and flavoprotein apoptosis-inducing factor.

The article reviews the particular qualities of the key signal component of anabolic pathways (serine/threonine kinase Akt1) in the regulation of skeletal muscle functioning, both under normal conditions and in the dystrophic process, including Duchenne’s muscular dystrophy. The current data confirm the participation of the Akt1 signal pathway in the processes of skeletal muscle regeneration, as well as in the mechanism of angiogenesis amplification, which demonstrates the great therapeutic potential of Akt1 as a target for the treatment of a wide range of hereditary and acquired neuromuscular diseases.

The current information on symbiotic interrelations of the intracellular bacterium Wolbachia and filariae (parasites of human and animals), as well as evidence of the joint evolution of the symbiont and hosts, are discussed. Data on the absence of the joint distribution of this bacterium with its host in some Wolbachia supergroups are also presented. The results of morphological, genome, and transcriptomiс analyses obtained in the last ten years are provided. Insight into the biology and evolution of Wolbachia endosymbionts in the filarial organism, which were obtained by cytological, biochemical, and molecular methods, makes it possible to use the bacterium, which is obligate for filariae, in the treatment of human diseases.

The estuarine ecosystem is characterized by the mixing of seawater and freshwater with a resulting salinity of 0.5 to 22–26‰, which is preserved for no less than 2–3 weeks, and by the presence of specific brackish water species. The distinguishing features of Arctic estuarine ecosystems are a sharp thermohaline stratification of the waters and, as a consequence, a difference in the boundaries of the brackish water biota distribution near the bottom and in the pelagic zone. Note that only the bottom estuarine biocenoses are characteristic of the river mouth area. The most important factor in the Arctic estuarine ecosystems is the longitudinal migrations of the halocline, especially seasonal ones. The coincidence of the borders of distribution of the true brackish water species with the borders of hydrological and morphological regions of the Yenisei River estuary defined according to long-term observations is noteworthy. Given the relative similarity of the Arctic estuarine ecosystems in their physical, chemical, and biotic components associated with the latitudinal uniformity of the mouths, we assume the presence of this correlation in other estuarine areas as well. In this case, a single survey of the benthos may give the same result as multiyear series of hydrological observations in the regionalization of an estuarine ecosystem.

Based on literature data and our own, changes in the Shannon diversity index for the communities of organisms under changing environmental factors are considered. The eutrophication and pollution of waterbodies are shown to reduce the diversity of the communities; they become simpler, and the ratio of steno- to eurybiotic species decreases.