Neural stem cells-from quiescence to differentiation and potential clinical uses

Specialised cells of the brain are generated from a population of multipotent stem cells found in the forming embryo and adult brain after birth, called neural stem cells. They reside in specific niches, usually in a quiescent, non-proliferating state that maintains their reservoir. Neural stem cells are kept inactive by various cues such as direct cell-cell contacts with neighbouring cells or by soluble molecules that trigger intracellular responses. They are activated in response to injuries, physical exercise, or hypoxia condition, through stimulation of signaling pathways that are usually correlated with increased proliferation and survival. Moreover, mature neurons play essential role in regulating the balance between active and quiescent state by realising inhibitory or activating neurotransmitters. Understanding molecular mechanisms underlying neuronal differentiation is of great importance in elucidating pathological conditions of the brain and treating neurodegenerative disorders that until now have no efficient therapies.

Green synthesized titanium dioxide nanoparticles and their future applications in biomedicine, agriculture and industry

In the green synthesis of titanium dioxide nanoparticles (TiO2 NPs) chemical reagents are replaced with biological extracts. Conventional methods used in the manufacture of TiO2 NPs raise environmental issues as they use harmful chemicals and spend a high amount of energy. At a laboratory scale, biologically synthesized titanium dioxide nanoparticles (bio-TiO2 NPs) proved to be a suitable alternative to the chemically synthesized ones. The biological activity of NPs is mainly determined by their shape, size and crystalline structure. However, these characteristics are hardly controlled when natural sources of reagents are used and so bio-TiO2 NPs did not reach an advanced technology readiness level. In this paper, we reviewed the majority of the available studies referring to bio-TiO2 NPs. Our aim is to briefly present the efficiency of biochemicals from different living organisms in producing TiO2 nano-scale particles as well as the benefits bio-TiO2 NPs would bring to the biomedical, agricultural and industrial sectors. Finally, based on the available data we discuss the sustainability of bio-TiO2 NPs referring to their possible environmental, economic and societal impacts.

The contribution of fish models in understanding of blood disorders

Human and fish peripheral blood contains erythrocytes or red blood cells, leukocytes or white blood cells and platelets or thrombocytes. Although the fish present the same types of blood cells as humans, studies have highlighted some morphological, ultrastructural and cytochemical differences in blood cells of the two groups of vertebrates. In both human and fish hematological tests are indispensable tools which provide a considerable amount of useful information for evaluation of the general state of health. Although there are limited amount of studies on blood cells in fish, over the years especially Danio rerio, has become an powerful model organism for studying human hematological diseases, as anemia, leukemia, myeloproliferative diseases and others human hematological diseases. Thereby, fish are ideal model organisms for studying hematological diseases due to external fertilization, brief development time, large number of embryos and the results can be extrapolated to mammals, including human. Furthermore, ikaros, rag-1, rag-2 and lck genes that are found in human were observed in Danio rerio revealing the spatio-temporal proximity between these groups of vertebrates. Therefore, studies realized on fish can offer essential information about molecular mechanism which causes the appearance of numerous human hematological diseases and discovery of possible therapeutic methods. This review provides a comparative overview of blood cells in fish and humans and describes zebrafish mutants as models of human hematologic disorders.

Modulation of Transient Receptor Potential (TRP) channels by tyrosine phosphorylation

Transient Receptor Potential (TRP) channels are a superfamily of polymodal, non-selective receptors, expressed in the nervous system and several other tissues, where they play many physiological or pathological roles. TRP channels are sensitive to a diverse range of stimuli, such as temperature, osmolarity, oxidative stress, external compounds and intracellular signaling molecules. The activity of TRP channels can be modulated by protein phosphorylation, including tyrosine phosphorylation. In this review, we present the studies carried out so far regarding the modulation of TRP channels by tyrosine phosphorylation.