The molecular machinery of myelin gene transcription in Schwann cells

During late fetal life, Schwann cells in the peripheral nerves, singled out by the larger axons will transit through a promyelinating stage before exiting the cell cycle and initiating myelin formation. A network of extra- and intracellular signaling pathways, regulating a transcriptional program of cell differentiation, governs this progression of cellular changes, culminating in a highly differentiated cell. In this review we focus on the roles of a number of transcription factors not only in myelination, during normal development, but also in demyelination, following nerve trauma. These factors include specification factors involved in early development of Schwann cells from neural crest (Sox10) as well as factors specifically required for transitions into the promyelinating and myelinating stages (Oct6/Scip and Krox20/Egr2). From this description we can glean the first, still very incomplete, contours of a gene regulatory network that governs myelination and demyelination during development and regeneration

Evaluating water balance components for forested headwater catchment undergoing environmental changes

&amp;lt;p&amp;gt;Evaluating seasonal and long-term variations in water balance at catchment scale can be useful for assessing the current status and trends in water resources availability. Components of water balance reflect meteorological and climate variability, and vegetation cover development.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;The experimental catchment Uhl&amp;amp;#237;&amp;amp;#345;sk&amp;amp;#225; is a small forested headwater catchment in the Jizera Mountains, Czech Republic. The catchment was extensively deforested in the 80&amp;amp;#180;s. Damaged trees long exposed to the effects of air pollutants were poorly resistant to wind and pests. In the 90&amp;amp;#180;s, new spruce forest was planted. The catchment has been subject to long-term monitoring. The 19-year series of data including air temperature, rain and snow precipitation, discharge, groundwater levels, wind velocity, and air humidity, is examined.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;Our study provides basic analysis of directly measured components of water balance (precipitation and discharge, annual and seasonal runoff coefficients). The study further deals with the evaluation of the unmeasured components of the water balance (evapotranspiration and water storage). An interception model was employed to calculate the interception loss. Potential evaporation and transpiration during vegetation seasons were estimated by Penman and Penman-Monteith methods. Snow sublimation was estimated in the winter seasons. Effect of the forest development during the period of interest was considered.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;The catchment water balance equation suggests significant changes of the water storage over the observation period, implying its decrease in recent years. However, baseflow and deep water storage seem to be unchanged. This discrepancy could be partly attributed to the decrease in shallow water storage and/or more pronounced transpiration reduction in recent vegetation seasons.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;The research is supported by the Czech Science Foundation Project No. 20-00788S.&amp;lt;/p&amp;gt; </jats:p

HDAC11 is a fatty-acid deacylase

ABSTRACTHistone deacetylase 11 (HDAC11) is a sole member of the class IV HDAC subfamily with negligible intrinsic deacetylation activity. Here we reportin vitroprofiling of HDAC11 deacylase activities, and our data unequivocally show that the enzyme efficiently removes acyl moieties spanning 8–18 carbons from the side chain nitrogen of the lysine residue of a peptidic substrate. Additionally, N-linked lipoic acid and biotin are removed by the enzyme, although with lower efficacy. Catalytic efficiencies toward dodecanoylated and myristoylated peptides exceed 70,000 M−1s−1making HDAC11 the most proficient fatty acid deacylase of the HDAC family. Interestingly, HDAC11 is strongly inhibited by free myristic, palmitic and stearic acids with inhibition constants of 6.5 µM, 0.9 µM, and 1.6 µM, respectively. At the same time, its deacylase activity is stimulated more than 2.5-fold by both palmitoyl-coenzyme A and myristoyl-coenzyme A, pointing toward metabolic control of the enzymatic activity by fatty acid metabolites. Our data reveal novel enzymatic activity of HDAC11 that can, in turn, facilitate the uncovering of additional biological functions of the enzyme as well as the design of isoform-specific HDAC inhibitors.</jats:p