Comparative analysis of human UCB and adipose tissue derived mesenchymal stem cells for their differentiation potential into brown and white adipocytes

The differentiation potential of umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs) into brown and white adipocytes in comparison to Adipose tissue derived MSCs (AD-MSCs) were investigated in order to characterize their potency for future cell therapies. MSCs were isolated from ten UCB samples and six liposuction materials. MSCs were differentiated into white and brown adipocytes after characterization by flow cytometry. Differentiated adipocytes were stained with Oil Red O and hematoxylin/eosin. The UCP1 protein levels in brown adipocytes were investigated by immunofluoresence and western blot analysis. Cells that expressed mesenchymal stem cells markers (CD34?, CD45?, CD90+ and CD105+) were successfully isolated from UCB and adipose tissue. Oil Red O staining demonstrated that white and brown adipocytes obtained from AD-MSCs showed 85 and 61% of red pixels, while it was 3 and 1.9%, respectively for white and brown adipocytes obtained from UCB-MSCs. Fluorescence microscopy analysis showed strong uncoupling protein 1 (UCP1) signaling in brown adipocytes, especially which were obtained from AD-MSCs. Quantification of UCP1 protein amount showed 4- and 10.64-fold increase in UCP1 contents of brown adipocytes derived from UCB-MSCs and AD-MSCs, respectively in comparison to undifferentiated MSCs (P?<?0.004). UCB-MSCs showed only a little differentiation tendency into adipocytes means it is not an appropriate stem cell type to be differentiated into these cell types. In contrast, high differentiation efficiency of AD-MSCs into brown and white adipocytes make it appropriate stem cell type to use in future regenerative medicine of soft tissue disorders or fighting with obesity and its related disorders.     

E. coli RNase I exhibits a strong Ca2+-dependent inherent double-stranded RNase activity

Since its initial characterization, Escherichia coli RNase I has been described as a single-strand specific RNA endonuclease that cleaves its substrate in a largely sequence independent manner. Here, we describe a strong calcium (Ca²⁺)-dependent activity of RNase I on double-stranded RNA (dsRNA), and a Ca²⁺-dependent novel hybridase activity, digesting the RNA strand in a DNA:RNA hybrid. Surprisingly, Ca²⁺ does not affect the activity of RNase I on single stranded RNA (ssRNA), suggesting a specific role for Ca²⁺ in the modulation of RNase I activity. Mutation of a previously overlooked Ca²⁺ binding site on RNase I resulted in a gain-of-function enzyme that is highly active on dsRNA and could no longer be stimulated by the metal. In summary, our data imply that native RNase I contains a bound Ca²⁺, allowing it to target both single- and double-stranded RNAs, thus having a broader substrate specificity than originally proposed for this traditional enzyme. In addition, the finding that the dsRNase activity, and not the ssRNase activity, is associated with the Ca²⁺-dependency of RNase I may be useful as a tool in applied molecular biology.     

Molekulare Mechanismen des Seckel-Syndroms

Seckel syndrome is an autosomal recessive disorder characterized by proportionately short stature, severe microcephaly, mental retardation and craniofacial deformities that give rise to the typical ??bird head?? appearance. In some patients, premature onset of aging-associated diseases is also observed. In terms of genetics, Seckel syndrome is a heterogeneous condition for which many causal genes have been identified in recent years. In addition to genes involved in cellular activities, these include genes with important roles in cell division processes and the activation of DNA damage responses.     

Effect of barnacle fouling on ship resistance and powering

Predictions of added resistance and the effective power of ships were made for varying barnacle fouling conditions. A series of towing tests was carried out using flat plates covered with artificial barnacles. The tests were designed to allow the examination of the effects of barnacle height and percentage coverage on the resistance and effective power of ships. The drag coefficients and roughness function values were evaluated for the flat plates. The roughness effects of the fouling conditions on the ships’ frictional resistances were predicted. Added resistance diagrams were then plotted using these predictions, and powering penalties for these ships were calculated using the diagrams generated. The results indicate that the effect of barnacle size is significant, since a 10% coverage of barnacles each 5 mm in height caused a similar level of added power requirements to a 50% coverage of barnacles each 1.25 mm in height.