Home-based fecal calprotectin utilization in a general pediatric gastroenterology clinic.

OBJECTIVE: Remote investigation and monitoring have gained importance in ambulatory practice. A home-based fecal calprotectin (FC) test has been developed where the sample is processed and analyzed at home through a smartphone application. We aimed to assess the use of standard ELISA (sFC) versus home-based (hFC) FC testing in a general pediatric gastroenterology clinic. METHODS: Ambulatory pediatric patients with hFC or sFC performed between August 2019 and November 2020 were included. Data regarding demographics, clinical characteristics, medication use, investigations, and final diagnosis, categorized as inflammatory bowel disease (IBD), functional gastrointestinal (GI) disorders, organic non-IBD (ONI) GI disorders, non-GI disorders, and undetermined after 6 months of investigation, were recorded. RESULTS: A total of 453 FC tests from 453 unique patients were included. Of those, 249 (55%) were hFC. FC levels (median) were higher in children with IBD compared to non-IBD diagnosis (sFC 795 vs. 57 µg/g, hFC 595 vs. 47 µg/g, p < 0.001), and in ONI compared to functional GI disorders (sFC 85 vs. 54 µg/g, p = 0.003, hFC 57 vs. 40 µg/g, p < 0.001). No significant difference was observed between different ONI GI disorders or subtypes of functional disorders. Age did not significantly influence levels. CONCLUSIONS: Overall, hFC and sFC provide similar results in the general pediatric GI ambulatory setting. FC is a sensitive but not disease-specific marker to identify patients with IBD. Values appear to be higher in ONI GI disorders over functional disorders, although cut-off values have yet to be determined.

Take your Positions and Shine: Effects of Positioning Aggregation-Induced Emission Luminophores within Sequence-Defined Macromolecules.

A luminophore with aggregation-induced emission (AIE) is employed for the conjugation onto supramolecular ligands to allow for detection of ligand binding. Supramolecular ligands are based on the combination of sequence-defined oligo(amidoamine) scaffolds and guanidiniocarbonyl-pyrrole (GCP) as binding motif. We hypothesize that AIE properties are strongly affected by positioning of the luminophore within the ligand scaffold. Therefore, we systematically investigate the effects placing the AIE luminophore at different positions within the overall construct, for example, in the main or side chain of the olig(amidoamine). Indeed, we can show that the position within the ligand structure strongly affects AIE, both for the ligand itself as well as when applying the ligand for the detection of different biological and synthetic polyanions.

An in vitro model of hemogenic endothelium commitment and hematopoietic production.

Adult-type hematopoietic stem and progenitor cells are formed during ontogeny from a specialized subset of endothelium, termed the hemogenic endothelium, via an endothelial-to-hematopoietic transition (EHT) that occurs in the embryonic aorta and the associated arteries. Despite efforts to generate models, little is known about the mechanisms that drive endothelial cells to the hemogenic fate and about the subsequent molecular control of the EHT. Here, we have designed a stromal line-free controlled culture system utilizing the embryonic pre-somitic mesoderm to obtain large numbers of endothelial cells that subsequently commit into hemogenic endothelium before undergoing EHT. Monitoring the culture for up to 12 days using key molecular markers reveals stepwise commitment into the blood-forming system that is reminiscent of the cellular and molecular changes occurring during hematopoietic development at the level of the aorta. Long-term single-cell imaging allows tracking of the EHT of newly formed blood cells from the layer of hemogenic endothelial cells. By modifying the culture conditions, it is also possible to modulate the endothelial cell commitment or the EHT or to produce smooth muscle cells at the expense of endothelial cells, demonstrating the versatility of the cell culture system. This method will improve our understanding of the precise cellular changes associated with hemogenic endothelium commitment and EHT and, by unfolding these earliest steps of the hematopoietic program, will pave the way for future ex vivo production of blood cells.

Stretch Out or Fold Back? Conformations of Dinuclear Gold(I) N-Heterocyclic Carbene Macrocycles.

We report the synthesis and characterization of 12 new dinuclear gold(I) N-heterocyclic carbene (NHC) complexes and the corresponding imidazolium precursors. The focus lies in a systematic study of conformational changes and intra- and intermolecular gold-gold and π-π interactions of dinuclear gold(I) carbene complexes. Common to all members of the series of gold macrocycles are NHC ligands on the basis of imidazole with ethyl side chains and bromide as well as hexafluorophosphate counterions, respectively. The compounds vary in the length of a flexible alkyl linker between the NHC units. For the methylene and ethylene bridged macrocycles, a ring inversion movement can be observed by VT-NMR. In total, 11 molecular structures have been characterized by X-ray diffraction. Open ring conformations with intermolecular π-π and Au-Au interactions prevail, but a backfolded conformation with a short intramolecular Au-Au distance has been found for the ethylene-bridged species. The presence of Au-Au interactions could be proven by quantum chemical calculations.

Health governance by collaboration: a case study on an area-based programme to tackle health inequalities in the Dutch city of the Hague.

BACKGROUND: Area-based programmes are seen as a promising strategy for tackling health inequalities. In these programmes, local authorities and other local actors collaborate to employ health promoting interventions and policies. Little is known about the underlying processes of collaborative governance. To unravel this black box, we explored how the authority of The Hague, The Netherlands, developed a programme tackling health inequalities drawing on a collaborative mode of governance. METHODS: Case study drawing on qualitative semi-structured interviews and document review. Data were inductively analysed against the concept of collaborative governance. RESULTS: The authority's ambition was to co-produce a programme on tackling health inequalities with local actors. Three stages could be distinguished in the governing process: (i) formulating policy objectives, (ii) translating policy objectives into interventions and (iii) executing health interventions. In the stage of formulating policy objectives, the collaboration led to a reframing of the initial objectives. Furthermore, the translation of the policy objectives into health interventions was rather pragmatic and loosely based on health needs and/or evidence. As a result, the concrete actions that ensued from the programme did not necessarily reflect the initial objectives. CONCLUSION: In a local system of health governance by collaboration, factors other than the stated policy objectives played a role, eventually undermining the effectiveness of the programme in reducing health inequalities. To be effective, the processes of collaborative governance underlying area-based programmes require the attention of the local authority, including the building and governing of networks, a competent public health workforce and supportive infrastructures.

Mistimed origin licensing and activation stabilize common fragile sites under tight DNA-replication checkpoint activation.

Genome integrity requires replication to be completed before chromosome segregation. The DNA-replication checkpoint (DRC) contributes to this coordination by inhibiting CDK1, which delays mitotic onset. Under-replication of common fragile sites (CFSs), however, escapes surveillance, resulting in mitotic chromosome breaks. Here we asked whether loose DRC activation induced by modest stresses commonly used to destabilize CFSs could explain this leakage. We found that tightening DRC activation or CDK1 inhibition stabilizes CFSs in human cells. Repli-Seq and molecular combing analyses showed a burst of replication initiations implemented in mid S-phase across a subset of late-replicating sequences, including CFSs, while the bulk genome was unaffected. CFS rescue and extra-initiations required CDC6 and CDT1 availability in S-phase, implying that CDK1 inhibition permits mistimed origin licensing and firing. In addition to delaying mitotic onset, tight DRC activation therefore supports replication completion of late origin-poor domains at risk of under-replication, two complementary roles preserving genome stability.

Epidemiology of Musculoskeletal Manifestations in Pediatric Inflammatory Bowel Disease: A Systematic Review.

OBJECTIVE: Pediatric inflammatory bowel disease (p-IBD) is a chronic relapsing gastrointestinal disorder of childhood with long-term morbidity. Several extraintestinal manifestations are described, the most common being joint pain and/or inflammation. However, patient and disease characteristics, treatments, and outcomes of p-IBD-associated musculoskeletal disease are not well established. Our study aims to summarize the recent literature on the epidemiology of musculoskeletal manifestations in p-IBD in the era of biologics. METHODS: A systematic search of PubMed, Embase, Cochrane Library, Web of Science Core Collection, and Cumulative Index to Nursing and Allied Health Literature databases was performed with relevant keywords. Studies in English published from January 1, 2000, to December 21, 2020, were included. In total, 3893 articles were identified and screened. Study and population characteristics and outcomes of interest were recorded. Risk of bias assessment was performed using the Joanna Briggs Institute Critical Appraisal Tools. RESULTS: Thirteen studies were included for full review, which were primarily single-center observational studies with retrospective or cross-sectional designs. The diagnostic criteria and definitions used for musculoskeletal manifestations varied. Musculoskeletal manifestation prevalence ranged from 2% to 35%. Only one study assessed the response of musculoskeletal manifestations to biologics. Risk of bias demonstrated heterogeneity in study quality. CONCLUSION: This is the first systematic review of musculoskeletal manifestations in p-IBD. Analysis was limited because of variability in study design and data-reporting methods. Definitions varied among included studies, with a clear lack in standardization. Our study demonstrates the need for standardized assessment of musculoskeletal manifestations of p-IBD and further research to explore optimal management to advance care for this group of children.

Induction of programmed cell death by inhibition of AKT with the alkylphosphocholine perifosine in in vitro models of platinum sensitive and resistant ovarian cancers.

PURPOSE: We analyzed the anti-tumor effect and the mechanism of action of perifosine, an orally active alkylphospholipid AKT inhibitor using in vitro models of human ovarian cancer. METHODS: Ovarian cancer cells OAW42, PA-1, SKOV3, and A2780 as well as platinum resistant A2780cis cells were incubated with increasing concentrations of perifosine, with and without multi-caspase inhibitor zVAD-FMK. The effect of a combined treatment with cisplatin and perifosine was investigated in OAW42, SKOV3, A2780 and A2780cis cells. Cytotoxic effects of perifosine were analyzed using crystal violet staining, FACS analysis of DNA content as well as Annexin V/propidium iodide-double staining. The effect of perifosine on AKT phosphorylation was determined by Western blotting. RESULTS: Perifosine displayed anti-tumor activity in all five cell lines, which increased time-dependently. While IC(50) values at 24 h were >40 µM, IC(50) values after 72 h decreased to 10 µM in OAW42 and 25 µM in PA-1 and 30 µm in SKOV3 cells. In platinum resistant A2780cis cells perifosine showed good antiproliferative activity (IC(50) = 3 µm). At adequate doses, perifosine increased cytotoxic effects of cisplatin in OAW42, A2780 and A2780cis cell. Anti-tumor activity of perifosine was not confined to a specific phase of the cell cycle and could not be decreased by the pan-caspase inhibitor zVAD-FMK. AnnexinV/propidium iodide-double staining after treatment with perifosine was not indicative of classical apoptosis. AKT phosphorylation was dose-dependently inhibited by perifosine. CONCLUSIONS: Perifosine showed substantial cytotoxic effects in various in vitro models of ovarian cancer. Since anti-tumor effects were not confined to platinum-sensitive cells perifosine seems to be a good candidate for clinical studies in patients especially with platinum resistant ovarian cancer.

Selective Adhesion and Switchable Release of Breast Cancer Cells via Hyaluronic Acid Functionalized Dual Stimuli-Responsive Microgel Films.

The detection of tumor cells from liquid biopsy samples is of critical importance for early cancer diagnosis, malignancy assessment, and treatment. In this work, coatings of hyaluronic acid (HA)-functionalized dual-stimuli responsive poly(N-isopropylacrylamide) (PNIPAM) microgels are used to study the specificity of breast cancer cell binding and to assess cell friendly release mechanisms for further diagnostic procedures. The microgels are established by straightforward precipitation polymerization with amine bearing comonomers and postfunctionalization with a UV-labile linker that covalently binds HA to the microgel network. Well-defined microgel coatings for cell binding are established via simple physisorption and annealing. The HA-presenting PNIPAM microgel films are shown to specifically adhere CD44 expressing breast cancer cell lines (MDA-MB-231 and MCF-7), where an increase in adhesion correlates with higher CD44 expression and HA functionalization. Upon cooling below the lower critical solution temperature of PNIPAM microgels, the cells could be released; however, 10-30% of the cells still remained on the surface even after prolonged cooling and mild mechanical agitation. A complete cell release is achieved after applying the light stimulus by short UV treatment cleaving HA units from the microgels. Owing to the comparatively straightforward preparation procedures, such dual-responsive microgel films could be considered for the effective capture, release, and diagnostics of tumor cells.

Secondary Anticoagulation Prophylaxis for Catheter-Related Thrombosis in Pediatric Intestinal Failure: Comparison of Short- Vs Long-Term Treatment Protocols.

INTRODUCTION: Catheter-related thrombosis (CRT) is a devastating complication of central venous catheters in children with intestinal failure (IF), but the optimal preventive therapy of CRT is unknown. This study assessed the efficacy and safety of 2 protocols of secondary anticoagulation prophylaxis with low-molecular-weight heparin (LMWH). METHODS: This is a comparative cohort study of children from 2 IF programs who received secondary anticoagulation prophylaxis with LMWH for CRT. The short-term protocol group (N = 13) received therapeutic dosing until thrombus resolution or ≤3 months. In the long-term protocol group (N = 26), prophylactic dosing continued until line removal. Patients underwent routine annual vascular ultrasound and were followed for ≥1 year. The primary outcome was development of secondary thrombosis; post hoc analysis assessed rates of secondary thrombosis at 12 months. RESULTS: Patient demographics were similar between groups. Secondary thrombosis occurred in 8 of 13 (62%) patients in the short-term group and in 9 of 26 (35%) in the long-term protocol group (P = .019) in a median time of 144.5 and 689 days, respectively (P = .01). Secondary thrombosis within 12 months occurred in 7 of 13 (54%, short term) and 2 of 26 (8%, long term) patients (P = .001). Secondary thrombosis was associated with catheter replacements (23.5 vs 5.5 catheters per 1000 catheter days; P = .016) and longer daily parenteral nutrition (PN) infusion (24 vs 15.25 hours; P = .044). Compliance was good (>80% of doses) in 92% of patients. CONCLUSIONS: Long-term secondary anticoagulation prophylaxis with LMWH reduces the incidence of secondary thrombosis and should be considered in children with CRT that require PN for prolonged periods of time.

Generating political priority to tackle health disparities: a case study in the Dutch city of The Hague.

OBJECTIVES: We sought to study the factors that determined the success of a recent initiative to generate political priority for the problem of health disparities in the city of The Hague, the Netherlands. METHODS: Our study had a prospective design. The qualitative data collection included interviews, document analyses, and observations. RESULTS: Crucial for the success of this initiative was the presence of powerful and credible actors. These actors effectively presented scientific evidence on health disparities and framed the issue in the light of shared values, priorities, and policy principles. Finally, their actions were supported by the national context, including the availability of national scientific research on health disparities. CONCLUSIONS: The project in The Hague shows that political priority for tackling health disparities can be generated at a local level. Key factors included framing the issue in the light of shared values and framing the problem and the solution as in line with existing policy principles.

Implementation of a Postpartum Hemorrhage Safety Bundle at an Urban Safety-Net Hospital.

Background Postpartum hemorrhage (PPH) is a leading cause of preventable maternal morbidity and mortality. Standardized response to obstetric hemorrhage is associated with significant improvement in maternal outcomes, yet implementation can be challenging. Objective The primary objective is to describe the methodology for program implementation of the Alliance for Innovation on Maternal Health Safety Bundle on PPH at an urban safety-net hospital. Methods Over an 18-month period, interventions geared toward (1) risk assessment and stratification, (2) hemorrhage identification and management, (3) team communication and simulation, and (4) debriefs and case review were implemented. Hemorrhage risk assessment stratification rates were tracked overtime as an early measure of bundle compliance. Results Hemorrhage risk assessment stratification rates improved to >90% during bundle implementation. Conclusion Keys to implementation included multidisciplinary stakeholder commitment, stepwise and iterative approach, and parallel systems for monitoring and evaluation Implementation of a PPH safety bundle is feasible in a resource-constrained setting.

Transcription-dependent regulation of replication dynamics modulates genome stability.

Common fragile sites (CFSs) are loci that are hypersensitive to replication stress and hotspots for chromosomal rearrangements in cancers. CFSs replicate late in S phase, are cell-type specific and nest in large genes. The relative impact of transcription-replication conflicts versus a low density in initiation events on fragility is currently debated. Here we addressed the relationships between transcription, replication, and instability by manipulating the transcription of endogenous large genes in chicken and human cells. We found that inducing low transcription with a weak promoter destabilized large genes, whereas stimulating their transcription with strong promoters alleviated instability. Notably, strong promoters triggered a switch to an earlier replication timing, supporting a model in which high transcription levels give cells more time to complete replication before mitosis. Transcription could therefore contribute to maintaining genome integrity, challenging the dominant view that it is exclusively a threat.

Transcription-mediated organization of the replication initiation program across large genes sets common fragile sites genome-wide.

Common fragile sites (CFSs) are chromosome regions prone to breakage upon replication stress known to drive chromosome rearrangements during oncogenesis. Most CFSs nest in large expressed genes, suggesting that transcription could elicit their instability; however, the underlying mechanisms remain elusive. Genome-wide replication timing analyses here show that stress-induced delayed/under-replication is the hallmark of CFSs. Extensive genome-wide analyses of nascent transcripts, replication origin positioning and fork directionality reveal that 80% of CFSs nest in large transcribed domains poor in initiation events, replicated by long-travelling forks. Forks that travel long in late S phase explains CFS replication features, whereas formation of sequence-dependent fork barriers or head-on transcription-replication conflicts do not. We further show that transcription inhibition during S phase, which suppresses transcription-replication encounters and prevents origin resetting, could not rescue CFS stability. Altogether, our results show that transcription-dependent suppression of initiation events delays replication of large gene bodies, committing them to instability.

Expression of VEGFR-1 (Flt-1) in breast cancer is associated with VEGF expression and with node-negative tumour stage.

BACKGROUND: Vascular endothelial growth factor (VEGF) promotes breast cancer progression by inducing angiogenesis via VEGF receptors on endothelial cells but also signals directly through receptors such as VEGFR-1 (Flt-1) expressed on tumour cells. The impact of autocrine signalling loops on treatment with VEGF inhibitors is still unclear. MATERIALS AND METHODS: Six breast cancer cell lines were tested for expression of VEGFR-1 by RT-PCR and Western blot. To assess clinical significance, 93 breast cancer lesions were evaluated for expression of VEGF and VEGFR-1 by immunohistochemistry. RESULTS: VEGFR-1 mRNA was found in all 6 cell lines, while protein expression was found in 5 cell lines. VEGF was expressed in 60% and VEGFR-1 in 39% of breast cancer specimens. VEGFR-1 expression was associated with VEGF expression and with node-negative tumour stage. CONCLUSION: Our data suggest that analysis of VEGF/VEGFR-1 expression might be relevant in identifying patients with different response rates upon treatment with antiangiogenic agents.

Which factors engage women in deprived neighbourhoods to participate in exercise referral schemes?

BACKGROUND: Exercise referral schemes (ERS) have become a popular way of promoting physical activity. The aim of these schemes is to encourage high risk patients to exercise. In evaluating these schemes, little attention has been paid to lower socio-economic groups in a multi-ethnic urban setting. This study aimed to explore the socio-demographic and psychosocial characteristics of female participants in ERS located in deprived neighbourhoods. The second aim was to determine which elements of the intervention make it appealing to participate in the scheme. METHODS: A mixed method approach was utilized, combining a cross-sectional descriptive study and a qualitative component. In the quantitative part of the study, all female participants (n = 523) filled out a registration form containing questions about socio-demographic and psychosocial characteristics. Height and weight were also measured. In the qualitative part of the study, 38 of these 523 participants were interviewed. RESULTS: The majority of the participants had a migrant background, a low level of education, no paid job and a high body mass index. Although most participants were living sedentary lives, at intake they were quite motivated to start exercising. The ERS appealed to them because of its specific elements: facilitating role of the health professional, supportive environment, financial incentive, supervision and neighbourhood setting. CONCLUSION: This study supports the idea that ERS interventions appeal to women from lower socio-economic groups, including ethnic minorities. The ERS seems to meet their contextual, economic and cultural needs. Since the elements that enabled the women to start exercising are specific to this ERS, we should become aware of whether this population continues to exercise after the end of the scheme.

Glucose metabolism and angiogenesis in granulosa cell tumors of the ovary: activation of Akt, expression of M2PK, TKTL1 and VEGF.

OBJECTIVES: Very little is known about the biology of granulosa cell tumors of the ovary. A hallmark of granulosa cell tumors of the ovary is extensive growth, distant metastases however, are rarely found. We hypothesise that granulosa cell tumors of the ovary on the one hand need to stimulate vascularisation; on the other hand glucose metabolism has to be altered to ensure the supply of nutrients and metabolites. Increased glycolysis, the main source of energy supply, is considered to be important during malignant transformation. Thus, we focussed on a selection of key factors in angiogenesis and tumor glycolysis to study metabolic characteristics of granulosa cell tumors of the ovary. STUDY DESIGN: We analysed 32 tumor specimens for immunohistochemical expression of vascular endothelial growth factor, phosphorylated Akt, M2 pyruvate kinase isoenzyme, and transketolase-like enzyme 1. As controls, we stained 10 samples of normal ovaries. RESULTS: We found expression of vascular endothelial growth factor in 94%, transketolase-like enzyme 1 in 81%, and phosphorylated Akt as well as M2 pyruvate kinase isoenzyme in 53% of the specimens. There were no significant differences between the expression levels in primary and those in recurrent tumors. Temporal analysis of marker expression in primary tumors and recurrences in the same patients revealed no increase or decrease of marker expression overtime. In contrast to granulosa cell tumors, normal ovaries showed no expression of the markers analysed in granulosa cells. CONCLUSION: Our results show that granulosa cell tumors of the ovary express vascular endothelial growth factor as an important stimulator of tumor angiogenesis as well as several molecular markers for glycolysis. The dependence of granulosa cell tumors of the ovary on the glycolytic pathway may provide a biochemical basis for therapeutic strategies involving glycolytic inhibitors.

A novel breast cancer cell line initially established from pleural effusion: evolution towards a more aggressive phenotype.

Many human breast cancer cell lines have been in culture for several years, serving as model systems for studying aspects of breast cancer biology. Molecular alterations might occur in these cells during cultivation, and it remains unknown to which extent findings in these cell lines can be related to human disease. Hereby, we describe the establishment of a breast cancer cell line, MW1, from malignant pleural effusion. We compare expression patterns of several molecular markers in breast biopsy tissue, in cultivated tumor cells derived from pleural effusion reflecting the metastatic state, and in late passages of a lineage derived from the pleural culture. Our data show that expression of estrogen and progesterone receptors was lost in the cultivated tumor cells derived from pleural effusion as shown by immunohistochemical staining. Cytokeratin expression patterns remained luminal. During cultivation, the growth rate of MW1 cells increased dramatically and the morphology underwent alterations. As shown by Western blotting, E-cadherin expression remained unchanged whereas P-cadherin expression had increased after 4 years of cultivation of the cell line. Integrin beta4 expression was low in early passages of the pleural effusion whereas the cell line exhibited high expression levels of beta4. HGF receptor (c-Met), EGF receptor, VEGF and VEGF receptor-2 (KDR) expression was detectable by semiquantitative RT-PCR and remained unchanged during cultivation. In contrast, VEGF receptor-1 (flt-1) expression showed lower expression after 4 years of cultivation. The cell line migrated towards HGF, but not towards VEGF. This study provides exemplary insight into the molecular metamorphosis tumor cells undergo in vivo or in vitro on their way from the primary tumor via an equivalent of the metastatic state and during the development of a clonal cell line.

Characterization of an intramolecular protein-protein interaction in c-Ets1 and its viral homologue v-Ets.

The proto-oncoprotein c-Ets1 is a well-known transcription factor that belongs to the Ets family and plays a role in haematopoietic differentiation, angiogenesis, and carcinogenesis. Ets family members share a unique DNA binding domain, the Ets domain, and are known to control DNA binding activity and transcriptional activation by autoinhibition. In c-Ets1 the DNA binding domain as well as N-terminal and C-terminal inhibitory domains are involved in autoinhibitory regulation. It has been proposed that intramolecular interactions are part of the autoinhibitory mechanism. We applied a GST pull-down assay as well as a two-hybrid system in yeast to show an interaction between the DNA binding domain of c-Ets1 and a domain N-terminal thereof. We have mapped the interaction sites within both of the c-Ets1 domains. Comparison of the analogous intramolecular interaction in c-Ets1 and in v-Ets revealed that the interaction we detected is stronger in v-Ets than in c-Ets1. In view of previous findings from DNA binding studies, and kinetic experiments as well as structural data, our results suggest a new model as to how intramolecular interactions might participate in the regulation of DNA binding. Binding of c-Ets1 to DNA temporarily changes the intramolecular pattern of interaction in c-Ets1, leading to an increase in affinity of c-Ets1 to DNA. In full-length c-Ets1 the intramolecular interactions re-form spontaneously and the protein-DNA complex dissociates. The interaction we characterize herein might increase the DNA binding affinity temporarily in DNA-bound c-Ets1. In v-Ets in which the C-terminal domain is mutated this interaction appears to lead to strong DNA binding affinity. Therefore, changes in v-Ets might contribute to the tumorigenic process by altering intramolecular interactions.

The creatine kinase system in human skin: protective effects of creatine against oxidative and UV damage in vitro and in vivo.

Cutaneous aging is characterized by a decline in cellular energy metabolism, which is mainly caused by detrimental changes in mitochondrial function. The processes involved seem to be predominantly mediated by free radicals known to be generated by exogenous noxes, e.g., solar ultraviolet (UV) radiation. Basically, skin cells try to compensate any loss of mitochondrial energetic capacity by extra-mitochondrial pathways such as glycolysis or the creatine kinase (CK) system. Recent studies reported the presence of cytosolic and mitochondrial isoenzymes of CK, as well as a creatine transporter in human skin. In this study, we analyzed the cutaneous CK system, focusing on those cellular stressors known to play an important role in the process of skin aging. According to our results, a stress-induced decline in mitochondrial energy supply in human epidermal cells correlated with a decrease in mitochondrial CK activity. In addition, we investigated the effects of creatine supplementation on human epidermal cells as a potential mechanism to reinforce the endogenous energy supply in skin. Exogenous creatine was taken up by keratinocytes and increased CK activity, mitochondrial function and protected against free oxygen radical stress. Finally, our new data clearly indicate that human skin cells that are energetically recharged with the naturally occurring energy precursor, creatine, are markedly protected against a variety of cellular stress conditions, like oxidative and UV damage in vitro and in vivo. This may have further implications in modulating processes, which are involved in premature skin aging and skin damage.