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Vitamin B 12 is a redox-active compound containing a cobalt atom that cycles between oxidation states. Superoxide scavenging induces its oxidation, disabling activation of the enzymes methionine synthase and methylmalonyl-CoA mutase, disrupting gene expression and energy production. High-dosed vitamin B 12 may be clinically used to reduce oxidative stress and preserve cofactor functions. [ABSTRACT FROM AUTHOR]

Results of randomized controlled trials (RCTs) and, ideally, the synthesis of RCT results into meta-analyses, drive both clinical and policy decision making about health care interventions and inform new avenues for research. Selection of the right health outcomes to measure, analyze, and report on when designing a trial therefore is key in ensuring that the research will be useful and will have maximum impact.1-3 As in many areas of medicine, wide variability exists in pediatric mental health research as to which outcomes are selected, how they are measured, and how they are reported. Variability in outcome selection and measurement may stem from various factors, including a tendency to select what is feasible or historical to measure rather than a focus on what is important to measure and how best to measure it. The resulting variability limits comparing and combining the results from different trials addressing a similar question in meta-analyses, hindering the translation of research to practice.1,2 The objective of this article is to highlight the importance of outcome selection, measurement, and reporting in the translation of research to clinical practice. [ABSTRACT FROM AUTHOR]

Purpose To compare the outcome of initially nonoperative treatment with immediate appendectomy for simple appendicitis in children. Methods Between September 2012 and June 2014 children aged 7–17 years with a radiologically confirmed simple appendicitis were invited to participate in a multicentre prospective cohort study in which they were treated with an initially nonoperative treatment strategy; nonparticipants underwent immediate appendectomy. In October 2015, their rates of complications and subsequent appendectomies, and health-related quality of life (HRQOL) were assessed. Results In this period, 25 children were treated with an initially nonoperative treatment strategy and 19 with immediate appendectomy; median (range) follow-up was 25 (16–36) and 26 (17–34) months, respectively. The percentage [95%CI] of patients experiencing complications in the initially nonoperative group and the immediate appendectomy group was 12 [4–30]% and 11 [3–31]%, respectively. In total 6/25 children (24%) underwent an appendectomy; none of the 6 patients operated subsequently experienced any postappendectomy complications. Overall, HRQOL in the nonoperative treatment group was similar to that of healthy peers. Conclusions Outcome of initially nonoperative treatment for acute simple appendicitis in children is similar to the outcome in those who undergo immediate appendectomy. Initially nonoperative management seems to be able to avoid appendectomy in 3 out of 4 children. Level of evidence 2 (prospective comparative study). This research did not receive any specific grant from funding agencies in the public, commercial or not-for-profit sectors. [ABSTRACT FROM AUTHOR]

Background Prospective clinical trial registration serves to increase transparency and to mitigate selective reporting bias. An assessment of adult surgical trials revealed poor trial registration practice with incomplete provision of information in registries and inconsistent information in the corresponding publication. The extent and completeness of pediatric surgical trial registration are unknown. We aimed to determine the proportion and adequacy of clinical trial registration in pediatric surgery trials published in 2014. Methods Using sensitive search strategies in MEDLINE, abstracts and full-texts of prospective pediatric intervention studies published in 2014 were screened in duplicate. Pediatric surgical trials were included. Clinical trial registration numbers obtained from publications were searched in trial registries. Data were extracted based on WHO 20-item minimum data set to determine the completeness of registration data. The proportion of registered trials was recorded and registration data were compared to reported data in the corresponding publication. Results Our search and abstract screening identified 3375 articles for full text review. Following coding, a total of 54 pediatric surgical trials were included and analyzed; 28% (15/54) of which published a registration number. In trials which reported a registration number, 40% (6/15) were retrospectively registered and 40% (6/15) had made changes to their registered primary and/or secondary outcome measures. One included published trial reported an incorrect registration number. Conclusions Analysis of pediatric surgery trials published in 2014 revealed a poor prospective trial registration rate and incomplete registration data. Our study supports future initiatives for improved registration behaviors in pediatric surgery trials to ensure high-quality, transparent, reproducible evidence is generated. Study type Therapeutic (clinical trials), level II. [ABSTRACT FROM AUTHOR]

Evidence-based mental health care for children and youth critically depends on properly conducted randomized controlled trials (RCTs) and prospective studies that investigate change in mental health outcomes over time. As evidence accumulates, it can be synthesized through systematic reviews and meta-analyses that combine the results of many studies into a single estimate of effect. Clinical practice guidelines incorporate this information along with input from stakeholders and content experts, who fill in evidence gaps to formulate recommendations for best practice. Collectively, this evidence generation and synthesis process, once implemented, supports better long-term outcomes for the population by highlighting the "best available evidence" and reducing variability in clinical care. In addition, this process identifies knowledge gaps that might inform the field's research agenda. The objective of this commentary is to examine the potential of developing and implementing "Core Outcome Sets" (COS) as a means of reducing variability in the measurement and reporting of outcomes across RCTs and cohort studies, and thereby promoting the translation of evidence to practice. [ABSTRACT FROM AUTHOR]

Systematic reviews and meta-analyses are at the top of the 'evidence hierarchy' when assessing the effectiveness of health interventions. As such, they are important sources of synthesized information for decision-makers including consumers, clinicians, funders, payers, regulators, and researchers. The main reasons for undertaking systematic reviews and meta-analyses are to minimize bias and to maximize data by collating all the relevant, available evidence on a particular topic. In order to correctly inform decision-makers, but not mislead them, a number of key methodological conditions need to be met when undertaking these types of analysis. In this article we first review the history of systematic reviews and meta-analyses and then outline those conditions that may lead to the correct, or incorrect, use of these types of study. Also, new variations on standard systematic review methods are explored, with the pros and cons of each outlined. [ABSTRACT FROM AUTHOR]

Background Initial antibiotic treatment for acute appendicitis has been shown to be safe in adults; so far, not much is known about the safety and efficacy of this treatment in children. The aims of this study were to investigate the feasibility of a randomized controlled trial (RCT) evaluating initial antibiotic treatment for acute appendectomy in children with acute simple appendicitis and to evaluate the safety of this approach. Methods In a multicenter, prospective cohort study patients aged 7–17 years with a radiologically confirmed simple appendicitis were eligible. Intravenous antibiotics (amoxicillin/clavulanic acid 250/25 mg/kg 4 times daily; maximum 6,000/600 mg/d and gentamicin 7 mg/kg once daily) were administered for 48–72 hours. Clinical reevaluation every 6 hours, daily blood samples, and ultrasound follow-up after 48 hours was performed. In case of improvement after 48 hours, oral antibiotics were given for a total of 7 days. At any time, in case of clinical deterioration or non-improvement after 72 hours, an appendectomy could be performed. Follow-up continued until 8 weeks after discharge. Adverse events were defined as major complications of antibiotic treatment, such as allergic reactions, perforated appendicitis, and recurrent appendicitis. Results Of 44 eligible patients, 25 participated (inclusion rate, 57%; 95% CI, 42%–70%). Delayed appendectomy was performed in 2, and the other 23 were without symptoms at the 8 weeks follow-up. Minor complications occurred in three patients. None of the patients suffered from an adverse event or a recurrent appendicitis. Conclusion Our study shows that an RCT comparing initial antibiotic treatment strategy with urgent appendectomy is feasible in children; the intervention seems to be safe. [ABSTRACT FROM AUTHOR]

Abstract: Standards for Research (StaR) in Child Health, founded in 2009, addresses the current scarcity of and deficiencies in pediatric clinical trials. StaR Child Health brings together leading international experts devoted to developing practical, evidence-based standards to enrich the reliability and relevance of pediatric clinical research. Through a systematic “knowledge to action” plan, StaR Child Health creates opportunities to improve the evidence base for child health across the world. To date, six standards have been published and four more are under development. It is now time to use these standards. Improving the design, conduct and reporting of pediatric clinical trials will ultimately advance the quality of health care provided to children across the globe. [Copyright &y& Elsevier]

Summary: GATA transcription factors regulate transcription during development and differentiation by recognizing distinct GATA sites with a tandem of two conserved zinc fingers, and by mediating long-range DNA looping. However, the molecular basis of these processes is not well understood. Here, we determined three crystal structures of the full DNA-binding domain (DBD) of human GATA3 protein, which contains both zinc fingers, in complex with different DNA sites. In one structure, both zinc fingers wrap around a palindromic GATA site, cooperatively enhancing the binding affinity and kinetic stability. Strikingly, in the other two structures, the two fingers of GATA DBD bind GATA sites on different DNA molecules, thereby bridging two separate DNA fragments. This was confirmed in solution by an in-gel fluorescence resonance energy transfer analysis. These findings not only provide insights into the structure and function of GATA proteins but also shed light on the molecular basis of long-range gene regulation. [Copyright &y& Elsevier]

Abstract: Introduction: There are no data on the intrauterine fatty acid (FA) compositions of brain, liver and adipose tissue of infants born to women with high fish intakes. Subjects and methods: We analyzed the brain (n=18), liver (n=14) and adipose tissue (n=11) FA compositions of 20 stillborn infants with different gestational ages (range 8–38 weeks) born to Tanzanian women with low linoleic acid (LA) intakes and high intakes of docosahexaenoic (DHA) and arachidonic (AA) acids from local fish. Results and discussion: With advancing gestation, brain saturated-FA (SAFA; in g/100g FA), polyunsaturated-FA (PUFA), DHA, 20:3ω6, 22:4ω6 and 22:5ω6 increased, while monounsaturated-FA (MUFA), 20:3ω9, 22:3ω9 and AA decreased. Decreasing brain AA might be caused by increasing AA-metabolism to 20:3ω6, 22:4ω6 and 22:5ω6. In the liver, SAFA, PUFA and LA increased, while MUFA decreased with gestation. The steep increase of (mostly de novo synthesized) SAFA in adipose tissue coincided with relative decreases of MUFA, PUFA, DHA, LA and AA with advancing gestation. Compared to Western infants, the currently studied African infants had higher DHA, lower AA, and a higher DHA/AA-ratio in brain and adipose tissue, while the LA content of adipose tissue was lower. Conclusion: The low LA and high DHA and AA intakes by the mothers of these infants might support optimal α-linolenic (ALA) vs. LA competition for Δ5D and Δ6D-activities and DHA vs. AA antagonism. Conversely, the Western diet, characterized by high LA and lower DHA and AA intakes, might disturb these evolutionary conserved mechanisms aiming at an optimal ω3/ω6-balance. [Copyright &y& Elsevier]

Abstract: Background: Little is known about the gestational age (GA) dependent content, composition and intrauterine accretion rates of fatty acids (FA) in fetal white adipose tissue (WAT). Objective & design: To acquire this information, we collected abdominal subcutaneous WAT samples from 40 preterm and term fetuses. Their GA ranged from 22 to 43 weeks. FA were expressed as mg/g wet WAT and g/100g FA (g%). Intrauterine WAT FA accretion rates were estimated for appropriate (AGA) and large (LGA) for gestational age infants. Results: From 25 to 40 weeks gestation, saturated-FA (SAFA) increased from 83 to 298mg/g WAT and monounsaturated-FA (MUFA) from 83 to 226mg/g WAT, while polyunsaturated-FA (PUFA) increased insignificantly from 18.0 to 23.2mg/g WAT. As percentages of total FA, SAFA increased from 46 to 55g%, MUFA decreased from 44 to 41g%, and PUFA from 10.3 to 4.26g%. Docosahexaenoic (DHA) and arachidonic acid (AA) accretion rates in WAT during the 3rd trimester for AGA infants were 88 and 193mg/week, respectively. Contemporaneous DHA and AA accretion rates for 4500g LGA infants were 184 and 402mg/week, respectively. Compared to the whole 3rd trimester, increment rates during the last 5 weeks of gestation were about 2-fold higher. Conclusion: FA accretion rates, notably those of DHA and AA, may be important for designing nutritional regiments for preterm infants. The current WAT-DHA and WAT-AA accretion rates are considerably lower than previously reported in the literature. [Copyright &y& Elsevier]

Abstract: Introduction: There is no information on the whole body fatty acid (FA) contents of preterm or term infants, although scattered information on the FA-composition of many organs is available. Material and methods: We collected data on the weights, lipid contents and FA-compositions of the quantitatively most important fetal organs of appropriate for gestational age (AGA) Western infants. From these we estimated the total body contents of linoleic (LA), arachidonic (AA) and docosahexaenoic (DHA) acids at 25, 35 and 40 weeks of gestation. Results: Western infants accrete FA in the order of LA>AA>DHA at all stages during pregnancy and the highest accretion rates are reached in the last 5 weeks of gestation, i.e. 342mg LA, 95mg AA and 42mg DHA/day. At term, most of the infant''s LA, AA and DHA is located in adipose tissue (68, 44 and 50%, respectively), with substantial amounts of LA also located in skeletal muscle (17%) and skin (13%); of AA in skeletal muscle (40%) and brain (11%); and of DHA in brain (23%) and skeletal muscle (21%). The term AGA infant has accreted about 21g LA, 7.5g AA and 3g DHA, which constitutes a gap of 12g LA, 3.3g AA and 1.5g DHA compared to a 35 weeks old AGA infant. Conclusion: The current fetal LA, AA and DHA pool sizes and accretion rates may especially be useful to estimate the preterm infant''s requirements and the maternal LCP needs during pregnancy. Since they derive from populations with typically Western diets they do not necessarily reflect ‘optimality’ or ‘health’. [Copyright &y& Elsevier]

Background: Posttraumatic stress disorder (PTSD) is marked by intrusive, chronic, and distressing memories of highly emotional events. Previous research has highlighted the role of the amygdala and its interactions with the hippocampus in mediating the effect of enhanced memory for emotional information in healthy individuals. As the functional integrity of these regions may be compromised in PTSD, the current study examined the neural correlates of emotional memory in PTSD. Methods: We used functional magnetic resonance imaging and an event-related subsequent memory recognition paradigm to study amygdala and hippocampus activation in 18 individuals with PTSD and 18 trauma-exposed non-PTSD control participants. Results: Memory enhancement for negative, relative to neutral, pictures was found across all subjects, without significant differences between groups. Relative to the trauma-exposed non-PTSD group, the PTSD group showed exaggerated amygdala activation during the encoding of negative versus neutral pictures. This effect was even more pronounced when the analysis included data from only pictures that were subsequently remembered 1 week later. In the PTSD group, degree of amygdala activation during the encoding of negative versus neutral pictures was positively correlated with hippocampal activation and current PTSD symptom severity. The PTSD group also showed exaggerated hippocampal activation in response to negative pictures that were remembered versus forgotten. Finally, hippocampal activation associated with the successful encoding of negative relative to neutral pictures was significantly greater in the PTSD group. Conclusions: Exaggerated amygdala activation during the encoding of emotionally negative stimuli in PTSD is related to symptom severity and to hippocampal activation. [ABSTRACT FROM AUTHOR]

Immunotherapy of cancer through adoptive transfer of genetically engineered T-cells constitutes a more powerful strategy than attempts to mobilize the endogenous T-cell repertoire. Application of this technology in patients offers great opportunities towards a long-awaited breakthrough in cancer immunotherapy. However, recent findings in preclinical mouse models indicate that infusion of T-cells directed against tumor-associated auto-antigens can be associated with higher ‘on target’ toxicity than was anticipated on the basis of anti-tumor vaccination studies. Critical evaluation of candidate target antigens is required to ensure that T-cell receptor gene therapy will result in preferential attack of tumor cells in the absence of irreversible damage to vital somatic tissues. [Copyright &y& Elsevier]

The plant hormone auxin controls plant development through gradients and maxima that are generated by PIN efflux carrier driven polar auxin transport. PIN proteins direct this cell-to-cell auxin transport, and thus orient plant development through their asymmetric subcellular distribution. PIN polarity is regulated by PINOID and the phototropins, members of the AGC protein serine/threonine kinase family. Here we review the signaling pathways of these kinases and the role of calcium and BTB proteins in translating both internal and external signals into developmental responses via PIN relocalization, to adapt plant development to changing environmental conditions. [Copyright &y& Elsevier]

The signaling molecule auxin is a central regulator of plant development, which instructs tissue and organ patterning, and couples environmental stimuli to developmental responses. Here, we discuss the function of PINOID (PID) and the phototropins, members of the plant specific AGCVIII protein kinases, and their role in triggering and regulating development by controlling PIN-FORMED (PIN) auxin transporter-generated auxin gradients and maxima. We propose that the AGCVIII kinase gene family evolved from an ancestral phototropin gene, and that the co-evolution of PID-like and PIN gene families marks the transition of plants from water to land. We hypothesize that the PID-like kinases function in parallel to, or downstream of, the phototropins to orient plant development by establishing the direction of polar auxin transport. [Copyright &y& Elsevier]

Abstract: Competitive adsorption isotherms for two conservative surface charge-neutralizing mutants of cytochrome b5, E11Q and E44Q, previously measured with competitor concentration held constant over the range of the isotherm, were used to test three widely-used multi-component isotherm models. The extended Langmuir–Freundlich, Langmuir and Jovanovic–Freundlich models each adequately described the weaker infinite dilution adsorption of the E44Q protein in the presence of the strong binding E11Q. The extended Langmuir–Freundlich model generally gave the lowest errors at higher concentrations, and the Jovanovic–Freundlich model gave the best fits when using empirically optimized maximal loading values based on multi-component as well as pure-component isotherm data. [Copyright &y& Elsevier]

Compelling new evidence supports the idea that regulatory T cells play a major role in our immune system. Several subsets of these regulators have been identified recently. Differences in the phenotypical and functional characteristics of these subsets have immunological implications. From our growing knowledge of the field of immunology, we could potentially generate a new class of therapeutic agents that target immune-related diseases. [Copyright &y& Elsevier]

Background: Little is known about the late effects of juvenile end-stage renal disease (ESRD) on bone integrity. To establish clinical manifestations of metabolic bone disease and bone mineral density (BMD) in young adult patients with juvenile ESRD, we performed a long-term outcome study. Methods: A cohort was formed of all Dutch patients with onset of ESRD between 1972 and 1992 at age 0 to 14 years, born before 1979. Data were collected by review of medical charts, current history, physical examination, and performing dual energy x-ray absorptiometry (DEXA) of the lumbar spine and the femoral neck. Results: Clinical information was retrieved in 247 out of 249 patients. Of all of these patients, 61.4% had severe growth retardation (<-2 SD), 36.8% had clinical symptoms of bone disease, and 17.8% were disabled by bone disease. Growth retardation and clinical bone disease were associated with a long duration of dialysis. DEXA was performed in 140 out of 187 living patients. Mean BMD +/- SD corrected for gender and age (Z score) of the lumbar spine was -2.12 +/- 1.4 and of the femoral neck was -1.77 +/- 1.4. A low lean body mass was associated with a low lumbar spine and a low femoral neck BMD; male gender, physical inactivity and aseptic bone necrosis were associated with a low lumbar spine BMD. Conclusion: Bone disease is a major clinical problem in young adults with pediatric ESRD. Further follow-up is needed to establish the impact of the low bone mineral densities found in these patients. [ABSTRACT FROM AUTHOR]

Oil-pollution monitoring at sea through beach bird surveying would undoubtedly benefit from a further standardisation of methods, enhancing the efficiency of data collection. In order to come up with useful recommendations, we evaluated various approaches of beached bird collection at the Belgian coast during seven winters (1993–1999). Data received in a passive way by one major rehabilitation centre were compared to the results of targeted beach surveys carried out at different scales by trained ornithologists: `weekly'' surveys – with a mean interval of 9 days – restricted to a fixed 16.7 km beach stretch, `monthly'' surveys over the entire coastline (62.1 km) and an annual `international'' survey in Belgium over the same distance at the end of February. Data collected through Belgian rehabilitation centres concern injured, living birds collected in a non-systematical way. Oil rates derived from these centres appear to be strongly biased to oiled auks and inshore bird species, and are hence of little use in assessing the extent of oil pollution at sea. The major asset of rehabilitation centres in terms of data collection seems to be their continuous warning function for events of mass mortality. Weekly surveys on a representative and large enough section rendered reliable data on oil rates, estimates of total number of bird victims, representation of various taxonomic groups and species-richness and were most sensitive in detecting events quickly (wrecks, oil-slicks, severe winter mortality, etc.). Monthly surveys gave comparable results, although they overlooked some important beaching events and demonstrated slightly higher oil rates, probably due to the higher chance to miss short-lasting wrecks of auks. Since the monthly surveys in Belgium were carried out by a network of volunteers and were spread over a larger beach section, they should be considered as best performing. Single `international beached bird surveys'' in February gave reliable data on total victim number (once the mean ratio between numbers in various months is known) and oil rate (provided a sufficiently large sample can be collected), but failed in tracking events. It is a particularly attractive approach because of its long tradition, resulting in invaluable long-term databases, and the uniformity in which these surveys are organised on a large scale. The minimal distance for a monthly survey amounts to 25–30 km (40–50% of Belgian coastline) up to 40 km (65%) in order to attain sound figures for oil rate and species-richness, respectively. These distances are primarily determined by the number of bird corpses that may be collected and are hence a function of beaching intensity and corpse detection rate. [Copyright &y& Elsevier]

In this issue of Cancer Cell , Dahan and colleagues demonstrate that the Fc region has a significant impact on the therapeutic capacity of checkpoint inhibitor antibodies targeting the PD-1/PD-L1 axis in pre-clinical tumor models. This work provides important insights with respect to the further clinical development of checkpoint inhibitors. [ABSTRACT FROM AUTHOR]

Infantile neuroaxonal dystrophy (INAD) and Duchenne muscular dystrophy (DMD) are two deadly neuromuscular degenerative diseases of childhood. Knowledge on their pathophysiological mechanisms may direct us towards treatment or a cure. Although these diseases are caused by two totally different gene-mutations and cause different clinical pictures, in this article I propose a common disease mechanism in the two. This common mechanism is induced by defects in the response to cellular stress and injury. THE HYPOTHESIS: Depletion of iPLA2β in INAD and increased activity of iPLA2β in DMD eventually lead to similar defects in the response to cell stress and injury. According to this hypothesis, the depletion of iPLA2β in INAD primarily blocks repair mechanisms by the inability to form a mitochondrial permeability transition pore (PTP). Forming of the PTP is necessary to release mitochondrial coenzyme A (CoA) into the cytoplasm for activation of palmitoylation and massive endocytosis as a repair response. In DMD the increased activity of iPLA2β causes exhaustion of the stress signalling cascade by increased and prolonged PTP opening. Continuous leaking of mitochondrial CoA through the PTP leads to the inability of the cell to build a sufficient mitochondrial:cytoplasmic CoA gradient, also causing insufficient release of mitochondrial CoA as a response to cell stress and injury. Decreased palmitoylation capacity and decreased endocytosis and membrane remodelling are implicated in proven pathophysiological mechanisms in INAD and DMD. The described mechanism in INAD and DMD, may be considered a common mechanism of repair in case of cell stress and injury. Beside their role in INAD and DMD, they may therefore be implicated in other neurodegenerative diseases as well. Available research shows involvement of iPLA2β in other neurodegenerative diseases. We might be able to divide neurodegenerative diseases in "INAD-like disease-mechanism" or "DMD-like disease-mechanism", depending on decreased or increased iPLA2β activity. [ABSTRACT FROM AUTHOR]

A lot of research has been done on Alzheimer's disease, especially focused on factors like amyloid beta, ApoE and tau-protein. However, a complete theory on the disease mechanism of AD, including and connecting all known pathological elements of AD in a conceivable context and order of occurrence, is still lacking. In this article I describe a hypothesis on the entire pathophysiology of Alzheimer's disease, based on the most wellknown pathological elements in AD, filling the gaps with hypothetical mechanisms. This proposed mechanism of derailed repair starts with an insufficiently increased level of injury signalling in the axon by ApoE, DLK, APP, BACE-1, Aβ and iPLA2β, followed by an excessive repair response induced by opening of the mitochondrial permeability transition pore, release of mitochondrial CoA and activation of palmitoylation and massive endocytosis. Excessive compounds, associated with injury signalling and repair, start to accumulate, adding to axonal injury. This increased activation of the repair mechanism causes exhaustion of the repair response by lack of mitochondrial CoA. A vicious circle of increased injury signalling and insufficient repair ensues. Based on this hypothesis, I propose possible markers for early diagnosis and disease-modifying treatments for Alzheimer's disease. [ABSTRACT FROM AUTHOR]

• Auxin receptors and transporters affected adventitious rooting (AR) in Arabidopsis. • AUX1 was essential for AR development, with LAX3 apparently acting in conjunction. • AR development required properly phosphorylated PINs by PID, WAG 1 and WAG2. • AFB2 , AUX1, LAX1, LAX3 , PIN1, PIN4 , and PIN7 may be targets for manipulation of AR. Adventitious roots (ARs) form from above-ground organs, and auxins are major regulators of AR development. TIR1/AFB F-box proteins act as well-established auxin receptors. Auxin transport involves the PINFORMED (PIN) auxin efflux carriers and AUXIN RESISTANT 1/LIKE AUX1 (AUX1/LAX1) influx carriers. To further elucidate the basis of AR development, we investigated the participation of these proteins and phosphorylation of PINs during adventitious rooting in hypocotyls of pre-etiolated flooded Arabidopsis thaliana seedlings. Mutant and GUS localization studies indicated that AFB2 is important in AR development. AUX1 loss-of-function reduced AR numbers, which could not be reversed by exogenous auxin. Single mutations in LAX1 , LAX2 and LAX3 had no negative impact on AR development and the first and last mutations even promoted it. Double and triple mutants of AUX1 , LAX1 , LAX2 and LAX3 significantly reduced rooting, which was reversed by exogenous auxin. AUX1 was essential in AR establishment, with LAX3 apparently acting in conjunction. Proper phosphorylation of PINs by PID, WAG1 and WAG2 and auxin transport direction were equally essential for AR establishment. PIN1, AUX1 and AFB2 (overexpression) and LAX1 , LAX3 , PIN4 and PIN7 (downregulation) emerged as potential targets for genetic manipulation aiming at improving AR development. [ABSTRACT FROM AUTHOR]

Background & Aims: Hepatic de-differentiation, liver development, and malignant transformation are processes in which the levels of hepatic S-adenosylmethionine are tightly regulated by 2 genes: methionine adenosyltransferase 1A (MAT1A) and methionine adenosyltransferase 2A (MAT2A). MAT1A is expressed in the adult liver, whereas MAT2A expression primarily is extrahepatic and is associated strongly with liver proliferation. The mechanisms that regulate these expression patterns are not completely understood. Methods: In silico analysis of the 3′ untranslated region of MAT1A and MAT2A revealed putative binding sites for the RNA-binding proteins AU-rich RNA binding factor 1 (AUF1) and HuR, respectively. We investigated the posttranscriptional regulation of MAT1A and MAT2A by AUF1, HuR, and methyl-HuR in the aforementioned biological processes. Results: During hepatic de-differentiation, the switch between MAT1A and MAT2A coincided with an increase in HuR and AUF1 expression. S-adenosylmethionine treatment altered this homeostasis by shifting the balance of AUF1 and methyl-HuR/HuR, which was identified as an inhibitor of MAT2A messenger RNA (mRNA) stability. We also observed a similar temporal distribution and a functional link between HuR, methyl-HuR, AUF1, and MAT1A and MAT2A during fetal liver development. Immunofluorescent analysis revealed increased levels of HuR and AUF1, and a decrease in methyl-HuR levels in human livers with hepatocellular carcinoma (HCC). Conclusions: Our data strongly support a role for AUF1 and HuR/methyl-HuR in liver de-differentiation, development, and human HCC progression through the posttranslational regulation of MAT1A and MAT2A mRNAs. [Copyright &y& Elsevier]