Real-time monitoring of cell surface protein arrival with split luciferases.

Each cell in a multicellular organism permanently adjusts the concentration of its cell surface proteins. In particular, epithelial cells tightly control the number of carriers, transporters and cell adhesion proteins at their plasma membrane. However, sensitively measuring the cell surface concentration of a particular protein of interest in live cells and in real time represents a considerable challenge. Here, we introduce a novel approach based on split luciferases, which uses one luciferase fragment as a tag on the protein of interest and the second fragment as a supplement to the extracellular medium. Once the protein of interest arrives at the cell surface, the luciferase fragments complement and generate luminescence. We compared the performance of split Gaussia luciferase and split Nanoluciferase by using a system to synchronize biosynthetic trafficking with conditional aggregation domains. The best results were achieved with split Nanoluciferase, for which luminescence increased more than 6000-fold upon recombination. Furthermore, we showed that our approach can separately detect and quantify the arrival of membrane proteins at the apical and basolateral plasma membrane in single polarized epithelial cells by detecting the luminescence signals with a microscope, thus opening novel avenues for characterizing the variations in trafficking in individual epithelial cells.

Engineering Material Properties of Transcription Factor Condensates to Control Gene Expression in Mammalian Cells and Mice.

Phase separation of biomolecules into condensates is a key mechanism in the spatiotemporal organization of biochemical processes in cells. However, the impact of the material properties of biomolecular condensates on important processes, such as the control of gene expression, remains largely elusive. Here, the material properties of optogenetically induced transcription factor condensates are systematically tuned, and probed for their impact on the activation of target promoters. It is demonstrated that transcription factors in rather liquid condensates correlate with increased gene expression levels, whereas stiffer transcription factor condensates correlate with the opposite effect, reduced activation of gene expression. The broad nature of these findings is demonstrated in mammalian cells and mice, as well as by using different synthetic and natural transcription factors. These effects are observed for both transgenic and cell-endogenous promoters. The findings provide a novel materials-based layer in the control of gene expression, which opens novel opportunities in optogenetic engineering and synthetic biology.

Maternal Sleep Health, Social Support, and Distress: A Mixed-Methods Analysis of Mothers of Infants and Young Children in Rural US.

OBJECTIVES: The purpose of this study was to explore sleep health in rural maternal populations through a social-ecological framework and identify risk and protective factors for this population. METHODS: 39 individuals who are mothers of infants or children under the age of 5 years completed an online survey, 35 of which completed a subsequent semi-structured interview. Recruitment was limited to one rural community and was in partnership with community healthcare providers. Results were integrated using a convergent, parallel mixed-methods design. RESULTS: Poor sleep health and high prevalence of insomnia symptoms in rural mothers were evident and associated with social support and maternal distress. Qualitative content from interviews indicated that well-established precipitating and perpetuating factors for insomnia may contribute to poor maternal sleep health. Results also revealed a gap in knowledge and language surrounding sleep health among rural mothers. CONCLUSIONS: Sleep health is challenged during the transition to motherhood and rural mothers have less access to specialized perinatal and behavioral health care than their urban counterparts. In this sample, poor sleep was attributable to distress in addition to nocturnal infant and child sleep patterns which has implications for psychoeducation and promotion of sleep health in mothers. Sleep is a modifiable health indicator that is associated with several other maternal health outcomes and should be considered an element of a comprehensive maternal health for prevention and intervention across individual, interpersonal, and societal domains of the social-ecological model of sleep health.

Bone marrow disease in rhabdomyosarcoma visualized by 2-[18F]fluorodeoxyglucose positron emission tomography/computed tomography.

Bone marrow metastases-noted in 6% of patients with rhabdomyosarcoma-have been linked to very poor outcomes. Bilateral bone marrow sampling from iliac crests has been the gold standard for bone marrow examination in rhabdomyosarcoma, but sampling errors due to patchy bone marrow involvement may limit its sensitivity. Here, we report the case of a 6-year-old boy with embryonal rhabdomyosarcoma of the skull base and multiple 2-[18F]fluoro-2-deoxy-D-glucose (2-[18F]FDG)-avid bone marrow metastases visualized by positron emission tomography and computed tomography (2-[18F]FDG PET/CT). His bone marrow aspirates were tumor-free. This case illustrates the diagnostic value of 2-[18F]FDG PET/CT in the detection of bone marrow metastases in rhabdomyosarcoma patients, which may re-shape the definition of bone marrow disease and, ultimately, alter disease staging and risk stratification.

Impaired systemic nucleocapsid antigen clearance in severe COVID-19.

The circulating nucleocapsid (NCP) antigen of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is detectable in coronavirus disease-2019 (COVID-19) patients. To better understand the biology of disease severity, we investigated NCP clearance kinetics in hospitalized COVID-19 patients. Serum NCP was quantified using a commercial NCP-specific enzyme-linked immunoassay in hospitalized COVID-19 patients (n = 63) during their hospital stay. Results were correlated to COVID-19 disease severity, inflammation parameters, antibody response, and results of SARS-CoV-2 PCR from nasopharyngeal swabs. We demonstrate that NCP antigen levels in serum remained elevated in 21/45 (46.7%) samples from patients in intensive care units (ICU) after >8 days postdiagnosis. The proportion of ICU patients with detectable antigenemia declined only gradually from 84.6% to 25.0% over several weeks. This was in contrast to complete NCP clearance in all non-ICU patients after 8 days, and also in contrast to mucosal clearance of the virus as measured by PCR. Antigen clearance was associated with higher IgG against S1 but not NCP. Clearance of NCP antigenemia is delayed in >40% of severely ill COVID-19 patients. Thus, NCP antigenemia detected after 8 days post COVID-19 diagnosis is a characteristic of patients requiring intensive care. Prospective trials should further investigate NCP antigen clearance kinetics as a mechanistic biomarker.

Socio-Ecological Context of Sleep: Gender Differences and Couples' Relationships as Exemplars.

PURPOSE OF REVIEW: We summarized recent findings on insufficient sleep and insomnia, two prominent sleep issues that impact public health. We demonstrate the socio-ecologial impact of sleep health with findings on gender and couples' relationships as exemplars. RECENT FINDINGS: Robust gender differences in sleep duration and insomnia are due to biological and socio-ecological factors. Gender differences in insufficient sleep vary by country of origin and age whereas gender differences in insomnia reflect minoritized identities (e.g., sexual, gender). Co-sleeping with a partner is associated with longer sleep and more awakenings. Gender differences and couples' sleep were affected by intersecting social and societal influences, which supports a socio-ecological approach to sleep. Recent and seminal contributions to sleep health highlight the importance of observing individual sleep outcomes in a socio-ecological context. Novel methodology, such as global measures of sleep health, can inform efforts to improve sleep and, ultimately, public health.

Chlorophyll-carotenoid excitation energy transfer and charge transfer in Nannochloropsis oceanica for the regulation of photosynthesis.

Nonphotochemical quenching (NPQ) is a proxy for photoprotective thermal dissipation processes that regulate photosynthetic light harvesting. The identification of NPQ mechanisms and their molecular or physiological triggering factors under in vivo conditions is a matter of controversy. Here, to investigate chlorophyll (Chl)-zeaxanthin (Zea) excitation energy transfer (EET) and charge transfer (CT) as possible NPQ mechanisms, we performed transient absorption (TA) spectroscopy on live cells of the microalga Nannochloropsis oceanica We obtained evidence for the operation of both EET and CT quenching by observing spectral features associated with the Zea S1 and Zea●+ excited-state absorption (ESA) signals, respectively, after Chl excitation. Knockout mutants for genes encoding either violaxanthin de-epoxidase or LHCX1 proteins exhibited strongly inhibited NPQ capabilities and lacked detectable Zea S1 and Zea●+ ESA signals in vivo, which strongly suggests that the accumulation of Zea and active LHCX1 is essential for both EET and CT quenching in N. oceanica.

Social-ecological considerations for the sleep health of rural mothers.

Using a social-ecological framework, we identify social determinants that interact to influence sleep health, identify gaps in the literature, and make recommendations for targeting sleep health in rural mothers. Rural mothers experience unique challenges and protective factors in maintaining adequate sleep health during the postpartum and early maternal years. Geographic isolation, barriers to comprehensive behavioral medicine services, and intra-rural ethno-racial disparities are discussed at the societal (e.g., public policy), social (e.g., community) and individual levels (e.g., stress) of the social-ecological model. Research on sleep health would benefit from attention to methodological considerations of factors affecting rural mothers such as including parity in population-level analyses or applying community-based participatory research principles. Future sleep health programs would benefit from using existing social support networks to disseminate sleep health information, integrating behavioral health services into clinical care frameworks, and tailoring culturally-appropriate Telehealth/mHealth programs to enhance the sleep health of rural mothers.

Supplementation with nitrate only modestly affects lipid and glucose metabolism in genetic and dietary-induced murine models of obesity.

To gain a better understanding of how nitrate may affect carbohydrate and lipid metabolism, female wild-type mice were fed a high-fat, high-fructose diet supplemented with either 0, 400, or 800 mg nitrate/kg diet for 28 days. Additionally, obese female db/db mice were fed a 5% fat diet supplemented with the same levels and source of nitrate. Nitrate decreased the sodium-dependent uptake of glucose by ileal mucosa in wild-type mice. Moreover, nitrate significantly decreased triglyceride content and mRNA expression levels of Pparγ in liver and Glut4 in skeletal muscle. Oral glucose tolerance as well as plasma cholesterol, triglyceride, insulin, leptin, glucose and the activity of ALT did not significantly differ between experimental groups but was higher in db/db mice than in wild-type mice. Nitrate changed liver fatty acid composition and mRNA levels of Fads only slightly. Further hepatic genes encoding proteins involved in lipid and carbohydrate metabolism were not significantly different between the three groups. Biomarkers of inflammation and autophagy in the liver were not affected by the different dietary treatments. Overall, the present data suggest that short-term dietary supplementation with inorganic nitrate has only modest effects on carbohydrate and lipid metabolism in genetic and dietary-induced mouse models of obesity.

Snapshot transient absorption spectroscopy: toward in vivo investigations of nonphotochemical quenching mechanisms.

Although the importance of nonphotochemical quenching (NPQ) on photosynthetic biomass production and crop yields is well established, the in vivo operation of the individual mechanisms contributing to overall NPQ is still a matter of controversy. In order to investigate the timescale and activation dynamics of specific quenching mechanisms, we have developed a technique called snapshot transient absorption (TA) spectroscopy, which can monitor molecular species involved in the quenching response with a time resolution of 30 s. Using intact thylakoid membrane samples, we show how conventional TA kinetic and spectral analyses enable the determination of the appropriate wavelength and time delay for snapshot TA experiments. As an example, we show how the chlorophyll-carotenoid charge transfer and excitation energy transfer mechanisms can be monitored based on signals corresponding to the carotenoid (Car) radical cation and Car S1 excited state absorption, respectively. The use of snapshot TA spectroscopy together with the previously reported fluorescence lifetime snapshot technique (Sylak-Glassman et al. in Photosynth Res 127:69-76, 2016) provides valuable information such as the concurrent appearance of specific quenching species and overall quenching of excited Chl. Furthermore, we show that the snapshot TA technique can be successfully applied to completely intact photosynthetic organisms such as live cells of Nannochloropsis. This demonstrates that the snapshot TA technique is a valuable method for tracking the dynamics of intact samples that evolve over time, such as the photosynthetic system in response to high-light exposure.

Adherence to a Mediterranean-like Diet as a Protective Factor Against COPD: A Nested Case-Control Study.

A diet rich in nutrients has been suggested to have protective effects against the development of chronic obstructive pulmonary disease (COPD). Since the traditional Mediterranean diet is high in nutrients, including antioxidants, vitamins, and minerals, it is of interest to study as a protective factor against COPD. Our aim was therefore to study its associations with development of COPD using population-based prospective data from the Västerbotten Intervention Programme (VIP) cohort. Data on diet from 370 individuals, who later visited the Department of Medicine at the University Hospital, Umeå, Sweden, with a diagnosis of COPD, were compared to 1432 controls. Adherence to a Mediterranean diet was assessed by a modified version of the Mediterranean diet score (MDS). Cases were diagnosed with COPD 11.1 years (mean) (standard deviation [SD] 4.5 years) after first stating their dietary habits in the VIP at a mean age of 55.5 years (SD 6.6 years). Higher MDS was associated with a higher level of education and not living alone. After adjustment for co-habiting and education level, individuals with an intermediate MDS and those with the highest MDS had a lower odds of developing COPD (odds ratio [OR] 0.73, 95% confidence interval [CI] 0.56-0.95; OR 0.56, 95% CI 0.37-0.86, respectively). These results remained also after adjustment for smoking intensity, i.e., numbers of cigarettes smoked per day (OR 0.73, 95% CI 0.53-0.99; OR 0.59, 95% CI 0.35-0.97), respectively). To conclude, adherence to a Mediterranean-like diet seems to be inversely associated with the development of COPD.

Chlorophyll-Carotenoid Excitation Energy Transfer in High-Light-Exposed Thylakoid Membranes Investigated by Snapshot Transient Absorption Spectroscopy.

Nonphotochemical quenching (NPQ) provides an essential photoprotection in plants, assuring safe dissipation of excess energy as heat under high light. Although excitation energy transfer (EET) between chlorophyll (Chl) and carotenoid (Car) molecules plays an important role in NPQ, detailed information on the EET quenching mechanism under in vivo conditions, including the triggering mechanism and activation dynamics, is very limited. Here, we observed EET between the Chl Q y state and the Car S1 state in high-light-exposed spinach thylakoid membranes. The kinetic and spectral analyses using transient absorption (TA) spectroscopy revealed that the Car S1 excited state absorption (ESA) signal after Chl excitation has a maximum absorption peak around 540 nm and a lifetime of ∼8 ps. Snapshot TA spectroscopy at multiple time delays allowed us to track the Car S1 ESA signal as the thylakoid membranes were exposed to various light conditions. The obtained snapshots indicate that maximum Car S1 ESA signal quickly rose and slightly dropped during the initial high-light exposure (<3 min) and then gradually increased with a time constant of ∼5 min after prolonged light exposure. This suggests the involvement of both rapidly activated and slowly activated mechanisms for EET quenching. 1,4-Dithiothreitol (DTT) and 3,3'-dithiobis(sulfosuccinimidyl propionate) (DTSSP) chemical treatments further support that the Car S1 ESA signal (or the EET quenching mechanism) is primarily dependent on the accumulation of zeaxanthin and partially dependent on the reorganization of membrane proteins, perhaps due to the pH-sensing protein photosystem II subunit S.

Distinct roles of the photosystem II protein PsbS and zeaxanthin in the regulation of light harvesting in plants revealed by fluorescence lifetime snapshots.

The photosystem II (PSII) protein PsbS and the enzyme violaxanthin deepoxidase (VDE) are known to influence the dynamics of energy-dependent quenching (qE), the component of nonphotochemical quenching (NPQ) that allows plants to respond to fast fluctuations in light intensity. Although the absence of PsbS and VDE has been shown to change the amount of quenching, there have not been any measurements that can detect whether the presence of these proteins alters the type of quenching that occurs. The chlorophyll fluorescence lifetime probes the excited-state chlorophyll relaxation dynamics and can be used to determine the amount of quenching as well as whether two different genotypes with the same amount of NPQ have similar dynamics of excited-state chlorophyll relaxation. We measured the fluorescence lifetimes on whole leaves of Arabidopsis thaliana throughout the induction and relaxation of NPQ for wild type and the qE mutants, npq4, which lacks PsbS; npq1, which lacks VDE and cannot convert violaxanthin to zeaxanthin; and npq1 npq4, which lacks both VDE and PsbS. These measurements show that although PsbS changes the amount of quenching and the rate at which quenching turns on, it does not affect the relaxation dynamics of excited chlorophyll during quenching. In addition, the data suggest that PsbS responds not only to ΔpH but also to the Δψ across the thylakoid membrane. In contrast, the presence of VDE, which is necessary for the accumulation of zeaxanthin, affects the excited-state chlorophyll relaxation dynamics.

Anti-Inflammatory Properties of Brazilian Green Propolis Encapsulated in a γ-Cyclodextrin Complex in Mice Fed a Western-Type Diet.

Ageing is often accompanied by chronic inflammation. A fat- and sugar-rich Western-type diet (WTD) may accelerate the ageing phenotype. Cell culture studies have indicated that artepillin C-containing Brazilian green propolis exhibits anti-inflammatory properties. However, little is known regarding its anti-inflammatory potential in mouse liver in vivo. In this study, female C57BL/6NRj wild-type mice were fed a WTD, a WTD supplemented with Brazilian green propolis supercritical extract (GPSE) encapsulated in γ-cyclodextrin (γCD) or a WTD plus γCD for 10 weeks. GPSE-γCD did not affect the food intake, body weight or body composition of the mice. However, mRNA levels of the tumour necrosis factor α were significantly downregulated (p < 0.05) in these mice compared to those in the WTD-fed controls. Furthermore, the gene expression levels of other pro-inflammatory markers, including serum amyloid P, were significantly (p < 0.001) decreased following GPSE-γCD treatment. GPSE-γCD significantly induced hepatic ferritin gene expression (p < 0.01), which may contribute to its anti-inflammatory properties. Conversely, GPSE-γCD did not affect the biomarkers of endogenous antioxidant defence, including catalase, glutathione peroxidase-4, paraoxonase-1, glutamate cysteine ligase and nuclear factor erythroid 2-related factor-2 (Nrf2). Overall, the present data suggest that dietary GPSE-γCD exhibits anti-inflammatory, but not antioxidant activity in mouse liver in vivo. Thus, GPSE-γCD has the potential to serve as a natural hepatoprotective bioactive compound for dietary-mediated strategies against chronic inflammation.

Regulatory T-cell impairment in cystic fibrosis patients with chronic pseudomonas infection.

RATIONALE: Patients with cystic fibrosis (CF) lung disease have chronic airway inflammation driven by disrupted balance of T-cell (Th17 and Th2) responses. Regulatory T cells (Tregs) dampen T-cell activation, but their role in CF is incompletely understood. OBJECTIVES: To characterize numbers, function, and clinical impact of Tregs in CF lung disease. METHODS: Tregs were quantified in peripheral blood and airway samples from patients with CF and from lung disease control patients without CF and healthy control subjects. The role of Pseudomonas aeruginosa and CF transmembrane conductance regulator (CFTR) in Treg regulation was analyzed by using in vitro and murine in vivo models. MEASUREMENTS AND MAIN RESULTS: Tregs were decreased in peripheral blood and airways of patients with CF compared with healthy controls or lung disease patients without CF and correlated positively with lung function parameters. Patients with CF with chronic P. aeruginosa infection had lower Tregs compared with patients with CF without P. aeruginosa infection. Genetic knockout, pharmacological inhibition, and P. aeruginosa infection studies showed that both P. aeruginosa and CFTR contributed to Treg dysregulation in CF. Functionally, Tregs from patients with CF or from Cftr(-/-) mice were impaired in suppressing conventional T cells, an effect that was enhanced by P. aeruginosa infection. The loss of Tregs in CF affected memory, but not naive Tregs, and manifested gradually with disease progression. CONCLUSIONS: Patients with CF who have chronic P. aeruginosa infection show an age-dependent, quantitative, and qualitative impairment of Tregs. Modulation of Tregs represents a novel strategy to rebalance T-cell responses, dampen inflammation, and ultimately improve outcomes for patients with infective CF lung disease.

Coenzyme Q10 serum concentration and redox status in European adults: influence of age, sex, and lipoprotein concentration.

Coenzyme Q10 (CoQ10) is synthesized in almost all human tissues and presumably involved in age-related alterations and diseases. Here, we examined the impact of aging and sex on the serum CoQ10 status in 860 European adults ranging in age from 18 to 82 years. We identified an inverse U-shaped relationship between CoQ10 concentration and age. Women showed lower cholesterol-adjusted CoQ10 levels than men, irrespective of age. As observed in both sexes, the decrease in CoQ10 concentration in older subjects was accompanied by a shift in the redox status in favour of the oxidized form. A strong positive correlation was found for total CoQ10 and cholesterol concentrations (Spearman's, p≤1E-74). We found strong negative correlations between total (Spearman's, p≤1E-07) and between cholesterol-adjusted CoQ10 concentration (Spearman's, p≤1E-14) and the proportion of the oxidized form of CoQ10. These correlations were not dependent on age and sex and were attenuated by supplementation with 150 mg/day reduced CoQ10 for 14 days. Overall, our results are useful to define risk groups with critical CoQ10 status in humans. In particular, older subjects were characterized by impaired CoQ10 status due to their lowered serum CoQ10 concentration and concomitant decrease of CoQ10 redox capacity.

Modular analysis of hipposin, a histone-derived antimicrobial peptide consisting of membrane translocating and membrane permeabilizing fragments.

Antimicrobial peptides continue to garner attention as potential alternatives to conventional antibiotics. Hipposin is a histone-derived antimicrobial peptide (HDAP) previously isolated from Atlantic halibut. Though potent against bacteria, its antibacterial mechanism had not been characterized. The mechanism of this peptide is particularly interesting to consider since the full hipposin sequence contains the sequences of parasin and buforin II (BF2), two other known antimicrobial peptides that act via different antibacterial mechanisms. While parasin kills bacteria by inducing membrane permeabilization, buforin II enters cells without causing significant membrane disruption, harming bacteria through interactions with intracellular nucleic acids. In this study, we used a modular approach to characterize hipposin and determine the role of the parasin and buforin II fragments in the overall hipposin mechanism. Our results show that hipposin kills bacteria by inducing membrane permeabilization, and this membrane permeabilization is promoted by the presence of the N-terminal domain. Portions of hipposin lacking the N-terminal sequence do not cause membrane permeabilization and function more similarly to buforin II. We also determined that the C-terminal portion of hipposin, HipC, is a cell-penetrating peptide that readily enters bacterial cells but has no measurable antimicrobial activity. HipC is the first membrane active histone fragment identified that does not kill bacterial or eukaryotic cells. Together, these results characterize hipposin and provide a useful starting point for considering the activity of chimeric peptides made by combining peptides with different antimicrobial mechanisms. This article is part of a Special Issue entitled: Interfacially Active Peptides and Proteins. Guest Editors: William C. Wimley and Kalina Hristova.

Coenzyme Q regulates the expression of essential genes of the pathogen- and xenobiotic-associated defense pathway in C. elegans.

Coenzyme Q (CoQ) is necessary for mitochondrial energy production and modulates the expression of genes that are important for inflammatory processes, growth and detoxification reactions. A cellular surveillance-activated detoxification and defenses (cSADDs) pathway has been recently identified in C. elegans. The down-regulation of the components of the cSADDs pathway initiates an aversion behavior of the nematode. Here we hypothesized that CoQ regulates genes of the cSADDs pathway. To verify this we generated CoQ-deficient worms ("CoQ-free") and performed whole-genome expression profiling. We found about 30% (120 genes) of the cSADDs pathway genes were differentially regulated under CoQ-deficient condition. Remarkably, 83% of these genes were down-regulated. The majority of the CoQ-sensitive cSADDs pathway genes encode for proteins involved in larval development (enrichment score (ES) = 38.0, p = 5.0E(-37)), aminoacyl-tRNA biosynthesis, proteasome function (ES 8.2, p = 5.9E(-31)) and mitochondria function (ES 3.4, p = 1.7E(-5)). 67% (80 genes) of these genes are categorized as lethal. Thus it is shown for the first time that CoQ regulates a substantial number of essential genes that function in the evolutionary conserved cellular surveillance-activated detoxification and defenses pathway in C. elegans.

Promotion of growth by Coenzyme Q10 is linked to gene expression in C. elegans.

Coenzyme Q (CoQ, ubiquinone) is an essential component of the respiratory chain, a cofactor of pyrimidine biosynthesis and acts as an antioxidant in extra mitochondrial membranes. More recently CoQ has been identified as a modulator of apoptosis, inflammation and gene expression. CoQ deficient Caenorhabditis elegans clk-1 mutants show several phenotypes including a delayed postembryonic growth. Using wild type and two clk-1 mutants, here we established an experimental set-up to study the consequences of endogenous CoQ deficiency or exogenous CoQ supply on gene expression and growth. We found that a deficiency of endogenous CoQ synthesis down-regulates a cluster of genes that are important for growth (i.e., RNA polymerase II, eukaryotic initiation factor) and up-regulates oxidation reactions (i.e., cytochrome P450, superoxide dismutase) and protein interactions (i.e., F-Box proteins). Exogenous CoQ supply partially restores the expression of these genes as well as the growth retardation of CoQ deficient clk-1 mutants. On the other hand exogenous CoQ supply does not alter the expression of a further sub-set of genes. These genes are involved in metabolism (i.e., succinate dehydrogenase complex), cell signalling or synthesis of lectins. Thus, our work provides a comprehensive overview of genes which can be modulated in their expression by endogenous or exogenous CoQ. As growth retardation in CoQ deficiency is linked to the gene expression profile we suggest that CoQ promotes growth via gene expression.

Comparison of horse and rabbit antithymocyte globulin in immunosuppressive therapy for refractory cytopenia of childhood.

Refractory cytopenia of childhood is the most common subtype of myelodysplastic syndrome in children. In this study, we compared the outcome of immunosuppressive therapy using horse antithymocyte globulin (n=46) with that using rabbit antithymocyte globulin (n=49) in 95 patients with refractory cytopenia of childhood and hypocellular bone marrow. The response rate at 6 months was 74% for horse antithymocyte globulin and 53% for rabbit antithymocyte globulin (P=0.04). The inferior response in the rabbit antithymocyte globulin group resulted in lower 4-year transplantation-free (69% versus 46%; P=0.003) and failure-free (58% versus 48%; P=0.04) survival rates in this group compared with those in the horse antithymocyte globulin group. However, because of successful second-line hematopoietic stem cell transplantation, overall survival was comparable between groups (91% versus 85%; P=ns). The cumulative incidence of relapse (15% versus 9%; P=ns) and clonal evolution (12% versus 4%; P=ns) at 4 years was comparable between groups. Our results suggest that the outcome of immunosuppressive therapy with rabbit antithymocyte globulin is inferior to that of horse antithymocyte globulin. Although immunosuppressive therapy is an effective therapy in selected patients with refractory cytopenia of childhood, the long-term risk of relapse or clonal evolution remains. (ClinicalTrial.gov identifiers: NCT00662090).