The zebrafish mutants dre, uki, and lep encode negative regulators of the hedgehog signaling pathway.

Proliferation is one of the basic processes that control embryogenesis. To identify factors involved in the regulation of proliferation, we performed a zebrafish genetic screen in which we used proliferating cell nuclear antigen (PCNA) expression as a readout. Two mutants, hu418B and hu540A, show increased PCNA expression. Morphologically both mutants resembled the dre (dreumes), uki (ukkie), and lep (leprechaun) mutant class and both are shown to be additional uki alleles. Surprisingly, although an increased size is detected of multiple structures in these mutant embryos, adults become dwarfs. We show that these mutations disrupt repressors of the Hedgehog (Hh) signaling pathway. The dre, uki, and lep loci encode Su(fu) (suppressor of fused), Hip (Hedgehog interacting protein), and Ptc2 (Patched2) proteins, respectively. This class of mutants is therefore unique compared to previously described Hh mutants from zebrafish genetic screens, which mainly show loss of Hh signaling. Furthermore, su(fu) and ptc2 mutants have not been described in vertebrate model systems before. Inhibiting Hh activity by cyclopamine rescues uki and lep mutants and confirms the overactivation of the Hh signaling pathway in these mutants. Triple uki/dre/lep mutants show neither an additive increase in PCNA expression nor enhanced embryonic phenotypes, suggesting that other negative regulators, possibly Ptc1, prevent further activation of the Hh signaling pathway. The effects of increased Hh signaling resulting from the genetic alterations in the uki, dre, and lep mutants differ from phenotypes described as a result of Hh overexpression and therefore provide additional insight into the role of Hh signaling during vertebrate development

Genetic analysis of the two zebrafish patched homologues identifies novel roles for the hedgehog signaling pathway

Aberrant activation of the Hedgehog (Hh) signaling pathway in different organisms has shown the importance of this family of morphogens during development. Genetic screens in zebrafish have assigned specific roles for Hh in proliferation, differentiation and patterning, but mainly as a result of a loss of its activity. We attempted to fully activate the Hh pathway by removing both receptors for the Hh proteins, called Patched1 and 2, which are functioning as negative regulators in this pathwa

No evidence for the effectiveness of a multidisciplinary group based treatment program in patients with osteoarthritis of hands on the short term; results of a randomized controlled trial

SummaryObjectiveTo examine the efficacy of a multidisciplinary non-pharmacological intervention in patients with hand osteoarthritis (OA).MethodParallel group randomized controlled trial was performed in three participating rheumatology outpatient clinics in the Netherlands. Block randomization was performed using a computer generated permuted block scheme (blocks of four). An independent person randomly assigned 151 participants with clinical hand OA to four sessions of multidisciplinary non-pharmacological treatment, or 30 min education followed by 3 months waiting time. Participants and therapists were not blinded to the assigned intervention. The research assistant who assessed all outcomes was blinded to the assigned intervention. Subscale limitations in activities of the Australian Canadian Osteoarthritis Hand Index (AUSCAN) and OARSI responder criteria (primary outcomes) and secondary outcome measures, were assessed at baseline and 12 weeks. Linear or logistic regression analyses were used, where appropriate, with the outcome as dependent and the intervention group as independent variable. The analyses were adjusted for baseline values.ResultsAt 3 months no significant and no relevant differences were observed between the experimental (n = 76) and control group (n = 75) in any of the primary or secondary outcome measures. In both groups about one-third of patients were classified as responder.ConclusionThere is insufficient evidence to confirm a clinically relevant treatment effect on the short term, between patients who followed a multidisciplinary treatment program and those who received only written information. Since hand OA causes a range of impairments and limitations in activities, programs with more guidance to formulate and implement individually tailored treatment plans could be probably more effective. Furthermore, more research is needed on the efficacy of single treatment elements.(Dutch Trial Register trial number NTR1191)

Bringing obesity to light: Rev-erbα, a central player in light-induced adipogenesis in the zebrafish?

Background:Recent studies have led to an expansion of potential factors capable of stimulating obesity. Increasing evidence indicates that environmental factors, including disturbance of circadian rhythms, also contribute to its etiology.Objectives:To determine the effects of altered circadian rhythms on adipogenesis and to better understand how circadian and adipogenic regulatory pathways are linked, zebrafish larvae were exposed to various light/dark cycles or hypercaloric feeding (HCF).Methods:Clock and adipogenic gene expression was quantitative real time PCR. Adipogenesis was characterized using coherent anti-Stokes Raman scattering microscopy (CARS) and whole-mount lipid composition was analyzed by gas chromatography. The clock protein Rev-erbα and the adipogenesis-regulating protein Pparγ were localized by immunohistochemistry.Results:Zebrafish larvae exposed to continuous light (LL) had a sevenfold higher prevalence of adipocytes compared with control fish under a 14 h light and 10 h dark cycle. It was also significantly higher compared with that in HCF larvae with control light/dark cycle, which showed a 5.5-fold increase compared with control animals. Although total fatty acid content was unaffected, adipocyte lipid composition was altered in LL zebrafish. In contrast, shifting the onset and duration of the light periods did not affect adipogenesis or total fatty acid content. Gene expression analysis revealed effects of LL and HCF on circadian cyclicity, with increased expression of the clock gene period2 and altered circadian rev-erbα expression in LL larvae. Immunostaining revealed for the first time that Rev-erbα and Pparγ colocalize in adipocytes, which together with the gene expression analysis suggests interplay between Rev-erbα and Ppar isoforms.Conclusions:The amount of light, but not shifted light/dark cycles, affected adipogenesis and lipid composition, possibly due to increased period2 expression, which, in turn, enhances Rev-erbα-regulated gene expression. As the pparβδ promoter includes three Rev-erbα binding sites, we hypothesize that pparβδ may be a direct target that ultimately activates Pparγ

Hen1 is required for oocyte development and piRNA stability in zebrafish

Piwi-interacting RNAs (piRNAs) are germ line-specific small RNA molecules that have a function in genome defence and germ cell development. They associate with a specific class of Argonaute proteins, named Piwi, and function through an RNA interference-like mechanism. piRNAs carry a 2'-O-methyl modification at their 3' end, which is added by the Hen1 enzyme. We show that zebrafish hen1 is specifically expressed in germ cells and is essential for maintaining a female germ line, whereas it is dispensable in the testis. Hen1 protein localizes to nuage through its C-terminal domain, but is not required for nuage formation. In hen1 mutant testes, piRNAs become uridylated and adenylated. Uridylation frequency is highest on retro-transposon-derived piRNAs and is accompanied by decreased piRNA levels and mild derepression of transposon transcripts. Altogether, our data suggest the existence of a uridylation-mediated 3'-5' exonuclease activity acting on piRNAs in zebrafish germ cells, which is counteracted by nuage-bound Hen1 protein. This system discriminates between piRNA targets and is required for ovary development and fully efficient transposon silencing

The effect of tumour necrosis factor inhibitors on radiographic progression in axial spondyloarthritis : A systematic literature review

The effect of TNF-α inhibitors (TNFi), with or without concomitant NSAIDs, on radiographic progression in axial SpA remains unclear. Therefore, we performed a systematic literature review up to January 2019 to determine whether longer use of standard dose TNFi is superior vs lower duration or lower dose TNFi therapy, conventional synthetic DMARDs alone, or no therapy in inhibiting radiographic progression in patients with axial SpA. Our search yielded 373 titles of which 14 full text articles and five abstracts were eligible for quantitative analysis. Studies had an overall moderate to critical risk of bias. Data could not be pooled due to clinical and methodological heterogeneity. Individual studies showed conflicting results with mainly no significant difference in radiographic progression when comparing effect of TNFi therapy to no TNFi therapy or when comparing to less TNFi therapy until 2 years of follow-up. Results that are more significant are shown after 2 years' follow-up, mainly in subgroups with baseline syndesmophytes. Data on the additional or synergistic effect of concomitant NSAID use were inconclusive

EFFECTIVENESS OF RADIATION THERAPY IN OSTEOARTHRITIS OF THE HAND AND KNEE: DESIGN OF TWO PARALLEL, TRIPLE BLINDED, RANDOMISED CONTROLLED TRIALS

Pathophysiology and treatment of rheumatic disease

Alpe d'HuZes Cancer Rehabilitation (A-CaRe) research: Four randomized controlled exercise trials and economic evaluations in cancer patients and survivors

Background: Previous studies showed that exercise in cancer patients is feasible and may reduce fatigue and improve physical fitness and quality of life. However, many previous studies had methodological weaknesses related to trial design, sample size, comparison group, outcome measures, short follow-up durations and programme content. Purpose: This paper aims to present the rationale and design of the clinical research subprogramme of the Alpe d’HuZes Cancer Rehabilitation (A-CaRe) programme. Method: A-CaRe Clinical Research includes four randomized controlled trials in patients: (a) after chemotherapy, (b) during chemotherapy, (c) after stem cell transplantation and (d) during childhood cancer. These trials compare high-intensity resistance and endurance exercise interventions with usual care or a waiting list control group. In two studies, a second intervention arm consisting of low-to-moderate intensity exercise is included. All four A-CaRe trials use similar methods. Results: Outcome measures are carefully chosen based on the International Classification of Functioning Disability and Health model. Measurements will be performed prior to randomization (T0), after completion of the intervention (T1) and at follow-up (T2). The primary outcome measures are cardiorespiratory fitness, muscle strength and fatigue. Secondary outcome measures include health-related quality of life and psychosocial functioning. Furthermore, cost-effectiveness and cost-utility analyses are performed from a societal perspective. Conclusion: We hypothesize that exercise is more effective at improving physical fitness and thereby reducing fatigue and more cost-effective compared with usual care or a waiting list control group. If so, the programmes will be implemented in the Dutch clinical practice