Non-clinical pharmacokinetic profiles of rovatirelin,an orally available thyrotropin-releasing hormone analogue

1. The non-clinical pharmacokinetic profiles of rovatirelin, a novel thyrotropin-releasing hormone (TRH) analogue, were investigated in vivo and in vitro.

2. Rovatirelin orally administered to rats and dogs was rapidly absorbed and bioavailability was estimated to be 7.3 and 41.3%, respectively. The extent of plasma protein binding of rovatirelin in rats, dogs, and humans was low in all species (～15%). The permeability of rovatirelin from blood to brain (permeability-surface area) ranged from 1.04?±?0.14 to 1.29?±?0.28?μL/min/g in rats, and rovatirelin was stable in rat plasma and brain homogenates.

3. The metabolite pattern was qualitatively similar in vitro and in vivo. In animals, rovatirelin aminopentanoic acid (rovatirelin-acid), rovatirelin aminopentanone (rovatirelin-ketone), rovatirelin pyrrolidine (4S)-hydroxy (rovatirelin-OH), (thiazoylalanyl)methylpyrrolidine (TAMP), 3-(4-thiazoyl)-l-alanine (TA), and unknown metabolites were observed. In human hepatocytes, TAMP was mainly formed and no unique human metabolite was observed.

4. The radioactivity from administered [¹⁴C]rovatirelin was predominantly excreted in faeces in rats and dogs, and almost all radioactivity was recovered 168?h after administration. Absorption, brain penetration, and stability of rovatirelin in the brain were greater than for taltirelin.

5. Thus, orally administered rovatirelin is a potentially improved treatment for spinocerebellar degeneration compared with taltirelin.     

Preparation of an experimental mouse model lacking selenium-dependent glutathione peroxidase activities by feeding a selenium-deficient diet

Relatively young (4-week-old) selenium deficient (SeD) mice, which lack the activity of selenium-dependent glutathione peroxidase (GSH-Px) isomers, were prepared using torula yeast-based SeD diet. Mice were fed the torula yeast-based SeD diet and ultra-pure water. Several different timings for starting the SeD diet were assessed. The weekly time course of liver comprehensive GSH-Px activity after weaning was monitored. Protein expression levels of GPx1 and 4 in the liver were measured by Western blot analysis. Gene expression levels of GPx1, 2, 3, 4, and 7 in the liver were measured by quantitative real-time PCR. Apoptotic activity of thymocytes after hydrogen peroxide (H₂O₂) exposure was compared. Thirty-day survival rates after whole-body X-ray irradiation were estimated. Pre-birth or right-after-birth starting of the SeD diet in dams was unable to lead to creation of SeD mice due to neonatal death. This suggests that Se is necessary for normal birth and healthy growing of mouse pups. Starting the mother on the SeD diet from 2 weeks after giving birth (SeD-trial-2w group) resulted in a usable SeD mouse model. The liver GSH-Px activity of the SeD-trial-2w group was almost none from 4 week olds, but the mice survived for more than 63 weeks. Protein and gene expression of GPx1 was suppressed in the SeD-trial-2w group, but that of GPx4 was not. The thymocytes of the SeD-trial-2w group were sensitive to H₂O₂-induced apoptosis. The SeD-trial-2w group was sensitive to whole-body X-ray irradiation compared with control mice. The SeD-trial-2w model may be a useful animal model for H₂O₂/hydroperoxide-induced oxidative stress.     

Influences of interferon-gamma on cell proliferation and interleukin-6 production in Down syndrome derived fibroblasts

Objective

Down syndrome, a frequently encountered genetic disorder, is usually associated with medical problems related to infectious disease, such as periodontal diseases and prolonged wound healing. Although affected individuals are considered to have clinical problems related to high interferon (IFN) sensitivity, the molecular mechanisms of IFN activities are not completely understood.

Design

Down syndrome derived fibroblasts, Detroit 539 (D1) and Hs 52.Sk (D2) cells, were used. To analyse the expressions of interferon (IFN) receptors and downstream of IFN-γ, western blotting was performed. Cell proliferation was determined by counting cells following trypan blue staining. Media levels of IL-1β, TNF-α, and IL-6 were quantified using ELISA.

Results

IFN-γ receptor 2 and IFN-α receptor 1, but not IFN-γ receptor 1, were highly expressed in D1 and D2 cells, as compared to the control fibroblast cells. Cell proliferation by D1 and D2 cells was lower than that by the control fibroblasts, further, IFN-γ had a greater effect to inhibit cell proliferation by D1 and D2 cells. In addition, IFN-γ treatment increased the phosphorylation of STAT1 and MAPK in D1 cells as compared to normal fibroblasts. Also, the presence of exogenous IFN-γ in the growth medium significantly induced IL-6, but not IL-1β or TNF-α, in D1 and D2 cells.

Conclusion

Taken together, our results are consistent with hypersensitive reactions to IFN-γ seen in patients with Down syndrome and may provide useful information to elucidate the mechanisms of IFN-γ activities in those individuals.     

Clinical and Immunological Characterization of ICF Syndrome in Japan

Objective

Immunodeficiency, centromeric instability, and facial anomalies (ICF) syndrome is a rare autosomal recessive primary immunodeficiency. Hypogammaglobulinemia is a major manifestation of ICF syndrome, but immunoglobulin replacement therapy does not seem to be effective for some ICF patients. Therefore, we aimed to reassess the immunological characteristics of this syndrome.

Methods

Eleven Japanese patients with ICF syndrome were enrolled. We performed whole-exome sequencing in four cases and homozygosity mapping using SNP analysis in two. We evaluated their clinical manifestations and immunological status.

Results

We newly diagnosed six ICF patients who had tentatively been diagnosed with common variable immunodeficiency. We identified two novel mutations in the DNMT3B gene and one novel mutation in the ZBTB24 gene. All patients showed low serum IgG and/or IgG₂ levels and were treated by periodic immunoglobulin replacement therapy. Three of the six patients showed worse results of the mitogen-induced lymphocyte proliferation test. Analyses of lymphocyte subpopulations revealed that CD19⁺CD27⁺ memory B cells were low in seven of nine patients, CD3⁺ T cells were low in three patients, CD4/8 ratio was inverted in five patients, CD31⁺ recent thymic emigrant cells were low in two patients, and CD19⁺ B cells were low in four patients compared with those in the normal controls. ICF2 patients showed lower proportions of CD19⁺ B cells and CD16⁺56⁺ NK cells and significantly higher proportions of CD3⁺ T cells than ICF1 patients. T cell receptor excision circles were undetectable in two patients. Despite being treated by immunoglobulin replacement therapy, three patients died of influenza virus, fatal viral infection with persistent Epstein–Barr virus infection, or JC virus infection. One of three dead patients showed normal intelligence with mild facial anomaly. Two patients presented with autoimmune or inflammatory manifestations. Infectious episodes decreased in three patients who were started on trimethoprim–sulfamethoxazole and/or antifungal drugs in addition to immunoglobulin replacement therapy. These patients might have suffered from T cell immunodeficiency.

Conclusion

These results indicate that patients with ICF syndrome have a phenotype of combined immunodeficiency. Thus, to achieve a better prognosis, these patients should be treated as having combined immunodeficiency in addition to receiving immunoglobulin replacement therapy.

     

Intersection of child abuse and children's exposure to domestic violence

This review addresses research on the overlap in physical child abuse and domestic violence, the prediction of child outcomes, and resilience in children exposed to family violence. The authors explore current findings on the intersection of physical child abuse and domestic violence within the context of other risk factors, including community violence and related family and environmental stressors. Evidence from the studies reviewed suggests considerable overlap, compounding effects, and possible gender differences in outcomes of violence exposure. The data indicate a need to apply a broad conceptualization of risk to the study of family violence and its effects on children. Further testing of competing theoretical models will advance understanding of the pathways through which exposure leads to later problems in youth, as well as protective factors and processes through which resilience unfolds.