Ribosomal Protein Gene Knockdown Causes Developmental Defects in Zebrafish

The ribosomal proteins (RPs) form the majority of cellular proteins and are mandatory for cellular growth. RP genes have been linked, either directly or indirectly, to various diseases in humans. Mutations in RP genes are also associated with tissue-specific phenotypes, suggesting a possible role in organ development during early embryogenesis. However, it is not yet known how mutations in a particular RP gene result in specific cellular changes, or how RP genes might contribute to human diseases. The development of animal models with defects in RP genes will be essential for studying these questions. In this study, we knocked down 21 RP genes in zebrafish by using morpholino antisense oligos to inhibit their translation. Of these 21, knockdown of 19 RPs resulted in the development of morphants with obvious deformities. Although mutations in RP genes, like other housekeeping genes, would be expected to result in nonspecific developmental defects with widespread phenotypes, we found that knockdown of some RP genes resulted in phenotypes specific to each gene, with varying degrees of abnormality in the brain, body trunk, eyes, and ears at about 25 hours post fertilization. We focused further on the organogenesis of the brain. Each knocked-down gene that affected the morphogenesis of the brain produced a different pattern of abnormality. Among the 7 RP genes whose knockdown produced severe brain phenotypes, 3 human orthologs are located within chromosomal regions that have been linked to brain-associated diseases, suggesting a possible involvement of RP genes in brain or neurological diseases. The RP gene knockdown system developed in this study could be a powerful tool for studying the roles of ribosomes in human diseases

Somatic chromosomal translocation between Ewsr1 and Fli1 loci leads to dilated cardiomyopathy in a mouse model

A mouse model that recapitulates the human Ewing's sarcoma-specific chromosomal translocation was generated utilizing the Cre/loxP-mediated recombination technique. A cross between Ewsr1-loxP and Fli1-loxP mice and expression of ubiquitous Cre recombinase induced a specific translocation between Ewsr1 and Fli1 loci in systemic organs of both adult mice and embryos. As a result Ewsr1-Fli1 fusion transcripts were expressed, suggesting a functional Ews-Fli1 protein might be synthesized in vivo. However, by two years of age, none of the Ewsr1-loxP/Fli1-loxP/CAG-Cre (EFCC) mice developed any malignancies, including Ewing-like small round cell sarcoma. Unexpectedly, all the EFCC mice suffered from dilated cardiomyopathy and died of chronic cardiac failure. Genetic recombination between Ewsr1 and Fli1 was confirmed in the myocardial tissue and apoptotic cell death of cardiac myocytes was observed at significantly higher frequency in EFCC mice. Moreover, expression of Ews-Fli1 in the cultured cardiac myocytes induced apoptosis. Collectively, these results indicated that ectopic expression of the Ews-Fli1 oncogene stimulated apoptotic signals, and suggested an important relationship between oncogenic signals and cellular context in the cell-of-origin of Ewing's sarcoma

C2C12筋管細胞においてモリンはデキサメタゾン誘導性の酸化ストレスと筋萎縮を抑制する

Glucocorticoids are the drugs most commonly used to manage inflammatory diseases. However, they are prone to inducing muscle atrophy by increasing muscle proteolysis and decreasing protein synthesis. Various studies have demonstrated that antioxidants can mitigate glucocorticoid-induced skeletal muscle atrophy. Here, we investigated the effect of a potent antioxidative natural flavonoid, morin, on the muscle atrophy and oxidative stress induced by dexamethasone (Dex) using mouse C2C12 skeletal myotubes. Dex (10 μM) enhanced the production of reactive oxygen species (ROS) in C2C12 myotubes via glucocorticoid receptor. Moreover, Dex administration reduced the diameter and expression levels of the myosin heavy chain protein in C2C12 myotubes, together with the upregulation of muscle atrophy-associated ubiquitin ligases, such as muscle atrophy F-box protein 1/atrogin-1, muscle ring finger protein-1, and casitas B-lineage lymphoma proto-oncogene-b. Dex also significantly decreased phosphorylated Foxo3a and increased total Foxo3a expression. Interestingly, Dex-induced ROS accumulation and Foxo3a expression were inhibited by morin (10 μM) pretreatment. Morin also prevented the Dex-induced reduction of myotube thickness, together with muscle protein degradation and suppression of the upregulation of atrophy-associated ubiquitin ligases. In conclusion, our results suggest that morin effectively prevents glucocorticoid-induced muscle atrophy by reducing oxidative stress

CINV related biomarkers and questionnaires

Purpose We assessed the efficacy of palonosetron (PAL) in comparison to granisetron (GRA) for the treatment of CINV using the self-assessment questionnaires. In addition, we analyzed the serum levels of emetic various biomarkers. Methods We conducted a randomized study of 70 patients naïve to chemotherapy. The primary endpoint was the late phase score on the MAT questionnaire. The plasma concentrations of the biomarkers were measured on days 1 and 3. Results There were no statistical differences in the scores on the questionnaires, but the mean values in response to PAL were higher than those in response to GRA. The value of ghrelin on day 1 was significantly higher for GRA than for PAL. Conclusions For the primary endpoint, the score of the late phase on the MAT questionnaire was not statistically different between the PAL and GRA treatment groups. Further studies are needed to clarify the role of ghrelin for the treatment of CINV

Norspermidine is not a self-produced trigger for biofilm disassembly

SummaryFormation of Bacillus subtilis biofilms, consisting of cells encapsulated within an extracellular matrix of exopolysaccharide and protein, requires the polyamine spermidine. A recent study reported that (1) related polyamine norspermidine is synthesized by B. subtilis using the equivalent of the Vibrio cholerae biosynthetic pathway, (2) exogenous norspermidine at 25 μM prevents B. subtilis biofilm formation, (3) endogenous norspermidine is present in biofilms at 50–80 μM, and (4) norspermidine prevents biofilm formation by condensing biofilm exopolysaccharide. In contrast, we find that, at concentrations up to 200 μM, exogenous norspermidine promotes biofilm formation. We find that norspermidine is absent in wild-type B. subtilis biofilms at all stages, and higher concentrations of exogenous norspermidine eventually inhibit planktonic growth and biofilm formation in an exopolysaccharide-independent manner. Moreover, orthologs of the V. cholerae norspermidine biosynthetic pathway are absent from B. subtilis, confirming that norspermidine is not physiologically relevant to biofilm function in this species

GPS and chemotherapy for elderly NSCLC

Background : Although platinum-combination chemotherapy is widely used to treat advanced non-small cell lung cancer (NSCLC), not all elderly patients benefit from this regimen. In this retrospective study, we aimed to evaluate whether the Glasgow Prognostic Score (GPS), an indicator of systemic inflammation and malnutrition, could predict the tolerability and efficacy of platinum-combination chemotherapy among elderly patients with NSCLC. Methods : The eligibility criteria included patients aged ≥ 70 years with NSCLC treated with first-line platinum-combination chemotherapy at Shimane University Hospital between January 2015 and December 2018. Results : Thirty-two patients with NSCLC (median age, 74 years) were included. The GPS scores were 0–1 for 19 patients and 2 for 13 patients. Four chemotherapy cycles were completed by 57.9% and 30.8% of patients in the GPS 0–1 and GPS 2 groups, respectively. The GPS 0–1 group experienced better outcomes than the GPS 2 group (response rate : 26% vs. 15%, P = 0.67 ; median progression-free survival : 4.1 vs. 2.1 months, P = 0.0026 ; median overall survival : 22.8 vs. 9.6 months, P = 0.0092). Conclusions : Platinum-combination chemotherapy demonstrated promising efficacy among elderly NSCLC patients with a GPS 0–1. Therefore, GPS may be crucial in determining whether treatments recommended for younger patients are suitable for older patients with NSCLC

Frail patients with respiratory failure

Background : Older patients with severe respiratory failure have higher mortality rates and are more likely to experience impairments in activities of daily living (ADL). Methods : We retrospectively reviewed patients (≥ 75 years) who received intubation and artificial ventilation for respiratory failure at Shimane University Hospital between November 2014 and December 2020. We compared the outcomes of frail patients with those of self-sufficient patients. Results : Thirty-two patients were included. ADL ability before respiratory failure was rated self-sufficient in 18 patients (self-sufficient group) and not self-sufficient in 14 patients (frail group). None of the patients in either group underwent advanced care planning prior to the onset of respiratory failure. In the self-sufficient and frail groups, the in-hospital mortality rates were 33% and 50%, and the incidence of bedridden patients at discharge was 6% and 43%, respectively. Most patients in the frail group (93%) died or were bedridden. The median hospitalization cost was JPY 2,984,000 for the self-sufficient group and JPY 3,008,000 for the frail group. Conclusion : The overall prognosis of frail older patients who underwent intubation and artificial ventilation was poor. When providing intensive care to such patients, it is important to carefully consider their suitability for the treatment