Isolation of a transcriptionally active element of high copy number retrotransposons in sweetpotato genome

Many plant retrotransposons have been characterized, but only three families (Tnt1, Tto1 and Tos17) have been demonstrated to be transpositionally competent. We followed a novel approach that enabled us to identify an active element of the Ty1-copia retrotransposon family with estimated 400 copies in the sweetpotato genome. DNA sequences of Ty1 -copia reverse transcriptase (RTase) from the sweetpotato genome were analyzed, and a group of retrotransposon copies probably formed by recent transposition events was further analyzed. 3’RACE on callus cDNA amplified transcripts containing long terminal repeats (LTR) of this group. The sequence -specific amplification polymorphism (S-SAP) patterns of the LTR sequence in the genomic DNA were compared between a normal plant and callus lines derived from it. A callus -specific S-SAP product was found into which the retrotransposon detected by the 3’RACE had been transposed apparently during cell culture. We conclude that our approach provides an effective way to identify active elements of retrotransposons with high copy numbers.</p

Utility of the low physical activity questionnaire for hemodialysis patients with frailty: a cross-sectional study

Abstract Background The low physical activity questionnaire (LoPAQ), which has been developed to assess the low levels of physical activity in patients on dialysis, is so far available only in English. Moreover, no study has examined whether the LoPAQ can be used to screen for frailty in patients on hemodialysis. The purpose of this study was to translate the original LoPAQ into Japanese and evaluate its utility in screening for frailty among patients on hemodialysis. Methods For this cross-sectional study, we enrolled patients from two hemodialysis facilities in Japan between April 2018 and June 2019. We used the LoPAQ to calculate physical activity for one week, with pedometer steps (steps/week) as the standard reference. We used Spearman’s rank test and two multiple linear regression models to assess the relationship between the Japanese LoPAQ results and pedometer step counts. Finally, we examined whether the LoPAQ had the ability to screen for frailty (Fried scale ≥ 3) using area under the curves. Results In total, 220 patients on hemodialysis completed the LoPAQ and wore a pedometer for one week. Their mean age was 67.8 ± 11.6 years, and 59.1% were men. The LoPAQ showed a total physical activity of 825.0 kilocalories/week and walking activity of 315.0 kilocalories/week. The LoPAQ total physical activity and walking activity were significantly correlated with pedometer step counts (r = 0.37–0.53, P < 0.01). Furthermore, LoPAQ total physical activity and walking activity were associated with pedometer step counts despite adjusting for covariates (β: 3.33–5.45, P < 0.001, β: 8.63–16.80, P < 0.001, respectively). In addition, the LoPAQ total physical activity and walking activity showed good values in the area under the curves to identify frailty (0.72 and 0.73, respectively). Conclusions Physical activity assessed using the LoPAQ significantly correlated with pedometer step counts in Japanese patients on hemodialysis. Furthermore, the LoPAQ total physical activity and walking activity had a moderate screening ability for frailty. The results indicate that the LoPAQ questionnaire is useful as a physical activity assessment tool and as a screening tool for frailty in patients on hemodialysis

Deficiency in interleukin-18 promotes differentiation of brown adipose tissue resulting in fat accumulation despite dyslipidemia

Abstract Background The cytokine, interleukin-18 (IL-18), was originally identified as an interferon-γ-inducing proinflammatory factor; however, there is increasing evidence suggesting that it has non-immunological effects on physiological functions. We have previously investigated the potential pathophysiological relationship between IL-18 and dyslipidemia, non-alcoholic fatty liver disease and non-alcoholic steatohepatitis, which were mediated by lipid energy imbalance. Therefore, herein we focused on brown adipocytes (BAs) and brown adipose tissue (BAT) related to energy consumption as non-shivering thermogenesis. Methods Il18 −/− male mice were generated on the C57Bl/6 background, and littermate C57Bl/6 Il18 +/+ male mice were used as controls. To reveal the direct effect of IL-18, primary cell cultures derived from both mice were established. Moreover, for molecular analysis, microarray, quantitative reverse transcription PCR and western blotting were performed using 6 and 12 weeks old mice. To evaluate the short- and long-term effects of IL-18 on BAT, recombinant IL-18 was administered for 2 and 12 weeks, respectively. Results Compared with Il18 +/+ mice, BAT of Il18 −/− mice showed earlier differentiation and lipid accumulation. To examine the direct effect of IL-18 on BAT, BA cell cultures were established. Myogenic factor 5-expressing adipose precursor cells were extracted from Il18 +/+ and Il18 −/− mice. PR domain containing 16 (PRDM16), a differentiation inducer, was strongly expressed in Il18 −/− BAs, and uncoupling protein 1, a thermogenic and differentiation marker, was upregulated, resulting in the promotion of BA differentiation. Moreover, PRDM16-dependent and independent molecules related to BAT function, such as fibroblast growth factor 21, were activated. These findings were confirmed by comparing Il18 +/+ and Il18 −/− mice at 6 and 12 weeks of age. Additional analyses of the molecular mechanisms influencing the ‘Quantity of adipocytes’ identified three associated genes, apolipoprotein C3 (Apoc3), insulin-induced gene 1 (Insig1) and vitamin D (1,25-dihydroxyvitamin D3) receptor (Vdr). Intravenous administration of IL-18 not only significantly improved the expression of some of these genes, but it also significantly decreased the adipocytes’ size. Conclusions This study demonstrated the critical function of IL-18 in differentiation and lipid metabolism in BAs. Furthermore, IL-18 may contribute to novel treatments by improving the energy imbalance