日本维持性血液透析患者蛋白质能量消耗的患病率和诊断标准评估

Background and Objectives: The International Society of Renal Nutrition and Metabolism (ISRNM) has recently recommended the use of the term “protein-energy wasting” (PEW). PEW is a state of malnutrition with decreased body stores of protein and energy fuel in hemodialysis patients and is known as a risk factor for morbidity and mortality. We examined the prevalence of PEW and the characteristics of PEW patients in a hemodialysis center in Japan. Methods and Study Design: Fifty-nine outpatients undergoing maintenance hemodialysis at Iga City General Hospital were evaluated. We observed their biochemical data, body composition, dietary intake, and the number of steps prospectively. PEW was defined according to ISRNM criteria. Results: Nine patients (15% of total) were diagnosed as having PEW. Among indicators of PEW criteria, the relevance ratios of “reduced muscle mass” and “unintentional low dietary energy intake” were significantly higher in PEW than in non-PEW. The number of steps was lower, and serum levels of glucose and C-reactive protein were higher in PEW. Conclusion: About 15% of Japanese hemodialysis patients are estimated to have PEW. Our results suggested that major contributing factors to PEW were reduced muscle mass, unintentional low dietary energy intake, lower amount of exercise, insulin resistance, and chronic inflammation.背景与目的：国际肾营养与代谢协会（ISRNM）最近推荐使用术语“蛋白质能量消耗（PEW）”。PEW 是血液透析患者体内蛋白质和能量储存减少的一种营养不良状态，并且被认为是患病率和死亡率的危险因素。我们在日本的一个血液透析中心研究了PEW 的患病率和PEW 患者的特征。方法与研究设计：我们评估了58 名在伊贺市综合医院做维持性血液透析的门诊患者，并观察了他们的生化数据、体成分、膳食摄入量和行走的步数。根据ISRNM 标准诊断PEW。结果：9 名（占总数的15%）患者被诊断为PEW。在PEW 诊断标准指标中，PEW 患者“肌肉量减少”和“无意识的低膳食能量摄入”的比例高于非PEW 患者。PEW 患者中行走的步数较低，而血清葡萄糖和C-反应蛋白水平较高。结论：约有15%的日本血液透析患者患有PEW。我们的研究结果表明：引起PEW 的主要因素是肌肉量减少、无意识的低膳食能量摄入、运动量低、胰岛素抵抗和慢性炎症

IRF7 mediates MCP-1 in adipocyte

Hypertrophy, associated with adipocyte dysfunction, causes increased pro-inflammatory adipokine, and abnormal glucose and lipid metabolism, leading to insulin resistance and obesity-related-health problems. By combining DNA microarray and genomic data analyses to predict DNA binding motifs, we identified the transcription factor Interferon Regulatory Factor 7 (IRF7) as a possible regulator of genes related to adipocyte hypertrophy. To investigate the role of IRF7 in adipocytes, we examined gene expression patterns in 3T3-L1 cells infected with a retrovirus carrying the IRF7 gene and found that enforced IRF7 expression induced the expression of monocyte chemoattractant protein-1 (MCP-1), a key initial adipokine in the chronic inflammation of obesity. CRISPR/Cas9 mediated-suppression of IRF7 significantly reduced MCP-1 mRNA. Luciferase assays, chromatin immunoprecipitation PCR analysis and gel shift assay showed that IRF7 transactivates the MCP-1 gene by binding to its proximal Interferon Stimulation Response Element (ISRE), a putative IRF7 binding motif. IRF7 knockout mice exhibited lower expression of MCP-1 in epidydimal white adipose tissue under high-fat feeding conditions, suggesting the transcription factor is physiologically important for inducing MCP-1. Taken together, our results suggest that IRF7 transactivates MCP-1 mRNA in adipocytes, and it may be involved in the adipose tissue inflammation associated with obesity

A YAC contig in Xp21 containing the adrenal hypoplasia congenita and glycerol kinase deficiency genes

The gene loci for adrenal hypoplasia congenita (AHC) and glycerol kinase deficiency (GK) map in Xp21 distal to Duchenne muscular dystrophy (DMD), and proximal to DXS28 (C7), by analysis of patient deletions. We have constructed a yeast artificial chromosome (YAC) contig encompassing a 1.2 Mb region extending distally from DMD, and containing DXS708 (JC-1), the distal junction clone of a patient with GK and DMD. A pulsed-field gel electrophoresis map of the YAC contig identified 3 potential CpG islands. Whole YAC hybridization identified cosmids both for construction of cosmid contigs, and isolation of single copy probes. Thirteen new single copy probes and DXS28 and DXS708 were hybridized on a panel of patients; the deletion mapping indicates that the YAC contig contains both GK and at least part of AHC, and together with the physical map defines a GK critical region of 50-250 kb. In one AHC patient with a cytogenetically detectable deletion we used the new probes to characterize a complex double deletion. Non-overlapping deletions observed in other unrelated AHC patients indicate that the AHC gene is large, extending over at least 200-500 kb. This mapping provides the basis for the identification of the AHC and GK gene

Body fat mass is correlated with serum transthyretin levels in maintenance hemodialysis patients

Serum transthyretin (TTR), also known as prealbumin, is a reliable nutritional indicator and an independent prognostic factor for maintenance hemodialysis patients. However, we recently reported that serum TTR levels did not affect protein−energy wasting (PEW). In this study, we investigated factors affecting serum TTR levels in 60 maintenance hemodialysis patients. The patients were divided into High-TTR and Low-TTR groups according to the median serum TTR level. Albumin levels were significantly higher and C-reactive protein (CRP) levels were significantly lower in the High-TTR group than in the Low-TTR group. Although body fat mass was significantly higher in the High-TTR group than in the Low-TTR group, no significant difference in body fat ratio were observed. These findings suggest that body fat mass is related to serum TTR levels, apart from factors such as albumin and CRP levels, which showed correlations with serum TTR levels. Because body fat mass is related to better survival in maintenance hemodialysis patients, it may contribute to the prognostic value of serum TTR levels. In addition, in such patients, it may be important to evaluate body fatmass rather than body fat ratio and to maintain the minimum necessary body fat mass

Mutant analyses reveal different functions of fgfr1 in medaka and zebrafish despite conserved ligand–receptor relationships

AbstractMedaka (Oryzias latipes) is a small freshwater teleost that provides an excellent developmental genetic model complementary to zebrafish. Our recent mutagenesis screening using medaka identified headfish (hdf) which is characterized by the absence of trunk and tail structures with nearly normal head including the midbrain–hindbrain boundary (MHB). Positional-candidate cloning revealed that the hdf mutation causes a functionally null form of Fgfr1. The fgfr1hdf is thus the first fgf receptor mutant in fish. Although FGF signaling has been implicated in mesoderm induction, mesoderm is induced normally in the fgfr1hdf mutant, but subsequently, mutant embryos fail to maintain the mesoderm, leading to defects in mesoderm derivatives, especially in trunk and tail. Furthermore, we found that morpholino knockdown of medaka fgf8 resulted in a phenotype identical to the fgfr1hdf mutant, suggesting that like its mouse counterpart, Fgf8 is a major ligand for Fgfr1 in medaka early embryogenesis. Intriguingly, Fgf8 and Fgfr1 in zebrafish are also suggested to form a major ligand–receptor pair, but their function is much diverged, as the zebrafish fgfr1 morphant and zebrafish fgf8 mutant acerebellar (ace) only fail to develop the MHB, but develop nearly unaffected trunk and tail. These results provide evidence that teleost fish have evolved divergent functions of Fgf8–Fgfr1 while maintaining the ligand–receptor relationships. Comparative analysis using different fish is thus invaluable for shedding light on evolutionary diversification of gene function