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Tofacitinib is the first Janus Kinase (JAK) inhibitor to treat moderately to severely active RA. In this study, we investigated whether the effect of tofacitinib have any effects on body composition in mice and female patients with RA. Female C57BL/6 mice fed with a high-fat diet were treated with 30 mg/kg/day tofacitinib or vehicle for 70 days. Following treatment, trunk muscle, subcutaneous fat, and visceral fats were measured using X-ray computed tomography CT scan. Glucose tolerance and insulin sensitivity were assessed. In female RA patients treated with biological disease modified anti-rheumatic-drugs (biological DMARDs) or tofacitinib (n=4 per group), we also evaluated the body composition after 3 months from the start of treatment initiation using bioelectrical impedance analysis. Treatment with tofacitinib did not affect the body weight, and body composition in C57BL/6mice. It also did not affect glucose, and insulin tolerance in mice. In patients with RA, treatment with biological DMARDs did not affect the body composition whereas the muscle mass was unchanged after receiving tofacitinib and the fat mass was significantly increased.

The physiological activity of the steroid derived hormone vitamin D is regulated by several enzymatic steps. Both 25-hydroxy vitamin D3 1a-hydroxylase (CYP27B1) and 25-hydroxyvitamin D3 24-hydroxylase (CYP24A1) modulate blood levels of 1,25-dihydroxyvitamin D3, an activated form of vitamin D. We previously demonstrated that CYP27B1 expression was trans-activated by sterol regulatory element binding protein 1 (SREBP1), although whether SREBP1 also regulates CYP24A1 transcription was unclear. Here we investigated the ability of SREBP1 to affect CYP24A1 transcription. In a luciferase reporter assay, mouse and human CYP24A1 promoter activity was strongly activated by SREBP1 in opossum kidney proximal tubular cells (OK-P). Three putative SREs (pSREs) were found in the mouse Cyp24a1 gene promoter and the SREBP1 protein showed specific binding to the pSRE1 element in EMSAs. Site-directed mutagenesis of the pSRE1 element strongly decreased SREBP1-mediated Cyp24a1 gene transcription. Moreover, siRNA-mediated SREBP1 knock-down repressed CYP24A1 expression in human renal proximal tubular epithelial cells (HKC-8). In animal studies, mice given various doses of thyroid hormone (T3) showed dose-dependent reductions in renal Srebp1c and Cyp24a1 mRNA levels. Taken together, our results suggest that SREBP1 trans-activates CYP24A1 expression through SREBP binding elements present in the promoter.

The Spontaneously-Running Tokushima Shikoku (SPORTS) strain is an original line derived from Wistar rats, which spontaneously runs >6 km/day on wheels, and has better glucose tolerance and less fat than Wistar rats. However, the molecular mechanism that contributes to the increased metabolic activity in SPORTS rats is unknown. The present study aimed to characterize the gene expression profiles of skeletal muscles in SPORTS rats housed under sedentary (SED) conditions. We found that the expression levels of genes encoding mitochondrial respiratory chain enzymes such as ATP synthase 6 (mt-Atp6) and cytochrome c oxidase subunit 6c (Cox 6c), were higher in the soleus (SOL) muscles of SED SPORTS than in SED Wistar rats. The ratio of type IIa myofibers was higher and glucose tolerance was better in SED SPORTS than in Wistar rats that were sedentary and trained daily on treadmills, respectively. We then investigated candidate genes that might contribute to the better glucose tolerance of SED SPORTS rats using DNA microarray analysis. Among 116 upregulated genes in the SOL muscles of SED SPORTS rats, only 19 were also increased in trained Wistar rats. We focused on v-erb-b2 erythroblastic leukemia viral oncogene homolog 3 (Erbb3), which was associated with glucose transport in myocytes, and found higher expression levels in the SOL muscles of SED SPORTS than in SED Wistar rats. The SOL muscles of SED SPORTS rats also contained more activity of β-hydroxy-acylCoA dehydrogenase, a key enzyme of β-oxidation, indicating enhanced lipid oxidation. These findings suggest that increased metabolic activity in skeletal muscle (especially the SOL muscle) of SPORTS rats is congenital and that gene expression profiles of SPORTS rats and Trained Wistar rats are different.

There is an increasing interest in elucidating the molecular mechanisms by which voluntary exercise is regulated. In this study, we examined how the central nervous system regulates exercise. We used SPORTS rats, which were established in our laboratory as a highly voluntary murine exercise model. SPORTS rats showed lower levels of serum ghrelin compared with those of the parental line of Wistar rats. Intrac-erebroventricular and intraperitoneal injection of ghrelin decreased wheel-running activity in SPORTS rats. In addition, daily injection of the ghrelin inhibitor JMV3002 into the lateral ventricles of Wistar rats increased wheel-running activity. Co-administration of obestatin inhibited ghrelin-induced increases in food intake but did not inhibit ghrelin-induced suppression of voluntary exercise in rats. Growth hormone secretagogue receptor (GHSR) in the hypothalamus and hippocampus of SPORTS rats was not difference that in control rats. We created an arcuate nucleus destruction model by administering monosodium glutamate (MSG) to neonatal SPORTS rats. Injection of ghrelin into MSG-treated rats decreased voluntary exercise but did not increase food intake, suggesting that wheel-running activity is not controlled by the arcuate nucleus neurons that regulate feeding. These results provide new insights into the mechanism by which ghrelin regulates voluntary activity independent of arcuate nucleus neurons.

Supportive therapy during chemotherapy has become essential, but effective preventive therapies to gastrointestinal mucosal injury are few. We investigated the efficacy of glutamine in rat anticancer drug-induced enteritis model. In this study, we used twenty male SD rats. They were divided into control, 5-fluorouracil (5-FU) (orally administered at 20mg/kg day), 5-FU+glutamine (1000 mg/kg/day) and 5-FU+glutamine+fiber and oligosaccharide (GFO[○R]) (1000 mg/kg/day) groups. All groups were sacrificed on day 6 and upper jejunums were excised. The jejunal villous height was measured in specimens. IgA level in jejunal washing solution, and serum diamine oxidase activity were also measured. The jejunal villous height was recognized as shorter in the specimen from 5-FU treated rats compared with 5-FU+glutamine treated rats (p

To identify the genes that determine differentiation phenotypes, we compared gene expression of pancreatic islet β- and α-cells, which are derived from the common precursor and secrete insulin and glucagon, respectively. The expression levels of homeotic genes including Hox genes known to determine region specificity in the antero-posterior (AP) body axis, tissue-specific homeobox genes, and other 8,734 genes were compared in a β- and α-cell line of MIN6 and αTC1.6. The expression of homeotic genes were surveyed with reverse transcription-polymerase chain reaction (RT-PCR) using degenerate primers corresponding to invariant amino acid sequences within the homeodomain and subsequently with specific primers. Expression of Hoxc6, Hoxc9, Hoxc10, Pdx1, Cdx2, Gbx2, Pax4, and Hlxb9 genes in MIN6 was higher than those in αTC1.6, while expression of Hoxa2, Hoxa3, Hoxa5, Hoxa6, Hoxa7, Hoxa9, Hoxa10, Hoxa13, Hoxb3, Hoxb5, Hoxb6, Hoxb13, Hoxb8, and Brain4 genes in αTC1.6 was higher than those in MIN6. Out of 8,734 mouse genes screened with high-density mouse cDNA microarrays for MIN6- and αTC1.6-derived cDNA, 58 and 25 genes were differentially over- and under-expressed in MIN6, respectively. GLUTag, which is derived from a large bowel tumor and expresses the proglucagon gene, showed a comparatively similar expression profile to that of αTC1.6 in both homeotic and other genes analyzed in cDNA microarray. Our results are consistent with the interpretation that not only the tissue-specific homeotic genes, but also Hox genes are related to differentiation phenotypes of pancreatic β- and α-cells rather than their regional specification of the body in vertebrates.

High-fat diets induce whole-body insulin resistance. The aim of this study was to compare the effect of two interventions:3-day food restriction (66%of ad libitum fed) and 3-day exercise training (voluntary running wheels), on decreased insulin-mediated whole body glucose uptake in high-fat fed rats (5 mo old) using the hyperinsulinemic euglycemic clamp procedure. The control group was maintained on rat chow alone. After high-fat feeding for2wk, insulin-stimulated whole body glucose utilization was significantly decreased by26%. The exercise training was more effective than food restriction in lowering plasma concentrations of insulin and triacylglycerol and tissue concentrations of triacylglycerol in soleus muscles. Diminished whole-body glucose uptake resulting from high-fat feeding was reversed completely by exercise training, but only partially by food restriction. The time course of starvation on insulin-stimulated glucose uptake was also observed in high-fat fed rats. Although the extension of starvation time to 48h resulted in decreased plasma glucose, insulin and triacylglycerol concentrations, whole body glucose uptake did not increase further. These findings suggest that short-term exercise has a higher restorative effect on insulin sensitivity in high-fat fed rats than food restriction, in spite of the same loss in body weight, presumably due in part to improved local lipid availability.