Involvement of prostacyclin synthase in high-fat-diet-induced obesity.

Prostacyclin (PGI2) synthase (PGIS) functions downstream of inducible cyclooxygenase COX-2 in the PGI2 biosynthetic pathway. Although COX-2 and PGI2 receptor (IP) are known to be involved in adipogenesis and obesity, the involvement of PGIS has not been fully elucidated. In this study, we examined the role of PGIS in adiposity by using PGIS-deficient mice. Although PGIS deficiency did not affect in vitro adipocyte differentiation, when fed a high-fat diet (HFD), PGIS knockout (KO) mice showed reductions in both body weight gain and epididymal fat mass relative to wild-type (WT) mice. PGIS deficiency might reduce HFD-induced obesity by suppressing PGI2 production. We further found that additional gene deletion of microsomal prostaglandin (PG) E synthase-1 (mPGES-1), one of the other PG terminal synthases that also functions downstream of COX-2, emphasized the metabolic phenotypes of PGIS-deficient mice. More marked reduction in obesity and improved insulin resistance were observed in PGIS/mPGES-1 double KO (DKO) mice. Since an additive increase in PGF2α level in epididymal fat was observed in DKO mice, mPGES-1 deficiency might affect adiposity by enhancing the production of PGF2α. Our immunohistochemical analysis further revealed that in adipose tissues, PGIS was expressed in vascular and stromal cells but not in adipocytes. These results suggested that PGI2 produced from PGIS-expressed stromal tissues might enhance HFD-induced obesity by acting on IP expressed in adipocytes. The balance of expressions of PG terminal synthases and the subsequent production of prostanoids might be critical for adiposity.

Patient-generated health data collection using a wearable activity tracker in cancer patients-a feasibility study.

PURPOSE: Incorporation of patient-generated health data (PGHD) into clinical research requires an investigation of the validity of outcomes and feasibility of implementation. This single-arm pilot trial investigated the feasibility of using a commercially available activity tracking wearable device in cancer patients to assess adherence to the device and real-time PGHD collection in a clinical research setting. METHODS: From July to November 2017, enrolled adult patients were asked to wear a wristband-style device. Brief Fatigue Inventory (BFI) and MD Anderson Symptom Inventory (MDASI) were assessed at baseline and on day 29. Furthermore, 29-day Pittsburgh Sleep Quality Index, global impression of the devices, and NCI CTCAE v4 were evaluated. RESULTS: Of 30 patients (mean age, 58.6 years; male, 21 [70%]), 15 (50%) and 11 (36.7%) had gastrointestinal and lung cancer, respectively, and 27 (90%, 95% CI: 0.74-0.98) were well adhered (> 70%) to the device for 28 days. The mean adherence was 84.9% (range: 41.7-95.2%). More frequent PGHD synchronization tended to show better device adherence, with moderate correlation (r = 0.62, 95% CI: 0.33-0.80, p < 000.1). CONCLUSIONS: The feasibility of using a wearable activity tracker was confirmed in cancer patients receiving chemotherapy for a month. For future implementation in clinical trials, there is a need for further comprehensive assessment of the validity and reliability of wearable activity trackers. TRIAL REGISTRATION: This trial was registered at the University Hospital Medical Information Network Clinical Trials Registry as UMIN: UMIN000027575.

Genetic-deletion of Cyclooxygenase-2 Downstream Prostacyclin Synthase Suppresses Inflammatory Reactions but Facilitates Carcinogenesis, unlike Deletion of Microsomal Prostaglandin E Synthase-1.

Prostacyclin synthase (PGIS) and microsomal prostaglandin E synthase-1 (mPGES-1) are prostaglandin (PG) terminal synthases that function downstream of inducible cyclooxygenase (COX)-2 in the PGI2 and PGE2 biosynthetic pathways, respectively. mPGES-1 has been shown to be involved in various COX-2-related diseases such as inflammatory diseases and cancers, but it is not yet known how PGIS is involved in these COX-2-related diseases. Here, to clarify the pathophysiological role of PGIS, we investigated the phenotypes of PGIS and mPGES-1 individual knockout (KO) or double KO (DKO) mice. The results indicate that a thioglycollate-induced exudation of leukocytes into the peritoneal cavity was suppressed by the genetic-deletion of PGIS. In the PGIS KO mice, lipopolysaccharide-primed pain nociception (as assessed by the acetic acid-induced writhing reaction) was also reduced. Both of these reactions were suppressed more effectively in the PGIS/mPGES-1 DKO mice than in the PGIS KO mice. On the other hand, unlike mPGES-1 deficiency (which suppressed azoxymethane-induced colon carcinogenesis), PGIS deficiency up-regulated both aberrant crypt foci formation at the early stage of carcinogenesis and polyp formation at the late stage. These results indicate that PGIS and mPGES-1 cooperatively exacerbate inflammatory reactions but have opposing effects on carcinogenesis, and that PGIS-derived PGI2 has anti-carcinogenic effects.