Comparing the effects of ipragliflozin versus metformin on visceral fat reduction and metabolic dysfunction in Japanese patients with type 2 diabetes treated with sitagliptin: A prospective, multicentre, open-label, blinded-endpoint, randomized controlled study (PRIME-V study).

A prospective, multicentre, open-label, blinded-endpoint, randomized controlled study was conducted to evaluate the efficacy of treatment with ipragliflozin (sodium-dependent glucose transporter-2 inhibitor) versus metformin for visceral fat reduction and glycaemic control among Japanese patients with type 2 diabetes treated with sitagliptin, HbA1c levels of 7%-10%, and body mass index (BMI) ≥ 22 kg/m2 . Patients were randomly assigned (1:1) to receive ipragliflozin 50 mg or metformin 1000-1500 mg daily. The primary outcome was change in visceral fat area as measured by computed tomography after 24 weeks of therapy. The secondary outcomes were effects on glucose metabolism and lipid metabolism. Mean percentage reduction in visceral fat area was significantly greater in the ipragliflozin group than in the metformin group (-12.06% vs. -3.65%, P = 0.040). Ipragliflozin also significantly reduced BMI, subcutaneous fat area, waist circumference, fasting insulin, and homeostatic model assessment (HOMA)-resistance, and increased HDL-cholesterol levels. Metformin significantly reduced HbA1c and LDL-cholesterol levels and increased HOMA-beta. There were no severe adverse events. The use of ipragliflozin or metformin in combination with dipeptidyl peptidase-4 inhibitors, widely used in Japan, may have beneficial effects in ameliorating multiple cardiovascular risk factors.

Assessing Patient Satisfaction Following Sodium Glucose Co-Transporter 2 Inhibitor Treatment for Type 1 Diabetes Mellitus: A Prospective Study in Japan.

INTRODUCTION: In Japan, several sodium glucose co-transporter 2 (SGLT2) inhibitors have been used for type 1 diabetes mellitus as an adjuvant therapy to insulin therapy; however, there are no clinical reports regarding the satisfaction of its use. Therefore, we conducted a survey among patients with type 1 diabetes undergoing treatment using an SGLT2 inhibitor. METHODS: This is a single-arm open-label prospective study including 24 patients with type 1 diabetes who were to be initiated on ipragliflozin treatment between March and August 2019. All participants provided written informed consent. They completed the Diabetes Treatment Satisfaction Questionnaire (DTSQ) for the survey and 3 months of observation after the administration of an SGLT2 inhibitor (50 mg of ipragliflozin), and changes from baseline diabetes treatment satisfaction were evaluated using modified DTSQ scores (five-step evaluation) and were analyzed. RESULTS: The average score for each question on DTSQ significantly increased [mean (standard deviation); 0.25 (0.25) vs 0.83 (0.77), P = 0.004]. Approximately 75% of the patients perceived an improvement in glycemic control over short periods of time. Finally, 54.2% of patients were highly satisfied and would recommend the SGLT2 inhibitor treatment [0.0 (0.0) vs. 0.92 (1.32), P < 0.001]. After the administration of ipragliflozin, reductions in body weight [24.0 (2.9) vs. 23.4 (2.9) kg/m2, P = 0.002], total insulin [39.1 (12.9) vs. 34.3 (12.5) units, P = 0.013], and glycated hemoglobin [7.77 (0.97) vs. 7.40 (0.86) %, P = 0.013] were observed, without any severe side effects. Improvements in glycemic variability indexes were observed through flash glucose monitoring. CONCLUSIONS: SGLT2 inhibitors may improve clinical treatment satisfaction by improving glycemic variability in patients with type 1 diabetes mellitus, while not inducing severe side effects with careful use. TRIAL REGISTRATION: This study is registered with the University Hospital Medical Information Network Clinical Trial Registry (UMIN000040487).

Effects of Sodium Glucose Co-Transporter 2 Inhibitors in Type 1 Diabetes Mellitus on Body Composition and Glucose Variabilities: Single-Arm, Exploratory Trial.

INTRODUCTION: Sodium glucose co-transporter 2 (SGLT2) inhibitors are widely used in the management of type 2 diabetes mellitus; they prevent cardiovascular events and reduce fat mass. However, little is known about the effects of SGLT2 inhibitors on type 1 diabetes mellitus as an adjuvant to insulin therapy. Therefore, we aimed to elucidate the effects of SGLT2 inhibitors on body composition of patients with type 1 diabetes mellitus and assess blood glucose variability. METHODS: A single-center, single-arm, prospective, interventional study was performed on Japanese patients with type 1 diabetes mellitus who were not administered SGLT2 inhibitors prior to this study. These patients were equipped with flash glucose monitoring (FGM) and administered ipragliflozin 50 mg daily. Body composition was evaluated using bioelectrical impedance analysis, and glycemic variabilities were assessed using FGM before and after SGLT2 inhibitor treatment. RESULTS: After 52 weeks of treatment, the total fat mass tended to be reduced (- 9.10% from baseline, P = 0.098). In addition, skeletal muscle mass also decreased (- 2.98% from baseline, P = 0.023). Although the basal insulin dose was reduced, SGLT2 inhibitors decreased HbA1c levels. FGM revealed that glycemic variabilities were also reduced, and time within the target glucose range increased (51.7% vs. 62.5%, P = 0.004). CONCLUSION: SGLT2 inhibitors have beneficial effects on glycemic variabilities and fat mass reductions in patients with type 1 diabetes mellitus. However, loss of skeletal muscle is a major concern; therefore, caution is required when using SGLT2 inhibitors in lean patients with type 1 diabetes mellitus. TRIAL REGISTRATION: University Hospital Medical Information Network Clinical Trial Registry (UMIN000042407).

Effects of ipragliflozin versus metformin in combination with sitagliptin on bone and muscle in Japanese patients with type 2 diabetes mellitus: Subanalysis of a prospective, randomized, controlled study (PRIME-V study).

AIMS/INTRODUCTION: Recent randomized clinical trials have suggested that sodium-glucose cotransporter 2 inhibitors might reduce cardiovascular events and heart failure, and have renal protective effects. Despite these remarkable benefits, the effects of sodium-glucose cotransporter 2 inhibitors on bone and muscle are unclear. MATERIALS AND METHODS: A subanalysis of a randomized controlled study was carried out to evaluate the effects of the sodium-glucose cotransporter 2 inhibitor, ipragliflozin, versus metformin on bone and muscle in Japanese patients with type 2 diabetes mellitus (baseline body mass index ≥22 kg/m2 and hemoglobin A1c 7-10%) who were already receiving sitagliptin. These patients were randomly administered ipragliflozin 50 mg or metformin 1,000-1,500 mg daily. The effects of these medications on the bone formation marker, bone alkali phosphatase; the bone resorption marker, tartrate-resistant acid phosphatase 5b (TRACP-5b); handgrip strength; abdominal cross-sectional muscle area; and bone density of the fourth lumbar vertebra were evaluated. RESULTS: After 24 weeks of treatment, the changes in bone density of the fourth lumbar vertebra, handgrip strength and abdominal cross-sectional muscle area were not significantly different between the two groups. However, TRACP-5b levels increased in patients treated with ipragliflozin compared with patients treated with metformin (median 11.94 vs -10.30%, P < 0.0001), showing that ipragliflozin can promote bone resorption. CONCLUSIONS: There were no adverse effects on bone or muscle when sitagliptin was used in combination with either ipragliflozin or metformin. However, ipragliflozin combination increased the levels of TRACP-5b. A long-term study is required to further understand the effects of this TRACP-5b increase caused by ipragliflozin.

Distinct regions of Galpha13 participate in its regulatory interactions with RGS homology domain-containing RhoGEFs.

Galpha12 and Galpha13 transduce signals from G protein-coupled receptors to RhoA through RhoGEFs containing an RGS homology (RH) domain, such as p115 RhoGEF or leukemia-associated RhoGEF (LARG). The RH domain of p115 RhoGEF or LARG binds with high affinity to active forms of Galpha12 and Galpha13 and confers specific GTPase-activating protein (GAP) activity, with faster GAP responses detected in Galpha13 than in Galpha12. At the same time, Galpha13, but not Galpha12, directly stimulates the RhoGEF activity of p115 RhoGEF or nonphosphorylated LARG in reconstitution assays. In order to better understand the molecular mechanism by which Galpha13 regulates RhoGEF activity through interaction with RH-RhoGEFs, we sought to identify the region(s) of Galpha13 involved in either the GAP response or RhoGEF activation. For this purpose, we generated chimeras between Galpha12 and Galpha13 subunits and characterized their biochemical activities. In both cell-based and reconstitution assays of RhoA activation, we found that replacing the carboxyl-terminal region of Galpha12 (residues 267-379) with that of Galpha13 (residues 264-377) conferred gain-of-function to the resulting chimeric subunit, Galpha12C13. The inverse chimera, Galpha13C12, exhibited basal RhoA activation which was similar to Galpha12. In contrast to GEF assays, GAP assays showed that Galpha12C13 or Galpha13C12 chimeras responded to the GAP activity of p115 RhoGEF or LARG in a manner similar to Galpha12 or Galpha13, respectively. We conclude from these results that the carboxyl-terminal region of Galpha13 (residues 264-377) is essential for its RhoGEF stimulating activity, whereas the amino-terminal alpha helical and switch regions of Galpha12 and Galpha13 are responsible for their differential GAP responses to the RH domain.

Genetically unique microsporidian Encephalitozoon cuniculi strain type III isolated from squirrel monkeys.

Microsporidian spores were isolated from two squirrel monkeys (Saimiri sciureus) that had been bred at an animal-breeding colony in Japan. The spores were identified as Encephalitozoon cuniculi on the basis of nucleotide sequence analysis of the small-subunit (SSU) rRNA gene. The internal transcribed spacer (ITS) gene sequence revealed that these isolates were classified into genotype III because it contained tetrarepeats of 5'-GTTT-3'. However, the sequences of the polar tube protein (PTP) gene of the monkey isolates were not identical to a reported sequence of genotype III but were quite similar to a reported sequence of genotype II. On the other hand, sequence analysis of the spore wall protein 1 (SWP-1) gene revealed that the monkey isolates did not belong to any of genotypes I, II and III. These results suggest that the present E. cuniculi isolates of squirrel monkey origin are a new subtype of E. cuniculi ITS genotype III that can cause a disseminated infection.

Helicobacter cinaedi infection in patients with diabetes: a case report.

BACKGROUND: Helicobacter cinaedi causes bacteremia without characteristic clinical symptoms and is firstly isolated from human immunodeficiency virus (HIV)-positive homosexual men. FINDINGS: Here we describe, for the first time case report, two female patients with diabetes who had H. cinaedi bacteremia. Some cases of H. cinaedi bacteremia may require long-term administration of multiple antibiotics prior to the resolution of infection. CONCLUSIONS: Therefore, these cases indicate that it is important to consider H. cinaedi in patients with diabetes presenting with bacteremia, especially in patients with poor glycemic control.

Galpha 12 activates Rho GTPase through tyrosine-phosphorylated leukemia-associated RhoGEF.

Heterotrimeric G proteins, G12 and G13, have been shown to transduce signals from G protein-coupled receptors to activate Rho GTPase in cells. Recently, we identified p115RhoGEF, one of the guanine nucleotide exchange factors (GEFs) for Rho, as a direct link between Galpha13 and Rho [Kozasa, T., et al. (1998) Science 280, 2109-2111; Hart, M. J., et al. (1998) Science 280, 2112-2114]. Activated Galpha13 stimulated the RhoGEF activity of p115 through interaction with the N-terminal RGS domain. However, Galpha12 could not activate Rho through p115, although it interacted with the RGS domain of p115. The biochemical mechanism from Galpha12 to Rho activation remained unknown. In this study, we analyzed the interaction of leukemia-associated RhoGEF (LARG), which also contains RGS domain, with Galpha12 and Galpha13. RGS domain of LARG demonstrated Galpha12- and Galpha13-specific GAP activity. LARG synergistically stimulated SRF activation by Galpha12 and Galpha13 in HeLa cells, and the SRF activation by Galpha12-LARG was further stimulated by coexpression of Tec tyrosine kinase. It was also found that LARG is phosphorylated on tyrosine by Tec. In reconstitution assays, the RhoGEF activity of nonphosphorylated LARG was stimulated by Galpha13 but not Galpha12. However, when LARG was phosphorylated by Tec, Galpha12 effectively stimulated the RhoGEF activity of LARG. These results demonstrate the biochemical mechanism of Rho activation through Galpha12 and that the regulation of RhoGEFs by heterotrimeric G proteins G1213 is further modulated by tyrosine phosphorylation.

Critical role of lysine 204 in switch I region of Galpha13 for regulation of p115RhoGEF and leukemia-associated RhoGEF.

Heterotrimeric G proteins of the G12 family regulate the Rho GTPase through RhoGEFs that contain an amino-terminal regulator of G protein signaling (RGS) domain (RGS-RhoGEFs). Direct regulation of the activity of RGS-RhoGEFs p115 or leukemia-associated RhoGEF (LARG) by Galpha13 has previously been demonstrated. However, the precise biochemical mechanism by which Galpha13 stimulates the RhoGEF activity of these proteins has not yet been well understood. Based on the crystal structure of Galphai1 in complex with RGS4, we mutated the Galpha13 residue lysine 204 to alanine (Galpha13K204A) and characterized the effect of this mutation in its regulation of RGS-RhoGEFs p115 or LARG. Compared with wild-type Galpha13, Galpha13K204A induced much less serum-response factor activation when expressed in HeLa cells. Recombinant Galpha13K204A exhibits normal function in terms of nucleotide binding, basal GTP hydrolysis, and formation of heterotrimer with betagamma. We found that lysine 204 of Galpha13 is important for interaction with the RGS domain of p115 or LARG and for the GTPase-activating protein activity of these proteins. In addition, the K204A mutation of Galpha13 impaired its regulation of the RhoGEF activity of p115 or LARG. We conclude that lysine 204 of Galpha13 is important for interaction with RGS-RhoGEFs and is critically involved in the regulation of their activity.

Rat cerebral endothelial cells express trk C and are regulated by neurotrophin-3.

Cerebral endothelial cells (CEC) are critical for formation of the vascular system in the mammalian central nervous system (CNS). We focused on the neurotrophin (NT) for its possible involvement in signaling for the regulation of CEC to control formation and maintenance of the vascular system in CNS in comparison of rat cerebral endothelial cells (RCEC) with rat aortic endothelial cells (RAEC). We found that (1) trk C, a receptor for neurotrophin-3 (NT-3), is dominantly expressed in RCEC, but trk B, a receptor for brain-derived neurotrophic factor, is dominantly expressed in RAEC; (2) NT-3 inhibited the proliferation of RCEC; and (3) NT-3 stimulated the production of nitric oxide (NO) with increases in protein expression of endothelial NO synthase. These data indicated that NT may regulate and/or maintain the functions of the brain microvasculature through the regulation of CEC.