Early effects of insulin therapy on cholesterol synthesis and absorption markers in patients with type 2 diabetes

Summary: Background &amp; aim: Metabolic abnormalities in type 2 diabetes affect the production and the clearance of plasma lipoproteins. Although the improvement of low-density lipoprotein cholesterol, triglyceride, and high-density lipoprotein cholesterol levels are important targets in diabetes, it is not established how changes occur in the production and clearance of plasma lipoproteins in the treatment of diabetes. Serum non-cholesterol sterols are introduced as practical markers to assess endogenous cholesterol synthesis and intestinal cholesterol absorption. This study aimed to investigate the effects of insulin therapy on cholesterol synthesis and absorption markers in patients with type 2 diabetes. Methods: This was a single-center, prospective, 2-week, longitudinal pilot study. Patients with type 2 diabetes who were admitted to start insulin therapy without using lipid-lowering agents were recruited. On the day of hospitalization, the patients discontinued all oral hypoglycemic agents and started with basal-bolus insulin therapy. Cholesterol synthesis (lathosterol) and absorption (campesterol, sitosterol, and cholestanol) markers were assessed at baseline and after 2 weeks of insulin treatment. Results: In eighteen subjects, the mean age of the patients was 56 ± 10 years (mean ± SD). At baseline, body mass index was 24.3 ± 5.0 kg/m2, and HbA1c was 11.6 ± 1.7%. After 2 weeks of insulin therapy, total cholesterol (from 205 ± 48 to 184 ± 43 mg/dL, p = 0.004), lathosterol (from 2.6 ± 1.3 to 2.0 ± 0.7 μg/mL, p = 0.001), campesterol (from 4.3 ± 2.7 to 3.0 ± 2.1 μg/mL, p < 0.0001), and sitosterol (from 2.4 ± 1.6 to 1.7 ± 1.4 μg/mL, p < 0.0001) were significantly decreased, and cholestanol (from 2.5 ± 1.0 to 2.3 ± 0.8 μg/mL, p = 0.05) tended to decrease. Conclusion: This study showed that insulin therapy reduces cholesterol synthesis and absorption markers in patients with type 2 diabetes hospitalized within 2 weeks. The decrease in cholesterol synthesis and absorption seems to be useful for improving lipid metabolism and reducing the risk of atherosclerosis. Further randomized controlled studies are required to confirm the efficacy of insulin therapy for cholesterol synthesis and absorption markers

Identification of the recognition sequence and target proteins for DJ-1 protease

DJ-1, the product of familial Parkinson's disease gene and an oncogene, is a cysteine protease which plays a role in anti-oxidative stress reaction. In this study, we identified the recognition sequence for DJ-1 protease by using recombinant DJ-1 and a peptide library. Protease activity of DJ-1 lacking C-terminal alpha-helix (DJ-1 Delta H9) was stronger than that of full-sized DJ-1, and the most susceptible sequence digested by DJ-1 Delta H9 was valine-lysine-valine-alanine (VKVA) under the optimal conditions of pH 5.5 and 0 mM NaCl. Divalent ions, especially Cu2+, were inhibitory to DJ-1's protease activity. c-abl oncogene 1 product (ABL1) and kinesin family member 1B (KIF1B) containing VKVA were digested by DJ-1 Delta H9. Structured summary of protein interactions: DJ-1 cleaves IUF1B by enzymatic study (View interaction) DJ-1 cleaves ABLI by enzymatic study (View interaction) (C) 2013 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved

Fasting plasma glucose level-based formula for estimating starting daily dose in basal-bolus insulin therapy

Abstract There is no standard formula for estimating the starting daily dose (SDD) of basal-bolus insulin therapy (BBT). We aimed to develop a formula for estimating SDD and evaluate its efficacy and safety in patients with type 2 diabetes hospitalized for BBT. In the first study (n = 104), we retrospectively analyzed the relationship between peak daily dose (PDD) during hospitalization and clinical parameters. The PDD was significantly associated with fasting plasma glucose (FPG) (R = 0.449, P < 0.0001) and HbA1c levels (R = 0.384, P < 0.0001) but not body weight, body mass index, body surface area, or serum C-peptide levels. Based on the results, we developed a formula for estimating SDD using FPG levels: SDD (U/day) = 0.08 × FPG (mg/dL). In the second study (n = 405), we assessed efficacy and safety of the formula by evaluating the M-value from the daily glucose profile and assessing the frequency of hypoglycemia (blood glucose level < 70 mg/dL). When BBT was initiated using the FPG level-based formula, the M-values decreased from 61.0 ± 52.8 to 12.8 ± 10.8 (P < 0.0001), and hypoglycemia was observed in only 3/405 cases (0.74%) under the SDD. The FPG level-based formula is useful for estimating SDD in BBT and is safe for clinical use

Additional file 1 of Ipragliflozin and sitagliptin differentially affect lipid and apolipoprotein profiles in type 2 diabetes: the SUCRE study

Supplementary Material

Construction of Continuous Capillary Networks Stabilized by Pericyte-like Perivascular Cells

Construction of small and continuous capillary networks is a fundamental challenge for the development of three-dimensional (3D) tissue engineering. In particular, to construct mature and stable capillary networks, it is important to consider interactions between endothelial cells and pericytes. This study aimed to construct stable capillary networks covered by pericyte-like perivascular cells, which maintain the lumen of small diameter similar to that of capillary structures in vivo. Vascular sprouting, capillary extension, and stabilization were investigated using a 3D angiogenesis model containing human umbilical vein endothelial cells (HUVECs) and mesenchymal stem cells (MSCs) in a microfluidic device. A series of HUVEC:MSC ratios was tested; the ratio was found to be an important factor in the construction of capillary structures. We found that stable capillary networks that were covered by MSC-derived perivascular cells can be constructed at 1:1 HUVEC:MSC ratio. The constructed capillary networks had continuous lumens with <10-μm diameter, which were maintained for at least 21 days. This angiogenic process and basement membrane formation were regulated by HUVEC-MSC interactions. Construction of capillary networks is a fundamental challenge for the development of three-dimensional (3D) tissue engineering. However, it is not well understood how to construct stable capillary networks that maintain a luminal size similar to that of capillary structures in vivo (i.e., <10 μm diameter). In this study, we demonstrated the construction of stable capillary networks covered by pericyte-like perivascular cells using an in vitro 3D angiogenesis model by optimizing interactions between endothelial cells and perivascular cells. Our 3D angiogenesis model can be combined with 3D culture of epithelial cells in the context of vascularization of 3D tissue-engineered constructs. Keywords:3D angiogenesis model; microfluidic device; pericytes; mesenchymal stem cellsJapan Society for Promotion of Science (16H03173 and 25560208