👤 Masaya Tanahashi

In the PEMA-FL study in patients with metabolic dysfunction-associated steatotic liver disease (MASLD), pemafibrate was shown to significantly decrease low-density lipoprotein cholesterol (LDL-C) levels. We aimed to investigate the mechanisms of pemafibrate-induced LDL-C reduction in patients with MASLD by conducting an additional sub-analysis of the PEMA-FL study. The PEMA-FL study randomized 118 patients with MASLD to receive pemafibrate or placebo for 72 weeks. This sub-analysis examined the percentage change in LDL-C and related lipid markers by tertile of baseline LDL-C levels and the correlation between these changes in the pemafibrate group. Pemafibrate significantly decreased LDL-C levels approximately 25% (p＜0.001 at all timepoints) from baseline in the highest tertile of baseline LDL-C levels (≥ 137.5 mg/dL), with similar trends for non-high-density lipoprotein cholesterol (non-HDL-C) and apolipoprotein B (ApoB) levels. Lipoprotein (a) [Lp(a)] levels decreased only in patients with the highest baseline LDL-C levels. Regardless of the baseline LDL-C levels, pemafibrate altered the LDL particle profile (increased LDL particle size and decreased the number); reduced lathosterol, β-sitosterol, and campesterol; and increased angiopoietin-like protein 3 (ANGPTL3). The percentage change in LDL-C positively correlated with that in ApoB, non-HDL-C, Lp(a), lathosterol, β-sitosterol, and campesterol but not HDL-C and ANGPTL3. Pemafibrate reduced LDL-C, ApoB, and non-HDL-C levels in patients with MASLD, and the effect was greater in those with higher baseline LDL-C levels. Pemafibrate may clinically benefit patients with MASLD by improving LDL-C levels and the LDL particle profile. Show less

To clarify the genetic background of ameloblastoma, expression of beta-catenin, and mutational status of genes involved in Wnt signaling pathway were investigated. We analyzed beta-catenin and cyclin D1 in 18 cases of ameloblastoma by immunohistochemical staining, and searched for mutations in CTNNB1 (gene for beta-catenin), APC, AXIN1, and AXIN2 by polymerase chain reaction (PCR) and direct sequencing method. We detected membranous and occasionally cytoplasmic expression of beta-catenin in 16 of 18 cases (89%), and nuclear expression of beta-catenin principally in the peripheral columnar cells in 11 of 18 cases (61%). In nine of the 18 cases (50%), we detected the expression of cyclin D1 principally in the peripheral columnar cells. However, there was no correlation between nuclear expressions of beta-catenin and cyclin D1. No missense mutations were found in CTNNB1, APC, AXIN1, and AXIN2 in all cases except for silent mutation and already-known single nucleotide polymorphism. Mutations in CTNNB1, APC, AXIN1, and AXIN2 are not implicated in nuclear accumulation of beta-catenin, and that the expression of cyclin D1 is accelerated independently of beta-catenin in ameloblastomas. Other Wnt signaling members or alternative pathways involved in the degradation of beta-catenin should be subject of further investigation. Show less

In an attempt to rectify the hyperglycemic state in obese insulin resistant db/db mice, a transgenic line was generated (db/db-CDK4(R24C)) that expresses a constitutively active form of cyclin-dependent kinase 4 (CDK4/R24C) under the control of the insulin promoter. Compared with non-transgenic db/db littermates, adult db/db-CDK4(R24C) mice show near-complete glycemic normalization and improved plasma lipid concentrations, but are also more susceptible to weight gain and have significantly lower plasma adiponection levels. They have striking islet hypertrophy and beta-cell hyperplasia, and retain an insulin secretory response during the glucose tolerance test. We examined the expression of several key regulatory transcription factor genes involved in lipid and glucose metabolism in insulin target tissues of db/db-CDK4(R24C) as well as db/db mice, and found that the expression levels of members of the peroxisome proliferator-activated receptor (PPAR) family are highly associated with metabolic alterations in a gene- and tissue-specific manner. We show for the first time that the Ppar-delta in skeletal muscle and white adipose tissues is transcriptionally down-regulated in db/db mice. The db/db-CDK4(R24C) mice present a novel model of leptin-resistant obesity with compensatory hyperinsulinemia and normalized blood glucose levels, and thus may be useful for future studies that aim to dissect relationships between insulin and leptin signaling. Show less