Hong, S.-K. | Search bioRxiv

bioRxiv2026

4-Hexylresorcinol Enhances Skeletal Muscle Glucose Handling through the AMPK-GLUT4 axis in Diabetic Rats

BackgroundSkeletal muscle insulin resistance in diabetes is characterized by impaired GLUT4 availability and dysregulated AMP-activated protein kinase (AMPK) signaling. We investigated whether 4-hexylresorcinol (4HR) modulates glucose metabolism and AMPK-acetyl-CoA carboxylase (ACC)-GLUT4 signaling in vitro and in streptozotocin (STZ)-induced diabetic rats. MethodsDifferentiated C2C12 myotubes were treated with 4HR (0.1-10 {micro}M) and assessed for glucose uptake, GLUT4 translocation, protein stability, proteasome involvement, and AMPK/ACC phosphorylation. In vivo, streptozotocin (STZ)-induced diabetic rats received subcutaneous 4HR (10 mg{middle dot}kgL{superscript 1}, 5 times/week for 7 weeks). Glycemic control, insulin secretion, muscle glycogen content, and serum protein profiles were evaluated. Results4HR markedly increased glucose uptake (>5-fold vs. control, p<0.05), accompanied by increased phosphorylation of AMPK (Thr172) and ACC (Ser79), and redistribution of GLUT4 toward the cell periphery. Cycloheximide chase and proteasome inhibition experiments indicated partial stabilization of GLUT4. In diabetic rats, 4HR reduced fasting glycemia, improved glucose tolerance, elevated circulating insulin, and restored glycogen-rich fibers in skeletal muscle. Serum profiling revealed a metabolic and anti-inflammatory shift, with increased AMPK, p-ACC, GLUT1, LGR4, LDHA, and PGC-1, alongside suppression of NF-{kappa}B and TNF-. Conclusion4HR improves skeletal muscle glucose metabolism in STZ-induced diabetes, associated with activation of AMPK-ACC signaling, preservation of GLUT4 expression, and restoration of glycogen content. These findings highlight 4HR as a promising candidate for further investigation in diabetic muscle dysfunction and metabolic disease.

molecular biology↗

bioRxiv2018

Novel allelic variant of Lpa1 gene associated with a significant reduction in seed phytic acid content in rice (Oryza sativa L.)

In plants, myo-inositol-1,2,3,4,5,6-hexakisphosphate (InsP6), also known as phytic acid (PA), is a major component of organic phosphorus (P), and accounts for up to 85% of the total P in seeds. In rice (Oryza sativa L.), PA mainly accumulates in rice bran, and chelates mineral cations, resulting in mineral deficiencies among brown rice consumers. Therefore, considerable efforts have been focused on the development of low PA (LPA) rice cultivars. In this study, we performed genetic and molecular analyses of OsLpa1, a major PA biosynthesis gene, in Sanggol, a low PA mutant variety developed via chemical mutagenesis of Ilpum rice cultivar. Genetic segregation and sequencing analyses revealed that a recessive allele, lpa1-3, at the OsLpa1 locus (Os02g0819400) was responsible for a significant reduction in seed PA content in Sanggol. The lpa1-3 gene harboured a point mutation (C623T) in the fourth exon of the predicted coding region, resulting in threonine (Thr) to isoleucine (Ile) amino acid substitution at position 208 (Thr208Ile). Three-dimensional analysis of Lpa1 protein structure indicated that myo-inositol 3-monophosphate [Ins(3)P1] kinase binds to the active site of Lpa1, with ATP as a cofactor for catalysis. Furthermore, the presence of Thr208 in the loop adjacent to the entry site of the binding pocket suggests that Thr208Ile substitution is involved in regulating enzyme activity via phosphorylation. Therefore, we propose that Thr208Ile substitution in lpa1-3 reduces Lpa1 enzyme activity in Sanggol, resulting in reduced PA biosynthesis.

plant biology↗