Methionine Promotes Milk Synthesis through the BRCC36-BRG1-mTOR Signaling Axis in Mammary Epithelial Cells.

Methionine (Met) functions as a key stimulator on the mTOR signaling pathway and milk synthesis, but the molecular mechanism remains incompletely understood. We investigated the regulatory roles of BRCC36 in Met-stimulated milk lipid and protein synthesis, cell proliferation, and the mTOR signaling pathway. Knockdown of BRCC36 promoted milk lipid and protein synthesis in HC11 cells as well as cell proliferation by increasing the levels of mTOR gene transcription and protein phosphorylation. Conversely, the gene activation of BRCC36 had opposite effects. Furthermore, BRCC36 gene activation completely blocked Met stimulation on the BRG1 protein level and mTOR mRNA level and protein phosphorylation. BRCC36 bound to BRG1, and BRCC36 and BRG1 bound to the same region on the mTOR promoter. BRCC36 inhibited the BRG1 protein level and the binding of BRG1 to the mTOR promoter. Met decreased the BRCC36 protein level, and this effect was significantly attenuated by MG132 but not affected by cycloheximide or chloroquine. We further showed that Met increased BRCC36 ubiquitination degradation. Our findings reveal that Met promotes milk lipid and protein synthesis in MECs through the BRCC36-BRG1-mTOR signaling axis.

Frost-resistant and ultrasensitive strain sensor based on a tannic acid-nanocellulose/sulfonated carbon nanotube-reinforced polyvinyl alcohol hydrogel.

The operating temperature of hydrogels, especially at low temperatures, is crucial due to their wide applicability in soft robots, sensors, and electronic skin. Hydrogels are often used at room temperature, but their performance may deteriorate at low temperatures. Therefore, it is crucial to develop hydrogels that can be used at low temperatures to expand their range of use. Herein, we have proposed a simple one-pot method to prepare a frost-resistant (-70 °C) and conductive hydrogel consisting of a glycerol (Gly)-water binary solvent. We have added tannic acid (TA)-coated carboxymethylated cellulose nanofibrils (CMCNFs) to poly (vinyl alcohol) (PVA) as a functional filler to improve the hydrogel's mechanical properties. The introduction of sulfonated carbon nanotubes (SCNT) has provided the hydrogel with high conductivity (0.1 S/m), strain sensitivity (gauge factor of 3.76), and cyclic stability (1600 cycles). Due to the strong hydrogen bonding and physical entanglement effects between the components, the hydrogel exhibied excellent tensile properties (297 %), high toughness (0.44 MJ/m3), and a high Young's modulus (1.25 MPa). These characteristics ensure that the hydrogel is well suited for low-temperature environments, health monitoring, and wearable devices.