Renal tubular epithelial cells (TECs) can initiate an adaptive response to completely recover from mild acute kidney injury (AKI), whereas severe injury often leads to persistence of maladaptive repair and progression to kidney fibrosis. Through profiling of active DNA regulatory elements by ATAC-seq, we reveal widespread, dynamic changes in the chromatin accessibility of TECs after ischemia–reperfusion injury. We show that injury-specific domains of regulatory chromatin become accessible prior to gene activation, creating poised chromatin states to activate the consequent gene expression program and injury response. We further identify RXRα as a key transcription factor in promoting adaptive repair. Activation of RXRα by bexarotene, an FDA-approved RXRα agonist, restores the chromatin state and gene expression program to protect TECs against severe kidney injury. Together, our findings elucidate a chromatin-mediated mechanism underlying differential responses of TECs to varying injuries and identify RXRα as a therapeutic target of acute kidney injury.

Jute fiber with high content and large aspect ratio is directly used to prepare PLA composites to show the effect on structure and properties. By comparing with bamboo powder, it is found that the large aspect ratio of jute fiber is helpful to form a crisscross structure in PLA composites to provide a strong framework. And the larger amount of jute fiber leads to the stronger framework in the PLA composites. Accordingly, the high comprehensive mechanical properties are produced of the PLA composites with jute fiber. Only through the simple blending of 70% jute fiber and PLA, the flexural strength and flexural modulus respectively reach 94.0 ± 4.4 MPa and 9116.7 ± 127.2 MPa, which obviously exceed the mechanical properties of PLA/bamboo blends. The addition of jute fiber also improves the thermal resistance of PLA composites as well as the crystallization ability and perfection of PLA. All the results exhibit the advantages of high content filling of jute fiber with large aspect ratio to modify PLA. Utilization of biomass filler with high content and large aspect ratio will provide an important methodology to expand the application capacity of fully degradable composites in many areas.