Dynamic regulation of palmitoyltransferases by synaptic activity

The formation and remodelling of synaptic contacts require the precise distribution and trafficking of proteins to specialized compartments. This dynamic trafficking of synaptic proteins is partly controlled by palmitoylation, which is the most common form of post-translational lipid modification in the brain. Notably, several studies have shown that synaptic proteins can be differentially palmitoylated in response to stress and synaptic activity. However, it is unclear how changes in synaptic activity alters protein palmitoylation. To further understand the mechanism underlying activity-induced differential palmitoylation of proteins, primary rat hippocampal cultures were used to test whether increased synaptic activity impacts transcriptional regulation or post-translational modifications of palmitoylating (zDHHCs) and depalmitoylating (ABHD17) enzymes. There were no overall changes in the transcriptional profile of the 23 DHHC enzymes nor the thioesterase, ABHD17. Post-translational modifications were not observed for zDHHC8 following increased synaptic activity. In contrast, changes were identified in the dynamic phosphorylation and/or palmitoylation of zDHHC2, zDHHC5, zDHHC6 and zDHHC9 that impact the stability or enzymatic activity of the enzymes. These modifications are likely to be important for downstream palmitoylation of synaptic proteins and the modulation of synapse plasticity.Medicine, Faculty ofGraduat

Recent Advances in Cellulose-Based Structures as the Wound-Healing Biomaterials: A Clinically Oriented Review

Application of wound-healing/dressing biomaterials is amongst the most promising approaches for wound repair through protection from pathogen invasion/contamination, maintaining moisture, absorbing exudates, modulating inflammation, and facilitating the healing process. A wide range of materials are used to fabricate wound-healing/dressing biomaterials. Active wound-healing/dressings are next-generation alternatives for passive biomaterials, which provide a physical barrier and induce different biological activities, such as antibacterial, antioxidant, and proliferative effects. Cellulose-based biomaterials are particularly promising due to their tunable physical, chemical, mechanical, and biological properties, accessibility, low cost, and biocompatibility. A thorough description and analysis of wound-healing/dressing structures fabricated from cellulose-based biomaterials is discussed in this review. We emphasize and highlight the fabrication methods, applied bioactive molecules, and discuss the obtained results from in vitro and in vivo models of cellulose-based wound-healing biomaterials. This review paper revealed that cellulose-based biomaterials have promising potential as the wound-dressing/healing materials and can be integrated with various bioactive agents. Overall, cellulose-based biomaterials are shown to be effective and sophisticated structures for delivery applications, safe and multi-customizable dressings, or grafts for wound-healing applications