Regulatory significance of CULLIN2 in neuronal differentiation and regeneration.

BACKGROUND: Scaffold proteins coordinate multiple signalling pathways by integrating various proteins but the role of these proteins in neuronal pathways remains to be elucidated. The present study focused to evaluate the expression of the scaffold protein CULLIN2 in neuronal cells. METHODS: The neuronal precursor cell line N2A was differentiated to neurons in-vitro with retinoic acid and biochemical assays were used to understand the gene expression profiling of CULLIN2. Moreover, neddylation inhibitor MLN4924 was used to inhibit the activity of CULLIN2 and the downstream substrates were validated. Finally, the role of CULLIN2 in nerve regeneration was evaluated in an in vivo zebrafish model. RESULTS: Experimental data showed that the neuronal cells N2A have lower expression of CULLIN2 compared to skin cell lines (HaCaT and A431) and inactivation with the neddylation inhibitor resulted in cell death. Furthermore differentiating the neural precursor cell line into neurons with retinoic acid enhanced the expression of CULLIN2. Examining downstream signalling molecules with the neddylation inhibitor illuminates that MLN4924 treatment influences the cytokine signalling cascade (JAK-STAT) in neuronal cells. Moreover, for the first time, we show that the ubiquitin ligase protein CULLIN2 is perturbed in neural regeneration. Expression profile of CULLIN2 was significantly decreased in response to a nerve injury in Zebra fish and as the nerve regenerates there is corresponding reduction in the mRNA levels. CONCLUSION: During differentiation CULLIN2 is upregulated whereas during regeneration there is significant downregulation. Thus, our findings reveal a crucial role of the scaffold protein CULLIN2 in nerve differentiation and regeneration which can be vital for the treatment of nerve injury.

Applications of molybdenum oxide nanoparticles impregnated collagen scaffolds in wound therapeutics.

INTRODUCTION: The highly complex pathophysiology of the wound micro-environment demands the development of a multi-faceted system which would enhance the wound healing cascade. Incorporation of nanotechnology in wound therapeutics has opened up new avenues to tourment the diseased condition. Amongst the various types of nanoparticles molybdenum oxide nanoparticles posses various inherent properties that makes it a versatile material to be used in healing. Incorporation of Molybdenum nanoparticles into collagen scaffolds would provide a synergistic and sequential healing process ensuring the formation of a fully functional tissue. MATERIALS AND METHODS: The physico-chemical characterization of the synthesized materials were done using SEM and FT-IR techniques. The bicompatibility and cell proliferation were tested using HaCaT cell lines. Pro-angiogenic ability of the scaffold was tested using CAM assay and Chick aortic arch assay. Finally the in-vivo wound healing ability of the material was tested by creating wound of about 6 cm2 on the dorsal side of Wistar rats and observed for about 21 days. RESULTS: The characterization of the scaffold revealed the presence MoO3 nanoparticles and their structural integrity within the scaffold. The synthesized MoO3-collagen nanocomposite was found to be biocompatible and hemocompatible. The in-vitro studies demonstrated that the MoO3-collagen scaffold significantly increased the cell adhesion and migration to nearly 2 fold. The MoO3 embedded collagen sheets synergistically favoured neovascularization and re-epithelization,which would potentially enhance therapeutic efficiency of the scaffold. The nanocomposite also encouraged results in in-vivo analysis, the Wistar rats treated with MoO3-collagen scaffolds showed complete healing in about 15 days. CONCLUSION: The fabricated MoO3-collagen scaffold was found to play an important role in all major events of wound healing such as adhesion, migration, proliferation and angiogenesis. The in-vivo healing assay also proved that the healing rate of animals treated with the samples was comparatively faster. Further research using various trace elements would open up promising avenues in healing therapeutics.

Decorin mediated biomimetic PCL-gelatin nano-framework to impede scarring.

Scars occur as a result of fibrosis after tissue damage or surgery and reports suggest that excessive Transforming growth factor-ß (TGF-ß) activity during the process of wound healing leads to progressive fibrosis. Decorin is an extracellular matrix (ECM) protein which regulates collagen fibrillogenesis. However, targeted delivery and effective protein therapy remains a challenge owing to degradation byproteases. Hence, we aimed to deliver Decorin in a sustainable mode for the reduction of TGF-ß levels and subsequent scar formation. Herein, we have fabricated PCL-Gelatin bio-mimetic scaffolds to optimize the bio-activity and provide localized delivery of recombinant Decorin. The degradation and drug release patterns reveals that this biomaterial is biodegradable and offers sustained release of the recombinant Decorin. Decorin loaded nanofiber displayed lower adhesion and proliferation rates in in-vitro conditions. Moreover, Decorin loaded scaffolds demonstrated morphological changes in cells, specifically targeting the myofibroblast. The expression of TGF-ß was also scrutinized to understand the effect of Decorin loaded nanofibers. Besides, in the in-vitro fibrotic model, Decorin loaded nanofibers efficiently reduced the expression of ECM related proteins. Therefore, we report the sustained delivery of the recombinant Decorin from nanofiber dressing to potentially obstruct scar formation during the process of wound healing.