The interplay between Hsf4 and Hsf1 plays an important role in the regulation of lens homeostasis. However, the mechanism of the intermolecular association involved is still unclear. In this paper, we find that reconstitution of Hsf4b into Hsf4-/- lens epithelial (mLEC/Hsf4-/-) cells can simultaneously downregulate Hsp70 expression and upregulate the expression of small heat shock proteins Hsp25 and αB-crystallin at both RNA and protein levels. ChIP assay results indicate Hsf4b, which binds to the promoters of Hsp90α, Hsp70.3, Hsp25 and αB-crystallin but not Hsp70.1, can inhibit Hsf1 binding to Hsp70.3 promoter and the heat shock mediated Hsp70 promoter activity by reducing Hsf1 protein expression. Hsf4b N-terminal hydrophobic region can interact with Hsf1 N-terminal hydrophobic region. Their interaction impairs Hsf1's intramolecular interaction between the N- and C-terminal hydrophobic regions, leading to Hsf1's cytosolic retention and protein degradation. Both lysosome inhibitors (chloroquine, pepstatin A plus E64d) and proteasome inhibitor MG132 can inhibit Hsf4-mediated Hsf1 protein degradation, but MG132 can induce Hsf1 activation as well. Upregulation of Hsf4b can significantly inhibit cisplatin and staurosporine induced lens epithelial cell apoptosis through direct upregulation of Hsp25 and αB-crystallin expression. Taken together, our results imply that upregulation of Hsf4b modulates the expression pattern of heat shock proteins in lens tissue by either directly binding to their promoters or promoting Hsf1 protein degradation. Moreover, upregulation of Hsf4b protects lens cell survival by upregulating anti-apoptotic pathways. These studies reveal a novel regulatory mechanism between Hsf1 and Hsf4b in modulating lens epithelial cell homeostasis.

A novel nerve conductor made out of polypyrrole (PPY), collagen (Coll) and nano-strontium substituted bioactive glass (n-Sr@BG) (PPY/Coll/n-Sr@BG) was fabricated by electrospinning. SEM demonstrated that the mean distances across of the pores in the nerve channels were under 15 mm and more prominent than 2 mm. These biocomposite films had biomimetic morphology, bigger porosity and moderately higher surface territory than customary nerve channels, consequently not just allowing the transportation of nerve development factor and glucose yet, in addition, hindering the section of lymphatic tissue and fibroblasts. The consistent filaments of the nerve can copy the characteristic ECM, which is valuable to cell bond, cell multiplication, and cell movement. PPY/Coll/n-Sr@BG demonstrated great cell fondness rate, which is useful for neurilemma cell cells bond, relocation and expansion. Its great viability empowers its wellbeing animal models. Sciatic nerve deformity was crossed over an animal model with PPY/Coll/n-Sr@BG in rodents. PPY/Coll and autotransplants were utilized as control gatherings. Contrasted with PPY/Coll and PPY/Coll/n-Sr@BG accomplished fundamentally increasingly viable recovery of sciatic nerve wounds following 24 weeks implantation and the mean distance across of muscle fibres occasions bigger than that in PPY/Coll/n-Sr@BG, and it was nearer to that in control. The rejuvenated nerve filaments in PPY/Coll/n-Sr@BG had an increasingly standard round shape, the thickness of neuro-filaments in c was more than those in PPY/Coll, and was near that in control. ARTICLE HISTORY