Engineering an autonomous VH domain to modulate intracellular pathways and to interrogate the eIF4F complex.

An attractive approach to target intracellular macromolecular interfaces and to model putative drug interactions is to design small high-affinity proteins. Variable domains of the immunoglobulin heavy chain (VH domains) are ideal miniproteins, but their development has been restricted by poor intracellular stability and expression. Here we show that an autonomous and disufhide-free VH domain is suitable for intracellular studies and use it to construct a high-diversity phage display library. Using this library and affinity maturation techniques we identify VH domains with picomolar affinity against eIF4E, a protein commonly hyper-activated in cancer. We demonstrate that these molecules interact with eIF4E at the eIF4G binding site via a distinct structural pose. Intracellular overexpression of these miniproteins reduce cellular proliferation and expression of malignancy-related proteins in cancer cell lines. The linkage of high-diversity in vitro libraries with an intracellularly expressible miniprotein scaffold will facilitate the discovery of VH domains suitable for intracellular applications.

Analysis of etiological composition and changing trend of chronic kidney disease / 中华健康管理学杂志

Objective:To analyze the etiological composition and changing trends in chronic kidney disease.Methods:CKD patients from our hospital were in cluded in the study from three separate periods, 173 patients from 1990-1991, 956 patients from 2009-2010, and 1440 patients from 2018-2019. The etiology of CKD in patients between the younger and middle-aged group and the elderly group were compared using the χ2 test, and the Bonferroni method was used to correct the pairwise comparisons.Results:The leading cause of CKD in 1990-1991, 2009-2010, and 2018-2019 was chronic glomerulonephritis (52%), chronic glomerulonephritis (35%), and diabetes (36%), respectively. The distribution of the etiologies was different signficantly among the three cohorts (χ2=74.375, P<0.001). Compared with 1990-1991, the percentage of CKD related to diabetes (χ2=14.847, P=0.001) and hypertension (χ2=12.279, P=0.002) significantly increased, while chronic glomerulonephritis showed a downward trend (χ2=19.976, P<0.001). Among the elderly CKD patients, the leading cause of CKD in the three cohorts was chronic glomerulonephritis (34%), diabetes (40%), and diabetes (43%), respectively. Conversely, diabetes and hypertension have become the predominant causes in 2009-2010 and 2018-2019. Although chronic glomerulonephritis remained the leading cause of CKD in the past 30 years, the percentage declined gradually among the younger and middle-aged patients with CKD. The percentage of CKD related to diabetes (χ2=31.345, P<0.001) and hypertension (χ2=15.485, P<0.001) significantly increased. In addition, in the 2018-2019 cohort, there were 494 patients with end-stage renal disease (ESRD), and the percentage of ESRD related to diabetes and hypertension were 48% and 37%, respectively. Conclusion:Diabetes and hypertension have become the predominant causes of CKD in Chinese elderly patients. Although chronic glomerulonephritis was the leading cause among the younger and middle-aged patients with CKD, the percentage declined gradually. Additionally, diabetes and hypertension were also the predominant causes of ESRD.

Macrocyclization of an all-d linear α-helical peptide imparts cellular permeability.

Peptide-based molecules hold great potential as targeted inhibitors of intracellular protein-protein interactions (PPIs). Indeed, the vast diversity of chemical space conferred through their primary, secondary and tertiary structures allows these molecules to be applied to targets that are typically deemed intractable via small molecules. However, the development of peptide therapeutics has been hindered by their limited conformational stability, proteolytic sensitivity and cell permeability. Several contemporary peptide design strategies are aimed at addressing these issues. Strategic macrocyclization through optimally placed chemical braces such as olefinic hydrocarbon crosslinks, commonly referred to as staples, may improve peptide properties by (i) restricting conformational freedom to improve target affinities, (ii) improving proteolytic resistance, and (iii) enhancing cell permeability. As a second strategy, molecules constructed entirely from d-amino acids are hyper-resistant to proteolytic cleavage, but generally lack conformational stability and membrane permeability. Since neither approach is a complete solution, we have combined these strategies to identify the first examples of all-d α-helical stapled and stitched peptides. As a template, we used a recently reported all d-linear peptide that is a potent inhibitor of the p53-Mdm2 interaction, but is devoid of cellular activity. To design both stapled and stitched all-d-peptide analogues, we used computational modelling to predict optimal staple placement. The resultant novel macrocyclic all d-peptide was determined to exhibit increased α-helicity, improved target binding, complete proteolytic stability and, most notably, cellular activity.