Anti-KRT2 monoclonal antibody, clone Lt3.453.8.2

Background. Proteinuria, one of the main manifestations of nephrotic syndrome, is an important risk factor for the progression of renal diseases. Podocyte foot processes (FPs) injury induces proteinuria in most renal diseases. The podocyte cytoskeleton plays important roles in maintaining the normal morphology of FPs. However, the underlying cytoskeletal component that initiates and regulates the dynamic changes of FPs is still unclear. Here, the involved podocyte cytoskeletal molecules were explored on different days in puromycin aminonucleoside nephropathy rats. Methods. Microarray analysis of isolated glomeruli was performed at Day 2, Day 10 and Day 15 in puromycin aminonucleoside nephropathy rats. Cytoskeletal genebank was established by sorting with the keyword 'cytoskeleton' from PUBMED genebank to identify the differential cytoskeleton genes. Microarray results were further confirmed by real-time PCR, western blot and double immunolabelling to validate their localizations. Results. Nine different cytoskeletal genes were found to be involved in the dynamic changes of FPs in puromycin aminonucleoside nephropathy rats, including six up-regulated (Tagln, Actr2, Dnm3, Arc, Vcl and Birc5) and three down-regulated (Krt2-7, Nebl and Tnncl). The differential expression of transgelin, survivin, arp2, cytokeratin7 and vinculin was verified by real-time PCR and western blot. Double immunolabelling revealed that five cytoskeletal proteins indeed colocalized with podocyte specific markers synaptopodin or alpha-actinin-4. In addition, similar expression and distribution changes were detected in patients with proteinuric renal diseases and puromycin aminonucleoside-treated podocytes. Conclusions. We identified five novel podocyte cytoskeletal proteins and found that they were associated with the dynamic changes of FPs in podocyte injury.

Comprehensive studies of the effects of prolonged exposure to space conditions and the overload experienced during landing on physiological and biochemical changes in the human body are extremely important in the context of planning long-distance space flights, which can be associated with constant overloads and various risk factors for significant physiological changes. Exhaled breath condensate (EBC) can be considered as a valuable subject for monitoring physiological changes and is more suitable for long-term storage than traditional monitoring subjects such as blood and urine. Herein, the EBC proteome changes due to the effects of spaceflight factors are analyzed. Thirteen EBC samples were collected from five Russian cosmonauts (i) one month before flight (background), (ii) immediately upon landing modules in the field (R0) after 169-199 days spaceflights, and (iii) on the seventh day after landing (R+7). Semi-quantitative label-free EBC proteomic analysis resulted in 164 proteins, the highest number of which was detected in EBC after landing (R0). Pathways enrichment analysis using the GO database reveals a large group of proteins which take part in keratinization processes (CASP14, DSG1, DSP, JUP, and so on). Nine proteins (including KRT2, KRT9, KRT1, KRT10, KRT14, DCD, KRT6C, KRT6A, and KRT5) were detected in all three groups. A two-sample Welch's t-test identified a significant change in KRT2 and KRT9 levels after landing. Enrichment analysis using the KEGG database revealed the significant participation of detected proteins in pathogenic E. coli infection (ACTG1, TUBA1C, TUBA4A, TUBB, TUBB8, and YWHAZ), which may indicate microbiota changes associated with being in space. This assumption is confirmed by microbial composition analysis. In general, the results suggest that EBC can be used for noninvasive monitoring of health status and respiratory tract pathologies during spaceflights, and that the obtained data are important for the development of medicine for use in extreme situations. Data are available from ProteomeXchange using the identifier PXD014191.