Feeding the Kidney Researcher Pipeline through R25-NIDDK Funded Summer Undergraduate Research Fellowships: A Student Perspective

Profilin1 is required for prevention of mitotic catastrophe in murine and human glomerular diseases

The progression of proteinuric kidney diseases is associated with podocyte loss, but the mechanisms underlying this process remain unclear. Podocytes reenter the cell cycle to repair double-stranded DNA breaks. However, unsuccessful repair can result in podocytes crossing the G1/S checkpoint and undergoing abortive cytokinesis. In this study, we identified Pfn1 as indispensable in maintaining glomerular integrity - its tissue-specific loss in mouse podocytes resulted in severe proteinuria and kidney failure. Our results suggest that this phenotype is due to podocyte mitotic catastrophe (MC), characterized histologically and ultrastructurally by abundant multinucleated cells, irregular nuclei, and mitotic spindles. Podocyte cell cycle reentry was identified using FUCCI2aR mice, and we observed altered expression of cell-cycle associated proteins, such as p21, p53, cyclin B1, and cyclin D1. Podocyte-specific translating ribosome affinity purification and RNA-Seq revealed the downregulation of ribosomal RNA-processing 8 (Rrp8). Overexpression of Rrp8 in Pfn1-KO podocytes partially rescued the phenotype in vitro. Clinical and ultrastructural tomographic analysis of patients with diverse proteinuric kidney diseases further validated the presence of MC podocytes and reduction in podocyte PFN1 expression within kidney tissues. These results suggest that profilin1 is essential in regulating the podocyte cell cycle and its disruption leads to MC and subsequent podocyte loss.

Impacts of a University Research Assistant Program: The First Decade

Purpose

There is a declining number of physician-scientists. Little is published about the potential for university student experiences to contribute to the pipeline of future researchers. The purpose of this study was to describe a unique university research program and report the outcomes of the first 10 years.

Method

The University Research Assistant Program (URAP) was described including course content, research experiences, and student composition. Outcomes of URAP student contributions to the literature and research presentations was reported. URAP students were also surveyed to assess their perspectives on the impact of the URAP program on career choices after graduation.

Results

URAP began as an independent study course and grew into for-credit university courses. A total of 212 students have taken at least one semester and 88 responded to the survey. All students who participated in URAP have graduated, and 77% (n = 68) reported the URAP program prepared them to reach their career goals. Most graduates pursued health care careers including medical school (55%), Master's programs in health care (29%), or PhD in health care (5%). URAP students participated in research involving 11 different pediatric subspecialties. Many attained co-authorship of abstracts and publications, 53 first-authored an abstract presentation and 7 manuscripts.

Conclusions

URAP significantly influenced university students who overwhelmingly entered health care fields. While difficult to assess if these early experiences will influence participation as future physician -scientists, these students made meaningful research contributions while enrolled in these courses.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40670-023-01852-6.