Biology subjects

Krawczyk, E.

Publications and source records attributed to Krawczyk, E..

3 recordsLinked to original sources

bioRxiv2026

ERRγ deletion in podocytes accelerates aging related kidney disease

We have recently demonstrated that treatment of aged mice with a pan-ERR agonist reverses age-related increase in urinary albumin, decrease in podocyte density, impaired mitochondrial function, and inflammation. The contribution of individual isoforms of ERRs however has not been determined. Since the aging kidney showed a possible compensatory increased expression of ERR{gamma} in the podocytes, in the face of decreased ERR expression, in the present study we aimed to determine the role of ERR{gamma} in aging podocyte. To this end, we cross bred ERR{gamma} floxed mice with podocin-Cre mice to achieve a podocyte-specific ERR{gamma} deletion. While these mice at 3 months of age showed no effect on albuminuria compared to the wild type, when the mice were aged to 21 months of age, there was a significant increase in albuminuria and decrease in podocyte density. Furthermore, we found that the podocyte deletion of ERR{gamma} primarily targeted the expression of mitochondrial biogenesis regulator PGC-1, and mitochondrial fatty acid oxidation enzymes CPT1a and MCAD in the kidney. Electron Microscopy (EM) revealed thickened glomerular basement membrane and diffuse podocyte foot process effacement, as well as severe mitochondrial damage including cristae abnormalities, fragmentation, and changes indicative of altered fusion and fission dynamics. Fluorescence Lifetime Imaging Microscopy (FLIM) to determine NADH and FAD lifetimes indicate a metabolic shift from mitochondrial oxidative phosphorylation towards glycolysis, and decrease in mitochondrial redox capacity. Considering a significantly decreased expression of ERR in aging podocytes plus its traditional role in mitochondrial function, these studies using podocyte ERR{gamma} deletion suggested an overlapping mechanism for ERR/ERR{gamma} to act as modulators of age-related mitochondrial dysfunction and age-related kidney disease.

pharmacology and toxicology↗

bioRxiv2025

The non-steroidal mineralocorticoid receptor (MR) antagonist (FINERENONE) reverses Western diet-induced kidney disease by enhancing mitochondrial metabolism and decreasing lipid accumulation and inflammation

Mineralocorticoid receptor (MR) overactivation plays a crucial role in the pathogenesis of chronic kidney disease, as well as several cardiovascular and arterial diseases. Current studies determined the mechanisms of the beneficial kidney effects of the non-steroidal MR antagonist Finerenone (FN) in a mouse model of western diet-induced obesity and insulin resistance. 10-week-old male C57BL/6J mice were fed a low fat (LF) or a western diet (WD) for 12 weeks followed by treatment with either vehicle or finerenone (FN) for another 14 weeks (intervention studies) until they were 36 weeks old. Finerenone treatment prevented a) the increased albuminuria and kidney injury molecule 1 (KIM1), b) the expanded extracellular mesangial matrix, and podocyte injury, c) fibronectin, collagen IV, CD45 and CD68 immunostaining, d) glomerular basement membrane disruption, podocyte foot process loss, and mitochondrial structural abnormalities, e) the pro-inflammatory cytokines (MCP1), innate immunity pathways (TLR2, STING, STAT3), and fibrosis markers fibronectin, TGF{beta} and Pai1, and f) the increased kidney cholesterol levels. There was also reduced expression of nuclear receptor ERR{gamma} without changes in ERR in WD-fed mice whereas both ERR and ERR{gamma} expression levels increased after Finerenone treatment. NADH lifetime analysis showed decreased bound NADH, compatible with decreased mitochondrial OXPHOS in the kidneys of WD-fed mice compared to controls, which was prevented by finerenone treatment. In conclusion, Finerenone treatment exhibits a renal protective role and prevents the progression of kidney disease by regulating mitochondrial function, most likely via ERR{gamma}, and reducing lipid accumulation and inflammation.

pharmacology and toxicology↗

bioRxiv2017

Expanding primary cells from mucoepidermoid and other salivary gland neoplasms for genetic and chemosensitivity testing

Restricted availability of cell and animal models is a rate-limiting step for investigation of salivary gland neoplasm pathophysiology and therapeutic response. Conditionally reprogrammed cell (CRC) technology enables establishment of primary epithelial cell cultures from patient material. This study tested a translational workflow for acquisition, expansion and testing of CRC-derived primary cultures of salivary gland neoplasms from patients presenting to an academic surgical practice. Results showed cultured cells were sufficient for epithelial cell-specific transcriptome characterization to detect candidate therapeutic pathways and fusion genes in addition to screening for cancer-risk-associated single nucleotide polymorphisms (SNPs) and driver gene mutations through exome sequencing. Focused study of primary cultures of a low-grade mucoepidermoid carcinoma demonstrated Amphiregulin-Mechanistic Target of Rapamycin-AKT/Protein kinase B (AKT) pathway activation, identified through bioinformatics and subsequently confirmed as present in primary tissue and preserved through different secondary 2D and 3D culture media and xenografts. Candidate therapeutic testing showed that the allosteric AKT inhibitor MK2206 reproducibly inhibited cell survival across different culture formats. In contrast, the cells appeared resistant to the adenosine triphosphate competitive AKT inhibitor GSK690693. Procedures employed here illustrate an approach for reproducibly obtaining material for pathophysiological studies of salivary gland neoplasms, and other less common epithelial cancer types, that can be executed without compromising pathological examination of patient specimens. The approach permits combined genetic and cell-based physiological and therapeutic investigations in addition to more traditional pathologic studies and can be used to build sustainable bio-banks for future inquiries.

cancer biology↗