Biology subjects

Zeczycki, T. N.

Publications and source records attributed to Zeczycki, T. N..

5 recordsLinked to original sources

bioRxiv2025

Deletion of Murine Endothelial Bag3 Alters the Cellular Proteome Among Organs of Origin

BAG3 (Bcl-2 associated athanogene 3) is a multifunctional protein with pleiotropic effects in multiple cell types. Despite our knowledge of its role in cardiovascular disease, its specific role in endothelial cells (ECs) is unknown. The purpose of this study was to identify differences in the EC proteome of multiple tissues before and after cell specific deletion of Bag3. We hypothesized that BAG3 loss would uniquely alter the baseline proteome landscape of ECs in each tissue. Cdh5(PAC)-CreERT2;Bag3f/f mice received tamoxifen (KO; n=18) or vehicle (WT; n=18) and tissues (brain, heart, lung, and peripheral skeletal muscle-skm) were collected for FACS sorting of ECs from equal numbers of male and female mice at >22 weeks of age, followed by LC-MS/MS label-free proteomics. Initial comparisons of the WT proteomes between tissues revealed differential abundance of EC proteins (p<0.05), including: 379 brain v heart; 325 brain v lung; 501 brain v skm; 354 heart v lung; 107 heart v skm; and 442 lung v skm. Additionally, the EC mitochondrial proteome was unique to each tissue of origin, with significantly (p<0.05) higher proportions dedicated to complexes I, III, IV and V, in heart compared to the other tissues. KO demonstrated the largest effect on skm ECs, increasing 30 proteins (Mybpc2 L2FC=4.81; PFKM L2FC=3.02) and decreasing 65 (CDC42 L2FC=-2.44; Prpf8 L2FC=-2.24). Overall, these results demonstrate that the EC proteome of different tissues is unique and that the loss of BAG3 in these cells differentially alters a small proportion of the EC specific proteome.

physiology↗

bioRxiv2025

Phase-Specific Antibiotic Resistance Mechanisms in an Escherichia coli B Strain

The majority of antibiotics developed to date target the fast-growing phase of bacteria, which typically occurs during active infection and resembles the exponential growth phase of laboratory-grown cultures. However, many pathogenic bacteria in the human body occupy environments where nutrients are limited and persist in a low-metabolic state, mirroring the stationary phase observed in laboratory-grown cultures. Bacteria in this latter phase are generally more resistant to antibiotics and are often responsible for recurrent infections. A comprehensive understanding of metabolic processes in both the exponential and stationary phases of bacterial growth could facilitate the development of phase-specific antibiotics. In this study, we adopted an untargeted proteomics approach to establish similarities and differences in the exponential and stationary phase proteome landscapes in BLR (DE3) cells, an Escherichia coli B strain. Our findings are consistent with previous studies, which show that metabolic processes such as translation and ribosome biogenesis decrease during the stationary phase compared to the fast-growing exponential phase, whereas tricarboxylic acid cycle activity increases. Importantly, our data reveal that distinct antibiotic resistance pathways are activated during the exponential and stationary phases, underscoring the potential for developing phase-specific antibiotic therapies.

biochemistry↗

bioRxiv2024

Matrix Metalloproteinase-2 as a novel regulator of glucose utilization by adipocytes

Glucose transporter 4 (GLUT4) expression on white adipocytes is critical for absorbing excess blood glucose, failure of which promotes hyperglycemia. Matrix metalloproteinases (MMPs) play a crucial role in remodeling the white adipose tissue (WAT) during obesity. MMPs have multiple protein substrates, and surprisingly, it is unknown if they can directly target GLUT4 on the adipocyte surface and impair glucose absorption. We identified MMP2 as the highly active gelatinase, a class of MMP, in the gonadal WAT of high-fat diet-induced obese mice. In vitro, metabolic studies in 3T3-L1 adipocytes revealed MMP2 attenuated glucose absorption and glycolysis, which were recovered by an MMP2 inhibitor. In silico structural analysis using AlphaFold identified a putative MMP2 cleavage site on the extracellular domain of GLUT4. Further, in a substrate competition assay, a peptide mimicking the MMP2 cleavage motif on GLUT4 attenuated the cleavage of an MMP substrate by MMP2. Altogether, our results suggest a novel mechanism of impaired glucose absorption by adipocytes, which may contribute to hyperglycemia during obesity. ARTICLE HIGHLIGHTSO_LIIt is unknown if MMPs directly affect adipocyte metabolism via targeting adipocyte surface proteins. C_LIO_LIWe aimed to determine the highly active gelatinases, a class of MMP, in the white adipose tissue of obese mice, and examined its effect on adipocyte glucose metabolism. C_LIO_LIMMP2 was the highly active gelatinase in obese adipose tissue and, in vitro, MMP2 reduced adipocyte glucose metabolism, in part, by targeting the GLUT4 receptor. C_LIO_LIA harmful role of MMP2 is implicated in cardiometabolic diseases and our novel finding on the role of MMP2 on glucose metabolism may add to the pathogenesis of the diseases. C_LI

pathology↗

bioRxiv2024

Maternal exercise alters placental proteome in an exercise mode-specific manner

Maternal exercise is a widely recommended and safe intervention associated with the improvement of maternal gestational and infant metabolic health. While various modes of exercise are deemed safe during pregnancy, the effects of supervised maternal aerobic, resistance, and combination (aerobic+resistance) exercise remain understudied. Specifically, it remains unknown how different modes of maternal exercise affect the placenta, an organ central to maternal-fetal communication and successful pregnancy outcomes. This study aimed to characterize the placental proteomic changes in response to controlled and supervised maternal exercise during gestation. Results showed that the placental proteomic landscape changes in an maternal exercise mode-specific way. Additionally, proteomics revealed that [~]20% of the identified placental proteins were associated with maternal exercise volume during gestation. These results highlight the differential effect maternal exercise modes have on the placental proteome and further implicate the placenta in mediating the effects of maternal exercise on maternal and infant health.

developmental biology↗

bioRxiv2019

Mitochondrial PE potentiates respiratory enzymes to amplify skeletal muscle aerobic capacity

Exercise capacity is a strong predictor of all-cause mortality. Skeletal muscle mitochondrial respiratory capacity, its biggest contributor, adapts robustly to changes in energy demands induced by contractile activity. While transcriptional regulation of mitochondrial enzymes has been extensively studied, there is limited information on how mitochondrial membrane lipids are regulated. Herein, we show that exercise training or muscle disuse alters mitochondrial membrane phospholipids including phosphatidylethanolamine (PE). Addition of PE promoted, whereas removal of PE diminished, mitochondrial respiratory capacity. Surprisingly, skeletal muscle-specific inhibition of mitochondrial-autonomous synthesis of PE caused a respiratory failure due to metabolic insults in the diaphragm muscle. While mitochondrial PE deficiency coincided with increased oxidative stress, neutralization of the latter did not rescue lethality. These findings highlight the previously underappreciated role of mitochondrial membrane phospholipids in dynamically controlling skeletal muscle energetics and function.

physiology↗