Biology subjects

Adams, V.

Publications and source records attributed to Adams, V..

3 recordsLinked to original sources

bioRxiv2026

Empagliflozin preserves mitochondrial function and reduces tubular injury in obese type 2 diabetic ZSF-1 rats

Diabetic nephropathy remains the leading cause of end-stage renal disease. The ZSF-1 rat model combines features known as the metabolic syndrome, such as type 2 diabetes mellitus, hypertension and obesity, developing progressive kidney disease. In this study, we investigated the nephroprotective mechanisms of the SGLT2 inhibitor empagliflozin, focusing on mitochondrial function. Obese ZSF-1 rats were randomized at 24 weeks of age to receive either placebo or empagliflozin for eight weeks, while lean ZSF-1 rats served as healthy controls. Kidney function, assessed by glomerular filtration rate (GFR), was significantly reduced in obese rats and was not improved by empagliflozin treatment. However, obese animals exhibited increased tubular injury, tubular cast formation, and elevated total and tubular proteinuria, all of which were attenuated by empagliflozin. Mitochondrial function was evaluated in freshly isolated cortical kidney mitochondria by measuring oxygen consumption. Obese ZSF-1 rats showed impaired respiratory capacity and reduced protein expression of oxidative phosphorylation (OXPHOS) complexes II, III, IV, and V, indicating mitochondrial dysfunction. Empagliflozin treatment improved mitochondrial function by enhancing complex I- and IV-linked respiration and restoring the expression of OXPHOS complexes II, III, and IV. In addition, empagliflozin treatment was linked to improved mitochondrial dynamics and modulation of autophagic activity, suggesting enhanced mitochondrial quality control. Overall, these findings demonstrate that empagliflozin exerts nephroprotective effects primarily at the tubular level in obese ZSF-1 rats. The beneficial effects appear to be mediated through improved mitochondrial function, enhanced mitochondrial integrity, and reduced tubular injury.

physiology↗

bioRxiv2024

Development of MHC Class I Blocking Peptides to Target Metabolic Dysfunction-Associated Steatohepatitis CD8+ T Cell Activation

MHC class I molecules play a crucial role in the immune system by presenting peptides derived from intracellular proteins to cytotoxic T lymphocytes (CTLs). This process is essential for immune surveillance and eliminating infected or malignant cells. In some diseases, the immune system fails to recognize and eliminate abnormal cells, leading to disease progression. Under conditions of metabolic dysfunction-associated steatohepatitis (MASH), subsets of CD8+ T cells have been identified as pathogenic, leading to inflammation and fibrosis. Therefore, explicitly targeting factors responsible for T cell activation may be necessary to prevent the onset of MASH and future complications such as cirrhosis or hepatocellular carcinoma. We have identified a specific MHC class I antigen that activates hepatic and splenic CD8+ T cells isolated from MASH mice. To specifically target the antigen, we developed two MHC H2-Kb blocking peptides, MHCP3 and MHCP5, that competitively inhibit the Ncf2 peptide from binding to H2-Kb and reduce activation and proliferation of CD8+ T cells. By inhibiting the recognition of specific antigens, these blocking peptides may prevent the activation of CD8+ T cells and progression of MASH.

immunology↗

bioRxiv2018

The specificity of ParR binding determines the compatibility of conjugative plasmids in Clostridium perfringens

Plasmids that encode the same replication machinery are generally unable to coexist in the same bacterial cell. However, Clostridium perfringens strains often carry multiple conjugative toxin or antibiotic resistance plasmids that are closely related and encode similar Rep proteins. In many bacteria, plasmid partitioning upon cell division involves a ParMRC system and there are ~10 different ParMRC families in C. perfringens, with differences in amino acid sequences between each ParM family (15% - 54% identity). Since plasmids encoding genes belonging to the same ParMRC family are not observed in the same strain, these families appear to represent the basis for plasmid compatibility in C. perfringens. To understand this process, we examined the key recognition steps between ParR DNA-binding proteins and their parC binding sites. The ParR proteins bound to sequences within a parC site from the same ParMRC family, but could not interact with a parC site from a different ParMRC family. These data provide evidence that compatibility of the conjugative toxin plasmids of C. perfringens is mediated by their parMRC-like partitioning systems. This process provides a selective advantage by enabling the host bacterium to maintain separate plasmids that encode toxins that are specific for different host targets.

microbiology↗