Empagliflozin improves kidney senescence induced by D-galactose by reducing sirt1-mediated oxidative stress

The role of SIRT1 in kidney diseases

SIRT1, a nicotinamide adenine dinucleotide (NAD +)-dependent class III histone deacetylase, exhibits a high level of expression within renal tissues. It has garnered considerable recognition for its pivotal role in modulating signaling pathways intricately linked with the aging process; however, it extends beyond this in the organism. The literature reports that SIRT1 regulates biological processes such as glucose metabolism, lipid metabolism, oxidative stress, inflammation, autophagy, endoplasmic reticulum stress, and apoptosis. Therefore, our study reviews the primary mechanisms by which SIRT1 induces kidney disease and the regulation of related signaling pathways in different models of renal disease. We also discuss commonly studied SIRT1-targeted interventional drugs reported in the literature, including inhibitors (e.g., Ex-527) and activators (e.g., resveratrol). This study aims to provide theoretical foundations and clinical insights for the development and screening of clinical drugs targeting SIRT1, aiming at enhanced scientific approaches for the prevention and treatment of kidney diseases.

Empagliflozin reduces renal calcium oxalate deposition in hyperoxaluria rats induced with ethylene glycol-ammonium chloride

A retrospective study reported that empagliflozin reduced the risk of urinary stone events in patients with diabetes mellitus. To further investigate empagliflozin's potential, we conducted an animal experiment to determine whether empagliflozin can prevent renal stone formation in hyperoxaluria rats. Hyperoxaluria rat models were constructed by administrating 0.75 % ethylene glycol and 1 % ammonium chloride in water. The empagliflozin-treated rats were gauged with empagliflozin at different concentrations, and their body weight and blood sugar data were recorded. After 30 days of treatment, we obtained 24-h urine, kidney, and blood samples. The urine samples were subjected to component detection. Blood samples were prepared for component detection and cytokines detection. Renal samples were subjected to von Kossa staining, transmission electron microscopy, immunohistochemistry, and transcriptome sequencing analysis. Results showed that in empagliflozin-treated hyperoxaluria rats, renal crystal deposition and mitochondria injury, urinary concentration, and excretion of oxalate were significantly decreased. Additionally, plasma levels of VEGF, IL-2, IL-1β, and MCP-1 were decreased. Immunohistochemistry showed that renal expression of KIM-1, MCP-1 was significantly decreased in empagliflozin-treated hyperoxaluria rats. Transcriptome sequencing of renal tissue represented that 25 genes were down-regulated while 12 were up-regulated in empagliflozin-treated hyperoxaluria rats. These regulated genes were mainly enriched in fatty acid metabolism, insulin resistance, muscle contraction, bile secretion, and parathyroid metabolism. Our animal experiments found that empagliflozin could reduce urinary concentration and excretion of oxalate and inhibit renal inflammation, then abating renal calcium oxalate deposition in hyperoxaluria rats in a non-diabetic state.

Integrated approach to reducing polypharmacy in older people: exploring the role of oxidative stress and antioxidant potential therapy

Increased life expectancy, attributed to improved access to healthcare and drug development, has led to an increase in multimorbidity, a key contributor to polypharmacy. Polypharmacy is characterised by its association with a variety of adverse events in the older persons. The mechanisms involved in the development of age-related chronic diseases are largely unknown; however, altered redox homeostasis due to ageing is one of the main theories. In this context, the present review explores the development and interaction between different age-related diseases, mainly linked by oxidative stress. In addition, drug interactions in the treatment of various diseases are described, emphasising that the holistic management of older people and their pathologies should prevail over the individual treatment of each condition.

Neonatal exposure to high D-galactose affects germ cell development in neonatal testes organ culture

Excess exogenous supplementation of D-galactose (D-gal), a monosaccharide and reducing sugar, generates reactive oxygen species (ROS), leading to cell damage and death. ROS accumulation is critical in aging. Therefore, D-gal-induced aging mouse models are used in aging studies. Herein, we evaluated D-gal's effect on neonatal testis development using an in vitro organ culture method. Mouse testicular fragments (MTFs) derived from neonatal testes (postnatal day 5) were cultured with 500 mM D-gal for 5 days. D-gal-treated MTFs showed a significantly increased and decreased expression of undifferentiated and differentiated germ cell markers, respectively, with a substantial reduction in meiotic cells. In D-gal-exposed MTFs, expression levels of Sertoli cell markers (Sox9 and Wt1) increased, while those of StAR and 17β-HSD3, whose expressions are abundant in D-Gal treated adult Leydig cells, decreased. Additionally, the enzyme 3 β-HSD1, essential for steroidogenesis in Leydig cells, was significantly reduced in D-gal-exposed MTFs compared to that in controls.D-gal significantly increased the expression of Bad, Bax, and cleaved caspase-3 and -8. Via oxidative stress in MTF. Overall, D-gal negatively regulates germ cell and Leydig cell development in neonatal testes through pro-apoptotic mechanisms and ROS.

Empagliflozin protects against heart failure with preserved ejection fraction partly by inhibiting the senescence-associated STAT1-STING axis

Heart failure with preserved ejection fraction (HFpEF) is a mortal clinical syndrome without effective therapies. Empagliflozin (EMPA) improves cardiovascular outcomes in HFpEF patients, but the underlying mechanism remains elusive. Here, mice were fed a high-fat diet (HFD) supplemented with L-NAME for 12 weeks and subsequently intraperitoneally injected with EMPA for another 4 weeks. A 4D-DIA proteomic assay was performed to detect protein changes in the failing hearts. We identified 310 differentially expressed proteins (DEPs) (ctrl vs. HFpEF group) and 173 DEPs (HFpEF vs. EMPA group). The regulation of immune system processes was enriched in all groups and the interferon response genes (STAT1, Ifit1, Ifi35 and Ifi47) were upregulated in HFpEF mice but downregulated after EMPA administration. In addition, EMPA treatment suppressed the increase in the levels of aging markers (p16 and p21) in HFpEF hearts. Further bioinformatics analysis verified STAT1 as the hub transcription factor during pathological changes in HFpEF mice. We next treated H9C2 cells with IFN-γ, a primary agonist of STAT1 phosphorylation, to investigate whether EMPA plays a beneficial role by blocking STAT1 activation. Our results showed that IFN-γ treatment caused cardiomyocyte senescence and STAT1 activation, which were inhibited by EMPA administration. Notably, STAT1 inhibition significantly reduced cellular senescence possibly by regulating STING expression. Our findings revealed that EMPA mitigates cardiac inflammation and aging in HFpEF mice by inhibiting STAT1 activation. The STAT1-STING axis may act as a pivotal mechanism in the pathogenesis of HFpEF, especially under inflammatory and aging conditions.

SGLT2 inhibition to target kidney aging

Anti-aging therapy is the latest frontier in the world of medical science, especially for widespread diseases such as chronic kidney disease (CKD). Both renal aging and CKD are characterized by increased cellular senescence, inflammation and oxidative stress. A variety of cellular signalling mechanisms are involved in these processes, which provide new potential targets for therapeutic strategies aimed at counteracting the onset and progression of CKD. At the same time, sodium-glucose co-transporter 2 inhibitors (SGLT2is) continuously demonstrate large beneficial effects at all stages of the cardiorenal metabolic continuum. The broad-spectrum benefits of SGLT2is have led to changes in several treatment guidelines and to growing scientific interest in the underlying working principles. Multiple mechanisms have been studied to explain these great renal benefits, but many things remain to be solved. With this in mind, we provide an overview of the experimental evidence for the effects of SGLT2is on the molecular pathway's ability to modulate senescence, aging and parenchymal damage, especially at the kidney level. We propose to shed some light on the role of SGLT2is in kidney care by focusing on their potential to reduce the progression of kidney disease across the spectrum of aging and dysregulation of senescence.

Empagliflozin Induces Vascular Relaxation in Rat Coronary Artery Due to Activation of BK Channels

Purpose

The aim of this study was to investigate the effects and mechanisms of SGLT2 inhibitor empagliflozin on diabetic coronary function.

Methods

A rat diabetic model was established by injection of streptozotocin. Rats in the treated group were administered empagliflozin by gavage and rat coronary vascular tensions were measured after eight weeks. Large conductance calcium activated K+ channel currents were recorded using a patch clamp technique, while human coronary artery smooth muscle cells were used to explore the underlying mechanisms.

Results

After incubation with empagliflozin (10, 30, 100, 300, 1000 μmol/L), the Δ relaxation % of rat coronary arteries were 2.459 ± 1.304, 3.251 ± 1.119, 6.946 ± 3.407, 28.36 ± 11.47, 86.90 ± 3.868, respectively. Without and with empagliflozin in the bath solution, BK channel opening probabilities at a membrane potential of +60 mV were 0.0458 ± 0.0517 and 0.3413 ± 0.2047, respectively (p < 0.05, n = 4 cells). After incubation with iberiotoxin, the Δ tensions of rat coronary arteries in the control (Ctrl), untreated (DM), low empagliflozin (10 mg/kg/d)-treated (DM+L-EMPA) and high empagliflozin (30mg/kg/d)-treated (DM+H-EMPA) group were 103.20 ± 5.85, 40.37 ± 22.12, 99.47 ± 28.51, 78.06 ± 40.98, respectively (p < 0.01 vs Ctrl, n = 3-7; p < 0.001 vs DM+L-EMPA, n = 5-7). Empagliflozin restored high glucose-induced downregulation of Sirt1, Nrf2, and BK-β1, while the effect of empagliflozin disappeared in the presence of EX-527, a Sirt1 selective inhibitor.

Conclusion

Empagliflozin has a vasodilation effect on the coronary arteries in a concentration-dependent manner and can activate BK channels via the Sirt1-Nrf2 mechanism.

Redox signaling and modulation in ageing

In spite of considerable progress that has been reached in understanding how reactive oxygen species (ROS) interact with its cellular targets, several important challenges regarding regulatory effects of redox signaling mechanisms remain to be addressed enough in aging and age-related disorders. Redox signaling is precisely regulated in different tissues and subcellular locations. It modulates the homeostatic balance of many regulatory facilities such as cell cycle, circadian rhythms, adapting the external environments, etc. The newly proposed term "adaptive redox homeostasis" describes the transient increase in ROS buffering capacity in response to amplified ROS formation rate within a physiological range. Redox-dependent second messengers are generated in subcellular locations according to a specific set of rules and regulations. Their appearance depends on cellular needs in response to variations in external and internal stimulus. The intensity and magnitude of ROS signaling determines its downstream effects. This issue includes review and research papers in the context of redox signaling mechanisms and related redox-regulatory interventions, aiming to guide for understanding the degenerative processes of biological ageing and alleviating possible prevention approaches for age-related complications.