Complex actions of sodium glucose transporter-2 inhibitors on lipids, calcific atherosclerosis, and bone density.

PURPOSE OF REVIEW: Inhibitors of sodium-glucose cotransporter-2 (SGLT2) lower renal glucose reabsorption and, thus, are used to treat patients with type 2 diabetes mellitus. Clinical trials coincidentally showed that SGLT2 inhibitors also benefitted patients with heart failure. This review explores the impact of SGLT2 inhibitors on other aspects of cardiovascular disease and skeletal health. RECENT FINDINGS: In some, but not all, clinical and preclinical studies, SGLT2 inhibitors are found to reduce serum levels of free fatty acids and triglycerides. Their effects on total and low-density lipoprotein cholesterol and cardiac function also vary. However, SGLT2 inhibitors reduce lipid accumulation in the liver, kidney, and heart, and alter expression of lipid metabolism genes. Effects on free fatty acid uptake in abdominal fat depots depend on the location of adipose tissue. In male, but not female, mice, SGLT2 inhibitors reduce the atherosclerotic lesions and aortic calcium deposition. With respect to skeletal health, recent literature has reported conflicting associations with the risks of fracture and amputation. SUMMARY: Studies suggest that SGLT2 inhibitors reduce tissue lipid accumulation, and in a sex-dependent manner, atherosclerosis and vascular calcification. However, their effects on lipid levels and bone health are complex and remain to be established.

Effects of Empagliflozin on Vascular and Skeletal Mineralization in Hyperlipidemic Mice.

Cardiovascular disease and osteoporosis, major causes of morbidity and mortality, are associated with hyperlipidemia. Recent studies show that empagliflozin (EMPA), an inhibitor of sodium-glucose cotransporter-2 (SGLT2), improves cardiovascular health. In preclinical animal studies, EMPA mitigates vascular calcification in the males but its effects in the females are not known. Thus, we used female mice to test the effects of EMPA on calcification in the artery wall, cardiac function, and skeletal bone. By serial in vivo microCT imaging, we followed the progression of aortic calcification and bone mineral density in young and older female Apoe-/- mice fed a high-fat diet with or without EMPA. The two different age groups were used to compare early vs. advanced stages of aortic calcification. Results show that EMPA treatment increased urine glucose levels. Aortic calcium content increased in both the controls and the EMPA-treated mice, and EMPA did not affect progression of aortic calcium content in both young and older mice. However, 3-D segmentation analysis of aortic calcium deposits on microCT images revealed that EMPA-treated mice had significantly less surface area and volume of calcified deposits as well as fewer numbers of deposits than the control mice. To test for direct effects on vascular cell calcification, we treated murine aortic smooth muscle cells with EMPA, and results showed a slight inhibition of alkaline phosphatase activity and inflammatory matrix calcification. As for skeletal bone, EMPA-treated mice had significantly lower BMD than the controls in both the lumbar vertebrae and femoral bones in both young and older mice. The findings suggest that, in hyperlipidemic female mice, unlike males, SGLT2 inhibition with empagliflozin does not mitigate progression of aortic calcification and may even lower skeletal bone density.

Effects of LP533401 on vascular and bone calcification in hyperlipidemic mice.

Peripheral serotonin levels are associated with cardiovascular disease risk. We previously found that serum serotonin levels are higher in hyperlipidemic mice than wild-type mice. Evidence also suggests that serotonin regulates biomineralization, in that serotonin treatment augments TNF-a-induced matrix calcification of aortic valve interstitial cells and that a selective inhibitor of peripheral serotonin, LP533401, rescues bone loss induced by ovariectomy in mice. Thus, in the present study, we examined the effects of LP533401 on both skeletal bone mineral density (BMD) and aortic calcification in both young and older hyperlipidemic mice susceptible to calcific atherosclerosis and bone loss. By serial in vivo microCT imaging, we assessed BMD and aortic calcification of Apoe-/- mice fed an atherogenic (high cholesterol) diet alone or mixed with LP533401. Results show that in the young mice, LP533401 blunted skeletal bone loss in lumbar vertebrae but not in femurs. LP533401 also blunted the initial development of aortic calcification but not its progression. Echocardiographic analysis showed that LP533401 blunted both hyperlipidemia-induced cardiac hypertrophy and left ventricular dysfunction. In the older mice, LP533401 increased the BMD of lumbar vertebrae but not of femurs. The aortic calcification progressed in both controls and LP533401-treated mice, but, at post-treatment, LP533401-treated mice had significantly less aortic calcification than the controls. These findings suggest that LP533401 mitigates adverse effects of hyperlipidemia on skeletal and vascular tissues in site- and stage-dependent manners.

Microarchitectural Changes of Cardiovascular Calcification in Response to In Vivo Interventions Using Deep-Learning Segmentation and Computed Tomography Radiomics.

BACKGROUND: Coronary calcification associates closely with cardiovascular risk, but its progress is accelerated in response to some interventions widely used to reduce risk. This paradox suggests that qualitative, not just quantitative, changes in calcification may affect plaque stability. To determine if the microarchitecture of calcification varies with aging, Western diet, statin therapy, and high intensity, progressive exercise, we assessed changes in a priori selected computed tomography radiomic features (intensity, size, shape, and texture). METHODS: Longitudinal computed tomography scans of mice (Apoe-/-) exposed to each of these conditions were autosegmented by deep learning segmentation, and radiomic features of the largest deposits were analyzed. RESULTS: Over 20 weeks of aging, intensity and most size parameters increased, but surface-area-to-volume ratio (a measure of porosity) decreased, suggesting stabilization. However, texture features (coarseness, cluster tendency, and nonuniformity) increased, suggesting heterogeneity and likely destabilization. Shape parameters showed no significant changes, except sphericity, which showed a decrease. The Western diet had significant effects on radiomic features related to size and texture, but not intensity or shape. In mice undergoing either pravastatin treatment or exercise, the selected radiomic features of their computed tomography scans were not significantly different from those of their respective controls. Interestingly, the total number of calcific deposits increased significantly less in the 2 intervention groups compared with the respective controls, suggesting more coalescence and/or fewer de novo deposits. CONCLUSIONS: Thus, aging and standard interventions alter the microarchitectural features of vascular calcium deposits in ways that may alter plaque biomechanical stability.

On Demand Biosensors for Early Diagnosis of Cancer and Immune Checkpoints Blockade Therapy Monitoring from Liquid Biopsy.

Recently, considerable interest has emerged in the development of biosensors to detect biomarkers and immune checkpoints to identify and measure cancer through liquid biopsies. The detection of cancer biomarkers from a small volume of blood is relatively fast compared to the gold standard of tissue biopsies. Traditional immuno-histochemistry (IHC) requires tissue samples obtained using invasive procedures and specific expertise as well as sophisticated instruments. Furthermore, the turnaround for IHC assays is usually several days. To overcome these challenges, on-demand biosensor-based assays were developed to provide more immediate prognostic information for clinicians. Novel rapid, highly precise, and sensitive approaches have been under investigation using physical and biochemical methods to sense biomarkers. Additionally, interest in understanding immune checkpoints has facilitated the rapid detection of cancer prognosis from liquid biopsies. Typically, these devices combine various classes of detectors with digital outputs for the measurement of soluble cancer or immune checkpoint (IC) markers from liquid biopsy samples. These sensor devices have two key advantages: (a) a small volume of blood drawn from the patient is sufficient for analysis, and (b) it could aid physicians in quickly selecting and deciding the appropriate therapy regime for the patients (e.g., immune checkpoint blockade (ICB) therapy). In this review, we will provide updates on potential cancer markers, various biosensors in cancer diagnosis, and the corresponding limits of detection, while focusing on biosensor development for IC marker detection.

Silver nanoparticles fabricated using medicinal plant extracts show enhanced antimicrobial and selective cytotoxic propensities.

Nanoparticles fabricated using medicinal plant extract have great potential in the area of nanomedicine. High surface-to-volume ratio of nanoparticle enhances the local active biomolecules concentration, leading to many fold increase in the medicinal potentials. The silver nanoparticles (AgNPs) fabricated using indigenous medicinal plants of India, Azadirachta indica and Syzygium cumini, have shown a significant effect on the viability of prokaryotic and eukaryotic cells. Biofabrication of AgNP was confirmed using different spectroscopic and microscopic techniques. Extraction and purification of AgNP from non-conjugated plant moieties are done using centrifugation and size exclusion chromatography. The cytotoxic propensity of AgNP formulations was screened against Gram-positive (Bacillus subtilis), Gram-negative (Escherichia coli) bacteria, cancerous (HT1080) and non-cancerous (HEK293) cell lines. The nanoparticle formulations showed a relatively higher cytotoxic propensity against Gram-positive bacteria and cancerous cell lines. In addition, the surface roughness and reactive oxygen species (ROS) measurements indicated that AgNP formulations mediate the cell activity predominantly by ROS-mediated disruptive change in membrane morphology upon direct interaction with the membrane. Hence, the nanoparticle formulations show an enhanced selective cytotoxic propensity towards Gram-positive bacteria and cancerous cell lines.