Aging results in an elevated burden of senescent cells, senescence‐associated secretory phenotype (SASP), and tissue infiltration of immune cells contributing to chronic low‐grade inflammation and a host of age‐related diseases. Recent evidence suggests that the clearance of senescent cells alleviates chronic inflammation and its associated dysfunction and diseases. However, the effect of this intervention on metabolic function in old age remains poorly understood. Here, we demonstrate that dasatinib and quercetin (D&Q) have senolytic effects, reducing age‐related increase in senescence‐associated β‐galactosidase, expression of p16 and p21 gene and P16 protein in perigonadal white adipose tissue (pgWAT; all p ≤ 0.04). This treatment also suppressed age‐related increase in the expression of a subset of pro‐inflammatory SASP genes (mcp1, tnf‐α, il‐1α, il‐1β, il‐6, cxcl2, and cxcl10), crown‐like structures, abundance of T cells and macrophages in pgWAT (all p ≤ 0.04). In the liver and skeletal muscle, we did not find a robust effect of D&Q on senescence and inflammatory SASP markers. Although we did not observe an age‐related difference in glucose tolerance, D&Q treatment improved fasting blood glucose (p = 0.001) and glucose tolerance (p = 0.007) in old mice that was concomitant with lower hepatic gluconeogenesis. Additionally, D&Q improved insulin‐stimulated suppression of plasma NEFAs (p = 0.01), reduced fed and fasted plasma triglycerides (both p ≤ 0.04), and improved systemic lipid tolerance (p = 0.006). Collectively, results from this study suggest that D&Q attenuates adipose tissue inflammation and improves systemic metabolic function in old age. These findings have implications for the development of therapeutic agents to combat metabolic dysfunction and diseases in old age.

Systemic inhibition of the mammalian target of rapamycin (mTOR) delays aging and many age‐related conditions including arterial and metabolic dysfunction. However, the mechanisms and tissues involved in these beneficial effects remain largely unknown. Here, we demonstrate that activation of S6K, a downstream target of mTOR, is increased in arteries with advancing age, and that this occurs preferentially in the endothelium compared with the vascular smooth muscle. Induced endothelial cell‐specific deletion of mTOR reduced protein expression by 60–70%. Although this did not significantly alter arterial and metabolic function in young mice, endothelial mTOR reduction reversed arterial stiffening and improved endothelium‐dependent dilation (EDD) in old mice, indicating an improvement in age‐related arterial dysfunction. Improvement in arterial function in old mice was concomitant with reductions in arterial cellular senescence, inflammation, and oxidative stress. The reduction in endothelial mTOR also improved glucose tolerance in old mice, and this was associated with attenuated hepatic gluconeogenesis and improved lipid tolerance, but was independent of alterations in peripheral insulin sensitivity, pancreatic beta cell function, or fasted plasma lipids in old mice. Lastly, we found that endothelial mTOR reduction suppressed gene expression of senescence and inflammatory markers in endothelial‐rich (i.e., lung) and metabolically active organs (i.e., liver and adipose tissue), which may have contributed to the improvement in metabolic function in old mice. This is the first evidence demonstrating that reducing endothelial mTOR in old age improves arterial and metabolic function. These findings have implications for future drug development.

BACKGROUND: Much of what we know about insulin resistance is based on studies from metabolically active tissues such as the liver, adipose tissue, and skeletal muscle. Emerging evidence suggests that the vascular endothelium plays a crucial role in systemic insulin resistance; however, the underlying mechanisms remain incompletely understood. Arf6 (ADP ribosylation factor 6) is a small GTPase that plays a critical role in endothelial cell function. Here, we tested the hypothesis that the deletion of endothelial Arf6 will result in systemic insulin resistance. METHODS: We used mouse models of constitutive endothelial cell–specific Arf6 deletion (Arf6 ^f/− Tie2Cre ⁺ ) and tamoxifen-inducible Arf6 knockout (Arf6 ^f/f Cdh5CreER+). Endothelium-dependent vasodilation was assessed using pressure myography. Metabolic function was assessed using a battery of metabolic assessments including glucose and insulin tolerance tests and hyperinsulinemic-euglycemic clamps. We used a fluorescence microsphere–based technique to measure tissue blood flow. Skeletal muscle capillary density was assessed using intravital microscopy. RESULTS: Endothelial Arf6 deletion impaired insulin-stimulated vasodilation in white adipose tissue and skeletal muscle feed arteries. The impairment in vasodilation was primarily due to attenuated insulin-stimulated nitric oxide bioavailability but independent of altered acetylcholine-mediated or sodium nitroprusside–mediated vasodilation. Endothelial cell–specific deletion of Arf6 also resulted in systematic insulin resistance in normal chow–fed mice and glucose intolerance in high-fat diet–fed obese mice. The underlying mechanisms of glucose intolerance were reductions in insulin-stimulated blood flow and glucose uptake in the skeletal muscle and were independent of changes in capillary density or vascular permeability. CONCLUSIONS: Results from this study support the conclusion that endothelial Arf6 signaling is essential for maintaining insulin sensitivity. Reduced expression of endothelial Arf6 impairs insulin-mediated vasodilation and results in systemic insulin resistance. These results have therapeutic implications for diseases that are associated with endothelial cell dysfunction and insulin resistance such as diabetes.

Cell segmentation is the foundation of a wide range of microscopy-based biological studies. Deep learning has revolutionized 2D cell segmentation, enabling generalized solutions across cell types and imaging modalities. This has been driven by the ease of scaling up image acquisition, annotation, and computation. However, 3D cell segmentation, requiring dense annotation of 2D slices still poses significant challenges. Manual labeling of 3D cells to train broadly applicable segmentation models is prohibitive. Even in high-contrast images annotation is ambiguous and time-consuming. Here we develop a theory and toolbox, u-Segment3D, for 2D-to-3D segmentation, compatible with any 2D method generating pixel-based instance cell masks. u-Segment3D translates and enhances 2D instance segmentations to a 3D consensus instance segmentation without training data, as demonstrated on 11 real-life datasets, >70,000 cells, spanning single cells, cell aggregates, and tissue. Moreover, u-Segment3D is competitive with native 3D segmentation, even exceeding when cells are crowded and have complex morphologies.

Tragia involucrata L. have been utilized as traditional medicine in Indian subcontinent for the treatment of numerous illnesses such as inflammation, pain and skin infection. In this current study we sought to assess the anxiolytic, sedative and analgesic activity of Tragia involucrata L. leaves extract. We first performed a phytochemical screening test of the leaves extracts following standard phytochemical screening protocols. We next examined the anxiolytic and sedative activity of crude methanol (TIME), ethyl acetate (TIEAE) and n-Hexane (TIHE) extract of Tragia involucrata L. leaves using mouse behavioral models such as elevated plus-maze test and pentobarbital-induced sleeping time test, respectively. Likewise, we evaluated the analgesic activity using acetic acid induced writhing test and formalin induced paw licking test. Additionally, we performed a quantitative analysis of heavy metals content of Tragia involucrata L. leaves by overnight digestion in concentrated nitric acid (HNO3). Phytochemical screening demonstrated that TIME, TIEAE and TIHE contain flavonoids, alkaloids, tannins, phenols, terpenoids and sterols. Administration of these extracts resulted in higher number of open arm entry, lower number of close arm entry and higher time spent in open arm compared to control treatment (p < 0.05). Moreover, these treatments decreased the onset of sleep time and increased the duration of sleep compared to control treated mice (all p < 0.05). Likewise, extracts treated mice exhibited decreased number of writhing as well as lower acute phase and late phase duration compared to control treatment (all p < 0.05). The average level of As and Fe in Tragia involucrata L. leaves was 5.16 ± 0.012 ppm and 2.76 ± 0.015 ppm, respectively. Results from this study support that Tragia involucrata L. leaves extracts exhibit an anxiolytic, sedative and analgesic activity in mice.