BackgroundThere has been uncertainty regarding the benefit of glycemic control with antidiabetic agents in prevention of diabetic macrovascular disease. Further development of novel antidiabetic agents is essential for overcoming the burden of diabetic macrovascular disease. The renal sodium glucose co-transporter 2 (SGLT2) inhibitor is a novel antihyperglycemic agent for treatment of type 2 diabetes. This work was performed to determine whether empagliflozin, a novel SGLT2 inhibitor, can ameliorate cardiovascular injury and cognitive decline in db/db mouse, a model of obesity and type 2 diabetes.Methods(1) Short-term experiment: The first experiment was performed to examine the effect of 7 days of empagliflozin treatment on urinary glucose excretion and urinary electrolyte excretion in db/db mice. (2) Long-term experiment: The second experiment was undertaken to examine the effect of 10 weeks of empagliflozin treatment on cardiovascular injury, vascular dysfunction, cognitive decline, and renal injury in db/db mice.Results(1) Short-term experiment: Empagliflozin administration significantly increased urinary glucose excretion, urine volume, and urinary sodium excretion in db/db mice on day 1, but did not increase these parameters from day 2. However, blood glucose levels in db/db mice were continuously decreased by empagliflozin throughout 7 days of the treatment. (2) Long-term experiment: Empagliflozin treatment caused sustained decrease in blood glucose in db/db mice throughout 10 weeks of the treatment and significantly slowed the progression of type 2 diabetes. Empagliflozin significantly ameliorated cardiac interstitial fibrosis, pericoronary arterial fibrosis, coronary arterial thickening, cardiac macrophage infiltration, and the impairment of vascular dilating function in db/db mice, and these beneficial effects of empagliflozin were associated with attenuation of oxidative stress in cardiovascular tissue of db/db mice. Furthermore, empagliflozin significantly prevented the impairment of cognitive function in db/db mice, which was associated with the attenuation of cerebral oxidative stress and the increase in cerebral brain-derived neurotrophic factor. Empagliflozin ameliorated albuminuria, and glomerular injury in db/db mice.ConclusionsGlycemic control with empagliflozin significantly ameliorated cardiovascular injury and remodeling, vascular dysfunction, and cognitive decline in obese and type 2 diabetic mice. Thus, empagliflozin seems to be potentially a promising therapeutic agent for diabetic macrovascular disease and cognitive decline.
Background and Purpose-FTY720 is a known sphingosine 1-phosphate receptor agonist. In the present study, we investigated the neuroprotective effect of postischemic administration of FTY720 in rats with 2 hours transient middle cerebral artery occlusion (MCAO). Methods-One hundred eleven male rats were randomly assigned to sham-operated and MCAO treated with vehicle, 0.25 mg/kg and 1 mg/kg of FTY720, another selective sphingosine 1-phosphate receptor-1 agonist SEW2871 (5 mg/kg), or 0.25 mg/kg of FTY720 plus a sphingosine 1-phosphate antagonist, VPC23019 (0.5 mg/kg). Drugs were injected intraperitoneally immediately after reperfusion. Neurological score and infarct volume were assessed at 24 and 72 hours after MCAO. Western blotting, immunohistochemistry, and terminal deoxynucleotidyl transferase-mediated uridine 5Ј-triphosphate-biotin nick end-labeling were conducted at 24 hours after MCAO. Results-FTY720 significantly reduced infarct volume and improved neurological score at 24 and 72 hours after MCAO compared with the vehicle group. SEW2871 showed similar neuroprotective effects to FTY720, whereas VPC 20319 abolished the neuroprotective effects of FTY720. FTY720 significantly retained Akt and extracellular signal-regulated kinase phosphorylation and Bcl-2 expression and decreased cleaved caspase-3 expression and terminal deoxynucleotidyl transferase-mediated uridine 5Ј-triphosphate-biotin nick end-labeling-positive neurons at 24 hours after MCAO. VPC23019 blocked the antiapoptotic effects of FTY720. Conclusions-These data suggest that activation of sphingosine 1-phosphate-1 by FTY720 reduces neuronal death after transient MCAO. (Stroke. 2010;41:368-374.)
T-lymphocytes promote cerebral inflammation, thus aggravating neuronal injury after stroke. Fingolimod, a sphingosine 1-phosphate receptor analog, prevents the egress of lymphocytes from primary and secondary lymphoid organs. Based on these findings, we hypothesized fingolimod treatment would reduce the number of T-lymphocytes migrating into the brain, thereby ameliorating cerebral inflammation following experimental intracerebral hemorrhage (ICH). We investigated the effects of fingolimod in two well-established murine models of ICH, implementing intrastriatal infusions of either bacterial collagenase (cICH) or autologous blood (bICH). Furthermore, we tested the long term neurological improvements by Fingolimod in a collagenase-induced rat model of ICH. Fingolimod, in contrast to vehicle administration alone, improved neurological functions and reduced brain edema at 24 and 72 hours following experimental ICH in CD-1 mice (n=103; p<0.05). Significantly fewer lymphocytes were found in blood and brain samples of treated animals when compared to the vehicle group (p<0.05). Moreover, fingolimod treatment significantly reduced the expression of intercellular adhesion molecule-1 (ICAM-1), interferon-γ (INF-γ), and interleukin-17 (IL-17) in the mouse brain at 72 hours post-cICH (p<0.05 compared to vehicle). Long-term neurocognitive performance and histopathological analysis were evaluated in Sprague-Dawley rats between 8 and 10 weeks post-cICH (n=28). Treated rats showed reduced spatial and motor learning deficits, along with significantly reduced brain atrophy and neuronal cell loss within the basal ganglia (p<0.05 compared to vehicle). We conclude that fingolimod treatment ameliorated cerebral inflammation, at least to some extent, by reducing the availability and subsequent brain infiltration of T-lymphocytes, which improved the short and long-term sequelae after experimental ICH in rodents.
Human milk is uniquely optimized for the needs of the developing infant. Its composition is complex and dynamic, driven primarily by maternal genetics, and to a lesser extent by diet and environment. One important component that is gaining attention is the milk fat globule (MFG). The MFG is composed of a triglyceride-rich core surrounded by a tri-layer membrane, also known as the milk fat globule membrane (MFGM) that originates from mammary gland epithelia. The MFGM is enriched with glycerophospholipids, sphingolipids, cholesterol, and proteins, some of which are glycosylated, and are known to exert numerous biological roles. Mounting evidence suggests that the structure of the MFG and bioactive components of the MFGM may benefit the infant by aiding in the structural and functional maturation of the gut through the provision of essential nutrients and/or regulating various cellular events during infant growth and immune education. Further, antimicrobial peptides and surface carbohydrate moieties surrounding the MFG might have a pivotal role in shaping gut microbial populations, which in turn may promote protection against immune and inflammatory diseases early in life. This review seeks to: (1) understand the components of the MFG, as well as maternal factors including genetic and lifestyle factors that influence its characteristics; (2) examine the potential role of this milk component on the intestinal immune system; and (3) delineate the mechanistic roles of the MFG in infant intestinal maturation and establishment of the microbiota in the alimentary canal.
Background and Purpose-The role of interleukin (IL)-1 remains unknown in early brain injury (EBI) after subarachnoid hemorrhage (SAH), although IL-1 has been repeatedly reported to increase in the brain and cerebrospinal fluid. The aim of this study is to examine the effects of IL-1 inactivation on EBI after SAH in mice. Methods-The endovascular perforation model of SAH was produced and 112 mice were assigned to sham, SAHϩ vehicle, and SAHϩ N-Ac-Tyr-Val-Ala-Asp-chloromethyl ketone (Ac-YVAD-CMK, 6 and 10 mg/kg) groups. Ac-YVAD-CMK, a selective inhibitor of IL-1 converting enzyme, or vehicle was administered intraperitoneally 1 hour post-SAH. EBI was assessed in terms of mortality within 24 hours, neurological scores, brain water content at 24 and 72 hours, Evans blue dye extravasation and Western blot for IL-1, c-Jun N-Terminal kinase (JNK), matrix metalloproteinase (MMP)-9, and zonula occludens (ZO)-1 at 24 hours after SAH. Results-High-dose (10 mg/kg) but not low-dose (6 mg/kg) treatment group significantly improved neurological scores, mortality, brain water content, and Evans blue dye extravasation compared with the vehicle group. Although both dosages of Ac-YVAD-CMK attenuated the mature IL-1 induction, only high-dose treatment group significantly inhibited the phosphorylation of JNK, MMP-9 induction, and ZO-1 degradation. Conclusion-IL-1
Background and Purpose-Osteopontin (OPN) is an inducible, multifunctional, extracellular matrix protein that may be protective against blood-brain barrier (BBB) disruption after subarachnoid hemorrhage (SAH). However, the protective mechanisms remain unclear. Methods-We produced the endovascular perforation model of SAH in rats and studied the time course of OPN induction in brains by Western blotting and immunofluorescence (nϭ50). Then, 34 rats were randomly assigned to sham (nϭ3), shamϩOPN small interfering RNA (siRNA, nϭ3), SAHϩnegative control siRNA (nϭ14), and SAHϩOPN siRNA (nϭ14) groups, and 109 rats were allocated to shamϩvehicle (nϭ17), shamϩrecombinant OPN (nϭ17), SAHϩvehicle (nϭ33), SAHϩrecombinant OPN (nϭ31), and SAHϩrecombinant OPNϩL-arginyl-glycyl-L-aspartate motif-containing hexapeptide (nϭ11) groups. The effects of OPN siRNA or recombinant OPN on BBB disruption and related proteins were studied. Results-OPN was significantly induced in reactive astrocytes and capillary endothelial cells, peaking at 72 hours after SAH, during the recovery phase of BBB disruption. Blockage of endogenous OPN induction exacerbated BBB disruption and was associated with a reduction of angiopoietin-1 and mitogen-activated protein kinase (MAPK) phosphatase-1 (an endogenous MAPK inhibitor), activation of MAPKs, and induction of vascular endothelial growth factor-A at 72 hours after SAH, whereas recombinant OPN treatment improved it and was associated with MAPK phosphatase-1 induction, MAPK inactivation, and vascular endothelial growth factor-A reduction, which was blocked by L-arginyl-glycyl-L-aspartate motif-containing hexapeptide at 24 hours after SAH. Vascular endothelial growth factor-B and angiopoietin-2 levels were unchanged. Conclusions-OPN
BackgroundThe potential benefit of SGLT2 inhibitors in metabolic syndrome is with prediabetic stage unclear. This work was undertaken to investigate the non-glycemic effect of empagliflozin on metabolic syndrome rats with prediabetes.MethodsSHR/NDmcr-cp(+/+) rats (SHRcp), a model of metabolic syndrome with prediabetes, were given empagliflozin for 10 weeks to examine the effects on urinary sodium and water balance, visceral and subcutaneous adipocyte, and cardiac injury. Further, the effect of empagliflozin on blood pressure and autonomic nervous system was continuously investigated by using radiotelemetry system.ResultsEmpagliflozin significantly reduced urinary sodium and water balance of SHRcp only within 1 week of the treatment, but later than 1 week did not alter them throughout the treatment. Empagliflozin significantly reduced body weight of SHRcp, which was mainly attributed to the significant reduction of subcutaneous fat mass. Empagliflozin significantly reduced the size of visceral adipocytes and increased the number of smaller size of adipocytes, which was associated with the attenuation of oxidative stress. Empagliflozin ameliorated cardiac hypertrophy and fibrosis of SHRcp, in association with the attenuation of cardiac oxidative stress and inflammation. However, empagliflozin did not significantly change blood pressure, heart rate, sympathetic activity, or baroreceptor function, as evidenced by radiotelemetry analysis.ConclusionsOur present work provided the evidence that SGLT2 inhibition reduced visceral adipocytes hypertrophy and ameliorated cardiac injury in prediabetic metabolic syndrome rat, independently of diuretic effect or blood pressure lowering effect. Thus, SGLT2 inhibition seems to be a promising therapeutic strategy for prediabetic metabolic syndrome.Electronic supplementary materialThe online version of this article (doi:10.1186/s12933-016-0473-7) contains supplementary material, which is available to authorized users.
Objective-Accumulated evidence suggests that the primary cause of poor outcome after subarachnoid hemorrhage (SAH) is not only cerebral arterial narrowing, but also early brain injury (EBI). Our objective was to determine the effect of recombinant osteopontin (r-OPN), a pleiotropic extracellular matrix glycoprotein, on post-SAH EBI in rats. Design-Controlled in vivo laboratory study. Setting-Animal research laboratory.Subjects-One hundred seventy-seven male adult Sprague-Dawley rats, 300-370g.Interventions-The endovascular perforation model of SAH was produced. SAH or shamoperated rats were treated with an equal volume (1μL) of pre-SAH intracerebroventricular administration of two dosages (0.02 and 0.1μg) of r-OPN, albumin or vehicle. Body weight, neurological scores, brain edema and blood-brain barrier (BBB) disruption were evaluated, and Western blot analyses were performed to determine the effect of r-OPN on matrix metalloproteinase (MMP)-9, substrates of MMP-9 (zona occludens [ZO]-1, laminin), tissue inhibitor of MMP (TIMP)-1, inflammation (interleukin-1β), and nuclear factor (NF)-κ B signaling pathways. Measurements and MainResults-Treatment with r-OPN prevented a significant loss in body weight, neurological impairment, brain edema, and BBB disruption after SAH. These effects were associated with the deactivation of NF-κB activity, inhibition of MMP-9 induction, the maintenance of TIMP-1, and the consequent preservation of the cerebral microvessel basal lamina protein laminin, and the tight junction protein ZO-1.Conclusions-These results demonstrate that r-OPN treatment is effective for post-SAH EBI. Aneurysmal subarachnoid hemorrhage (SAH) is a common and devastating neurological disorder (1). Cerebral vasospasm has been believed to be a leading cause of mortality and morbidity (2). Recent randomized clinical trials, however, showed that clazosentan significantly reduced angiographic vasospasm but failed to improve long-term neurological outcome (3,4). This means that the treatment efforts targeting only angiographic vasospasm might not be enough to achieve a better outcome. Thus, new research efforts have focused on clarifying the pathophysiology of early brain injury (EBI) following SAH, and on developing protective strategies against it (5).Osteopontin (OPN) is a secreted extracellular matrix (ECM) glycoprotein that is involved in both physiological and pathological processes in a wide range of tissue (6). The biological functions of OPN are highly variable, and often seemingly contradictory depending on the biological scenario surrounding its induction (7). However, there is compelling evidence that OPN can, in a variety of situations, help cells survive an otherwise lethal insult (8). For example, endogenous OPN induction has consistently been found to have protective effects on ischemic injuries involving the brain and other organs (9,10). Moreover, the administration of recombinant OPN (r-OPN) markedly reduced the infarct size via anti-apoptotic actions in a transient focal cerebral ischemi...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.