scholarly journals Restoring HSP70 deficiencies improves glucose tolerance in diabetic monkeys

2011 ◽  
Vol 300 (5) ◽  
pp. E894-E901 ◽  
Author(s):  
Kylie Kavanagh ◽  
David M. Flynn ◽  
Kurt A. Jenkins ◽  
Li Zhang ◽  
Janice D. Wagner
Keyword(s):  
Heat Shock ◽  
Glucose Tolerance ◽  
Ex Vivo ◽  
Heat Shock Factor 1 ◽  
Vervet Monkeys ◽  
Primate Model ◽  
Chronic Hyperglycemia ◽  
Dose Dependent Fashion ◽  
Dose Dependent ◽  
Improve Glucose Tolerance

We evaluated heat shock protein 70 (HSP70) changes in diabetes mellitus (DM) in a nonhuman primate model. To this end, two studies were conducted in DM vervet monkeys. 1) Normal control and streptozotocin-induced DM monkeys (Stz-DM) that were differentiated into moderately or poorly controlled DM by judicious insulin administration were evaluated. Liver was collected at 4, 8, 12, 16, and 20 wk after streptozotocin, exposed to ex vivo heat shock at 42°C, and immunoblotted for heat shock factor 1 (HSF1), HSP70, and phosphorylated HSF1. 2) Spontaneous DM monkeys that were not pharmacologically induced were included in a crossover study of the HSP70-inducing drug geranylgeranylacetone (GGA). GGA at 20 mg/kg was given for 14 days with a 6-wk washout period. Glucose tolerance testing and plasma and muscle HSP70 were the primary outcome measurements. In Stz-DM, hyperglycemia reduced hepatic HSP70 in a dose-dependent fashion. HSF1 was increased in livers of monkeys with Stz-DM, but responses to ex vivo heat shock were impaired vs. normal monkeys. Activation of HSF1 appears to be important, because the phosphorylation change with heat stress was nearly perfectly correlated with HSP70 increases. Impaired HSF1 activation was also seen in Stz-DM after chronic hyperglycemia (>12 wk). In naturally occurring DM, increased circulating HSP70 resulted in significantly improved glucose tolerance and significant, positive trends in other measurements of insulin resistance. No change in muscle HSP70 content was observed. We conclude that increasing HSP70, potentially through targeting hyperglycemia-related deficits in HSF1 induction and activation in the liver, is a potent and viable strategy to improve glucose tolerance.

scholarly journals Ketamine Inhibits Lung Fluid Clearance through Reducing Alveolar Sodium Transport

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Yong Cui ◽  
Hongguang Nie ◽  
Hong Ma ◽  
Lei Chen ◽  
Lin Zhang ◽  
...  
Keyword(s):  
Pulmonary Edema ◽  
Clinical Evidence ◽  
Ex Vivo ◽  
A549 Cells ◽  
Intratracheal Instillation ◽  
Lung Fluid ◽  
Whole Cell Patch Clamp ◽  
Dose Dependent Fashion ◽  
Dose Dependent ◽  
Lung Lobes

Ketamine is a broadly used anaesthetic for analgosedation. Accumulating clinical evidence shows that ketamine causes pulmonary edema with unknown mechanisms. We measured the effects of ketamine on alveolar fluid clearance in human lung lobesex vivo. Our results showed that intratracheal instillation of ketamine markedly decreased the reabsorption of 5% bovine serum albumin instillate. In the presence of amiloride (a specific ENaC blocker), fluid resolution was not further decreased, suggesting that ketamine could decrease amiloride-sensitive fraction of AFC associated with ENaC. Moreover, we measured the regulation of amiloride-sensitive currents by ketamine in A549 cells using whole-cell patch clamp mode. Our results suggested that ketamine decreased amiloride-sensitive Na+currents (ENaC activity) in a dose-dependent fashion. These data demonstrate that reduction in lung ENaC activity and lung fluid clearance following administration of ketamine may be the crucial step of the pathogenesis of resultant pulmonary edema.

Glutamine's protection against cellular injury is dependent on heat shock factor-1

2006 ◽  
Vol 290 (6) ◽  
pp. C1625-C1632 ◽  
Author(s):  
Angela L. Morrison ◽  
Martin Dinges ◽  
Kristen D. Singleton ◽  
Kelli Odoms ◽  
Hector R. Wong ◽  
...  
Keyword(s):  
Heat Stress ◽  
Heat Shock ◽  
Heat Shock Factor ◽  
Tetrazolium Salt ◽  
Heat Shock Factor 1 ◽  
Dependent Manner ◽  
Hsp 70 ◽  
Stress Injury ◽  
Cellular Protection ◽  
Dose Dependent

Glutamine (GLN) has been shown to protect cells, tissues, and whole organisms from stress and injury. Enhanced expression of heat shock protein (HSP) has been hypothesized to be responsible for this protection. To date, there are no clear mechanistic data confirming this relationship. This study tested the hypothesis that GLN-mediated activation of the HSP pathway via heat shock factor-1 (HSF-1) is responsible for cellular protection. Wild-type HSF-1 (HSF-1+/+) and knockout (HSF-1−/−) mouse fibroblasts were used in all experiments. Cells were treated with GLN concentrations ranging from 0 to 16 mM and exposed to heat stress injury in a concurrent treatment model. Cell viability was assayed with phenazine methosulfate plus tetrazolium salt, HSP-70, HSP-25, and nuclear HSF-1 expression via Western blot analysis, and HSF-1/heat shock element (HSE) binding via EMSA. GLN significantly attenuated heat-stress induced cell death in HSF-1+/+ cells in a dose-dependent manner; however, the survival benefit of GLN was lost in HSF-1−/− cells. GLN led to a dose-dependent increase in HSP-70 and HSP-25 expression after heat stress. No inducible HSP expression was observed in HSF-1−/− cells. GLN increased unphosphorylated HSF-1 in the nucleus before heat stress. This was accompanied by a GLN-mediated increase in HSF-1/HSE binding and nuclear content of phosphorylated HSF-1 after heat stress. This is the first demonstration that GLN-mediated cellular protection after heat-stress injury is related to HSF-1 expression and cellular capacity to activate an HSP response. Furthermore, the mechanism of GLN-mediated protection against injury appears to involve an increase in nuclear HSF-1 content before stress and increased HSF-1 promoter binding and phosphorylation.

2002 - EX VIVO ACTIVATION OF HEAT SHOCK FACTOR 1 (HSF1) PROMOTES SUSTAINED HEMATOPOIETIC STEM CELL SELF-RENEWAL

2019 ◽  
Vol 76 ◽  
pp. S42-S43
Author(s):  
Robert Signer ◽  
Miriama Kruta ◽  
Mary Jean Sunshine ◽  
Yunpeng Fu ◽  
Lorena Hidalgo San Jose
Keyword(s):  
Stem Cell ◽  
Heat Shock ◽  
Hematopoietic Stem Cell ◽  
Ex Vivo ◽  
Heat Shock Factor ◽  
Heat Shock Factor 1 ◽  
Self Renewal ◽  
Hematopoietic Stem

scholarly journals Generation of GCaMP6s-Expressing Zebrafish to Monitor Spatiotemporal Dynamics of Calcium Signaling Elicited by Heat Stress

2021 ◽  
Vol 22 (11) ◽  
pp. 5551
Author(s):  
Fengyang Li ◽  
Yong Long ◽  
Juhong Xie ◽  
Jing Ren ◽  
Tong Zhou ◽  
...  
Keyword(s):  
Heat Stress ◽  
Heat Shock ◽  
Calcium Signaling ◽  
Ex Vivo ◽  
Spatiotemporal Dynamics ◽  
Transgenic Zebrafish ◽  
Heat Shock Factor 1 ◽  
Response Patterns ◽  
Calcium Indicator

The ability of organisms to quickly sense and transduce signals of environmental stresses is critical for their survival. Ca2+ is a versatile intracellular messenger involved in sensing a wide variety of stresses and regulating the subsequent cellular responses. So far, our understanding for calcium signaling was mostly obtained from ex vivo tissues and cultured cell lines, and the in vivo spatiotemporal dynamics of stress-triggered calcium signaling in a vertebrate remains to be characterized. Here, we describe the generation and characterization of a transgenic zebrafish line with ubiquitous expression of GCaMP6s, a genetically encoded calcium indicator (GECI). We developed a method to investigate the spatiotemporal patterns of Ca2+ events induced by heat stress. Exposure to heat stress elicited immediate and transient calcium signaling in developing zebrafish. Cells extensively distributed in the integument of the head and body trunk were the first batch of responders and different cell populations demonstrated distinct response patterns upon heat stress. Activity of the heat stress-induced calcium signaling peaked at 30 sec and swiftly decreased to near the basal level at 120 sec after the beginning of exposure. Inhibition of the heat-induced calcium signaling by LaCl3 and capsazepine and treatment with the inhibitors for CaMKII (Ca²⁺/calmodulin-dependent protein kinase II) and HSF1 (Heat shock factor 1) all significantly depressed the enhanced heat shock response (HSR). Together, we delineated the spatiotemporal dynamics of heat-induced calcium signaling and confirmed functions of the Ca2+-CaMKII-HSF1 pathway in regulating the HSR in zebrafish.

scholarly journals Novel GLP-1 analog supaglutide improves glucose homeostasis in diabetic monkeys

2020 ◽  
Author(s):  
Qiaoli Cui ◽  
Yijing Liao ◽  
Yaojing Jiang ◽  
Xiaohang Huang ◽  
Weihong Tao ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Glucose Tolerance ◽  
Glucose Homeostasis ◽  
Rhesus Monkeys ◽  
Intravenous Glucose Tolerance Test ◽  
Intravenous Glucose ◽  
Glucose Levels ◽  
Blood Glucose Levels ◽  
Dose Dependent Fashion ◽  
Dose Dependent

Glucagon-like peptide 1 (GLP-1) is an insulinotropic hormone and plays an important role in regulating glucose homeostasis. GLP-1 has a short half-life (t1/2<2 min) due to degrading enzyme dipeptidyl peptidase-IV and rapid kidney clearance, which limits its clinical application as a therapeutic reagent. We demonstrated recently that supaglutide, a novel GLP-1 mimetic generated by recombinant fusion protein techniques, exerted hypoglycemic and beta cell trophic effects in type 2 diabetes db/db mice. In the present study, we examined supaglutide’s therapeutic efficacy and pharmacokinetics in diabetic rhesus monkeys. We found that a single subcutaneous injection of supaglutide of tested doses transiently and significantly reduced blood glucose levels in a dose-dependent fashion in the diabetic monkeys. During a 4-weeks intervention period, treatment of supaglutide of weekly dosing dose-dependently decreased fasting and random blood glucose levels. This was associated with significantly declined plasma fructosamine levels. The repeated administration of supaglutide remarkably also decreased body weight in a dose-dependent fashion accompanied by decreased food intake. Intravenous glucose tolerance test results showed that supaglutide improved glucose tolerance. The intervention also showed enhanced glucose-stimulated insulin secretion and improved lipid profile in diabetic rhesus monkeys. These results reveal that supaglutide exerts beneficial effects in regulating blood glucose and lipid homeostasis in diabetic rhesus monkeys.

Plasminogen Interactions with Immobilized Fibrinogen

1989 ◽  
Vol 62 (04) ◽  
pp. 1078-1082 ◽  
Author(s):  
Burt Adelman ◽  
Patricia Ouynn
Keyword(s):  
Immunosorbent Assay ◽  
Aminocaproic Acid ◽  
Enzyme Linked Immunosorbent Assay ◽  
Binding Regions ◽  
Dose Dependent Fashion ◽  
Epsilon Aminocaproic Acid ◽  
Dose Dependent

SummaryThis report describes the binding of plasminogen to fibrinogen adsorbed onto polystyrene wells. Binding was determined by enzyme linked immunosorbent assay. Both glu- and lys-plasminogen bound to immobilized fibrinogen in a dose-dependent fashion. However, more lys- than glu-plasminogen bound when equal concentrations of either were added to immobilized fibrinogen. Plasminogen binding was inhibited by epsilon aminocaproic acid indicating that binding was mediated via lysine-binding regions of plasminogen. Soluble fibrinogen added in excess of immobilized fibrinogen did not compete for plasminogen binding but fibrinogen fragments produced by plasmin digestion of fibrinogen did. Treatment of immobilized fibrinogen with thrombin caused a small but significant (p <0.01) increase in plasminogen binding. These studies demonstrate that immobilized fibrinogen binds both glu- and lys-plasminogen and that binding is mediated via lysine-binding regions. These interactions may facilitate plasminogen binding to fibrinogen adsorbed on to surfaces and to cells such as platelets which bind fibrinogen.

Soluble Thrombomodulin Purified from Human Urine Exhibits a Potent Anticoagulant Effect In Vitro and In Vivo

1995 ◽  
Vol 73 (05) ◽  
pp. 805-811 ◽  
Author(s):  
Yasuo Takahashi ◽  
Yoshitaka Hosaka ◽  
Hiromi Niina ◽  
Katsuaki Nagasawa ◽  
Masaaki Naotsuka ◽  
...  
Keyword(s):  
Human Urine ◽  
Specific Activity ◽  
Anticoagulant Activity ◽  
Rabbit Lung ◽  
Soluble Thrombomodulin ◽  
Molecular Weights ◽  
Dose Dependent Fashion ◽  
Dose Dependent

SummaryWe examined the anticoagulant activity of two major molecules of soluble thrombomodulin purified from human urine. The apparent molecular weights of these urinary thrombomodulins (UTMs) were 72,000 and 79,000, respectively. Both UTMs showed more potent cofactor activity for protein C activation [specific activity >5,000 thrombomodulin units (TMU)/mg] than human placental thrombomodulin (2,180 TMU/mg) and rabbit lung thrombomodulin (1,980 TMU/mg). The UTMs prolonged thrombin-induced fibrinogen clotting time (>1 TMU/ml), APTT (>5 TMU/ml), TT (>5 TMU/ml) and PT (>40 TMU/ml) in a dose-dependent fashion. These effects appeared in the concentration range of soluble thrombomodulins present in human plasma and urine. In the rat DIC model induced by thromboplastin, administration of UTMs by infusion (300-3,000 TMU/kg) restored the hematological abnormalities derived from DIC in a dose-dependent fashion. These results demonstrate that UTMs exhibit potent anticoagulant and antithrombotic activities, and could play a physiologically important role in microcirculation.

Adenosine Diphosphate (ADP)-Induced ⍺-Granules Release from Platelets of Native Whole Blood Is Reduced by Ticlopidine but Not by Aspirin or Dipyridamole

1986 ◽  
Vol 56 (02) ◽  
pp. 147-150 ◽  
Author(s):  
V Pengo ◽  
M Boschello ◽  
A Marzari ◽  
M Baca ◽  
L Schivazappa ◽  
...  
Keyword(s):  
Whole Blood ◽  
Light Transmission ◽  
Ex Vivo ◽  
Early Stage ◽  
Shape Change ◽  
Adenosine Diphosphate ◽  
Dose Dependent ◽  
Plateletderived Growth Factor ◽  
Platelet Shape

SummaryA brief contact between native whole blood and ADP promotes a dose-dependent release of platelet a-granules without a fall in the platelet number. We assessed the “ex vivo” effect of three widely used antiplatelet drugs, aspirin dipyridamole and ticlopidine, on this system. Aspirin (a single 800 mg dose) and dipyridamole (300 mg/die for four days) had no effect, while ticlopidine (500 mg/die for four days) significantly reduced the a-granules release for an ADP stimulation of 0.4 (p <0.02), 1.2 (p <0.01) and 2 pM (p <0.01). No drug, however, completeley inhibits this early stage of platelet activation. The platelet release of α-granules may be related to platelet shape change of the light transmission aggregometer and may be important “in vivo” by enhancing platelet adhesiveness and by liberating the plateletderived growth factor.

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