Liraglutide Preserves CD34 + Stem Cells from Dysfunction Induced by High Glucose Exposure

Abstract Background: Glucagon like peptide-1 receptor agonists (GLP-1RAs) have shown to reduce mortality and cardiovascular events in patients with type 2 diabetes mellitus (T2DM). Since the impairment in number and function of vasculotrophic circulating CD34+ hematopoietic stem progenitor cells (HSPCs) in T2D has been reported to increase cardiovascular (CV) risk, we hypothesized that one of the mechanisms whereby GLP-1 RAs exert CV protective effects may be related to the ability to improve CD34+ HSPC function.Methods: In cord blood (CB)-derived CD34+ HSPC, the expression of GLP-1 receptor (GLP-1R) mRNA, receptor protein and intracellular signaling was evaluated by RT-qPCR and by Western Blot respectively. CD34+ HSPCs were exposed to high glucose (HG) condition and GLP-1RA liraglutide (LIRA) was added before as well as after functional impairment. Proliferation, CXCR4/SDF-1α axis activity and intracellular ROS production of CD34+ HSPC were evaluated. Results: CD34+ HSPCs express GLP-1R at transcriptional and protein level. LIRA treatment prevented and rescued HSPC proliferation and CXCR4/SDF-1α axis activity from HG-induced impairment. LIRA stimulation promoted intracellular cAMP accumulation as well as ERK1/2 and AKT signaling activation. The selective GLP-1R antagonist exendin (9-39) abrogated LIRA-dependent ERK1/2 and AKT phosphorylation along with the related protective effects. Conclusion: We provided the first evidence that CD34+ HSPC express GLP-1R and that LIRA can favorably impact on cell dysfunction due to HG exposure. These findings open new perspectives on the favorable CV effects of GLP-1 RAs in T2DM patients.

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Abstract 59: Vascular Glucagon-like Peptide 1 (GLP-1) Signaling Is Reduced In Obesity-related Hypertension In Female Rats

Hypertension ◽

10.1161/hyp.78.suppl_1.59 ◽

2021 ◽

Vol 78 (Suppl_1) ◽

Author(s):

Risa Kiernan ◽

Dhandevi Persand ◽

Nicole Maddie ◽

Maria Alicia Carrillo-Sepulveda

Keyword(s):

Weight Loss ◽

Vascular Dysfunction ◽

Serum Levels ◽

Western Diet ◽

Obese Group ◽

Female Rats ◽

Receptor Protein ◽

Chow Diet ◽

Protective Effects ◽

Glucagon Like Peptide 1

Obesity is a major risk factor for hypertension. Obesity-related hypertension impacts more women than men, but the underlying mechanisms remain unclear. GLP-1, an incretin released after food intake, exerts vasculo-protective effects. Human studies have shown that GLP-1 levels are decreased in obese patients. We hypothesized that vascular GLP-1 signaling is reduced in obesity and weight loss rescues this signaling. Eight-week-old female Wistar rats were randomized into three groups: LEAN (n=9) received a chow diet (5% fat, 48.7% carbohydrate [3.2% sucrose], 24.1% protein) for 28 weeks, OBESE (n=7) received a Western diet (21% fat, 50% carbohydrate [34% sucrose], 20% protein) for 28 weeks, and reverse obese (rOBESE) (n=7) received a Western diet for 18 weeks followed by 12 weeks of chow diet. The OBESE group exhibited increased body weight (395.6 vs. 285.4g LEAN, p<0.0001) and body mass index (6.8 vs. 5.1kg/m 2 LEAN, p<0.01), while the rOBESE group lost weight (337.0 vs. 395.6g OBESE, p<0.01). Direct measurement of blood pressure (BP) using a pressure-volume catheter inserted in the carotid artery revealed increased systolic (142.8 vs. 117.2mmHg LEAN, p<0.001), diastolic (125.0 vs. 92.7mmHg LEAN, p<0.001), and mean arterial BP (130.9 vs. 107.9mmHg LEAN, p<0.001) in the OBESE group. The rOBESE group sustained elevated systolic BP (139.1 vs.117.2mmHg LEAN, p<0.05). Endothelium-dependent vasodilation studies assessed by wire myograph demonstrated that the OBESE group exhibited impaired response to acetylcholine (Emax: 82.7% vs. 97.9% LEAN, p<0.001). Similar vascular impairment was observed in the rOBESE group (EMax: 81.3% vs 97.9% LEAN, p<0.001). Strikingly, while decreased GLP-1 serum levels in the OBESE group (10.6 vs. 18.4pM/mL LEAN, p<0.05) returned to normal levels in the rOBESE group (19.4 vs.18.4pM/mL LEAN), GLP-1 receptor protein expression was reduced in both groups (24% decrease in OBESE, 52% decrease in rOBESE) as compared to LEAN. Our results support that GLP-1 signaling is implicated in obesity-related vascular dysfunction in females and weight loss does not guarantee recovery of protective GLP-1 signaling nor improvement of vasodilation. Conclusion: GLP-1 is a potential therapeutic target for obesity-related hypertension in females.

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Mitochondria damaged by Oxygen Glucose Deprivation can be Restored through Activation of the PI3K/Akt Pathway and Inhibition of Calcium Influx by Amlodipine Camsylate

Scientific Reports ◽

10.1038/s41598-019-52083-y ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 3

Author(s):

Hyun-Hee Park ◽

Myung-Hoon Han ◽

Hojin Choi ◽

Young Joo Lee ◽

Jae Min Kim ◽

...

Keyword(s):

Intracellular Signaling ◽

Calcium Influx ◽

Neuroprotective Effect ◽

Glucose Deprivation ◽

Structure And Function ◽

Oxygen Glucose Deprivation ◽

Protective Effects ◽

Neuroprotective Effects ◽

Mitochondrial Structure ◽

And Function

Abstract Amlodipine, a L-type calcium channel blocker, has been reported to have a neuroprotective effect in brain ischemia. Mitochondrial calcium overload leads to apoptosis of cells in neurologic diseases. We evaluated the neuroprotective effects of amlodipine camsylate (AC) on neural stem cells (NSCs) injured by oxygen glucose deprivation (OGD) with a focus on mitochondrial structure and function. NSCs were isolated from rodent embryonic brains. Effects of AC on cell viability, proliferation, level of free radicals, and expression of intracellular signaling proteins were assessed in OGD-injured NSCs. We also investigated the effect of AC on mitochondrial structure in NSCs under OGD by transmission electron microscopy. AC increased the viability and proliferation of NSCs. This beneficial effect of AC was achieved by strong protection of mitochondria. AC markedly enhanced the expression of mitochondrial biogenesis-related proteins and mitochondrial anti-apoptosis proteins. Together, our results indicate that AC protects OGD-injured NSCs by protecting mitochondrial structure and function. The results of the present study provide insight into the mechanisms underlying the protective effects of AC on NSCs.

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Critical Role Of Jak2 In The Maintenance and Function Of Adult Hematopoietic Stem Cells

Blood ◽

10.1182/blood.v122.21.1180.1180 ◽

2013 ◽

Vol 122 (21) ◽

pp. 1180-1180

Author(s):

Hajime Akada ◽

Saeko Akada ◽

Golam Mohi

Keyword(s):

Stem Cells ◽

Bone Marrow ◽

Hematopoietic Stem Cells ◽

Critical Role ◽

Receptor Protein ◽

Specific Gene ◽

Hematopoietic Stem ◽

And Function

Abstract Hematopoietic stem cells (HSCs) play an essential role in the long-term maintenance of hematopoiesis. Various intracellular signaling proteins, transcription factors and extracellular matrix proteins contribute to the maintenance and function of HSCs. Jak2, a member of the Janus family of non-receptor protein tyrosine kinases, is activated in response to a variety of cytokines. It has been shown that germ-line deletion of Jak2 results in embryonic lethality whereas post-natal or adult stage deletion of Jak2 results in anemia and thrombocytopenia in mice. However, the role of Jak2 in the maintenance and function of adult HSCs has remained elusive. Understanding the normal function of Jak2 in adult HSC/progenitors is of considerable significance since mutations in Jak2 have been associated with several myeloproliferative neoplasms (MPNs), and most patients treated with Jak2 inhibitors exhibit significant hematopoietic toxicities. To assess the role of Jak2 in adult HSCs, we have utilized a conditional Jak2 knock-out (Jak2 floxed) allele and an inducible MxCre line that can efficiently express Cre recombinase in adult HSC/progenitors after injections with polyinosine-polycytosine (pI-pC). We have found that deletion of Jak2 in adult mice results in pancytopenia, bone marrow aplasia and 100% lethality within 25 to 42 days after pI-pC induction. Analysis of the HSC/progenitor compartments revealed that Jak2-deficiency causes marked decrease in long-term HSCs, short-term HSCs, multipotent progenitors and early progenitors of all hematopoietic lineages, indicating a defect at the earliest stage of adult hematopoietic development. We have found that deletion of Jak2 leads to increased HSC cell cycle entry, suggesting that Jak2-deficiency results in loss of quiescence in HSCs. Jak2-deficiency also resulted in significant apoptosis in HSCs. Furthermore Jak2-deficient bone marrow cells were severely defective in reconstituting hematopoiesis in lethally-irradiated recipient animals. Competitive repopulations experiments also show that Jak2 is essential for HSC functional activity. We also have confirmed that the requirement for Jak2 in HSCs is cell-autonomous. To gain insight into the mechanism by which Jak2 controls HSC maintenance and function, we have performed phospho flow analysis on HSC-enriched LSK (lin-Sca-1+c-kit+) cells. TPO and SCF-evoked Akt and Erk activation was significantly reduced in Jak2-deficient LSK compared with control LSK. Stat5 phosphorylation in response to TPO was also completely inhibited in Jak2-deficient LSK cells. In addition, we observed significantly increased intracellular reactive oxygen species (ROS) levels and enhanced activation of p38 MAPK in Jak2-deficient LSK cells, consistent with the loss of quiescence observed in Jak2-deficient HSCs. Treatment with ROS scavenger N-acetyl cysteine partially rescued the defects in Jak2-deficient HSCs in reconstituting hematopoiesis in lethally irradiated recipient animals. Gene expression analysis revealed significant downregulation of HSC-specific gene sets in Jak2-deficient LSK cells. Taken together, our data strongly suggest that Jak2 plays a critical role in the maintenance of quiescence, survival and self-renewal of adult HSCs. Disclosures: No relevant conflicts of interest to declare.

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Annexin A2 Regulates AKT Upon H2O2-Dependent Signaling Activation in Cancer Cells

Cancers ◽

10.3390/cancers11040492 ◽

2019 ◽

Vol 11 (4) ◽

pp. 492 ◽

Cited By ~ 5

Author(s):

Stéphanie Castaldo ◽

Tom Ajime ◽

Gisela Serrão ◽

Fábio Anastácio ◽

Joana Rosa ◽

...

Keyword(s):

Regulatory Protein ◽

Growth Factor Receptor ◽

Annexin A2 ◽

Dependent Manner ◽

Oncogenic Signaling ◽

Akt Phosphorylation ◽

Oncogenic Ras ◽

Signaling Activation ◽

And Function ◽

Phosphatase And Tensin Homologue

Hydrogen peroxide (H2O2) is a main second messenger in oncogenic signaling networks including the Ras and the growth factor receptor pathways. This is achieved predominantly through the oxidation of redox-sensitive cysteine (Cys) residues in proteins resulting in changes to their structure and function. We previously identified annexin A2 (ANXA2) as a redox regulatory protein that plays an important cellular role during oxidative stress and also promoting tumorigenesis. Here we investigated the role of ANXA2 in the regulation of H2O2-dependent signaling that drives tumor progression. We show that depletion of ANXA2 leads to the enhanced activation of AKT following either EGF/EGFR stimulation or oncogenic Ras transformation. The phosphatase and tensin homologue (PTEN) protein negatively regulates the PI3K/AKT pathway. We demonstrate that ANXA2 via its reactive Cys-8 residue, binds to PTEN and that the co-expression of PTEN and ANXA2, but not ANXA2 Cys-8-Ala mutant, inhibits AKT phosphorylation on Ser 473. These results indicate that ANXA2 is important for PTEN regulation within the PI3K/AKT signaling cascade. Furthermore, we also reveal that ANXA2 inversely regulates the expression of the peroxidase, peroxiredoxin 2, in a reactive oxygen species dependent manner.

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Protective effects of Notch1 signaling activation against high glucose-induced myocardial cell injury: Analysis of its mechanisms of action

International Journal of Molecular Medicine ◽

10.3892/ijmm.2015.2294 ◽

2015 ◽

Vol 36 (3) ◽

pp. 897-903 ◽

Cited By ~ 11

Author(s):

JIAN ZHANG ◽

BINGONG LI ◽

ZEQI ZHENG ◽

TING KANG ◽

MINGHUI ZENG ◽

...

Keyword(s):

High Glucose ◽

Cell Injury ◽

Myocardial Cell ◽

Mechanisms Of Action ◽

Protective Effects ◽

Notch1 Signaling ◽

Myocardial Cell Injury ◽

Signaling Activation ◽

Injury Analysis

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Red wine extract, resveratrol, on maintenance of organ function following trauma-hemorrhage

Functional Foods in Health and Disease ◽

10.31989/ffhd.v2i10.76 ◽

2012 ◽

Vol 2 (10) ◽

pp. 351

Author(s):

Fu-Chao Liu ◽

Huang-Ping Yu

Keyword(s):

Intracellular Signaling ◽

Red Wine ◽

Antioxidant Properties ◽

Neutrophil Function ◽

Protective Effects ◽

Organ Function ◽

Mitogen Activated Protein ◽

Ros Formation ◽

Anti Inflammatory ◽

And Control

Resveratrol, is a polyphenol that can be extracted from grapes and red wine, possess potential anti-inflammatory effects, which would result in the reduction of cytokine production, the alteration of the expression of adhesion molecule molecules, and the inhibition of neutrophil function. Resveratrol might also act as an antioxidant, anti-aging, and control of cell cycle and apoptosis. Resveratrol has been shown to have protective effects for patients in shock-like states. Such protective phenomenon is reported to be implicated in a variety of intracellular signaling pathways including the regulation of the mitogen-activated protein kinases (MAPK)/ hemeoxygenase-1 (HO-1) pathway, activates estrogen receptor (ER), and the mediation of pro-inflammatory cytokines, reactive oxygen species (ROS) formation and reactive. Moreover, through anti-inflammatory effects and antioxidant properties, the resveratrol is believed to maintain organ function following trauma-hemorrhage.Key words: resveratrol, anti-inflammatory, trauma-hemorrhage.

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