Metformin Prevents Progression of Experimental Pulmonary Hypertension via Inhibition of Autophagy and Activation of Adenosine Monophosphate-Activated Protein Kinase

2019 ◽  
Vol 56 (3) ◽  
pp. 117-128 ◽  
Author(s):  
Yun Liu ◽  
Yi Xu ◽  
Jinquan Zhu ◽  
Honglei Li ◽  
Jie Zhang ◽  
...  
Antioxidants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1913
Author(s):  
Ahmed Elsaie ◽  
Renuka T. Menon ◽  
Amrit K. Shrestha ◽  
Sharada H. Gowda ◽  
Nidhy P. Varghese ◽  
...  

Bronchopulmonary dysplasia and pulmonary hypertension, or BPD-PH, are serious chronic lung disorders of prematurity, without curative therapies. Hyperoxia, a known causative factor of BPD-PH, activates adenosine monophosphate-activated protein kinase (AMPK) α1 in neonatal murine lungs; however, whether this phenomenon potentiates or mitigates lung injury is unclear. Thus, we hypothesized that (1) endothelial AMPKα1 is necessary to protect neonatal mice against hyperoxia-induced BPD-PH, and (2) AMPKα1 knockdown decreases angiogenesis in hyperoxia-exposed neonatal human pulmonary microvascular endothelial cells (HPMECs). We performed lung morphometric and echocardiographic studies on postnatal day (P) 28 on endothelial AMPKα1-sufficient and -deficient mice exposed to 21% O2 (normoxia) or 70% O2 (hyperoxia) from P1–P14. We also performed tubule formation assays on control- or AMPKα1-siRNA transfected HPMECs, exposed to 21% O2 or 70% O2 for 48 h. Hyperoxia-mediated alveolar and pulmonary vascular simplification, pulmonary vascular remodeling, and PH were significantly amplified in endothelial AMPKα1-deficient mice. AMPKα1 siRNA knocked down AMPKα1 expression in HPMECs, and decreased their ability to form tubules in normoxia and hyperoxia. Furthermore, AMPKα1 knockdown decreased proliferating cell nuclear antigen expression in hyperoxic conditions. Our results indicate that AMPKα1 is required to reduce hyperoxia-induced BPD-PH burden in neonatal mice, and promotes angiogenesis in HPMECs to limit lung injury.


2019 ◽  
Vol 18 (1) ◽  
pp. 34-38
Author(s):  
Chen Lei ◽  
Pan Xiang ◽  
Shen Yonggang ◽  
Song Kai ◽  
Zhong Xingguo ◽  
...  

The aim of this study was to determine whether polydatin, a glucoside of resveratrol isolated from the root of Polygonum cuspidatum, warranted development as a potential therapeutic for ameliorating the pain originating from gallbladder spasm disorders and the underlying mechanisms. Guinea pig gallbladder smooth muscles were treated with polydatin and specific inhibitors to explore the mechanisms underpinning polydatin-induced relaxation of carbachol-precontracted guinea pig gallbladder. Our results shown that polydatin relaxed carbachol-induced contraction in a dose-dependent manner through the nitric oxide/cyclic guanosine monophosphate/protein kinase G and the cyclic adenosine monophosphate/protein kinase A signaling pathways as well as the myosin light chain kinase and potassium channels. Our findings suggested that there was value in further exploring the potential therapeutic use of polydatin in gallbladder spasm disorders.


2021 ◽  
Vol 22 (14) ◽  
pp. 7256
Author(s):  
Vianet Argelia Tello-Flores ◽  
Fredy Omar Beltrán-Anaya ◽  
Marco Antonio Ramírez-Vargas ◽  
Brenda Ely Esteban-Casales ◽  
Napoleón Navarro-Tito ◽  
...  

Long non-coding RNAs (lncRNAs) are single-stranded RNA biomolecules with a length of >200 nt, and they are currently considered to be master regulators of many pathological processes. Recent publications have shown that lncRNAs play important roles in the pathogenesis and progression of insulin resistance (IR) and glucose homeostasis by regulating inflammatory and lipogenic processes. lncRNAs regulate gene expression by binding to other non-coding RNAs, mRNAs, proteins, and DNA. In recent years, several mechanisms have been reported to explain the key roles of lncRNAs in the development of IR, including metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), imprinted maternal-ly expressed transcript (H19), maternally expressed gene 3 (MEG3), myocardial infarction-associated transcript (MIAT), and steroid receptor RNA activator (SRA), HOX transcript antisense RNA (HOTAIR), and downregulated Expression-Related Hexose/Glucose Transport Enhancer (DREH). LncRNAs participate in the regulation of lipid and carbohydrate metabolism, the inflammatory process, and oxidative stress through different pathways, such as cyclic adenosine monophosphate/protein kinase A (cAMP/PKA), phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT), polypyrimidine tract-binding protein 1/element-binding transcription factor 1c (PTBP1/SREBP-1c), AKT/nitric oxide synthase (eNOS), AKT/forkhead box O1 (FoxO1), and tumor necrosis factor-alpha (TNF-α)/c-Jun-N-terminal kinases (JNK). On the other hand, the mechanisms linked to the molecular, cellular, and biochemical actions of lncRNAs vary according to the tissue, biological species, and the severity of IR. Therefore, it is essential to elucidate the role of lncRNAs in the insulin signaling pathway and glucose and lipid metabolism. This review analyzes the function and molecular mechanisms of lncRNAs involved in the development of IR.


2014 ◽  
Vol 306 (4) ◽  
pp. L383-L391 ◽  
Author(s):  
Dhara Patel ◽  
Sharath Kandhi ◽  
Melissa Kelly ◽  
Boon Hwa Neo ◽  
Michael S. Wolin

The activity of glucose-6-phosphate dehydrogenase (G6PD) controls a vascular smooth muscle relaxing mechanism promoted by the oxidation of cytosolic NADPH, which has been associated with activation of the 1α form of protein kinase G (PKG-1α) by a thiol oxidation-elicited subunit dimerization. This PKG-1α-activation mechanism appears to contribute to responses of isolated endothelium-removed bovine pulmonary arteries (BPA) elicited by peroxide, cytosolic NADPH oxidation resulting from G6PD inhibition, and hypoxia. Dehydroepiandrosterone (DHEA) is a steroid hormone with pulmonary vasodilator activity, which has beneficial effects in treating pulmonary hypertension. Because multiple mechanisms have been suggested for the vascular effects of DHEA and one of the known actions of DHEA is inhibiting G6PD, we investigated whether it promoted relaxation associated with NADPH oxidation, PKG-1α dimerization, and PKG activation detected by increased vasodilator-stimulated phosphoprotein (VASP) phosphorylation. Relaxation of BPA to DHEA under aerobic or hypoxic conditions was associated with NADPH oxidation, PKG-1α dimerization, and increased VASP phosphorylation. The vasodilator activity of DHEA was markedly attenuated in pulmonary arteries and aorta from a PKG knockin mouse containing a serine in place of a cysteine involved in PKG dimerization. DHEA promoted increased PKG dimerization in lungs from wild-type mice, which was not detected in the PKG knockin mouse model. Thus PKG-1α dimerization is a major contributing factor to the vasodilator actions of DHEA and perhaps its beneficial effects in treating pulmonary hypertension.


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