ABSTRACT
Salusin-ß is abundantly expressed in many organs and tissues including heart, blood vessels, brain and kidneys. Recent studies have identified salusin-ß as a bioactive peptide that contributes to various diseases, such as atherosclerosis, hypertension, diabetes and metabolic syndrome. However, the role of salusin-ß in the pathogenesis of acute kidney injury (AKI) is largely unclear. In the present study, we investigated the roles of salusin-ß in cisplatin or lipopolysaccharide (LPS)-induced renal injury. Herein, we found that salusin-ß expression was upregulated in both renal tubular cells and kidney tissues induced by both cisplatin and LPS. In vitro, silencing of salusin-ß diminished, whereas overexpression of salusin-ß exaggerated the increased PKC phosphorylation, oxidative stress, histone γH2AX expression, p53 activation and apoptosis in either cisplatin or LPS-challenged renal tubular cells. More importantly, salusin-ß overexpression-induced tubular cell apoptosis were abolished by using the PKC inhibitor Go 6976, reactive oxygen species (ROS) scavenger NAC, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitor apocynin (Apo) or p53 inhibitor Pifithrin-α. In animals, blockade of salusin-ß alleviated PKC phosphorylation, ROS accumulation, DNA damage, and p53 activation as well as renal dysfunction in mice after administration of cisplatin or LPS. Taken together, these results suggest that overexpressed salusin-ß is deleterious in AKI by activation of the PKC/ROS signaling pathway, thereby priming renal tubular cells for apoptosis and death.
Subject(s)
Acute Kidney Injury/chemically induced , Cisplatin/adverse effects , Intercellular Signaling Peptides and Proteins/metabolism , Kidney Tubules/cytology , Lipopolysaccharides/adverse effects , Acute Kidney Injury/genetics , Acute Kidney Injury/metabolism , Animals , Apoptosis , Cell Line , Disease Models, Animal , Humans , Intercellular Signaling Peptides and Proteins/genetics , Kidney Tubules/metabolism , Male , Mice , Phosphorylation , Protein Kinase C/metabolism , Reactive Oxygen Species/metabolism , Signal Transduction , Up-RegulationABSTRACT
The phenotypic transformation from differentiated to dedifferentiated vascular smooth muscle cells (VSMCs) plays a crucial role in VSMC proliferation and vascular remodeling in many cardiovascular diseases including hypertension. Nesfatin-1, a multifunctional adipocytokine, is critically involved in the regulation of blood pressure. However, it is still largely unexplored whether nesfatin-1 is a potential candidate in VSMC phenotypic switch and proliferation in hypertension. Experiments were carried out in Wistar-Kyoto rats (WKY), spontaneously hypertensive rats (SHR), human VSMCs and primary rat aortic VSMCs. We showed that the expression of nesfatin-1 was upregulated in media layer of the aorta in SHR and SHR-derived VSMCs. Nesfatin-1 promoted VSMC phenotypic transformation, accelerated cell cycle progression and proliferation. Knockdown of nesfatin-1 inhibited the VSMC phenotype switch from a contractile to a synthetic state, attenuated cell cycle progression and retarded VSMC proliferation in SHR-derived VSMCs. Moreover, nesfatin-1-activated PI3K/Akt/mTOR signaling was abolished by JAK/STAT inhibitor WP1066, and the increased phosphorylation levels of JAK2/STAT3 in response to nesfatin-1 were suppressed by inhibition of PI3K/Akt/mTOR in VSMCs. Pharmacological blockade of the forming feedback loop between PI3K/Akt/mTOR and JAK2/STAT3 prevented the proliferation of nesfatin-1-incubated VSMCs and primary VSMCs from SHR. Chronic intraperitoneal injection of nesfatin-1 caused severe hypertension and cardiovascular remodeling in normal rats. In contrast, silencing of nesfatin-1 gene ameliorated hypertension, phenotype switching, and vascular remodeling in the aorta of SHR. Therefore, our data identified nesfatin-1 as a key modulator in hypertension and vascular remodeling by facilitating VSMC phenotypic switching and proliferation.
Subject(s)
Calcium-Binding Proteins/physiology , DNA-Binding Proteins/physiology , Hypertension/etiology , Myocytes, Smooth Muscle/physiology , Nerve Tissue Proteins/physiology , Vascular Remodeling/physiology , Animals , Aorta/cytology , Blood Pressure/physiology , Cell Proliferation , Cells, Cultured , Disease Models, Animal , Gene Knockdown Techniques , Humans , Hypertension/pathology , Male , Muscle, Smooth, Vascular/cytology , Nucleobindins , Phenotype , Primary Cell Culture , RNA, Small Interfering/metabolism , Rats , Rats, Inbred SHR , Rats, Inbred WKY , Signal Transduction/physiologyABSTRACT
The dedifferentiation, proliferation and migration of vascular smooth muscle cells (VSMCs) are essential in the progression of hypertension, atherosclerosis and intimal hyperplasia. Nesfatin-1 is a potential modulator in cardiovascular functions. However, the role of nesfatin-1 in VSMC biology has not been explored. The present study was designed to determine the regulatory role of nesfatin-1 in VSMC proliferation, migration and intimal hyperplasia after vascular injury. Herein, we demonstrated that nesfatin-1 promoted VSMC phenotype switch from a contractile to a synthetic state, stimulated VSMC proliferation and migration in vitro. At the molecular level, nesfatin-1 upregulated the protein and mRNA levels, as well as the promoter activities of matrix metalloproteinase 2 (MMP-2) and MMP-9, but downregulated peroxisome proliferator-activated receptor γ (PPARγ) levels and promoter activity in VSMCs. Blockade of MMP-2/9 or activation of PPARγ prevented the nesfatin-1-induced VSMC proliferation and migration. In vivo, knockdown of nesfatin-1 ameliorated neointima formation following rat carotid injury. Taken together, our results indicated that nesfatin-1 stimulated VSMC proliferation, migration and neointimal hyperplasia by elevating MMP2/MMP-9 levels and inhibiting PPARγ gene expression.
