Anti-Proliferative Effects of Rutin on OLETF Rat Vascular Smooth Muscle Cells Stimulated by Glucose Variability

Abstract

PurposeProliferation of vascular smooth muscle cells (VSMCs) plays a crucial role in atherosclerosis. Rutin is a major representative of the flavonol subclass of flavonoids and has various pharmacological activities. Currently, data are lacking regarding its effects on VSMC proliferation induced by intermittent hyperglycemia. Here, we demonstrate the effects of rutin on VSMC proliferation and migration according to fluctuating glucose levels.Materials and MethodsPrimary cultures of male Otsuka Long-Evans Tokushima Fatty (OLETF) rat VSMCs were obtained from enzymatically dissociated rat thoracic aortas. VSMCs were incubated for 72 h with alternating normal (5.5 mmol/L) and high (25.0 mmol/L) glucose media every 12 h. Proliferation and migration of VSMCs, the proliferative molecular pathway [including p44/42 mitogen-activated protein kinases (MAPK), mitogen-activated protein kinase kinase 1/2 (MEK1/2), p38 MAPK, phosphoinositide 3-kinase (PI3K), c-Jun N-terminal protein kinase (JNK), nuclear factor kappa B (NF-κB), and Akt], the migratory pathway (big MAPK 1, BMK1), reactive oxygen species (ROS), and apoptotic pathway were analyzed.ResultsWe found enhanced proliferation and migration of VSMCs when cells were incubated in intermittent high glucose conditions, compared to normal glucose. These effects were lowered upon rutin treatment. Intermittent treatment with high glucose for 72 h increased the expression of phospho-p44/42 MAPK (extracellular signal regulated kinase 1/2, ERK1/2), phospho-MEK1/2, phospho-PI3K, phospho-NF-κB, phospho-BMK1, and ROS, compared to treatment with normal glucose. These effects were suppressed by rutin. Phospho-p38 MAPK, phospho-Akt, JNK, and apoptotic pathways [B-cell lymphoma (Bcl)-xL, Bcl-2, phospho-Bad, and caspase-3] were not affected by fluctuations in glucose levels.ConclusionFluctuating glucose levels increased proliferation and migration of OLETF rat VSMCs via MAPK (ERK1/2), BMK1, PI3K, and NF-κB pathways. These effects were inhibited by the antioxidant rutin.

Molecular Mechanisms of Glucose Fluctuations on Diabetic Complications

“…In the condition of glucose fluctuations, p38 signaling pathway activation is involved in ROS overproduction, mitochondrial dysfunction, and cell proliferation with consequent cellular damage in astroglial cells (94). Rutin, belonging to the flavonoid family, is reported to effectively reduce the vascular smooth muscle cell migration, and proliferation induced by intermittent hyperglycemia (115). Rutin can decrease ROS production, phospho-NF-κB and phosphorylation of MAPK (ERK1/2) and PI3K.…”

“…Rutin can decrease ROS production, phospho-NF-κB and phosphorylation of MAPK (ERK1/2) and PI3K. Further, anti-oxidative and anti-atherosclerotic properties of rutin can be a potential treatment for diabetic patients with cardiovascular complications (115). P38 MAPK inhibitors have been used in clinical studies for cardiovascular diseases in patients with diabetes (116).…”

Effects of Homocysteine and Hyperglycemia on the Proliferation of Aortic Vascular Smooth Muscle Cells of Obese Type 2 Diabetes Rat

“…VSMCs were harvested from the thoracic aorta of 12-weekold male OLETF and LETO rats by elastase and collagenase digestion as previously described 16,17) . The cells were grown in Dulbecco's modified Eagle's medium (DMEM, Gibco-BRL, Grand Island, NY, USA) containing 10% fetal bovine serum (FBS) in a 37°C, 5% CO2 humidified incubator.…”

The Abnormal Architecture of Healed Diabetic Ulcers Is the Result of FAK Degradation by Calpain 1

“…To investigate the effect of high glucose on FAK expression, we cultured human dermal fibroblasts in different concentrations of glucose (5.5 mM, 12 mM, and 25 mM) representing normoglycemia, moderate hyperglycemia, and severe hyperglycemic conditions, respectively (Fan et al, 2016;Silambarasan et al, 2016;Yamamoto et al, 1999;Yu et al, 2016). We compared these with human epidermal keratinocytes cultured in the same concentrations of glucose (5.5 mM, 12 mM, and 25 mM).…”