Role of the JAK2/STAT3 pathway in angiotensin II-induced enhanced expression of Giα proteins and hyperproliferation of aortic vascular smooth muscle cells

Mechanism of Hypoxia-Mediated Smooth Muscle Cell Proliferation Leading to Vascular Remodeling

Vascular remodeling refers to changes in the size, contraction, distribution, and flow rate of blood vessels and even changes in vascular function. Vascular remodeling can cause cardiovascular and cerebrovascular diseases. It can also lead to other systemic diseases, such as pulmonary hypertension, pulmonary atherosclerosis, chronic obstructive pulmonary disease, stroke, and ascites of broilers. Hypoxia is one of the main causes of vascular remodeling. Prolonged hypoxia or intermittent hypoxia can lead to loss of lung ventilation, causing respiratory depression, irregular respiratory rhythms, and central respiratory failure. Animals that are unable to adapt to the highland environment are also prone to sustained constriction of the small pulmonary arteries, increased resistance to pulmonary circulation, and impaired blood circulation, leading to pulmonary hypertension and right heart failure if they live in a highland environment for long periods of time. However, limited studies have been found on the relationship between hypoxia and vascular remodeling. Therefore, this review will explore the relationship between hypoxia and vascular remodeling from the aspects of endoplasmic reticulum stress, mitochondrial dysfunction, abnormal calcium channel, disordered cellular metabolism, abnormal expression of miRNA, and other factors. This will help to understand the detailed mechanism of hypoxia-mediated smooth muscle cell proliferation and vascular remodeling for the better treatment and management of diseases due to vascular remodeling.

Natural products of traditional Chinese medicine treat atherosclerosis by regulating inflammatory and oxidative stress pathways

Atherosclerosis (AS) is a prevalent arteriosclerotic vascular disease that forms a pathological basis for coronary heart disease, stroke, and other diseases. Inflammatory and oxidative stress responses occur throughout the development of AS. Treatment for AS over the past few decades has focused on administering high-intensity statins to reduce blood lipid levels, but these inevitably damage liver and kidney function over the long term. Natural medicines are widely used to prevent and treat AS in China because of their wide range of beneficial effects, low toxicity, and minimal side effects. We searched for relevant literature over the past 5 years in databases such as PubMed using the keywords, “atherosclerosis,” “traditional Chinese medicine,” “natural medicines,” “inflammation,” and “oxidative stress.” We found that the PI3K/AKT, TLR4, JAK/STAT, Nrf2, MAPK, and NF-κB are the most relevant inflammatory and oxidative stress pathways in AS. This review summarizes studies of the natural alkaloid, flavonoid, polyphenol, saponin, and quinone pathways through which natural medicines used to treat AS. This study aimed to update and summarize progress in understanding how natural medicines treat AS via inflammatory and oxidative stress-related signaling pathways. We also planned to create an information base for the development of novel drugs for future AS treatment.

Adropin Inhibits Vascular Smooth Muscle Cell Osteogenic Differentiation to Alleviate Vascular Calcification via the JAK2/STAT3 Signaling Pathway

Vascular calcification is characterized as the deposition of hydroxyapatite mineral in the form of calcium-phosphate complexes in the vasculature. Transdifferentiation between vascular smooth muscle cells (VSMCs) and osteoblast-like cells is considered essential in the progression of vascular calcification. The pathophysiological mechanisms underlying vascular calcification and VSMC osteogenic differentiation remain to be fully elucidated, and the development of novel therapies is required. In the present study, PCR and western blot analysis were conducted to quantify the mRNA and protein expression levels of calcification-associated markers (bone morphogenetic protein 2, alkaline phosphatase, osteoprotegerin, osteocalcin, and runt-related transcription factor 2) and adropin in VSMCs and rat vascular tissues. The calcification of VSMCs was assessed using alizarin red staining. Moreover, adropin expression levels in VSMCs were analyzed using immunofluorescence. Lentiviral transfection and small interfering RNA were used for overexpression and knockdown of adropin in VSMCs, respectively. The results demonstrated that adropin alleviated vascular calcification in vivo. Moreover, adropin also inhibited osteogenic differentiation and the calcification of VSMCs in vitro. Notably, results of the present study revealed that the tyrosine protein kinase JAK2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway played a key role in the aforementioned inhibition. In conclusion, the results of the present study demonstrated that adropin inhibited VSMC osteogenic differentiation to alleviate vascular calcification via the JAK2/STAT3 signaling pathway.

The lncRNA Punisher Regulates Apoptosis and Mitochondrial Homeostasis of Vascular Smooth Muscle Cells via Targeting miR-664a-5p and OPA1

Long noncoding RNAs (lncRNAs) are important regulators of various cellular functions. Recent studies have shown that a novel lncRNA termed Punisher is highly expressed in cardiovascular progenitors and has potential role in cardiovascular diseases. However, its role, especially in molecular mechanism, is unclear. In our present study, we observed that Punisher was obviously downregulated in atherosclerotic plaques. Further research proved that it can suppress the apoptosis of VSMCs potentially contributing to the progression of atherosclerosis. Intriguingly, Punisher revealed to regulate mitochondria fission as well as mitochondrial functions induced by hydrogen peroxide (H₂O₂) in VSMCs. Mechanistically, Punisher was further proved to serve as a ceRNA which directly binds to miR-664a-5p and consequently regulates its target OPA1, and finally contributes to the biological function of VSMCs. Particularly, Punisher overexpression distinctly suppressed neointima formation and VSMC apoptosis in vivo. Encouragingly, these results were in accordance with findings obtained with the clinical evaluation of patients with atherosclerosis. Our data provides the significant relationship among OPA1, mitochondrial homeostasis, VSMC apoptosis, and atherosclerosis. And lncRNA Punisher and miR-664a-5p could serve as the novel and potential targets in the diagnosis and treatment of cardiovascular diseases.

Effect of profilin-1 on the asymmetric dimethylarginine-induced vascular lesion-associated hypertension

Previous studies have demonstrated that the levels of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide (NO) synthesis, are strongly associated with hypertension, diabetes, and cardiovascular diseases. Profilin-1, an actin-binding protein, has been documented to be involved in endothelial injury and in the proliferation of vascular smooth muscle cells resulting from hypertension. However, the role of profilin-1 in ADMA-induced vascular injury in hypertension remains largely unknown. Forty healthy subjects and forty-two matched patients with essential hypertension were enrolled, and the related indexes of vascular injury in plasma were detected. Rat aortic smooth muscle cells (RASMCs) were treated with different concentrations of ADMA for different periods of time and transfected with profilin-1 small hairpin RNA to interrupt the expression of profilin-1. To determine the role of the Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) pathway, RASMCs were pretreated with AG490 or rapamycin. The expression of profilin-1 was tested using real-time polymerase chain reaction (PCR) and western blot analysis. Cell proliferation was measured by flow cytometry and 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazoliumbromide assays. Compared with healthy subjects, the levels of ADMA and profilin-1 were markedly elevated in hypertensive individuals, while the levels of NO were significantly decreased (p < 0.05). In vitro, studies showed ADMA-induced profilin-1 expression in a concentration- and time-dependent manner in RASMCs (p < 0.05), concomitantly with promoting the proliferation of RASMCs. Furthermore, ADMA-mediated proliferation of RASMCs and upregulation expression of profilin-1 were inhibited by blockade of the JAK2/STAT3 pathway or knockdown of profilin-1. Profilin-1 implicated in the ADMA-mediated vascular lesions in hypertension.

IL13Rα2 Is Involved in the Progress of Renal Cell Carcinoma through the JAK2/FOXO3 Pathway

Previously, we reported a close relationship between type II IL4Rα and IL13Rα1 complex and poor outcomes in renal cell carcinoma (RCC). In this study, we investigated the clinicopathologically significant oncogenic role of IL13Rα2, a kind of the independent receptor for IL13, in 229 RCC patients. The high expression of IL13Rα2 was closely related to relapse-free survival in specific cancers in univariate and multivariate analysis. Then, the oncogenic role of IL13Rα2 was evaluated by performing in vitro assays for cell proliferation, cell cycle arrest, and apoptosis in A498, ACHN, Caki1, and Caki2, four kinds of RCC cells after transfection of siRNA against IL13Rα2. Cell proliferation was suppressed, and apoptosis was induced in A498, ACHN, Caki1, and Caki2 cells by knockdown of IL13Rα2. Interestingly, the knockdown of IL13Rα2 decreased the phosphorylation of JAK2 and increased the expression of FOXO3. Furthermore, the knockdown of IL13Rα2 reduced the protein interaction among IL13Rα2, phosphorylated JAK2, and FOXO3. Since phosphorylation of JAK2 was regulated by IL13Rα2, we tried to screen a novel JAK2 inhibitor from the FDA-approved drug library and selected telmisartan, a clinically used medicine against hypertension, as one of the strongest candidates. Telmisartan treatment decreased the cell proliferation rate and increased apoptosis in A498, ACHN, Caki1, and Caki2 cells. Mechanistically, telmisartan treatment decreased the phosphorylation of JAK2 and increased the expression of FOXO3. Taken together, these results suggest that IL13Rα2 regulates the progression of RCC via the JAK2/FOXO3-signaling path pathway, which might be targeted as the novel therapeutic option for RCC patients.

Paeoniflorin protects PC12 cells from oxygen-glucose deprivation/reoxygenation-induced injury via activating JAK2/STAT3 signaling

Ischemic stroke is the most common type of stroke, and it has become a major health issue as it is characterized by high mortality and morbidity rates. Paeoniflorin (PF) is a natural compound and the main active ingredient of Radix Paeoniae. The aim of the present study was to investigate the role of PF in oxygen-glucose deprivation/reoxygenation (OGD/R)-induced injury of PC12 cells and its association with the Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathway. An in vitro model of OGD/R injury was established in PC12 cells. Subsequently, Cell Counting Kit-8 assay and ELISA were used to evaluate cell viability and the secretion of inflammatory factors, respectively, in PC12 cells subjected to OGD/R and treated with PF. The levels of oxidative stress indicators and inflammatory factors were measured using corresponding commercial kits. In addition, the apoptosis rate of PC12 cells subjected to OGD/R and treated with PF was determined by flow cytometry, and the expression of apoptosis-related proteins was analyzed by western blotting. Additionally, the expression levels of JAK2/STAT3 pathway-related proteins were also evaluated. The cell viability, levels of oxidative stress, inflammation and apoptosis were also measured in OGD/R-induced PC12 cell injury models following co-treatment of cells with PF and FLLL32, a specific inhibitor of JAK2/STAT3 signaling. Cell viability was reduced, while oxidative stress and inflammation were increased after OGD/R-induced injury. However, the treatment of cells with PF significantly enhanced cell viability, and alleviated oxidative stress, inflammation and apoptosis of OGD/R-treated PC12 cells. Furthermore, PF activated the JAK2/STAT3 signaling pathway. Following FLLL32 intervention, the effects of PF on oxidative stress, inflammation and apoptosis of OGD/R-treated PC12 cells were reversed. In conclusion, the findings of the present study suggested that PF may protect PC12 cells from OGD/R-induced injury via activating the JAK2/STAT3 signaling pathway, thus providing novel insight into the mechanism through which PF may alleviate ischemic stroke and indicating a potential strategy for ischemic stroke treatment.