Central administration of AICAR attenuates hypertension via AMPK/Nrf2 pathway in the hypothalamic paraventricular nucleus of hypertensive rats

Sex-Specific Antioxidant and Anti-Inflammatory Protective Effects of AMPK in Cardiovascular Diseases

Cardiovascular diseases such as coronary heart disease, heart failure, or stroke are the most common cause of death worldwide and are regularly based on risk factors like diabetes mellitus, hypertension, or obesity. At the same time, both diseases and risk factors are significantly influenced by sex hormones. In order to better understand this influence and also specifically improve the therapy of female patients, medical research has recently focused increasingly on gender-specific differences. The goal is to develop personalized, gender-specific therapy concepts for these diseases to further enhance health outcomes. The enzyme adenosine monophosphate-activated protein kinase (AMPK) is a central regulator of energy metabolism, protecting the cardiovascular system from energy depletion, thereby promoting vascular health and preventing cellular damage. AMPK confers cardioprotective effects by preventing endothelial and vascular dysfunction, and by controlling or regulating oxidative stress and inflammatory processes. For AMPK, sex-specific effects were reported, influencing metabolic and cardiovascular responses. Exercise and metabolic stress generally cause higher AMPK activity in males. At the same time, females exhibit protective mechanisms against insulin resistance or oxidative stress, particularly in conditions like obesity. Additionally, males subject to AMPK deficiency seem to experience greater cardiac and mitochondrial dysfunction. In contrast, females show improvement in cardiovascular function after pharmacological AMPK activation. These differences, influenced by hormones, body composition, and gene expression, highlight the potential to develop personalized, sex-specific AMPK-targeted therapeutic strategies for cardiovascular diseases in the future. Here, we discuss the most actual scientific background, focusing on the protective, gender-specific effects of AMPK, and highlight potential clinical applications.

Myricetin promotes migration and prevents palmitate-induced apoptosis in cultured tenocytes through AMPK-dependent pathways

Myricetin (Myr), a flavonoid present in vegetables and fruits, has been shown to ameliorate inflammation and oxidative stress in various disease models. However, the effects of Myr on hyperlipidemic tenocytes have not been studied. Herein, we aimed to investigate the effects of Myr on the features of tendinopathy in cultured tenocytes under hyperlipidemic conditions. Reactive oxygen species (ROS) were detected by DCFDA. Hydrogen peroxide (H2O2), malondialdehyde (MDA), and caspase 3 activity were quantified via matched assay kits. Apoptotic cells were detected via TUNEL staining. Proteins investigated in this study were evaluated through Western blotting. Treatment with Myr enhanced tenocyte migration and prevented apoptosis, inflammation and oxidative stress in palmitate-treated tenocytes. Myr treatment increased the phosphorylation of AMPK, and the expression of PGC1α and FGF2. siRNA targeting AMPK abrogated the effects of Myr on palmitate-treated tenocytes. However, FGF2 siRNA reduced the impacts of Myr on only cell migration and ECM signaling. These in vitro results suggest that Myr promotes tenocyte migration and ECM signaling via AMPK/FGF2 signaling and attenuates apoptosis through the AMPK-mediated suppression of inflammation and oxidative stress in hyperlipidemic tenocytes. This study sheds light on therapeutic strategies for treating obesity-related tendinopathy.

Blockade of PVN neuromedin B receptor alleviates inflammation via the RAS/ROS/NF-κB pathway in spontaneously hypertensive rats

Neuromedin B (NMB) has potentially great impacts on the development of cardiovascular diseases by promoting hypertensive and sympatho-excitation effects. However, studies regarding the NMB function in paraventricular nucleus (PVN) are lacking. With selective neuromedin B receptor (NMBR) antagonist, BIM-23127, we aim to determine whether the blockade of NMB function in PVN could alleviate central inflammation and attenuate hypertensive responses. Spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY) were chronically infused with BIM-23127 in the PVN for 6 weeks. Mean arterial pressure (MAP) was assessed with tail cuff and electrophysiological acquisition systems. PVN tissues were collected to analyze expressions of Fra-LI, inflammatory cytokines (IL-1β, TNF-α, IL-6, IL-10, and IL-4), renin-angiotensin system (angiotensin-converting enzyme (ACE), ACE2, and AT1-reporter (AT1-R)) and oxidative stress (reactive oxygen species (ROS), superoxide dismutase (SOD)1, NADPH oxidase (NOX)2, and NOX4). ELISA was used to detect inflammation indices, norepinephrine (NE), and nuclear factor κB (NF-κB) p65 in plasma and PVN tissue homogenate. Compared to WKY, SHR exhibited higher mean arterial pressure (MAP), plasma NE, and pro-inflammatory cytokines (PICs). Higher PVN levels of Fra-LI, PICs, ACE, AT1-R, ROS, NOX2, NOX4, and NF-κB p65, while lower central levels of anti-inflammatory cytokines (AICs), ACE2, and SOD1 were observed in SHR. Administration of BIM-23127 in PVN reversed all these changes in SHR. In SHR, blockade of NMBR in the PVN inhibited sympatho-excitation and attenuated hypertensive response. The attenuation mechanism may involve reducing inflammation and the RAS/ROS/ NF-κB pathways in PVN.

Xiasangju alleviate metabolic syndrome by enhancing noradrenaline biosynthesis and activating brown adipose tissue

Metabolic syndrome (MetS) is a clinical condition associated with multiple metabolic risk factors leading to type 2 diabetes mellitus and other metabolic diseases. Recent evidence suggests that modulating adipose tissue to adaptive thermogenesis may offer therapeutic potential for MetS. Xiasangju (XSJ) is a marketed drug and dietary supplement used for the treatment of metabolic disease with anti-inflammatory activity. This study investigated the therapeutic effects of XSJ and the underlying mechanisms affecting the activation of brown adipose tissue (BAT) in MetS. The results revealed that XSJ ameliorated MetS by enhancing glucose and lipid metabolism, leading to reduced body weight and abdominal circumference, decreased adipose tissue and liver index, and improved blood glucose tolerance. XSJ administration stimulated catecholamine biosynthesis, increasing noradrenaline (NA) levels and activating NA-mediated proteins in BAT. Thus, BAT enhanced thermogenesis and oxidative phosphorylation (OXPHOS). Moreover, XSJ induced changes in gut microbiota composition, with an increase in Oscillibacter abundance and a decrease in Bilophila, Candidatus Stoquefichus, Holdemania, Parasutterella and Rothia. XSJ upregulated the proteins associated with intestinal tight junctions corresponding with lower serum lipopolysaccharide (LPS), tumor necrosis factor α (TNF-α) monocyte chemoattractant protein-1 (MCP-1) and interleukin-6 (IL-6) levels to maintain NA signaling transport. In summary, XSJ may alleviate MetS by promoting thermogenesis in BAT to ultimately boost energy metabolism through increasing NA biosynthesis, strengthening intestinal barrier integrity and reducing low-grade inflammation. These findings suggest XSJ has potential as a natural therapeutic agent for the treatment of MetS.