Phillyrin attenuates norepinephrine-induced cardiac hypertrophy and inflammatory response by suppressing p38/ERK1/2 MAPK and AKT/NF-kappaB pathways

NF-ĸB axis in diabetic neuropathy, cardiomyopathy and nephropathy: A roadmap from molecular intervention to therapeutic strategies

Diabetes mellitus (DM) is a metabolic illness defined by elevated blood glucose levels, mediating various tissue alterations, including the dysfunction of vital organs. Diabetes mellitus (DM) can lead to many consequences that specifically affect the brain, heart, and kidneys. These issues are known as neuropathy, cardiomyopathy, and nephropathy, respectively. Inflammation is acknowledged as a pivotal biological mechanism that contributes to the development of various diabetes consequences. NF-κB modulates inflammation and the immune system at the cellular level. Its abnormal regulation has been identified in several clinical situations, including cancer, inflammatory bowel illnesses, cardiovascular diseases, and Diabetes Mellitus (DM). The purpose of this review is to evaluate the potential impact of NF-κB on complications associated with DM. Enhanced NF-κB activity promotes inflammation, resulting in cellular harm and compromised organ performance. Phytochemicals, which are therapeutic molecules, can potentially decline the NF-κB level, therefore alleviating inflammation and the progression of problems correlated with DM. More importantly, the regulation of NF-κB can be influenced by various factors, such as TLR4 in DM. Highlighting these factors can facilitate the development of novel therapies in the future.

Development and Evaluation of a Water-Free In Situ Depot Gel Formulation for Long-Acting and Stable Delivery of Peptide Drug ACTY116

In situ depot gel is a type of polymeric long-acting injectable (pLAI) drug delivery system; compared to microsphere technology, its preparation process is simpler and more conducive to industrialization. To ensure the chemical stability of peptide ACTY116, we avoided the use of harsh conditions such as high temperatures, high shear mixing, or homogenization; maintaining a water-free and oxygen-free environment was also critical to prevent hydrolysis and oxidation. Molecular dynamics (MDs) simulations were employed to assess the stability mechanism between ACTY116 and the pLAI system. The initial structure of ACTY116 with an alpha helix conformation was constructed using SYBYL-X, and the copolymer PLGA was generated by AMBER 16; results showed that PLGA-based in situ depot gel improved conformational stability of ACTY116 through hydrogen bonds formed between peptide ACTY116 and the components of the pLAI formulation, while PLGA (Poly(DL-lactide-co-glycolide)) also created steric hindrance and shielding effects to prevent conformational changes. As a result, the chemical and conformational stability and in vivo long-acting characteristics of ACTY116 ensure its enhanced efficacy. In summary, we successfully achieved our objective of developing a highly stable peptide-loaded long-acting injectable (LAI) in situ depot gel formulation that is stable for at least 3 months under harsh conditions (40 °C, above body temperature), elucidating the underlying stabilisation mechanism, and the high stability of the ACTY116 pLAI formulation creates favourable conditions for its in vivo pharmacological activity lasting for weeks or even months.

Norepinephrine-Activated p38 MAPK Pathway Mediates Stress-Induced Cytotoxic Edema of Basolateral Amygdala Astrocytes

The amygdala is a core region in the limbic system that is highly sensitive to stress. Astrocytes are key players in stress disorders such as anxiety and depression. However, the effects of stress on the morphology and function of amygdala astrocytes and its potential mechanisms remain largely unknown. Hence, we performed in vivo and in vitro experiments using a restraint stress (RS) rat model and stress-induced astrocyte culture, respectively. Our data show that norepinephrine (NE) content increased, cytotoxic edema occurred, and aquaporin-4 (AQP4) expression was up-regulated in the basolateral amygdala (BLA) obtained from RS rats. Additionally, the p38 mitogen-activated protein kinase (MAPK) pathway was also observed to be significantly activated in the BLA of rats subjected to RS. The administration of NE to in vitro astrocytes increased the AQP4 level and induced cell edema. Furthermore, p38 MAPK signaling was activated. The NE inhibitor alpha-methyl-p-tyrosine (AMPT) alleviated cytotoxic edema in astrocytes, inhibited AQP4 expression, and inactivated the p38 MAPK pathway in RS rats. Meanwhile, in the in vitro experiment, the p38 MAPK signaling inhibitor SB203580 reversed NE-induced cytotoxic edema and down-regulated the expression of AQP4 in astrocytes. Briefly, NE-induced activation of the p38 MAPK pathway mediated cytotoxic edema in BLA astrocytes from RS rats. Thus, our data provide novel evidence that NE-induced p38 MAPK pathway activation may be one of the mechanisms leading to cytotoxic edema in BLA under stress conditions, which also could enable the development of an effective therapeutic strategy against cytotoxic edema in BLA under stress and provide new ideas for the treatment of neuropsychiatric diseases.

Salidroside attenuates myocardial remodeling in DOCA-salt-induced mice by inhibiting the endothelin 1 and PI3K/AKT/NFκB signaling pathways

Myocardial remodeling, which occurs in the final stage of cardiovascular diseases such as hypertension, can ultimately result in heart failure. However, the pathogenesis of myocardial remodeling remains incompletely understood, and there is currently a lack of safe and effective treatment options. Salidroside, which is extracted from the plant Rhodiola rosea, shows remarkable antioxidant and anti-inflammatory characteristics. The purpose of this investigation was to examine the cardioprotective effect of salidroside on myocardial remodeling, and clarify the associated mechanism. Salidroside effectively attenuated cardiac dysfunction, myocardial hypertrophy, myocardial fibrosis, and cardiac inflammation, as well as renal injury and renal fibrosis in an animal model of deoxycortone acetate (DOCA)-salt-induced myocardial remodeling. The cardioprotective effect of salidroside was mediated by inhibiting the endothelin 1 and PI3K/AKT/NFκB signaling pathways. Salidroside was shown to inhibit the expression of endothelin1 in the hearts of mice treated with DOCA-salt. Additionally, it could prevent cardiomyocyte hypertrophy induced by endothelin-1 stimulation. Furthermore, Salidroside could effectively inhibit the excessive activation of the PI3K/AKT/NFκB pathway, which was caused by DOCA-salt treatment in mouse hearts and endothelin 1 stimulation in cardiomyocytes. Our study suggests that salidroside can be used as a therapeutic agent for the treatment of myocardial remodeling.

Improvement of the cardiovascular effect of methyldopa by complexation with Zn(II): Synthesis, characterization and mechanism of action

BACKGROUND

the antihypertensive drug α-methyldopa (MD) stands as one of the extensively used medications for managing hypertension during pregnancy. Zinc deprivation has been associated with many diseases. In this context, the synthesis of a Zn coordination complex [Zn(MD)(OH)(H2O)2]·H2O (ZnMD) provide a promising alternative pathway to improve the biological properties of MD.

METHODS

ZnMD was synthesized and physicochemically characterized. Fluorescence spectral studies were conducted to examine the binding of both, the ligand and the metal with bovine serum albumin (BSA). MD, ZnMD, and ZnCl2 were administered to spontaneous hypertensive rats (SHR) rats during 8 weeks and blood pressure and echocardiographic parameters were determined. Ex vivo assays were conducted to evaluate levels of reactive oxygen species (ROS), thiobarbituric acid reactive substances (TBARS), and nitric oxide (NO). Cross-sectional area (CSA) and collagen levels of left ventricular cardiomyocytes were also assessed. Furthermore, the expression of NAD(P)H oxidase subunits (gp91phox and p47phox) and Superoxide Dismutase 1 (SOD1) was quantified through western blot analysis.

RESULTS

The complex exhibited a moderate affinity for binding with BSA showing a spontaneous interaction (indicated by negative ΔG values) and moderate affinity (determined by affinity constant values). The binding process involved the formation of Van der Waals forces and hydrogen bonds. Upon treatment with MD and ZnMD, a reduction in the systolic blood pressure in SHR was observed, being ZnMD more effective than MD (122 ± 8.1 mmHg and 145 ± 5.6 mmHg, at 8th week of treatment, respectively). The ZnMD treatment prevented myocardial hypertrophy, improved the heart function and reduced the cardiac fibrosis, as evidenced by parameters such as left ventricular mass, fractional shortening, and histological studies. In contrast, MD did not show noticeable differences in these parameters. ZnMD regulates negatively the oxidative damage by reducing levels of ROS and lipid peroxidation, as well as the cardiac NAD(P)H oxidase, and increasing SOD1 expression, while MD did not show significant effect. Moreover, cardiac nitric oxide levels were greater in the ZnMD therapy compared to MD treatment.

CONCLUSION

Both MD and ZnMD have the potential to be transported by albumin. Our findings provide important evidence suggesting that this complex could be a potential therapeutic drug for the treatment of hypertension and cardiac hypertrophy and dysfunction.

Targeting oxidative stress as a preventive and therapeutic approach for cardiovascular disease

Cardiovascular diseases (CVDs) continue to exert a significant impact on global mortality rates, encompassing conditions like pulmonary arterial hypertension (PAH), atherosclerosis (AS), and myocardial infarction (MI). Oxidative stress (OS) plays a crucial role in the pathogenesis and advancement of CVDs, highlighting its significance as a contributing factor. Maintaining an equilibrium between reactive oxygen species (ROS) and antioxidant systems not only aids in mitigating oxidative stress but also confers protective benefits on cardiac health. Herbal monomers can inhibit OS in CVDs by activating multiple signaling pathways, such as increasing the activity of endogenous antioxidant systems and decreasing the level of ROS expression. Given the actions of herbal monomers to significantly protect the normal function of the heart and reduce the damage caused by OS to the organism. Hence, it is imperative to recognize the significance of herbal monomers as prospective therapeutic interventions for mitigating oxidative damage in CVDs. This paper aims to comprehensively review the origins and mechanisms underlying OS, elucidate the intricate association between CVDs and OS, and explore the therapeutic potential of antioxidant treatment utilizing herbal monomers. Furthermore, particular emphasis will be placed on examining the cardioprotective effects of herbal monomers by evaluating their impact on cardiac signaling pathways subsequent to treatment.

Caveolin-1 alleviates acetaminophen-induced vascular oxidative stress and inflammation in non-alcoholic fatty liver disease

Acetaminophen (APAP) is one of the most widely used drugs in the world. The literature shows that excessive or long-term use of APAP can lead to increased cardiovascular dysfunction. An acute increase in angiotensin Ⅱ (Ang Ⅱ) caused by APAP use in fatty liver disease may increase the risk and severity of vascular injury. However, the underlying mechanism remains unclear. Caveolin-1 (CAV1) is a broad-spectrum kinase inhibitor that significantly determines endothelial function. This study aimed to observe the effects of APAP on the vasculature in non-alcoholic fatty liver disease (NAFLD) and to determine whether CAV1 could alleviate vascular oxidative stress and inflammation by targeting Ang Ⅱ or its downstream pathways. In this study, 7-week-old C57BL/6 male mice (18-20 g) were administered APAP by gavage after eight weeks of a high-fat diet. Any resulting vascular oxidative stress and inflammation were assessed. Levels of Ang Ⅱ, CAV1, and other related proteins were measured using ELISA and western blotting. In APAP-treated NAFLD mice, CAV1 expression was downregulated and Ang Ⅱ expression was upregulated compared to normal APAP-treated mice. In vitro, HUVECs were incubated with Ang Ⅱ (300 nM) for 48 h. Overexpression of CAV1 in HUVECs attenuated Ang Ⅱ-induced oxidative stress and inflammation and downregulated the expression of Protein kinase C (PKC) and p-P38/P38. After intervention with CAV1-siRNA, immunofluorescence results showed that the fluorescence intensity of PKC on mitochondria was further increased, and flow cytometry results showed that the mitochondrial membrane potential increased. PKC inhibitors alleviated Ang Ⅱ-induced endothelial injury. In conclusion, our findings confirmed that CAV1 exerts a protective effect against vascular injury by inhibiting oxidative stress and inflammation through the PKC/MAPK pathway. Therefore, restoration of CAV1 may have clinical benefits in reducing APAP-induced vascular damage in NAFLD patients.

The Role of PKC-MAPK Signalling Pathways in the Development of Hyperglycemia-Induced Cardiovascular Complications

Cardiovascular disease is the most common cause of death among diabetic patients worldwide. Hence, cardiovascular wellbeing in diabetic patients requires utmost importance in disease management. Recent studies have demonstrated that protein kinase C activation plays a vital role in the development of cardiovascular complications via its activation of mitogen-activated protein kinase (MAPK) cascades, also known as PKC-MAPK pathways. In fact, persistent hyperglycaemia in diabetic conditions contribute to preserved PKC activation mediated by excessive production of diacylglycerol (DAG) and oxidative stress. PKC-MAPK pathways are involved in several cellular responses, including enhancing oxidative stress and activating signalling pathways that lead to uncontrolled cardiac and vascular remodelling and their subsequent dysfunction. In this review, we discuss the recent discovery on the role of PKC-MAPK pathways, the mechanisms involved in the development and progression of diabetic cardiovascular complications, and their potential as therapeutic targets for cardiovascular management in diabetic patients.