Chronic stress: a crucial promoter of cell apoptosis in atherosclerosis

Dipeptidyl peptidase-4 deficiency prevents chronic stress-induced cardiac remodeling and dysfunction in mice

Exposure to chronic psychosocial stress is a risk factor for metabolic cardiovascular disorders. Dipeptidyl peptidase-4 (DPP-4) plays essential roles in human pathobiology, and we recently showed that DPP-4 levels are increased by chronic stress in murine models. We here investigated the role of DPP-4 in stress-related cardiac injury and dysfunction in mice, focusing on oxidative stress and cardiac apoptosis. Male mice were randomly assigned to non-stress and two-week immobilized-stress groups for biological and morphological studies. On day 14 post-stress, stress had increased blood pressure, heart weight, cardiac myocyte size, and interstitial fibrosis, impaired cardiac diastolic function, and increased plasma levels of DPP-4 and glucose. The stressed mice also had increased levels of monocyte chemoattractant protein-1, inteleukin-6, gp91phox, matrix metalloproteinase-2 (MMP-2), MMP-9, tissue inhibitor of MMP-1/-2, caspase-8, and Bax genes and/or proteins and lowered levels of Bcl-2, p-Akt, and endothelial nitric oxide synthase (eNOS) proteins. DPP-4 inhibition by either a genetic or pharmacological approach ameliorated the stress-induced targeted molecular and morphological changes. In vitro, DPP-4 inhibition also mitigated the alterations in the targeted caspase-8, Bcl-2, eNOS, and p-Akt proteins in H9c2 cardiomyocytes in response to H2O2. DPP-4 inhibition appeared to improve the stress-induced cardiac injury and dysfunction in mice, possibly via the improvement of oxidative stress and apoptosis, suggesting that DPP-4 could become a novel therapeutic target for chronic psychological stress-related metabolic cardiovascular disorders.

Microglial circ-UBE2K exacerbates depression by regulating parental gene UBE2K via targeting HNRNPU

Background: Knowledge about the pathogenesis of depression and treatments for this disease are lacking. Epigenetics-related circRNAs are likely involved in the mechanism of depression and have great potential as treatment targets, but their mechanism of action is still unclear. Methods: Circular RNA UBE2K (circ-UBE2K) was screened from peripheral blood of patients with major depressive disorder (MDD) and brain of depression model mice through high-throughput sequencing. Microinjection of circ-UBE2K overexpression lentivirus and adeno-associated virus for interfering with microglial circ-UBE2K into the mouse hippocampus was used to observe the role of circ-UBE2K in MDD. Sucrose preference, forced swim, tail suspension and open filed tests were performed to evaluate the depressive-like behaviors of mice. Immunofluorescence and Western blotting analysis of the effects of circ-UBE2K on microglial activation and immune inflammation. Pull-down-mass spectrometry assay, RNA immunoprecipitation (RIP) test and fluorescence in situ hybridization (FISH) were used to identify downstream targets of circ-UBE2K/ HNRNPU (heterogeneous nuclear ribonucleoprotein U) axis. Results: In this study, through high-throughput sequencing and large-scale screening, we found that circ-UBE2K levels were significantly elevated both in the peripheral blood of patients with MDD and in the brains of depression model mice. Functionally, circ-UBE2K-overexpressing mice exhibited worsened depression-like symptoms, elevated brain inflammatory factor levels, and abnormal microglial activation. Knocking down circ-UBE2K mitigated these changes. Mechanistically, we found that circ-UBE2K binds to heterogeneous nuclear ribonucleoprotein U (HNRNPU) to form a complex that upregulates the expression of the parental gene ubiquitin conjugating enzyme E2 K (UBE2K), leading to abnormal microglial activation and neuroinflammation and promoting the occurrence and development of depression. Conclusions: The findings of the present study revealed that the expression of circUBE2K, which combines with HNRNPU to form the circUBE2K/HNRNPU complex, is increased in microglia after external stress, thus regulating the expression of the parental gene UBE2K and mediating the abnormal activation of microglia to induce neuroinflammation, promoting the development of MDD. These results indicate that circ-UBE2K plays a newly discovered role in the pathogenesis of depression.

Cardiomyopathies and Psychiatric Disorders: An Overview and General Clinical Recommendations

The association between cardiomyopathies (CMPs) and psychiatric disorders is a complex and bidirectional phenomenon that involves multiple mechanisms and factors. CMPs may raise the risk of psychiatric disorders due to the psychological stress, physical limitations, social isolation, or poor prognosis associated with the underlying disease. Psychiatric disorders, on the other hand, can increase the possibility of developing or worsening CMPs due to the behavioral, neuroendocrine, inflammatory, or pharmacological effects of mental illness or its treatment. Moreover, some common genetic or environmental factors may have a relevant influence on both conditions. With this comprehensive review, we sought to provide an overview of the current evidence on the strict and intriguing interconnection between CMPs and psychiatric disorders, focusing on the epidemiology, pathophysiology, clinical implications, and management strategies.

The potential role of the novel orodispersible film from rice polymer loaded with silkworm pupae hydrolysate and the combined extract of holy basil and ginger for the management of stroke with stress

The prevalence of stroke under stress conditions is rising and the severity of stroke is increasing. Owing to the limitation of the current therapeutic strategy, a novel effective strategy for treating this condition is needed. In this study, we explored the neuroprotective effect of an orodispersible film derived from a rice polymer loaded with silkworm pupae and the combined extract of holy basil and ginger (JP1). Male Wistar rats weighing 200-250 g were administered JP1 at the doses of 1, 10, and 100 mg/kg BW 45 min prior to an exposure to a 6-h immobilization stress for 14 days. Permanent, occlusion of the right middle cerebral artery (MCAO) was performed, and JP1 was administered continually for 21 days after MCAO. Assessments of the brain infarction volume, oxidative stress, inflammation, and apoptosis in the cerebral cortex were carried out 24 h after MCAO. Neurological severity scores were also determined for the rats every 7 days after MCAO until the end of the study period. The results clearly showed that all doses of JP1 decreased the brain infarct volume, oxidative stress, inflammation, and apoptosis and improved neurological deficits. Therefore, JP1 is a potential novel neuroprotective supplement for combating ischemic stroke under stress conditions. However, a clinical trial is essential to confirm this beneficial effect.

Recent Progress of Chronic Stress in the Development of Atherosclerosis

With the development of the times, cardiovascular diseases have become the biggest cause of death in the global aging society, causing a serious social burden. Atherosclerosis is a chronic inflammatory disease, which can occur in large and medium-sized blood vessels in the whole body. It takes atherosclerotic plaque as the typical pathological change and endothelial injury as the core pathophysiological mechanism. It is the pathological basis of coronary heart disease, peripheral artery disease, cerebrovascular disease, and other diseases. Recent studies have shown that chronic stress plays an important role in the occurrence and development of atherosclerosis, endothelial injury, lipid metabolism, and chronic inflammation. This process involves a large number of molecular targets. It is usually the cause of atherosclerotic cardiovascular and cerebrovascular diseases. If chronic stress factors exist for a long time, patients have genetic susceptibility, and the combination of environmental factors triggers the pathogenesis, which may eventually lead to complete blockage of the blood vessels, unstable rupture of plaques, and serious adverse cardiovascular events. This paper reviews the role of chronic stress in the occurrence and development of atherosclerosis, focusing on the pathophysiological mechanism.

Citrate Synthase and OGDH as Potential Biomarkers of Atherosclerosis under Chronic Stress

Background

Pathological changes of the adrenal gland and the possible underlying molecular mechanisms are currently unclear in the case of atherosclerosis (AS) combined with chronic stress (CS).

Methods

New Zealand white rabbits were used to construct a CS and AS animal model. Proteomics and bioinformatics were employed to identify hub proteins in the adrenal gland related to CS and AS. Hub proteins were detected using immunohistochemistry, immunofluorescence assays, and Western blotting. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to analyze the expression of genes. In addition, a neural network model was constructed. The quantitative relationships were inferred by cubic spline interpolation. Enzymatic activity of mitochondrial citrate synthase and OGDH was detected by the enzymatic assay kit. Function of citrate synthase and OGDH with knockdown experiments in the adrenal cell lines was performed. Furthermore, target genes-TF-miRNA regulatory network was constructed. Coimmunoprecipitation (IP) assay and molecular docking study were used to detect the interaction between citrate synthase and OGDH.

Results

Two most significant hub proteins (citrate synthase and OGDH) that were related to CS and AS were identified in the adrenal gland using numerous bioinformatic methods. The hub proteins were mainly enriched in mitochondrial proton transport ATP synthase complex, ATPase activation, and the AMPK signaling pathway. Compared with the control group, the adrenal glands were larger and more disordered, irregular, and necrotic in the AS+CS group. The expression of citrate synthase and OGDH was higher in the AS+CS group than in the control group, both at the protein and mRNA levels (P < 0.05). There were strong correlations among the cross-sectional areas of adrenal glands, citrate synthase, and OGDH (P < 0.05) via Spearman's rho analysis, receiver operating characteristic curves, a neural network model, and cubic spline interpolation. Enzymatic activity of citrate synthase and OGDH increased under the situation of atherosclerosis and chronic stress. Through the CCK8 assay, the adrenal cell viability was downregulated significantly after the knockdown experiment of citrate synthase and OGDH. Target genes-TF-miRNA regulatory network presented the close interrelations among the predicted microRNA, citrate synthase and OGDH. After Coimmunoprecipitation (IP) assay, the result manifested that the citrate synthase and OGDH were coexpressed in the adrenal gland. The molecular docking study showed that the docking score of optimal complex conformation between citrate synthase and OGDH was -6.15 kcal/mol.

Conclusion

AS combined with CS plays a significant role on the hypothalamic–pituitary–adrenal (HPA) axis, promotes adrenomegaly, increases the release of glucocorticoid (GC), and might enhance ATP synthesis and energy metabolism in the body through citrate synthase and OGDH gene targets, providing a potential research direction for future related explorations into this mechanism.

Apoptosis and Cell Proliferation Markers in Inflammatory-Fibroproliferative Diseases of the Vessel Wall (Review)

Apoptosis is the main feature of inflammatory-fibroproliferative disorders of the vessel wall. Studies in animal models have shown that smooth muscle cells (SMCs) cultured from endarterectomy specimens from the affected area proliferate more slowly and display higher apoptotic indices than SMCs derived from the normal vessel wall. Apoptotic cells were found in the destabilized atherosclerotic plaques, as well as in the samples with restenosis of the reconstruction area. Injury to the vessel wall causes two waves of apoptosis. The first wave is the rapid apoptosis in the media that occurs within a few hours after injury and leads to a marked reduction in the number of vascular wall cells. The second wave of apoptosis occurs much later (from several days to weeks) and is limited by the SMCs within the developing neointima. Up to 14% of the neointimal SMCs undergo apoptosis 20 days after balloon angioplasty. Ligation of the external carotid artery in a rabbit model led to a marked decrease in blood flow in the common carotid artery, which correlated with the increased apoptosis of endothelial cells and SMCs. Angioplasty-induced death of SMCs is regulated by a redox-sensitive signaling pathway, and topical administration of antioxidants can minimize vascular cell loss. On the whole, studies show that apoptosis is prevalent in vascular lesions, controlling the viability of both inflammatory and vascular cells, determining the cellular composition of the vessel wall. The main markers of apoptosis (Fas, Fas ligand, p53, Bcl-2, Bax) and cell proliferation (toll receptor) have been considered in the current review.

Therapeutic Potential of Oxytocin in Atherosclerotic Cardiovascular Disease: Mechanisms and Signaling Pathways

Coronary artery disease (CAD) is a major cardiovascular disease responsible for high morbidity and mortality worldwide. The major pathophysiological basis of CAD is atherosclerosis in association with varieties of immunometabolic disorders that can suppress oxytocin (OT) receptor (OTR) signaling in the cardiovascular system (CVS). By contrast, OT not only maintains cardiovascular integrity but also has the potential to suppress and even reverse atherosclerotic alterations and CAD. These protective effects of OT are associated with its protection of the heart and blood vessels from immunometabolic injuries and the resultant inflammation and apoptosis through both peripheral and central approaches. As a result, OT can decelerate the progression of atherosclerosis and facilitate the recovery of CVS from these injuries. At the cellular level, the protective effect of OT on CVS involves a broad array of OTR signaling events. These signals mainly belong to the reperfusion injury salvage kinase pathway that is composed of phosphatidylinositol 3-kinase-Akt-endothelial nitric oxide synthase cascades and extracellular signal-regulated protein kinase 1/2. Additionally, AMP-activated protein kinase, Ca²⁺/calmodulin-dependent protein kinase signaling and many others are also implicated in OTR signaling in the CVS protection. These signaling events interact coordinately at many levels to suppress the production of inflammatory cytokines and the activation of apoptotic pathways. A particular target of these signaling events is endoplasmic reticulum (ER) stress and mitochondrial oxidative stress that interact through mitochondria-associated ER membrane. In contrast to these protective effects and machineries, rare but serious cardiovascular disturbances were also reported in labor induction and animal studies including hypotension, reflexive tachycardia, coronary spasm or thrombosis and allergy. Here, we review our current understanding of the protective effect of OT against varieties of atherosclerotic etiologies as well as the approaches and underlying mechanisms of these effects. Moreover, potential cardiovascular disturbances following OT application are also discussed to avoid unwanted effects in clinical trials of OT usages.