Inhibition of inflammation by minocycline improves heart failure and depression-like behaviour in rats after myocardial infarction

Mental disorders after myocardial infarction: potential mediator role for chemokines in heart-brain interaction?

Acute myocardial infarction (MI) remains one of the leading causes of mortality and morbidity in the global communities. A prevailing topic that has attracted increasing attentions over the past few decades is the so-called heart-brain interaction, in particular following a major traumatic event such as MI. Increased prevalence of depression and other mental disorders has been recognized in cardiac patients after MI, coronary catheterization, or cardiothoracic surgeries. In this review, we focus on the potential pathogenic mechanisms and pre-clinical transcriptomic evidence for identifying potential mediators of post-MI depression. We first summarize the conventional mechanistic understanding that leads to the current clinical management of post-MI depression with the use of selective serotonin reuptake inhibitors (SSRIs) and cognitive behavior and exercise therapies. We further envisage a possible role played by certain chemokines, e.g., Chemokine (C-X-C motif) ligand 12 (CXCL12) and Chemokine (C-C motif) ligand 2 (CCL22), in serving as signaling molecules to connect the MI-induced heart damage to the pro-depressive changes in brain during the post-MI period. Future in-depth investigations into this chemokine hypothesis will be instrumental in developing new chemokine-targeted therapies for better management of the cardiac patients suffering from post-MI depression.

Antioxidative and cardioprotective effects of minocycline in ischemia/reperfusion injury in experimental model of hypertension

Cardiovascular diseases remains leading cause of death and disabilities. Coronary artery occlusion and consequent ischemia leads to acute myocardial infarction, but restoration of blood flow, paradoxically, provokes further myocardial damage known as reperfusion injury. Minocycline is possessing anti-inflammatory and anti-apoptotic activity, immune-modulating and antioxidative properties besides its primary antibacterial effect. Recently it gained significant interest in preventing cardiac damage especially due to myocardial ischemia/reperfusion injury (MI/RI). The aim of this study was to assess the protective ability of pre-treatment and post-treatment of isolated hearts from healthy and spontaneously hypertensive rats with minocycline, on functional recovery and redox status after MI/RI using Langendorff technique. Using sensor in the left ventricle, the cardiodynamic parameters were recorded and in the samples of the coronary venous effluent oxidative stress biomarkers were analyzed. Minocycline was injected directly into the coronary vessels, in pre-treatment 5 min before global ischemia, and in post-treatment during the first 5 min of reperfusion. Changes in redox balance induced by minocycline were more prominent in post-treatment fashion of application. Cardioprotective effects of minocycline due to MI/RI are even more significant in hypertensive hearts. Minocycline showed significant cardioprotective effects, which was more pronounced in hypertensive compared to healthy hearts. Reduction of pro-oxidative biomarkers was more prominent in hypertensive hearts compared to the normotensive, especially if it is applied in the form of post-treatment. Minocycline could be important tool in reduction of heart damage induced by MI/RI due to its antioxidative potential, if these results are confirmed by clinical study.

Neuroimmunology of Cardiovascular Disease

PURPOSE OF REVIEW

Cardiovascular disease (CVD) is a leading cause of death and chronic disability worldwide. Yet, despite extensive intervention strategies the number of persons affected by CVD continues to rise. Thus, there is great interest in unveiling novel mechanisms that may lead to new treatments. Considering this dilemma, recent focus has turned to the neuroimmune mechanisms involved in CVD pathology leading to a deeper understanding of the brain's involvement in disease pathology. This review provides an overview of new and salient findings regarding the neuroimmune mechanisms that contribute to CVD.

RECENT FINDINGS

The brain contains neuroimmune niches comprised of glia in the parenchyma and immune cells at the brain's borders, and there is strong evidence that these neuroimmune niches are important in both health and disease. Mechanistic studies suggest that the activation of glia and immune cells in these niches modulates CVD progression in hypertension and heart failure and contributes to the inevitable end-organ damage to the brain. This review provides evidence supporting the role of neuroimmune niches in CVD progression. However, additional research is needed to understand the effects of prolonged neuroimmune activation on brain function.

Association between blood inflammatory indices and heart failure: a cross-sectional study of NHANES 2009-2018

BACKGROUND

Inflammation plays a pivotal role in the pathogenesis of heart failure (HF). This study was aimed to the potential association between complete blood cell count (CBC)-derived inflammatory biomarkers and HF.

METHODS

Data from the National Health and Nutrition Examination Survey (NHANES) 2009-2018 were utilised. We evaluated the associations between HF and five systemic inflammation markers derived from CBC: systemic immune-inflammation index (SII), systemic inflammatory response index (SIRI), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and monocyte-to-lymphocyte ratio (MLR). Demographic characteristics, physical examinations, and laboratory data were systematically collected for comparative analysis between HF and non-HF individuals. Fitted smoothing curves and threshold effect analysis delineated the relationship. In addition, Spearman correlation and subgroup analyses were further conducted.

RESULTS

A total of 26,021 participants were categorised into HF (n = 858) and non-HF (n = 25,163) groups. After adjusting for confounding variables, SIRI, NLR, and MLR had significant positive correlations with the risk of HF. Participants in the highest quarter groups of SIRI, NLR, and MLR showed a increased risk of developing HF compared to those in the lowest quarter group. Furthermore, subgroup and sensitivity analyses indicated that SIRI, NLR, and MLR had a stronger correlation to HF (all p < 0.05). Smoothing curve fitting highlighted a nonlinear relationship between CBC-derived inflammatory biomarkers and HF.

CONCLUSIONS

Our results illustrated a significant association between elevated levels of SIRI, NLR, and MLR and an increased risk of HF. SIRI, NLR, and MLR could potentially serve as systemic inflammation hazard markers for HF.

Integrated miRNA-mRNA networks underlie attenuation of chronic β-adrenergic stimulation-induced cardiac remodeling by minocycline

Adverse cardiac remodeling contributes to heart failure development and progression, partly due to inappropriate sympathetic nervous system activation. Although β-adrenergic receptor (β-AR) blockade is a common heart failure therapy, not all patients respond, prompting exploration of alternative treatments. Minocycline, an FDA-approved antibiotic, has pleiotropic properties beyond antimicrobial action. Recent evidence suggests it may alter gene expression via changes in miRNA expression. Thus, we hypothesized that minocycline could prevent adverse cardiac remodeling induced by the β-AR agonist isoproterenol, involving miRNA-mRNA transcriptome alterations. Male C57BL/6J mice received isoproterenol (30 mg/kg/day sc) or vehicle via osmotic minipump for 21 days, along with daily minocycline (50 mg/kg ip) or sterile saline. Isoproterenol induced cardiac hypertrophy without altering cardiac function, which minocycline prevented. Total mRNA sequencing revealed isoproterenol altering gene networks associated with inflammation and metabolism, with fibrosis activation predicted by integrated miRNA-mRNA sequencing, involving miR-21, miR-30a, miR-34a, miR-92a, and miR-150, among others. Conversely, the cardiac miRNA-mRNA transcriptome predicted fibrosis inhibition in minocycline-treated mice, involving antifibrotic shifts in Atf3 and Itgb6 gene expression associated with miR-194 upregulation. Picrosirius red staining confirmed isoproterenol-induced cardiac fibrosis, prevented by minocycline. These results demonstrate minocycline's therapeutic potential in attenuating adverse cardiac remodeling through miRNA-mRNA-dependent mechanisms, especially in reducing cardiac fibrosis. NEW & NOTEWORTHY We demonstrate that minocycline treatment prevents cardiac hypertrophy and fibrotic remodeling induced by chronic β-adrenergic stimulation by inducing antifibrotic shifts in the cardiac miRNA-mRNA transcriptome.

Angiotensin-II drives changes in microglia-vascular interactions in rats with heart failure

Activation of microglia, the resident immune cells of the central nervous system, leading to the subsequent release of pro-inflammatory cytokines, has been linked to cardiac remodeling, autonomic disbalance, and cognitive deficits in heart failure (HF). While previous studies emphasized the role of hippocampal Angiotensin II (AngII) signaling in HF-induced microglial activation, unanswered mechanistic questions persist. Evidence suggests significant interactions between microglia and local microvasculature, potentially affecting blood-brain barrier integrity and cerebral blood flow regulation. Still, whether the microglial-vascular interface is affected in the brain during HF remains unknow. Using a well-established ischemic HF rat model, we demonstrate increased vessel-associated microglia (VAM) in HF rat hippocampi, which showed heightened expression of AngII AT1a receptors. Acute AngII administration to sham rats induced microglia recruitment to the perivascular space, along with increased expression of TNFa. Conversely, administering an AT1aR blocker to HF rats prevented the recruitment of microglia to the perivascular space, normalizing their levels to those in healthy rats. These results highlight the critical importance of a rather understudied phenomenon (i.e., microglia-vascular interactions in the brain) in the context of the pathophysiology of a highly prevalent cardiovascular disease, and unveil novel potential therapeutic avenues aimed at mitigating neuroinflammation in cardiovascular diseases.

Glial Activation, Mitochondrial Imbalance, and Akt/mTOR Signaling May Be Potential Mechanisms of Cognitive Impairment in Heart Failure Mice

Heart failure (HF) is a major health burden worldwide, with approximately half of HF patients having a comorbid cognitive impairment (CI). However, it is still unclear how CI develops in patients with HF. In the present study, a mice model of heart failure was established by ligating the left anterior descending coronary artery. Echocardiography 1 month later confirmed the decline in ejection fraction and ventricular remodeling. Cognitive function was examined by the Pavlovian fear conditioning and the Morris water maze. HF group cued fear memory, spatial memory, and learning impairment, accompanied by activation of glial cells (astrocytes, microglia, and oligodendrocytes) in the hippocampus. In addition, the mitochondrial biogenesis genes TFAM and SIRT1 decreased, and the fission gene DRP1 increased in the hippocampus. Damaged mitochondria release excessive ROS, and the ability to produce ATP decreases. Damaged swollen mitochondria with altered morphology and aberrant inner-membrane crista were observed under a transmission electron microscope. Finally, Akt/mTOR signaling was upregulated in the hippocampus of heart failure mice. These findings suggest that activation of Akt/mTOR signaling, glial activation, and mitochondrial dynamics imbalance could trigger cognitive impairment in the pathological process of heart failure mice.

Acute Myocardial Infarction and Risk of Cognitive Impairment and Dementia: A Review

Cognitive impairment (CI) shares common cardiovascular risk factors with acute myocardial infarction (AMI), and is increasingly prevalent in our ageing population. Whilst AMI is associated with increased rates of CI, CI remains underreported and infrequently identified in patients with AMI. In this review, we discuss the evidence surrounding AMI and its links to dementia and CI, including pathophysiology, risk factors, management and interventions. Vascular dysregulation plays a major role in CI, with atherosclerosis, platelet activation, microinfarcts and perivascular inflammation resulting in neurovascular unit dysfunction, disordered homeostasis and a dysfunctional neurohormonal response. This subsequently affects perfusion pressure, resulting in enlarged periventricular spaces and hippocampal sclerosis. The increased platelet activation seen in coronary artery disease (CAD) can also result in inflammation and amyloid-β protein deposition which is associated with Alzheimer's Dementia. Post-AMI, reduced blood pressure and reduced left ventricular ejection fraction can cause chronic cerebral hypoperfusion, cerebral infarction and failure of normal circulatory autoregulatory mechanisms. Patients who undergo coronary revascularization (percutaneous coronary intervention or bypass surgery) are at increased risk for post-procedure cognitive impairment, though whether this is related to the intervention itself or underlying cardiovascular risk factors is debated. Mortality rates are higher in dementia patients with AMI, and post-AMI CI is more prevalent in the elderly and in patients with post-AMI heart failure. Medical management (antiplatelet, statin, renin-angiotensin system inhibitors, cardiac rehabilitation) can reduce the risk of post-AMI CI; however, beta-blockers may be associated with functional decline in patients with existing CI. The early identification of those with dementia or CI who present with AMI is important, as subsequent tailoring of management strategies can potentially improve outcomes as well as guide prognosis.

Systemic immune profile in Prader-Willi syndrome: elevated matrix metalloproteinase and myeloperoxidase and reduced macrophage inhibitory factor

BACKGROUND

Prader-Willi syndrome (PWS) is a rare genetic neurodevelopmental syndrome with highly increased risk of obesity and cardiovascular disease (CVD). Recent evidence suggests that inflammation is implicated in the pathogenesis. Here we investigated CVD related immune markers to shed light on pathogenetic mechanisms.

METHODS

We performed a cross-sectional study with 22 participants with PWS and 22 healthy controls (HC), and compared levels of 21 inflammatory markers that reflect activity in different aspects of CVD related immune pathways and analyzed their association with clinical CVD risk factors.

RESULTS

Serum levels of matrix metalloproteinase 9 (MMP-9) was (median (range)) 121 (182) ng/ml in PWS versus 44 (51) ng/ml in HC, p = 1 × 10^-9), myeloperoxidase (MPO) was 183 (696) ng/ml versus 65 (180) ng/ml, p = 1 × 10^-5) and macrophage inhibitory factor (MIF) was 46 (150) ng/ml versus 121 (163) ng/ml (p = 1 × 10^-3), after adjusting for age and sex. Also other markers tended to be elevated (OPG, sIL2RA, CHI3L1, VEGF) but not significantly after Bonferroni correction (p > 0.002). As expected PWS had higher body mass index, waist circumference, leptin, C-reactive protein, glycosylated hemoglobin (HbA1c), VAI and cholesterol, but MMP-9, MPO and MIF remained significantly different in PWS after adjustment for these clinical CVD risk factors.

CONCLUSION

PWS had elevated levels of MMP-9 and MPO and of reduced levels of MIF, which were not secondary to comorbid CVD risk factors. This immune profile suggests enhanced monocyte/neutrophil activation, impaired macrophage inhibition with enhanced extracellular matrix remodeling. These findings warrant further studies targeting these immune pathways in PWS.

Chronic Neuroinflammation and Cognitive Decline in Patients with Cardiac Disease: Evidence, Relevance, and Therapeutic Implications

Acute and chronic cardiac disorders predispose to alterations in cognitive performance, ranging from mild cognitive impairment to overt dementia. Although this association is well-established, the factors inducing and accelerating cognitive decline beyond ageing and the intricate causal pathways and multilateral interdependencies involved remain poorly understood. Dysregulated and persistent inflammatory processes have been implicated as potentially causal mediators of the adverse consequences on brain function in patients with cardiac disease. Recent advances in positron emission tomography disclosed an enhanced level of neuroinflammation of cortical and subcortical brain regions as an important correlate of altered cognition in these patients. In preclinical and clinical investigations, the thereby involved domains and cell types of the brain are gradually better characterized. Microglia, resident myeloid cells of the central nervous system, appear to be of particular importance, as they are extremely sensitive to even subtle pathological alterations affecting their complex interplay with neighboring astrocytes, oligodendrocytes, infiltrating myeloid cells, and lymphocytes. Here, we review the current evidence linking cognitive impairment and chronic neuroinflammation in patients with various selected cardiac disorders including the aspect of chronic neuroinflammation as a potentially druggable target.

Shuangxinfang Prevents S100A9-Induced Macrophage/Microglial Inflammation to Improve Cardiac Function and Depression-Like Behavior in Rats After Acute Myocardial Infarction

Background: Depression is a common complication of cardiovascular disease, which deteriorates cardiac function. Shuangxinfang (psycho-cardiology formula, PCF) was reported to alleviate myocardial ischemia injury and improve depression-like behavior. Interestingly, our previous proteomics study predicted that the protein S100A9 appeared as an important target, and macrophage/microglial inflammation might be involved in the process of PCF improving depression induced by acute myocardial infarction (AMI). This study aims to validate the proteomics results.

Methods: AMI rat models were established in vivo, followed by the administration of PCF or ABR-215757 (also named paquinimod, inhibiting S100A9 binding to TLR4) for 5 days. Forced swimming test (FST) and open field test (OFT) were applied to record depression-like behavior, and echocardiography was employed to evaluate cardiac function. Morphological changes of cardiomyocytes were assessed by HE staining and TUNEL staining on day 7 after cardiac surgery, as well as Masson trichrome staining on day 21. Hippocampal neurogenesis was determined by Nissl staining, while 5-hydroxytryptamine (5-HT), tryptophan/kynurenine ratio, and brain-derived neurotrophic factor (BDNF) in the hippocampus were analyzed as biochemical indicators of depression. We employed RT-qPCR, western blotting, and immunofluorescence to detect the expression of pathway-related genes and proteins. Myocardial and hippocampal expression of inflammatory factors were performed by ELISA. The activation of macrophage and microglia was assessed via immunoreaction using CD68 and Iba1, respectively. For in vitro confirmation, BV2 cells were primed with recombinant protein S100A9 and then treated with PCF serum or ferulic acid to determine alterations in microglial inflammation.

Results: Rats in the AMI group showed heart function deterioration and depression-like behavior. Coronary ligation not only brought about myocardial inflammation, cell apoptosis, and fibrosis but also reduced the neurogenesis, elevated the tryptophan/kynurenine ratio, and decreased the content of 5-HT. PCF could ameliorate the pathological and phenotypic changes in the heart and brain and inhibit the expression of the S100A9 protein, the activation of the microglial cell, and the secretion of IL-1β and TNF-α raised by AMI. ABR-215757 showed therapeutic effect and molecular biological mechanisms similar to PCF. Treatment with PCF serum or ferulic acid in vitro was proved to efficiently block the hyperactivation of BV2 cells and increment of cytokine contents induced by recombinant protein S100A9.

Conclusion: We identify S100A9 as a novel and potent regulator of inflammation in both the heart and brain. Macrophage/microglia inflammation mediated by S100A9 is considered a pivotal pathogenic in depression after AMI and a major pathway for the treatment of PCF, suggesting that PCF is a promising therapeutic candidate for psycho-cardiology disease.

Minocycline as heart conditioning agent in experimental type 2 diabetes mellitus - an antibacterial drug in heart protection

Cardiovascular diseases, and among them certainly myocardial infarction, remain leading cause of death worldwide. Diabetes increases risk of occurrence as well as adverse outcome of myocardial infarction. Conditioning maneuvers are the most attractive method for alleviating both the consequences of ischemia and reperfusion. Minocycline is a tetracycline derivative which exerts antioxidant, anti-inflammatory, and anti-apoptotic effects. The aim of this study was to assess the protective ability of preconditioning and postconditioning of isolated hearts from healthy and rats with experimentally induced type 2 diabetes with minocycline on functional recovery and redox status after ischemia and reperfusion. The hearts from healthy and diabetic rats were excised and retrogradely perfused according to the Langendorff technique. Using sensor in the left ventricle, the cardiodynamic parameters were recorded and in the samples of the coronary venous effluent oxidative stress biomarkers were analyzed. Minocycline was injected directly into the coronary vessels, in preconditioning 5 min before global ischemia, and in postconditioning during the first 5 min of reperfusion. Results of this study clearly show beneficial effects of minocycline applied both before ischemia and in the first minutes of reperfusion fashion in both healthy and diabetic rat hearts. The most prominent protective effect regarding oxidative stress is related to the decreased production of superoxide anion radical due postconditioning with minocycline in diabetic hearts. Cardiodynamic parameters were significantly improved in minocycline conditioned groups. Superoxide anion radical stands out as the most susceptible to changes induced by minocycline.

Effect of minocycline on the left ventricular function following ST-elevation myocardial infarction treated by primary percutaneous coronary intervention

BACKGROUND

Cardiac remodeling following myocardial infarction is a pathological process. We aimed to examine the effect of early short-term minocycline on the left ventricular function following ST-elevation myocardial infarction treated by the primary percutaneous coronary intervention.

METHODS

In this double-blind, randomized controlled trial, data of 73 patients STEMI patients who were candidates for primary PCI were enrolled. Patients were then randomized to receive minocycline 50 mg orally, followed by 50 mg once a day for 5 days or a placebo with the same schedule. Measurement of serum matrix metalloproteinase-9 (MMP-9) and 2-dimensional speckle tracking echocardiography was performed at baseline and between 4 and 6 months after discharge. Then the demographic, clinical, echocardiographic, and angiographic data, as well as the levels of MMP-9, were compared between the study groups.

RESULTS

There was no statistically significant difference between the study groups regarding the baseline characteristics. Serum levels of MMP-9 did not change following the intervention within each group and were not significantly different between the groups after follow-up. In the follow-up echocardiography, we also did not observe any difference between the two groups CONCLUSION: In this study, we did not observe any effect of minocycline on cardiac remodeling based on 2-dimensional speckle tracking echocardiography and MMP-9 levels.

TRIAL REGISTRATION

Iranian Registry of Clinical Trials IRCT201411188698N15 . Registered on 22 June 2015, prospectively.

Chemical profiles with cardioprotective and anti-depressive effects of Morus macroura Miq. leaves and stem branches dichloromethane fractions on isoprenaline induced post-MI depression

This study was conducted to explore the potential cardioprotective and anti-depressive effects of dichloromethane (DCM) fractions of Morus macroura leaves (L) and stem branches (S) on post-myocardial infarction (MI) depression induced by isoprenaline (ISO) in rats in relation to their metabolites. The study was propped with a UPLC-ESI-MS/MS profiling and chromatographic isolation of the secondary metabolites. Column chromatography revealed the isolation of lupeol palmitate (6) that was isolated for the first time from nature with eight known compounds. In addition, more than forty metabolites belonging, mainly to flavonoids, and anthocyanins groups were identified. The rats were injected with ISO (85 mg kg⁻¹, s.c) in the first two days, followed by the administration of M. macroura DCM-L and DCM-S fractions (200 mg kg⁻¹ p.o) for 19 days. Compared with the ISO exposed rats, the treated rats displayed a reduction in cardiac biomarkers (LDH and CKMB), anxiety, and depressive-like behaviour associated with an increase in the brain defense system (SOD and GSH), neuronal cell energy, GABA, serotonin, and dopamine, confirmed by histopathological investigations. In conclusion, DCM-L and DCM-S fractions' cardioprotective and anti-depressive activities are attributed to their metabolite profile. Therefore, they could serve as a potential agent in amending post-MI depression.

This study was conducted to explore the potential cardioprotective and anti-depressive effects of dichloromethane fractions of Morus macroura leaves and stem branches on post-myocardial infarction depression induced by isoprenaline in rats in relation to their metabolites.

Death-Associated Protein Kinase 1 (DAPK1) Protects against Myocardial Injury Induced by Myocardial Infarction in Rats via Inhibition of Inflammation and Oxidative Stress

Objective

Heart failure and ventricular remodeling after acute myocardial infarction (AMI) are important factors affecting the prognosis of patients. Therefore, we expected to explore the therapeutic target of AMI by studying the effect of death-associated protein kinase 1 (DAPK1) on AMI rat model.

Materials and Methods

We used male Sprague-Dawley rats to make AMI model, and after 1, 3, 7, and 14 d, we detect the success rate of modeling and the expression change of DAPK1 through 2, 3, 5-triphenyl tetrazolium chloride staining, myocardial injury markers detection, echocardiographic detection, and histological experiment. In addition, we determined the effect of DAPK1 on AMI by subcutaneous injection of the DAPK1 inhibitor (TC-DAPK 6). The effect of DAPK1 on cardiomyocytes has also been verified in cell experiments on H9c2 cells.

Results

The expression of DAPK1 in AMI rats was significantly higher than that in sham group, and it increased with time. The expression of inflammatory factors (interleukin- (IL-) 1β, IL-6, and tumor necrosis factor-α) in AMI rats treated by TC-DAPK 6 was reduced. In addition, TC-DAPK 6 also reduced the activity of malonaldehyde and increased the activities of superoxide dismutase, glutathione, and catalase. The expression of antioxidant molecules such as peroxiredoxin1/4 and glutathione peroxidase1/3 was also promoted by TC-DAPK 6. In H9c2 cells, TC-DAPK 6 also reduced its oxidative stress level.

Conclusions

The increase of DAPK1 may be related to the pathogenesis of AMI. DAPK1 inhibitors protect cardiomyocytes from AMI-induced myocardial injury by reducing levels of inflammation and oxidative stress in myocardial tissue and cells.

Cerebral derailment after myocardial infarct: mechanisms and effects of the signaling from the ischemic heart to brain

Myocardial infarction (MI) is the leading cause of death among ischemic heart diseases and is associated with several long-term cardiovascular complications, such as angina, re-infarction, arrhythmias, and heart failure. However, MI is frequently accompanied by non-cardiovascular multiple comorbidities, including brain disorders such as stroke, anxiety, depression, and cognitive impairment. Accumulating experimental and clinical evidence suggests a causal relationship between MI and stroke, but the precise underlying mechanisms have not yet been elucidated. Indeed, the risk of stroke remains a current challenge in patients with MI, in spite of the improvement of medical treatment among this patient population has reduced the risk of stroke. In this review, the effects of the signaling from the ischemic heart to the brain, such as neuroinflammation, neuronal apoptosis, and neurogenesis, and the possible actors mediating these effects, such as systemic inflammation, immunoresponse, extracellular vesicles, and microRNAs, are discussed.

Cardioprotective Effects of Oroxylum indicum Extract Against Doxorubicin and Cyclophosphamide-Induced Cardiotoxicity

Administration of Chemotherapeutics, especially doxorubicin (DOX) and cyclophosphamide (CPS), is commonly associated with adverse effects such as myelosuppression and cardiotoxicity. At this time, few approved therapeutic options are currently available for the management of chemotherapy-associated cardiotoxicity. Thus, identification of novel therapeutics with potent cardioprotective properties and minimal adverse effects are pertinent in treating Doxorubicin and Cyclophosphamide-induced cardiotoxicity. Oroxylum indicum extract (OIE, Sabroxy®) is a natural product known to possess several beneficial biological functions including antioxidant, anti-inflammatory and cytoprotective effects. We therefore set to investigate the cardioprotective effects of OIE against Doxorubicin and Cyclophosphamide-induced cardiotoxicity and explore the potential cardioprotective mechanisms involved. Adult male mice were treated with DOX and CPS in combination, OIE alone, or a combination of OIE and DOX & CPS. Swimming test was performed to assess cardiac function. Markers of oxidative stress were assessed by levels of reactive oxygen species (ROS), nitrite, hydrogen peroxide, catalase, and glutathione content. The activity of interleukin converting enzyme and cyclooxygenase was determined as markers of inflammation. Mitochondrial function was assessed by measuring Complex-I activity. Apoptosis was assessed by Caspase-3 and protease activity. Mice treated with DOX and CPS exhibited reduced swim rate, increased oxidative stress, increased inflammation, and apoptosis in the heart tissue. These cardiotoxic effects were significantly reduced by co-administration of OIE. Furthermore, computational molecular docking studies revealed potential binding of DOX and CPS to tyrosine hydroxylase which validated our in vivo findings regarding the inhibition of tyrosine hydroxylase activity. Our current findings indicated that OIE counteracts Doxorubicin and Cyclophosphamide-induced cardiotoxicity-through inhibition of ROS-mediated apoptosis and by blocking the effect on tyrosine hydroxylase. Taken together, our findings suggested that OIE possesses cardioprotective effects to counteract potentially fatal cardiac complications associated with chemotherapy treatment.

Psycho-cardiology therapeutic effects of Shuangxinfang in rats with depression-behavior post acute myocardial infarction: Focus on protein S100A9 from proteomics

BACKGROUND

Depressive disorders induced by acute myocardial infarction (AMI) play a pivotal role in the deterioration of cardiac function, and Shuangxinfang (Psycho-cardiology Formula, PCF) was reported to alleviate heart function damage and improve depression-like behavior, but the complex mechanism in such process has not been clarified.

METHODS

AMI models were established and PCF was administered in rats. Subjects were then assessed in open field test (OFT) and forced swimming test (FST) recapitulating symptoms of depressive disorder. Afterward, pharmacoproteomic profiling of the hippocampus and peri-infarct border zone (BZ) was performed using a label-free liquid chromatography-tandem mass spectrometry (LC-MS/MS) technique, to identify contributing proteins and pathways responsible for myocardial ischemia and behavioral allostasis. Bioinformatics analysis was processed for further investigation, while western blotting was employed for testing dominating proteins to validate proteomic results.

RESULTS

Rats in the AMI group showed depression-like behavior in OFT and FST, which was improved by PCF. There were 131 differentially expressed proteins (DEPs) in BZ and 64 proteins in the hippocampus being detected and quantified shared by the sham group, the AMI group, and the PCF group. Subsequently, pertinent pathways and molecular functions were further identified. Altered molecules were discovered to be enriched in the apoptotic process, innate immune response, and NF-κB transcription factor activity in BZ, as well as chemical synaptic transmission, axon, collagen binding, cell adhesion, response to carbohydrate, laminin binding, and cellular response to nitric oxide in the hippocampus. Groups of signal transducers were also able to select multiple pathways, including innate immunity and arginine biosynthesis in the heart, also integrin signaling in the brain. DEPs were intersected from the myocardium and hippocampus to screen out the protein S100A9, which was up-regulated in the AMI group compared with the sham, and showed a down-regulation trend after treatment with PCF.

CONCLUSION

Taken together, we present a comprehensive proteomics analysis of rat models with depression post-AMI. Reviewing the literatures concerned, it's hypothesized that macrophage/microglia inflammation mediated by S100A9 might be the pivotal pathogenic process of psycho-cardiology disease, as well as potential mechanisms for the treatment of PCF.

Human umbilical cord mesenchymal stem cells ameliorate depression by regulating Jmjd3 and microglia polarization in myocardial infarction mice

RATIONALE

Microglia regulate the inflammation of the central nervous system and play a crucial role in the pathogenesis of depression. Moreover, Jmjd3 is involved in microglia polarization. Mounting studies reported the beneficial effects of human umbilical cord mesenchymal stem cells (HUC-MSCs) on myocardial infarction (MI), Unfortunately, its effects on MI-induced depression and its underlying mechanisms remain unclear.

OBJECTIVES

We aimed to investigate the antidepressant effects of HUC-MSCs and their impacts on microglia polarization.

METHODS

In the current study, the MI model was established by ligating the left anterior descending coronary artery. Mice were injected with HUC-MSCs or PBS through the tail vein 1week after the surgery. The sucrose preference test (SPT), tail suspension test (TST), and forced swim test (FST) were performed to evaluate depression-like behavior. Cardiac function and myocardial fibrosis were evaluated at the end of the experiments. Immunofluorescence, Western blot, ELISA, and qRT-PCR were used to detect the levels of Jmjd3 and microglia-related markers and inflammatory factors.

RESULTS

HUC-MSC treatment significantly improved cardiac function, reduced the area of myocardial fibrosis, and alleviated depression-like behaviors induced by MI. HUC-MSCs inhibited the expression of Jmjd3 and promoted the switch of microglia in the prefrontal cortex, hypothalamus, and hippocampus from M1 to M2, thereby decreased the level of pro-inflammatory factors.

CONCLUSION

HUC-MSCs have cardioprotective and potential anti-depressive effects induced by MI related to the inflammation improved by regulating Jmjd3 and microglial polarization.

Heart failure impairs mood and memory in male rats and down-regulates the expression of numerous genes important for synaptic plasticity in related brain regions

Chronic heart failure (HF) is a serious disorder that afflicts more than 26 million patients worldwide. HF is comorbid with depression, anxiety and memory deficits that have serious implications for quality of life and self-care in patients who have HF. Still, there are few studies that have assessed the effects of severely reduced ejection fraction (≤40 %) on cognition in non-human animal models. Moreover, limited information is available regarding the effects of HF on genetic markers of synaptic plasticity in brain areas critical for memory and mood regulation. We induced HF in male rats and tested mood and anxiety (sucrose preference and elevated plus maze) and memory (spontaneous alternation and inhibitory avoidance) and measured the simultaneous expression of 84 synaptic plasticity-associated genes in dorsal (DH) and ventral hippocampus (VH), basolateral (BLA) and central amygdala (CeA) and prefrontal cortex (PFC). We also included the hypothalamic paraventricular nucleus (PVN), which is implicated in neurohumoral activation in HF. Our results show that rats with severely reduced ejection fraction recapitulate behavioral symptoms seen in patients with chronic HF including, increased anxiety and impaired memory in both tasks. HF also downregulated several synaptic-plasticity genes in PFC and PVN, moderate decreases in DH and CeA and minimal effects in BLA and VH. Collectively, these findings identify candidate brain areas and molecular mechanisms underlying HF-induced disturbances in mood and memory.

Mechanism and therapeutic strategies of depression after myocardial infarction

Depression resulted as an important factor associated with the myocardial infarction (MI) prognosis. Patients with MI also have a higher risk for developing depression. Although the issue of depression after MI has become a matter of clinical concern, the molecular mechanism underlying depression after MI remains unclear, whereby several strategies suggested have not got ideal effects, such as selective serotonin reuptake inhibitors. In this review, we summarized and discussed the occurrence mechanism of depression after MI, such as 5-hydroxytryptamine (5-HT) dysfunction, altered hypothalamus-pituitary-adrenal (HPA) axis function, gut microbiota imbalance, exosomal signal transduction, and inflammation. In addition, we offered a succinct overview of treatment, as well as some promising molecules especially from natural products for the treatment of depression after MI.

Three-dimensional morphometric analysis reveals time-dependent structural changes in microglia and astrocytes in the central amygdala and hypothalamic paraventricular nucleus of heart failure rats

BACKGROUND

Cardiovascular diseases, including heart failure, are the most common cause of death globally. Recent studies support a high degree of comorbidity between heart failure and cognitive and mood disorders resulting in memory loss, depression, and anxiety. While neuroinflammation in the hypothalamic paraventricular nucleus contributes to autonomic and cardiovascular dysregulation in heart failure, mechanisms underlying cognitive and mood disorders in this disease remain elusive. The goal of this study was to quantitatively assess markers of neuroinflammation (glial morphology, cytokines, and A1 astrocyte markers) in the central amygdala, a critical forebrain region involved in emotion and cognition, and to determine its time course and correlation to disease severity during the progression of heart failure.

METHODS

We developed and implemented a comprehensive microglial/astrocyte profiler for precise three-dimensional morphometric analysis of individual microglia and astrocytes in specific brain nuclei at different time points during the progression of heart failure. To this end, we used a well-established ischemic heart failure rat model. Morphometric studies were complemented with quantification of various pro-inflammatory cytokines and A1/A2 astrocyte markers via qPCR.

RESULTS

We report structural remodeling of central amygdala microglia and astrocytes during heart failure that affected cell volume, surface area, filament length, and glial branches, resulting overall in somatic swelling and deramification, indicative of a change in glial state. These changes occurred in a time-dependent manner, correlated with the severity of heart failure, and were delayed compared to changes in the hypothalamic paraventricular nucleus. Morphometric changes correlated with elevated mRNA levels of pro-inflammatory cytokines and markers of reactive A1-type astrocytes in the paraventricular nucleus and central amygdala during heart failure.

CONCLUSION

We provide evidence that in addition to the previously described hypothalamic neuroinflammation implicated in sympathohumoral activation during heart failure, microglia, and astrocytes within the central amygdala also undergo structural remodeling indicative of glial shifts towards pro-inflammatory phenotypes. Thus, our studies suggest that neuroinflammation in the amygdala stands as a novel pathophysiological mechanism and potential therapeutic target that could be associated with emotional and cognitive deficits commonly observed at later stages during the course of heart failure.