Modulation of cardiac stem cell characteristics by metoprolol in hypertensive heart disease

Ageing and Polypharmacy in Mesenchymal Stromal Cells: Metabolic Impact Assessed by Hyperspectral Imaging of Autofluorescence

The impact of age on mesenchymal stromal cell (MSC) characteristics has been well researched. However, increased age is concomitant with increased prevalence of polypharmacy. This adjustable factor may have further implications for the functionality of MSCs and the effectiveness of autologous MSC procedures. We applied hyperspectral microscopy of cell autofluorescence-a non-invasive imaging technique used to characterise cytometabolic heterogeneity-to identify changes in the autofluorescence signals of MSCs from (1) young mice, (2) old mice, (3) young mice randomised to receive polypharmacy (9-10 weeks of oral therapeutic doses of simvastatin, metoprolol, oxycodone, oxybutynin and citalopram), and (4) old mice randomised to receive polypharmacy. Principal Component Analysis and Logistic Regression Analysis were used to assess alterations in spectral and associated metabolic characteristics. Modelling demonstrated that cells from young mice receiving polypharmacy had less NAD(P)H and increased porphyrin relative to cells from old control mice, allowing for effective separation of the two groups (AUC of ROC curve > 0.94). Similarly, cells from old polypharmacy mice were accurately separated from those from young controls due to lower levels of NAD(P)H (p < 0.001) and higher porphyrin (p < 0.001), allowing for an extremely accurate logistic regression (AUC of ROC curve = 0.99). This polypharmacy regimen may have a more profound impact on MSCs than ageing, and can simultaneously reduce optical redox ratio (ORR) and increase porphyrin levels. This has implications for the use of autologous MSCs for older patients with chronic disease.

Comparison of the Protective Effects of Nebivolol and Metoprolol against LPS-Induced Injury in H9c2 Cardiomyoblasts

Here, we, for the first time, compared the cardioprotective effects of third-generation vasodilating beta-blocker nebivolol (Neb) and conventional beta-blocker metoprolol (Met) on LPS-induced injury in H9c2 cardiomyoblasts. Our findings denoted that Neb and Met pretreatment diminish LPS-mediated cytotoxicity and oxidative stress. Concomitantly, LPS-triggered inflammatory cytokines activation was significantly suppressed by Neb but not by Met. Pretreatment with either Neb or Met alleviated LPS-mediated mitochondrial impairment by enhancing the expression of genes related to its biogenesis such as PGC-1α, NRF1, and TFAM. On the contrary, Neb but not Met-upregulated mitochondrial fusion-related genes such as OPA, and MFN2. In summary, our findings suggest that Neb and Met treatment significantly ameliorated the LPS-induced cytotoxicity and oxidative stress. Additionally, these findings suggest that Neb but not Met significantly down-regulates LPS-induced proinflammatory factors, probably by enhancing mitochondrial biogenesis and fusion.

Ginsenoside Rb1 Modulates the Migration of Bone-Derived Mesenchymal Stem Cells through the SDF-1/CXCR4 Axis and PI3K/Akt Pathway

Methods

Wound-healing assay and Transwell assay were utilized to evaluate the effect of ginsenoside Rb1 on the migration of BMSCs. RT-PCR and Western blotting were performed to evaluate the expression of stromal-derived factor 1 (SDF-1), C-X-C chemokine receptor type 4 (CXCR4), phosphatidylinositol 3-kinase (PI3K), and protein kinase B (PKB; AKT).

Results

Ginsenoside Rb1 significantly enhanced the migration of BMSCs through the activation of SDF-1, CXCR4, p-PI3K/PI3K, and p-Akt/Akt relative expression. Furthermore, this stimulus was blocked by the pretreatment with AMD3100 and LY294002.

Conclusions

Ginsenoside Rb1 facilitated the migration of BMSCs through the activation of the SDF-1/CXCR4 axis and PI3K/Akt pathway.

β3-Adrenoceptor, a novel player in the round-trip from neonatal diseases to cancer: Suggestive clues from embryo

The role of the β-adrenoceptors (β-ARs) in hypoxia-driven diseases has gained visibility after the demonstration that propranolol promotes the regression of infantile hemangiomas and ameliorates the signs of retinopathy of prematurity (ROP). Besides the role of β2-ARs, preclinical studies in ROP have also revealed that β3-ARs are upregulated by hypoxia and that they are possibly involved in retinal angiogenesis. In a sort of figurative round trip, peculiarities typical of ROP, where hypoxia drives retinal neovascularization, have been then translated to cancer, a disease equally characterized by hypoxia-driven angiogenesis. In this step, investigating the role of β3-ARs has taken advantage of the assumption that cancer growth uses a set of strategies in common with embryo development. The possibility that hypoxic induction of β3-ARs may represent one of the mechanisms through which primarily embryo (and then cancer, as an astute imitator) adapts to grow in an otherwise hostile environment, has grown evidence. In both cancer and embryo, β3-ARs exert similar functions by exploiting a metabolic shift known as the Warburg effect, by acquiring resistance against xenobiotics, and by inducing a local immune tolerance. An additional potential role of β3-AR as a marker of stemness has been suggested by the finding that its antagonism induces cancer cell differentiation evoking that β3-ARs may help cancer to grow in a nonhospital environment, a strategy also exploited by embryos. From cancer, the round trip goes back to neonatal diseases for which new possible interpretative keys and potential pharmacological perspectives have been suggested.

In search of elixir: Pharmacological agents against stem cell senescence

Stem cell senescence causes different complications. In addition to the aging phenomenon, stem cell senescence has been investigated in various concepts such as cancer, adverse drug effects, and as a limiting factor in cell therapy. This manuscript examines protective medicines and supplements which are capable of hindering stem cell senescence. We searched the databases such as EMBASE, PubMed, and Web of Science with the keywords "stem cell," "progenitor cell," "satellite," "senescence" and excluded the keywords "cancer," "tumor," "malignancy" and "carcinoma" until June 2020. Among these results, we chose 47 relevant studies. Our investigation indicates that most of these studies examined endothelial progenitor cells, hematopoietic stem cells, mesenchymal stem cells, adipose-derived stem cells, and a few others were about less-discussed types of stem cells such as cardiac stem cells, myeloblasts, and induced pluripotent stem cells. From another aspect, 17β-Estradiol, melatonin, metformin, rapamycin, coenzyme Q10, N-acetyl cysteine, and vitamin C were the most studied agents, while the main protective mechanism was through telomerase activity enhancement or oxidative damage ablation. Although many of these studies are in vitro, they are still worthwhile. Stem cell senescence in the in vitro expansion stage is an essential concern in clinical procedures of cell therapy. Moreover, in vitro studies are the first step for further in vivo and clinical studies. It is noteworthy to mention the fact that these protective agents have been used in the clinical setting for various purposes for a long time. Given that, we only need to examine their systemic anti-senescence effects and effective dosages.

Cellular Senescence Affects Cardiac Regeneration and Repair in Ischemic Heart Disease

Ischemic heart disease (IHD) is defined as a syndrome of ischemic cardiomyopathy. Myogenesis and angiogenesis in the ischemic myocardium are important for cardiomyocyte (CM) survival, improving cardiac function and decreasing the progression of heart failure after IHD. Cellular senescence is a state of permanent irreversible cell cycle arrest caused by stress that results in a decline in cellular functions, such as proliferation, migration, homing, and differentiation. In addition, senescent cells produce the senescence-associated secretory phenotype (SASP), which affects the tissue microenvironment and surrounding cells by secreting proinflammatory cytokines, chemokines, growth factors, and extracellular matrix degradation proteins. The accumulation of cardiovascular-related senescent cells, including vascular endothelial cells (VECs), vascular smooth muscle cells (VSMCs), CMs and progenitor cells, is an important risk factor of cardiovascular diseases, such as vascular aging, atherosclerotic plaque formation, myocardial infarction (MI) and ventricular remodeling. This review summarizes the processes of angiogenesis, myogenesis and cellular senescence after IHD. In addition, this review focuses on the relationship between cellular senescence and cardiovascular disease and the mechanism of cellular senescence. Finally, we discuss a potential therapeutic strategy for MI targeting senescent cells.

Cell seeding accelerates the vascularization of tissue engineering constructs in hypertensive mice

Rapid blood vessel ingrowth into transplanted constructs represents the key requirement for successful tissue engineering. Seeding three-dimensional scaffolds with suitable cells is an approved technique for this challenge. Since a plethora of patients suffer from widespread diseases that limit the capacity of neoangiogenesis (e.g., hypertension), we investigated the incorporation of cell-seeded poly-L-lactide-co-glycolide scaffolds in hypertensive (BPH/2J, group A) and nonhypertensive (BPN/3J, group B) mice. Collagen-coated scaffolds (A1 and B1) were additionally seeded with osteoblast-like (A2 and B2) and mesenchymal stem cells (A3 and B3). After implantation into dorsal skinfold chambers, inflammation and newly formed microvessels were measured using repetitive intravital fluorescence microscopy for 2 weeks. Apart from a weak inflammatory response in all groups, significantly increased microvascular densities were found in cell-seeded scaffolds (day 14, A2: 192 ± 12 cm/cm², A3: 194 ± 10 cm/cm², B2: 249 ± 19 cm/cm², B3: 264 ± 17 cm/cm²) when compared with controls (A1: 129 ± 10 cm/cm², B1: 185 ± 8 cm/cm²). In this context, hypertensive mice showed reduced neoangiogenesis in comparison with nonhypertensive animals. Therefore, seeding approved scaffolds with organ-specific or pluripotent cells is a very promising technique for tissue engineering in hypertensive organisms.

Metoprolol alleviates arginine vasopressin-induced cardiomyocyte hypertrophy by upregulating the AKT1-SERCA2 cascade in H9C2 cells

BACKGROUND

Arginine vasopressin (AVP) is elevated in patients with heart failure, and the increase in the AVP concentration in plasma is positively correlated with disease severity and mortality. Metoprolol (Met) is a beta blocker that is widely used in the clinic to treat pathological cardiac hypertrophy and to improve heart function. However, the specific mechanism by which Met alleviates AVP-induced pathological cardiac hypertrophy is still unknown. Our current study aimed to evaluate the inhibitory effects of Met on AVP-induced cardiomyocyte hypertrophy and the underlying mechanisms.

METHODS

AVP alone or AVP plus Met was added to the wild type or AKT1-overexpressing rat cardiac H9C2 cell line. The cell surface areas and ANP/BNP/β-MHC expressions were used to evaluate the levels of hypertrophy. Western bolting was used to analyze AKT1/P-AKT1, AKT2/P-AKT2, total AKT, SERCA2, and Phospholamban (PLN) expression. Fluo3-AM was used to measure the intracellular Ca2+ stores.

RESULTS

In the current study, we found that AKT1 but not AKT2 mediated the pathogenesis of AVP-induced cardiomyocyte hypertrophy. Sustained stimulation (48 h) with AVP led to hypertrophy in the H9C2 rat cardiomyocytes, resulting in the downregulation of AKT1 (0.48 fold compared to control) and SERCA2 (0.62 fold), the upregulation of PLN (1.32 fold), and the increase in the cytoplasmic calcium concentration (1.52 fold). In addition, AKT1 overexpression increased the expression of SERCA2 (1.34 fold) and decreased the expression of PLN (0.48 fold) in the H9C2 cells. Moreover, we found that Met could attenuate the AVP-induced changes in AKT1, SERCA2 and PLN expression and decreased the cytoplasmic calcium concentration in the H9C2 cells.

CONCLUSIONS

Our results demonstrated that the AKT1-SERCA2 cascade served as an important regulatory pathway in AVP-induced pathological cardiac hypertrophy.

The Relationship between Left Ventricular Function Indices in Tissue Doppler Imaging and Exaggerated Blood Pressure Response During the Exercise Stress Test

Background:

Studies have indicated that exaggerated hypertension during activity and stress can be a good predictor of the incidence of hypertension. This study tries to evaluate left ventricular (LV) function by tissue Doppler to assess early changes in ventricular compliance before the onset of Hypertension (HTN) in patients with exaggerated blood pressure response during the exercise test.

Materials and Methods:

In this case-control study, 40 patients without a history of hypertension with systolic blood pressure less than 140/90 which referred for exercise test, were included. The exercise test was performed for all patients. Patients who had exaggerated blood pressure during the stress test were considered as cases and the controls with normal blood pressure responses. Then standard echocardiography and Tissue Doppler imaging performed and indices of LV systolic and diastolic were recorded.

Results:

The LV mass in cases and controls were 174.9±50.78 and 152.9±33.59, respectively (P=0.114), and LV mass index in cases and controls were 127.4±13.5 and 79.8±15.75, respectively (P=0.023). Moreover, the LV Myocardial Performance Index were 0.68±0.11 and 0.48±0.06 in cases and controls, respectively (P<0.001). The heart rate, E/A, EE, E Velocity and S velocity were measuremented. Except E/A (P=0.009), there was no significant difference between the other variables measured between the cases and controls (P>0.05).

Conclusion:

The results of this study showed that using 2D conventional echocardiography as a noninvasive method if performed in prestigious centers can evaluate systolic and diastolic function Tissue Doppler parameters very well in the early stages of heart disease caused by HTN.