a-fluorescence-assay-for-evaluating-permeability-cardiac

A Fluorescence Assay for Evaluating the Permeability of a Cardiac Microvascular Endothelial Barrier in a Rat Model of Ischemia/reperfusion

Revascularization therapies for culprit arteries, regardless of percutaneous coronary intervention and coronary artery bypass grafting, are considered the ...

Chinese Academy of Medical Sciences and Peking Union Medical College

The characteristic morphologic lesions observed in the lungs of patients with congenital cardiac anomalies have not been closely modeled in rat shunt-related models, except for the reversible grade 1 changes. The present study reported an original rat model of unilateral pulmonary hypertension surgically induced by combined surgery to reproduce more advanced pulmonary vascular lesions.

Original rat model of high kinetic unilateral pulmonary hypertension surgically induced by combined surgery.

A key feature of pulmonary hypertension (PH) is the remodeling of small pulmonary arteries due to abnormal pulmonary artery smooth muscle cell (PASMC) proliferation and resistance to apoptosis. However, the cellular mechanisms underlying how PASMCs in the pathological condition of pulmonary hypertension become resistant to apoptosis remain unknown. It was recently reported that lipocalin 2 (Lcn2) is up-regulated in a wide array of malignant conditions, which facilitates tumorigenesis partly by inhibiting cell apoptosis. In this study, we observed that the expression levels of Lcn2 were significantly elevated in a rat PH model induced with monocrotaline and in patients with congenital heart disease-associated PH (CHD-PH) when compared with respective control. Therefore, we hypothesize that Lcn2 could regulate human PASMC (HPASMC) apoptosis through a mechanism. By the detection of DNA fragmentation using the TUNEL assay, the detection of Annexin V/PI-positive cells using flow cytometry, and the detection of cleaved caspase-3 and caspase-3 activity, we observed that Lcn2 significantly inhibited HPASMC apoptosis induced by serum withdrawal and H2O2 treatment. We also observed that Lcn2 down-regulated the proapoptotic protein Bax, decreased the levels of cellular ROS, and up-regulated the expression of superoxide dismutases (SOD1 and SOD2). In conclusion, Lcn2 significantly inhibits HPASMC apoptosis induced by oxidative stress via decreased intracellular ROS and elevated SODs. Up-regulation of Lcn2 in a rat PH model and CHD-PH patients may be involved in the pathological process of PH. 

Up-regulated lipocalin-2 in pulmonary hypertension involving in pulmonary artery SMC resistance to apoptosis.

Recent studies demonstrated that the heart of 1-day-old neonatal mice could regenerate, with Wt1(+) EPDCs migrating into myocardial regions after partial surgical resection, but this capacity was lost by 7 days of age. By treatment with Tβ4 to maintain Wt1 expression and retain the migrating feature of EPDCs in neonatal mice, we explored the possibility of restoring the cardiac regeneration potential of mice. We intraperitoneally injected Tβ4 into 1-day-old mice on daily basis and then apical resection was performed on the mice 7 days later. Twenty one days after the resection, morphological analysis revealed that the Tβ4-treated mice regenerated the resected ventricular apex, while the mice in PBS control group developed significant fibrosis without apical regeneration. The Tβ4-treated mice had significantly better ventricular ejection fraction and fractional shortening than controls. During the process of regeneration, Wt1(+) EPDCs migrated into myocardial region and some of them expressed Islet1 and the markers for mature cardiomyocytes, such as cTnT and SαA. These characteristics of Wt1(+) EPDCs were also seen in the heart regeneration of mice subjected to apical resection 1 day after birth. Tβ4 has no essential effect on cell cycle activity as no disruption of actin filaments was observed in Tβ4-treated hearts. These results revealed that the cardiac regeneration potential of neonatal mice could be extended to the 7th post-natal day by Tβ4 and Wt1(+) EPDCs mobilization might play an important role in the extension.

Extending the time window of mammalian heart regeneration by thymosin beta 4.

The aberrant immune responses play a critical role in the pathogenesis of myocarditis. Vitamin D receptor (VDR) has immune regulatory functions. This study aims to investigate the role of VDR in restricting the immune inflammation in the heart.

Vitamin D receptor restricts T helper 2-biased inflammation in the heart.

Deletion of mPGES-1 (microsomal prostaglandin E synthase-1)-an anti-inflammatory target alternative to COX (cyclooxygenase)-2-attenuates injury-induced neointima formation in mice. This is attributable to the augmented levels of PGI (prostacyclin)-a known restraint of the vascular response to injury, acting via IP (I prostanoid receptor). To examine the role of mPGES-1-derived PGE (prostaglandin E) in vascular remodeling without the IP.

Protective Role of mPGES-1 (Microsomal Prostaglandin E Synthase-1)-Derived PGE (Prostaglandin E) and the Endothelial EP4 (Prostaglandin E Receptor) in Vascular Responses to Injury.

Immune deregulation is a causative factor in pathogenesis of myocarditis. Histone deacetylases (HDAC) involve multiple biochemical activities in the cell. This study aims to elucidate the role of HDAC11 in the regulation of interleukin (IL)-13-expression in CD4 T cells of heart tissue in patients with myocarditis (MCD).

HDAC11 regulates interleukin-13 expression in CD4+ T cells in the heart.

Objective- Pulmonary arterial hypertension is characterized by progressive pulmonary vascular remodeling and persistently elevated mean pulmonary artery pressures and pulmonary vascular resistance. We aimed to investigate whether transthoracic pulmonary artery denervation (TPADN) attenuated pulmonary artery (PA) remodeling, improved right ventricular (RV) function, and affected underlying mechanisms. We also explored the distributions of sympathetic nerves (SNs) around human PAs for clinical translation. Approach and Results- We identified numerous SNs in adipose and connective tissues around the main PA trunks and bifurcations in male Sprague Dawley rats, which were verified in samples from human heart transplant patients. Pulmonary arterial hypertensive rats were randomized into TPADN and sham groups. In the TPADN group, SNs around the PA trunk and bifurcation were completely and accurately removed under direct visualization. The sham group underwent thoracotomy. Hemodynamics, RV function, and pathological changes in PA and RV tissues were measured via right heart catheterization, cardiac magnetic resonance imaging, and pathological staining, respectively. Compared with the sham group, the TPADN group had lower mean pulmonary arterial pressures, less PA and RV remodeling, and improved RV function. Furthermore, TPADN inhibited neurohormonal overactivation of the sympathetic nervous system and renin-angiotensin-aldosterone system and regulated abnormal expressions and signaling of neurohormone receptors in local tissues. Conclusions- There are numerous SNs around the rat and human main PA trunks and bifurcations. TPADN completely and accurately removed the main SNs around PAs and attenuated pulmonary arterial hypertensive progression by inhibiting excessive activation of the sympathetic nervous system and renin-angiotensin-aldosterone system neurohormone-receptor axes.

Article	Year
Original rat model of high kinetic unilateral pulmonary hypertension surgically induced by combined surgery. The Journal of thoracic and cardiovascular surgery\| PubMed ID: 23395098	2013
Up-regulated lipocalin-2 in pulmonary hypertension involving in pulmonary artery SMC resistance to apoptosis. International journal of biological sciences\| PubMed ID: 25076856	2014
Extending the time window of mammalian heart regeneration by thymosin beta 4. Journal of cellular and molecular medicine\| PubMed ID: 25284727	2014
Vitamin D receptor restricts T helper 2-biased inflammation in the heart. Cardiovascular research\| PubMed ID: 29444238	2018
Protective Role of mPGES-1 (Microsomal Prostaglandin E Synthase-1)-Derived PGE (Prostaglandin E) and the Endothelial EP4 (Prostaglandin E Receptor) in Vascular Responses to Injury. Arteriosclerosis, thrombosis, and vascular biology\| PubMed ID: 29599139	2018
HDAC11 regulates interleukin-13 expression in CD4+ T cells in the heart. Journal of molecular and cellular cardiology\| PubMed ID: 30063898	2018
Transthoracic Pulmonary Artery Denervation for Pulmonary Arterial Hypertension. Arteriosclerosis, thrombosis, and vascular biology\| PubMed ID: 30816802	2019

Jian Meng

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