Cardiac Capillary Research Articles

Voluntary wheel running reduces tumor growth and increases capillarity in the heart during doxorubicin chemotherapy in a murine model of breast cancer.

Introduction: The possible beneficial effects of physical activity during doxorubicin treatment of breast cancer need further investigation as many of the existing studies have been done on non-tumor-bearing models. Therefore, in this study, we aim to assess whether short-term voluntary wheel-running exercise during doxorubicin treatment of breast cancer-bearing mice could induce beneficial cardiac effects and enhance chemotherapy efficacy. Methods: Murine breast cancer I3TC cells were inoculated subcutaneously to the flank of female FVB mice (n = 16) that were divided into exercised and non-exercised groups. Two weeks later, doxorubicin treatment was started via intraperitoneal administration (5mg/kg weekly for 3weeks). Organs were harvested a day after the last dose. Results: The tumor volume over time was significantly different between the groups, with the exercising group having lower tumor volumes. The exercised group had increased body weight gain, tumor apoptosis, capillaries per cardiomyocytes, and cardiac lactate dehydrogenase activity compared to the unexercised group, but tumor blood vessel density and maturation and tumor and cardiac HIF1-α and VEGF-A levels did not differ from those of the non-exercised group. Discussion: We conclude that even short-term light exercise such as voluntary wheel running exercise can decrease the subcutaneous mammary tumor growth, possibly via increased tumor apoptosis. The increase in cardiac capillaries per cardiomyocytes may also have positive effects on cancer treatment outcomes.

VAERS Vasculitis Adverse Events Retrospective Study: Etiology Model of Immune Complexes Activating Fc Receptors in Kawasaki Disease and Multisystem Inflammatory Syndromes.

Vasculitis diseases include Kawasaki disease (KD), Kawasaki disease shock syndrome (KDSS), Multisystem Inflammatory Syndrome (MIS), Henoch-Schönlein purpura (HS), or IgA vasculitis, and additional vasculitis diseases. These diseases are often preceded by infections or immunizations. Disease incidence rates are higher in children than in adults. These diseases have been extensively studied, but understanding of the disease etiology remains to be established. Many studies have failed to demonstrate an association between vasculitis diseases and vaccination; this study examines possible associations. Herein, the Vaccine Adverse Event Reporting System (VAERS) database is retrospectively examined for associations between vasculitis diseases and immunizations. For some vaccines, the number of rare cases of KD, MIS, and HS are higher than the background rates. These rare cases are predicted to occur in individuals with (1) genetic risk factors with (2) antibody titer levels above the primary immune response level. Herein, the model of humoral immune response antibodies bound to antigens (pathogen or vaccine) creating immune complexes is proposed. These immune complexes are proposed to bind Fc receptors on immune cells and platelets, resulting in cell activation and the release of inflammatory molecules including histamine and serotonin. Immune complexes and inflammatory molecules including serotonin and histamine likely trigger vasculitis. Elevated serotonin and possibly histamine drive initial vasoconstrictions, disrupting blood flow. Increased blood flow pressure from cardiac capillary vasoconstrictions is predicted to trigger coronary artery aneurysms (CAA) or lesions (CAL) in some patients. For KDSS and MIS patients, these cardiac capillary vasoconstrictions are predicted to result in ischemia followed by ventricular dysfunction. Ongoing ischemia can result in long-term cardiac damage. Cases associated with pathogens are likely to have persistent infections triggering disease onset. The proposed model of immune complexes driving disease initial disease etiology by Fc receptor activation of immune cells and platelets, resulting in elevated histamine and serotonin levels, is testable and is consistent with disease symptoms and current treatments.

OP17.02: Fetal cardiac capillary hemangioma presenting various types of arrhythmias, and its cardiac function assessment

OP17.02: Fetal cardiac capillary hemangioma presenting various types of arrhythmias, and its cardiac function assessment

Zymosan A Improved Doxorubicin-Induced Ventricular Remodeling by Evoking Heightened Cardiac Inflammatory Responses and Healing in Mice.

Background Doxorubicin-induced myocardial injury is reflected by the presence of vacuolization in both clinical and animal models. The lack of scar tissue to replace the vacuolizated cardiomyocytes indicates that insufficient cardiac inflammation and healing occurred following doxorubicin injection. Whether improved macrophage activity by zymosan A (zymosan) ameliorates doxorubicin-induced ventricular remodeling in mice is unknown. Methods and Results Mice were intravenously injected with vehicle or doxorubicin (5 mg/kg per week, 4 weeks), and cardiac structure and function were assessed by echocardiography. Two distinct macrophage subsets in hearts following doxorubicin injection were measured at different time points by flow cytometry. Moreover, cardiomyocyte vacuolization, capillary density, collagen content, and ventricular tensile strength were assessed. The therapeutic effect of zymosan (3 mg/kg, single injection) on doxorubicin-induced changes in the aforementioned parameters was determined. At the cellular level, the polarization of monocytes to proinflammatory or reparative macrophages were measured, with or without doxorubicin (0.25 and 0.5 μmol/L). Doxorubicin led to less proinflammatory and reparative macrophage infiltration in the heart in the early phase, with decreased cardiac capillary density and collagen III in the chronic phase. In cell culture, doxorubicin (0.5 μmol/L) repressed macrophage transition toward both proinflammatory and reparative subset. Zymosan enhanced both proinflammatory and reparative macrophage infiltration in doxorubicin-injected hearts, evoking a heightened acute inflammatory response. Zymosan alleviated doxorubicin-induced cardiomyocyte vacuolization in the chronic phase, in parallel with enhanced collagen content, capillary density, and ventricular tensile strength. Conclusions Zymosan improved cardiac healing and ameliorated doxorubicin-induced ventricular remodeling and dysfunction by activating macrophages at an optimal time.

Effect of Intracoronary Adenosine on No Reflow in Patients with Acute ST Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

Abstract Background When total coronary artery occlusion was found in the early hours of transmural myocardial infarction, most of our research interest and treatment strategies focused on epicardial coronary arteries. Little attention, however, is paid to the coronary microvasculature. When a coronary artery is occluded, detrimental changes occur in the cardiac capillaries and arterioles. After relief of the occlusion, blood flow to the ischemic tissue may still be impeded, a phenomenon known as no reflow. This abstract attempt to provide an in-depth understanding of this phenomenon and comparative review of intracoronary adenosine used in no reflow settings. Aim and objectives The aim of the study was to evaluate the impact of intracoronary adenosine on preventing no-reflow phenomenon as being assessed by tissue perfusion TIMI flow and myocardial blush grade as the primary objective in patients presented with ST elevation myocardial infarction (STEMI) undergoing primary PCI as the strategy of reperfusion and its effect on Left ventricular ejection fraction and LV dimensions as the secondary objective. Patients and Methods This study included 200 patients presented to emergency departments of Ain shams university hospitals from January 2021 till June 2022 and diagnosed with STEMI as being defined as Patients with ST elevation myocardial infarction defined as having symptoms of ischemia and ST-segment elevation of at least two contiguous leads with ST-segment elevation ≥ 2.5 mm in men < 40 years, ≥2 mm in men ≥ 40 years, or ≥ 1.5 mm in women in leads V2–V3 and/or ≥ 1 mm in the other leads [1.2], that had been revascularized by primary PCI as per the recommendations of The European society of cardiology guidelines for diagnosis and management of ST elevation myocardial infarction published in 2017 [2]. The patients were randomized using dedicated software programme into two groups. Group A including 100 patients was the adenosine group. Group B including 100 patients was the standard control group. Results Our study had demonstrated that There was a statistically significant difference between the two groups, group A (Adenosine group) and group B (control group), regarding the occurrence of no reflow as there were 12 no reflow cases in group A versus 23 no reflow cases in group B with P value of 0.041). Off note, in our study no reflow was defined as TIMI score of < 3 and MBG grade of 0, 1, 2 in the absence of evident vessel dissection, obstruction or distal vessel embolic cutoff. There was a highly significant difference between the two groups in the tissue perfusion post primary PCI as being assessed by TIMI flow classification and myocardial blush grade. As for TIMI flow grading; TIMI I flow was achieved in 4 patients in group A versus 7 patients in group B, TIMI II flow was achieved in 10 patients in group A versus 44 patients in group B, TIMI III flow was achieved in 86 patients in group A versus 49 patients in group B, with P value of 0.000. As regard myocardial blush grade; MBG 0 was achieved in 3 patients in group A versus 5 patients in group B, MBG I was achieved 2 patients in group A versus 5 patients in group B, MBG II was achieved in 27 patients in group A versus 48 patients in group B, MGB III was achieved in 68 patients in group A versus 42 patients in group B, with P value of 0.003. Conclusion We concluded that intracoronary adenosine may be used for prevention of no reflow in patients presented with STEMI undergoing primary PCI as reperfusion strategy. Intracoronary adenosine was associated with better myocardial salvage in the context of left ventricular ejection fraction and dimensions. Tissue perfusion as being assessed by TIMI flow grade and MBG was inversely related to the reduction of LVEF.

The Immediate and Short-Term Outcomes of Patients with ST Elevation Myocardial Infarction with High Thrombus Burden Receiving Intracoronary Verapamil versus Epinephrine during Primary Percutaneous Coronary Intervention

Abstract Background When total coronary artery occlusion was found in the early hours of transmural myocardial infarction, most of our research interest and treatment strategies focused on epicardial coronary arteries. Little attention, however, is paid to the coronary microvasculature. When a coronary artery is occluded, detrimental changes occur in the cardiac capillaries and arterioles. After relief of the occlusion, blood flow to the ischemic tissue may still be impeded, a phenomenon known as no reflow. This abstract attempt to provide an in-depth understanding of this phenomenon and comparative review of two intracoronary agents used in no reflow settings. Aim of the Study This study is a comparative prospective study designed to compare between two agents‟ verapamil and adrenaline in treatment of no reflow in patients presenting with STEMI (ST elevation myocardial infarction) and a high thrombus burden developing no reflow during PPCI. Patients and Methods This study is a comparative prospective clinical trial designed to compare between two agents‟ verapamil and adrenaline in treatment of no reflow in patients presenting with STEMI and a high thrombus burden developing no reflow during PPCI. Results We have compared two of the proposed agents adrenaline and verapamil in the management of CNF and found out that verapamil is better in terms of improving LV functions but not the coronary flow. This further supported the consideration that MVO and CNF are two different entities and that we should be fully satisfied with restoration of coronary flow however all possible solutions should be spent to achieve adequate coronary perfusion so as not to give any change to MVO and microvascular dysfunction. We need a better understanding of the pathology of CNF and MVO for better solutions. It is time that we include agents more concerned with the ischemic reperfusion injury, looking at it not solely as a mechanical issue but also as an inflammatory and cellular pathology. Fighting the No reflow should be broad spectrum until such time we have a deep insight to the main pathology behind it. Conclusion The study concluded that the verapamil and adrenaline were not superior the standard treatment in term of TFG, but the verapamil was superior to both groups in improving the MBG while the adrenaline was not superior to the control group. The short-term outcomes were better in verapamil group than the adrenaline and control group who were equivocal.

Characteristic cardiac capillary pericytes in a Fabry disease patient receiving enzyme replacement therapy

Fabry disease, a lysosomal disorder caused by deficiency in α-galactosidase A, patients report chest pain in the absence of epicardial coronary artery stenosis. Although it is conceivable that coronary microvascular dysfunction due to globotriaosylceramide (GL-3) accumulation within the vasculature causes angina, the precise histology was unknown. A 34-year-old male patient diagnosed with Fabry disease [NM_000169.3:c.1089_1090insTCGC (p.Tyr365Lysfs*11)] and treated for 6 years with enzyme replacement therapy (ERT) was referred to our cardiology department because of palpitations and precordial discomfort. He was diagnosed for paroxysmal atrial fibrillation and subsequently underwent catheter ablation therapy. The procedure resolved his palpitations, but his precordial discomfort remained. Again, coronary angiography showed no organic stenosis. A 24-hour Holter electrocardiogram detected neither arrhythmia nor ischemic changes. Echocardiography showed normal wall motion with diffuse left ventricular hypertrophy. Endomyocardial biopsy revealed severe vacuolated hypertrophied myocytes appearing transparent, like a lace curtain, which is characteristic of Fabry disease (Figure A, A’ and B). Electron microscopic examination revealed abundant lamellar bodies with a myelin-like configuration within cardiomyocytes and interstitial macrophages, indicating GL-3 deposition (Figure C, D and E). We also detected numerous interstitial microcapillaries showing abundant lamellar body deposits within the capillary pericytes but not the endothelial cells (Figure F, F’-1 and F’-2. Pericytes surrounding the endothelial cells can regulate capillary blood flow in microvascular beds. Our pathological findings suggest progressive lamellar body accumulation caused angina by disrupting microvascular circulation. This case highlights progression of microvascular Fabry disease especially in capillary pericytes and also a need for develop therapies targeting capillary circulation.

Dietary choline, via gut microbe- generated trimethylamine-N- oxide, aggravates chronic kidney disease-induced cardiac dysfunction by inhibiting hypoxia-induced factor 1α.

Chronic kidney disease (CKD) is a global public health problem that shortens lifespan primarily by increasing the risk of cardiovascular diseases. Trimethylamine-N-oxide (TMAO), a gut microbiota-derived toxin produced by metabolizing high-choline or carnitine foods, is associated with cardiovascular events in patients with CKD. Although the deleterious effect of TMAO on CKD-induced cardiac injury has been confirmed by various researches, the mechanisms remain unclear. Here, we tested the hypothesis that TMAO aggravates CKD-induced cardiac injury and explores the potential mechanism. CD1 mice underwent 5/6 nephrectomy to induce CKD, and then fed with a diet supplemented with choline (1.2% total) for 8weeks. Serum TMAO levels were elevated in CKD mice compared with SHAM group, and higher TMAO levels were found in choline-supplemented CKD mice compared with CKD group. Dietary choline aggravated CKD-induced cardiac dysfunction, and reducing TMAO levels via medicinal charcoal tablets improved cardiac dysfunction. RNA-seq analysis revealed that dietary choline affected cardiac angiogenesis in CKD mice. Reduced cardiac capillary density and expressions of angiogenesis-related genes were observed in choline-treated CKD mice. Furthermore, dietary choline inhibited cardiac Hif-1α protein level in CKD mice, and Hif-1α stabilizer FG-4592 could improve cardiac angiogenesis and dysfunction in CKD mice on a high-choline diet. In conclusion, these data indicate that dietary choline, via gut microbe-generated TMAO, inhibits cardiac angiogenesis by reducing Hif-1α protein level, ultimately aggravates cardiac dysfunction in CKD mice.

Understanding Cell Model Characteristics-RNA Expression Profiling in Primary and Immortalized Human Mesothelial Cells, and in Human Vein and Microvascular Endothelial Cells.

In vitro studies are essential in pre-clinical research. While choice of cell lines is often driven by handling and cost-effectiveness, in-depth knowledge on specific characteristics is scant. Mesothelial cells, which interact with endothelial cells, are widely used in research, including cancer and drug development, but have not been comprehensively profiled. We therefore performed RNA sequencing of polarized, primary peritoneal (HPMC) and immortalized pleural mesothelial cells (MeT-5A), and compared them to endothelial cells from umbilical vein (HUVEC) and cardiac capillaries (HCMEC). Seventy-seven per cent of 12,760 genes were shared between the 4 cell lines, 1003 were mesothelial and 969 were endothelial cell specific. The transcripts reflected major differences between HPMC and MeT-5A in DNA-related processes, extracellular matrix, migration, proliferation, adhesion, transport, growth factor- and immune response, and between HUVEC and HCMEC in DNA replication, extracellular matrix and adhesion organization. Highly variable shared genes were related to six clusters, cell tissue origin and immortalization, but also cell migration capacity, cell adhesion, regulation of angiogenesis and response to hypoxia. Distinct, cell type specific biological processes were further described by cellular component-, molecular function- and Reactome pathway analyses. We provide crucial information on specific features of the most frequently used mesothelial and endothelial cell lines, essential for appropriate use.

Relationship between capillaries, mitochondria and maximum power of the heart: a meta-study from shrew to elephant.

This meta-study uses phylogenetic scaling models across more than 30 species, spanning five orders of magnitude in body mass, to show that cardiac capillary numerical density and mitochondrial volume density decrease with body mass raised to the -0.07 ± 0.03 and -0.04 ± 0.01 exponents, respectively. Thus, while an average 10 g mammal has a cardiac capillary density of approximately 4150 mm-2 and a mitochondrial density of 33%, a 1 t mammal has considerably lower corresponding values of 1850 mm-2 and 21%. These similar scaling trajectories suggest quantitative matching for the primary oxygen supply and oxygen consuming structures of the heart, supporting economic design at the cellular level of the oxygen cascade in this aerobic organ. These scaling trajectories are nonetheless somewhat shallower than the exponent of -0.11 calculated for the maximum external mechanical power of the cardiac tissue, under conditions of heavy exercise, when oxygen flow between capillaries and mitochondria is probably fully exploited. This mismatch, if substantiated, implies a declining external mechanical efficiency of the heart with increasing body mass, whereby larger individuals put more energy in but get less energy out, a scenario with implications for cardiovascular design, aerobic capacity and limits of body size.

Drug Repurposing Patent Applications April–June 2021

Drug Repurposing Patent Applications April–June 2021

Abstract P165: Cardiac Capillary Pericytes Constriction Mediates Sleep Deprivation Induced Coronary Microcirculation Dysfunction

Background: Lack of sleep can lead to a variety of adverse cardiovascular events and even sudden death. In most cases, there is no obstructive coronary artery. Coronary microcirculation dysfunction (CMD) is thereby thought to play an important role in cardiovascular events caused by sleep loss. Pericytes regulate blood flow and mediate neurovascular signaling in brain. Here, we hypothesized that cardiac capillary pericytes mediate sleep loss related CMD. Methods and Results: Eight-week-old male C57BL/6J mice were deprived sleep for 6 hours or 72 hours. Cardiac function was detected by transthoracic echocardiography before and after sleep deprivation (SD). Vascular endothelial dyes were perfusion before tissue harvest to evaluate cardiac perfusion. By whole heart clearing, 3D immunolabeling and imaging, the effect of pericytes on cardiac capillary was accessed. Acute 6-hours total sleep deprivation or 72-hours severe sleep deprivation led to decreased cardiac systolic and diastolic dysfunction. Left ventricular end diastolic diameter and left ventricular end systolic diameter increased by 10.12% (0.32 mm of 3.14 mm) and 19.00% (0.31 mm of 1.63 mm). Although coronary flow velocity reserve showed no differences between sleep deprivation and control groups, the basal and maximum coronary blood velocity were increased in acute and severe total sleep deprivation mice, which illustrated CMD. Compared with mice in the control group, the area of cardiac perfusion in the sleep deprivation group was significantly reduced (33.42 ± 4.30% vs. 53.81 ± 7.42%, P < 0.05; SD group, n=7; control group, n=6). Whole mount heart imaging showed pericytes were widely distributed around the microvascular, without difference in regional distribution in the heart. In the area of cardiac perfusion defect, capillary blockages colocalized with pericytes, and the capillary diameter at the pericyte body was significantly reduced in sleep deprived mice (2.01 ± 0.12 μm vs. 2.92 ± 0.07 μm, P < 0.05; SD group, n=10; control group, n=10). Conclusion: Sleep restriction led to cardiac dysfunction and CMD, that pericytes mediated contraction of capillaries might contribute to the process. Cardiac pericytes would be a novel therapeutic target in sleep loss associated heart disease.

3D Imaging and Quantitative Characterization of Mouse Capillary Coronary Network Architecture.

Simple SummaryThe cardiovascular system is composed of two physically and functionally linked parts, the heart and the vascular network, composed of the arteries, capillaries, and veins. In this system, the heart maintains the blood flow, including its own through the coronary vascular network, bringing oxygen and nutrients required for its activity. Microvascularization constitutes the distal part of this network and is composed of small vessels, i.e., arterioles and capillaries. Coronary microvascular diseases are associated with the development of cardiac dysfunction. Identification of the coronary microvascular network structure is hence of critical importance for the understanding of heart diseases. The aim of our study was to establish an accessible methodology for 3D imaging and 3D processing to quantitatively characterize the capillary coronary network architecture in mice, a species largely used as an animal model of cardiac failure. This study proposes a standardized methodology for 3D image processing that allows the quantification of the 3D capillary architecture. Based on an open source software, the whole process is easily accessible for biologists. It is hence useful for the study of cardiovascular diseases and the development of future therapies.Characterization of the cardiac capillary network structure is of critical importance to understand the normal coronary functional properties and coronary microvascular diseases. The aim of our study was to establish an accessible methodology for 3D imaging and 3D processing to quantitatively characterize the capillary coronary network architecture in mice. Experiments were done on C57BL/6J mice. 3D imaging was performed by light sheet microscopy and confocal microscopy on iDISCO+ optical cleared hearts after labelling of the capillary endothelium by lectin injection. 3D images were processed with the open source software ImageJ. Non-visual image segmentation was based of the frequency distribution of the voxel greyscale values, followed by skeletonization and distance mapping. Capillary networks in left and right ventricles and septum were characterized by the volume network density, the fractal dimension, the number of segments and nodes and their ratio, the total network length, and the average length, diameter, and tortuosity of the segments. Scale-dependent parameter values can be impacted by the resolution limit of the 3D imaging technique. The proposed standardized methodology for 3D image processing is easily accessible for a biologist in terms of investment and difficulty level, and allows the quantification of the 3D capillary architecture and its statistical comparison in different conditions.

Increased prostaglandin-D2 in male STAT3-deficient hearts shifts cardiac progenitor cells from endothelial to white adipocyte differentiation.

Cardiac levels of the signal transducer and activator of transcription factor-3 (STAT3) decline with age, and male but not female mice with a cardiomyocyte-specific STAT3 deficiency conditional knockout (CKO) display premature age-related heart failure associated with reduced cardiac capillary density. In the present study, isolated male and female CKO-cardiomyocytes exhibit increased prostaglandin (PG)-generating cyclooxygenase-2 (COX-2) expression. The PG-degrading hydroxyprostaglandin-dehydrogenase-15 (HPGD) expression is only reduced in male cardiomyocytes, which is associated with increased prostaglandin D2 (PGD2) secretion from isolated male but not female CKO-cardiomyocytes. Reduced HPGD expression in male cardiomyocytes derive from impaired androgen receptor (AR)-signaling due to loss of its cofactor STAT3. Elevated PGD2 secretion in males is associated with increased white adipocyte accumulation in aged male but not female hearts. Adipocyte differentiation is enhanced in isolated stem cell antigen-1 (SCA-1)+ cardiac progenitor cells (CPC) from young male CKO-mice compared with the adipocyte differentiation of male wild-type (WT)-CPC and CPC isolated from female mice. Epigenetic analysis in freshly isolated male CKO-CPC display hypermethylation in pro-angiogenic genes (Fgfr2, Epas1) and hypomethylation in the white adipocyte differentiation gene Zfp423 associated with up-regulated ZFP423 expression and a shift from endothelial to white adipocyte differentiation compared with WT-CPC. The expression of the histone-methyltransferase EZH2 is reduced in male CKO-CPC compared with male WT-CPC, whereas no differences in the EZH2 expression in female CPC were observed. Clonally expanded CPC can differentiate into endothelial cells or into adipocytes depending on the differentiation conditions. ZFP423 overexpression is sufficient to induce white adipocyte differentiation of clonal CPC. In isolated WT-CPC, PGD2 stimulation reduces the expression of EZH2, thereby up-regulating ZFP423 expression and promoting white adipocyte differentiation. The treatment of young male CKO mice with the COX inhibitor Ibuprofen or the PGD2 receptor (DP)2 receptor antagonist BAY-u 3405 in vivo increased EZH2 expression and reduced ZFP423 expression and adipocyte differentiation in CKO-CPC. Thus, cardiomyocyte STAT3 deficiency leads to age-related and sex-specific cardiac remodeling and failure in part due to sex-specific alterations in PGD2 secretion and subsequent epigenetic impairment of the differentiation potential of CPC. Causally involved is the impaired AR signaling in absence of STAT3, which reduces the expression of the PG-degrading enzyme HPGD.

Pericyte coverage of cardiac capillaries is decreased in diabetic obese mice

Heart failure with preserved ejection fraction (HFpEF) which results from diastolic dysfunction is a growing epidemiologic problem. The pathophysiology of this disease is poorly understood nevertheless a theory suggests a central role of microvessel disease. Our goal is to investigate the role of pericyte in the pathophysiology of cardiac microvessel disease and diastolic dysfunction. Pericytes are mural cells known to be essential for microvascular integrity especially in the brain, and in the retina. We have used Leptin receptor deficient (Leprdb/db) female mice as a model of HFpEF and assessed pericyte coverage of cardiac capillaries. Besides, to identify factors that may cause pericyte loss in the heart, we performed, cell viability assays using cultured human pericytes from placenta. In Leprdb/db mice, end-diastolic pressure (EDP) signing diastolic dysfunction is significantly increased from 3 month of age [12.0 ± 1.4 vs 4.4 ± 0.4 mmHg ( P < 0.001)]. It is correlated with signs of microvessel disease especially vascular leakage and endothelial cell activation. Interestingly, we found that pericyte coverage of cardiac capillaries is significantly reduced in Leprdb/db female mice from 6 weeks of age [93.88 ± 2.30 vs 54.67 ± 5.32 ( P < 0.001)]. Notably, this anomaly precedes the onset of endothelial dysfunction and diastolic dysfunction. Cell culture assay showed that oxidized LDLs but not high glucose or TNFα significantly decrease pericyte survival [100.00 ± 6.48 vs 76.22 ± 4.49 with 30 μg/mL ( P < 0.01)]. Our results show that pericyte coverage of capillaries is significantly decreased in the heart of diabetic obese mice probably because of increased oxidized LDL and support that degeneration of cardiac pericytes may contribute to the development of cardiac microvessel disease and diastolic dysfunction in diabetic obese mice and may be due to oxidized LDL.

A Histopathological Study of Cisplatin-induced Acute Vascular Injuries in Vital Organs and Protective Effect of Achillea millefolium

The aim was to study the protective effect of ethanolic extract of Achillea millefolium on acute vascular injuries induced by cisplatin in liver, heart and renal tissues 24 hour after administration and using histopathological surveys in wistar rats. 24 adult male wistar rats were randomly divided into four groups. Group I (control group) received physiological saline for 10 days. Animals of group II had single dose of injection of CP (cisplatin) (6 mg/kg, IP) on the ninth day. Group III received Achillea millefolium extract (250 mg/kg, gavage) for 10 consecutive days. Group IV had both Achillea millefolium extract (250 mg/kg, gavage) for 10 consecutive days and a single dose of injection of CP (6 mg/kg, IP) on the ninth day. Kidney, liver and heart organs were collected on 10th day from sacrificed rats and subjected to histopathological analysis. Then the possible histopathological vascular effects of cisplatin on liver, heart, kidney tissues and the protective effect of Achillea millefolium extract was analysed. Obtained data showed the vascular injuries in CP group as congestion of cardiac capillaries (p=0.00) and interstitial edema (p=0.03). In the kidney, shrinkage of glomeruli (p=0.04), widening of Bowman's space (p=0.04), dilatation of cortical capillaries (p=0.01) were significantly altered. The findings of liver organ were increased sinusoidal space (p=0.00) and infiltration of neutrophils in portal space (p=0.01). Pretreatment with ethanolic extract of Achillea millefolium could attenuate these vascular injuries. Briefly, 24 hour after single injection of cisplatin the inflammatory process was seen in vital organs and administration of Achillea millefolium could mitigate these side effects.

KLF15 is a protective regulatory factor of heart failure induced by pressure overload.

The aim of the present study was to investigate the protective effect of Kruppel‑like factor 15 (KLF15) overexpression on heart failure (HF) induced by left ventricular (LV) pressure overload in mice. Wild‑type (WT) mice and cardiac‑specific KLF15‑overexpressed transgenic (TG) mice were selected as research subjects, and an LV pressure overload model was constructed by ascending aortic constriction surgery. Changes in cardiac morphology and function, and ultrastructure and molecular expression were observed via M‑mode echocardiography, histological and immunohistochemical staining, ELISA and western blotting at 2 and 6weeks of LV overload. WT and TG mice subjected to 2weeks of overload displayed adaptive LV hypertrophy characterized by ventricular thickness, cardiomyocyte size, ejection fraction and fractional shortening of heart‑lung weight ratio and KLF15, and increases in vascular endothelial growth factor (VEGF) expression without other pathological changes. WT mice subjected to 6 weeks of overload displayed enlargement of the LV chamber, severe interstitial remodeling, and HW/LW, cardiac capillary and heart function decline, accompanied by downregulated expression of KLF15 and VEGF, and upregulated expression of connective tissue growth factor, phosphorylated p38 (p‑p38) and phosphorylated Smad3 (p‑Smad3). In contrast, TG mice exhibited improved resistance to 6 weeks of overload and a slighter molecular expression response compared with WT mice. KLF15 was revealed to be a critical factor regulating the expression of CTGF, VEGF, p‑p38 and p‑Smad3, and could alleviate the progression from adaptive LV hypertrophy to decompensatory cardiac insufficiency.

Endothelial EphB4 maintains vascular integrity and transport function in adult heart.

The homeostasis of heart and other organs relies on the appropriate provision of nutrients and functional specialization of the local vasculature. Here, we have used mouse genetics, imaging and cell biology approaches to investigate how homeostasis in the adult heart is controlled by endothelial EphB4 and its ligand ephrin-B2, which are known regulators of vascular morphogenesis and arteriovenous differentiation during development. We show that inducible and endothelial cell-specific inactivation of Ephb4 in adult mice is compatible with survival, but leads to rupturing of cardiac capillaries, cardiomyocyte hypertrophy, and pathological cardiac remodeling. In contrast, EphB4 is not required for integrity and homeostasis of capillaries in skeletal muscle. Our analysis of mutant mice and cultured endothelial cells shows that EphB4 controls the function of caveolae, cell-cell adhesion under mechanical stress and lipid transport. We propose that EphB4 maintains critical functional properties of the adult cardiac vasculature and thereby prevents dilated cardiomyopathy-like defects.

Plin5/p-Plin5 Guards Diabetic CMECs by Regulating FFAs Metabolism Bidirectionally.

Background Hyper-free fatty acidemia (HFFA) impairs cardiac capillaries, as well as type 2 diabetes mellitus (T2DM). Perilipin 5 (Plin5) maintains metabolic balance of free fatty acids (FFAs) in high oxidative tissues via the states of nonphosphorylation and phosphorylation. However, when facing to T2DM-HFFA, Plin5's role in cardiac microvascular endothelial cells (CMECs) is not defined. Methods In mice of WT or Plin5−/−, T2DM models were rendered by high-fat diet combined with intraperitoneal injection of streptozocin. CMECs isolated from left ventricles were incubated with high glucose (HG) and high FFAs (HFFAs). Plin5 phosphorylation was stimulated by isoproterenol. Plin5 expression was knocked down by small interfering RNA (siRNA). We determined cardiac function by small animal ultrasound, apoptotic rate by flow cytometry, microvessel quantity by immunohistochemistry, microvascular integrity by scanning electron microscopy, intracellular FFAs by spectrophotometry, lipid droplets (LDs) by Nile red staining, mRNAs by quantitative real-time polymerase chain reaction, proteins by western blots, nitric oxide (NO) and reactive oxygen species (ROS) by fluorescent dye staining and enzyme-linked immunosorbent assay kits. Results In CMECs, HFFAs aggravated cell injury induced by HG and activated Plin5 expression. In mice with T2DM-HFFA, Plin5 deficiency reduced number of cardiac capillaries, worsened structural incompleteness, and enhanced diastolic dysfunction. Moreover, in CMECs treated with HG-HFFAs, both ablation and phosphorylation of Plin5 reduced LDs content, increased intracellular FFAs, stimulated mitochondrial β-oxidation, added ROS generation, and reduced the expression and activity of endothelial nitric oxide synthase (eNOS), eventually leading to increased apoptotic rate and decreased NO content, all of which were reversed by N-acetyl-L-cysteine. Conclusion Plin5 preserves lipid balance and cell survival in diabetic CMECs by regulating FFAs metabolism bidirectionally via the states of nonphosphorylation and phosphorylation.

Plin5/p-Plin5 Guards Diabetic CMECs by Regulating FFAs Metabolism Bidirectionally

Background: Hyper-free fatty academia (HFFA) impairs cardiac capillaries, as well as type 2 diabetes mellitus (T2DM). Perilipin 5 (Plin5) maintains metabolic balance of free fatty acids (FFAs) in high oxidative tissues via the states of non-phosphorylation and phosphorylation. However, when facing to T2DM-HFFA, Plin5's role in cardiac microvascular endothelial cells (CMECs) is not defined. Methods: In mice of WT or Plin5-/-, T2DM models were rendered by high-fat diet combined with intraperitoneal injection of streptozocin. CMECs isolated from left ventricles were incubated with high glucose (HG) and high FFAs (HFFAs). Plin5 phosphorylation was stimulated by isoproterenol. Plin5 expression was knocked down by siRNA. We determined cardiac function by small animal ultrasound, apoptotic rate by flow cytometry, microvessel quantity by immunohistochemistry, microvascular integrity by scanning electron microscopy, intracellular FFAs by spectrophotometry, lipid droplets (LDs) by nile red staining, mRNAs by quantitative real time polymerase chain reaction, proteins by western blots, nitric oxide (NO) and reactive oxygen species (ROS) by fluorescent dye staining and enzyme-linked immunosorbent assay kits. Results: In CMECs, HFFAs aggravated cell injury induced by HG and activated Plin5 expression. In mice with T2DM-HFFA, Plin5 deficiency reduced number of cardiac capillaries, worsened structural incompleteness and enhanced diastolic dysfunction. Moreover, in CMECs treated with HG-HFFAs, both ablation and phosphorylation of Plin5 reduced LDs content, increased intracellular FFAs, stimulated mitochondrial β-oxidation and added ROS generation, reduced the expression and activity of endothelial nitric oxide synthase (eNOS), eventually leading to increased apoptotic rate and decreased NO content, all of which were reversed by acetylcysteine. Conclusion: Plin5 preserves lipid balance and cell survival in diabetic CMECs by regualting FFAs metabolism bidirectionally via the states of non-phosphorylation and phosphorylation. Funding Statement: This work was supported by grants from Science Fund for Distinguished Young Scholars of Sichuan Province (No.2017JQ0012), National Science Funds of China (No.81500208), China Postdoctoral Science Foundation (No.2017M613429). Declaration of Interests: The authors declare: No competing financial interests exist. Ethics Approval Statement: All experiments were conducted in adherence with National Institutes of Health Guidelines on the Use of Laboratory Animals, and were approved by Institutional Animal Care and Use Committee of Chengdu Military General Hospital.