Inhibition of integrin alpha v/beta 5 mitigates the protective effect induced by irisin in hemorrhage

INTRODUCTION

Irisin plays an important role in regulating tissue stress, cardiac function, and inflammation. Integrin αvβ5 was recently identified as a receptor for irisin to elicit its physiologic function. It remains unknown whether integrin αvβ5 is required for irisin's function in modulating the physiologic response to hemorrhage. The objective of this study is to examine if integrin αvβ5 contributes to the effects of irisin during the hemorrhagic response.

METHODS

Hemorrhage was induced in mice by achieving a mean arterial blood pressure of 35-45 mmHg for one hour, followed by two hours of resuscitation. Irisin (0.5  μg/kg) was administrated to assess its pharmacologic effects in hemorrhage. Cilengitide, a cyclic Arg-Gly-Asp peptide (cRGDyK) which is an inhibitor of integrin αvβ5, or control RGDS (1 mg/kg) was administered with irisin. In another cohort of mice, the irisin-induced protective effect was examined after knocking down integrin β5 with nanoparticle delivery of integrin β5 sgRNA using CRSIPR/Cas-9 gene editing. Cardiac function and hemodynamics were measured using echocardiography and femoral artery catheterization, respectively. Systemic cytokine releases were measured using Enzyme-linked immunosorbent assay (ELISA). Histological analyses were used to determine tissue damage in myocardium, skeletal muscles, and lung tissues. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) was carried out to assess apoptosis in tissues.

RESULTS

Hemorrhage induced reduction of integrin αvβ5 in skeletal muscles and repressed recovery of cardiac performance and hemodynamics. Irisin treatment led to significantly improved cardiac function, which was abrogated by treatment with Cilengitide or knockdown of integrin β5. Furthermore, irisin resulted in a marked suppression of tumor necrosis factor-α (TNF-α) and interleukin-1 (IL-1), muscle edema, and inflammatory cells infiltration in myocardium and skeletal muscles, which was attenuated by Cilengitide or knockdown of integrin β5. Irisin-induced reduction of apoptosis in the myocardium, skeletal muscles, and lung, which were attenuated by either the inhibition of integrin αvβ5, or knockdown of integrin β5.

CONCLUSION

Integrin αvβ5 plays an important role for irisin in modulating the protective effect during hemorrhage.

Irisin deficiency exacerbates diet-induced insulin resistance and cardiac dysfunction in type II diabetes in mice

Irisin is involved in the regulation of a variety of physiological conditions, metabolism, and survival. We and others have demonstrated that irisin contributes critically to modulation of insulin resistance and the improvement of cardiac function. However, whether the deletion of irisin will regulate cardiac function and insulin sensitivity in type II diabetes remains unclear. We utilized the CRISPR/Cas-9 genome-editing system to delete irisin globally in mice and high-fat diet (HFD)-induced type II diabetes model. We found that irisin deficiency did not result in developmental abnormality during the adult stage, which illustrates normal cardiac function and insulin sensitivity assessed by glucose tolerance test in the absence of stress. The ultrastructural analysis of the transmission electronic microscope (TEM) indicated that deletion of irisin did not change the morphology of mitochondria in myocardium. Gene expression profiling showed that several key signaling pathways related to integrin signaling, extracellular matrix, and insulin-like growth factors signaling were coordinately downregulated by deletion of irisin. However, when mice were fed a high-fat diet and chow food for 16 wk, ablation of irisin in mice exposed to HFD resulted in much more severe insulin resistance, metabolic derangements, profound cardiac dysfunction, and hypertrophic response and remodeling as compared with wild-type control mice. Taken together, our results indicate that the loss of irisin exacerbates insulin resistance, metabolic disorders, and cardiac dysfunction in response to HFD and promotes myocardial remodeling and hypertrophic response. This evidence reveals the molecular evidence and the critical role of irisin in modulating insulin resistance and cardiac function in type II diabetes.NEW & NOTEWORTHY By utilizing the CRISPR/Cas-9 genome-editing system and high-fat diet (HFD)-induced type II diabetes model, our results provide direct evidence showing that the loss of irisin exacerbates cardiac dysfunction and insulin resistance while promoting myocardial remodeling and a hypertrophic response in HFD-induced diabetes. This study provides new insight into understanding the molecular evidence and the critical role of irisin in modulating insulin resistance and cardiac function in type II diabetes.

Leukocyte-Specific Morrbid Promotes Leukocyte Differentiation and Atherogenesis

Monocyte-to-M0/M1 macrophage differentiation with unclear molecular mechanisms is a pivotal cellular event in many cardiovascular diseases including atherosclerosis. Long non-coding RNAs (lncRNAs) are a group of protein expression regulators; however, the roles of monocyte-lncRNAs in macrophage differentiation and its related vascular diseases are still unclear. The study aims to investigate whether the novel leukocyte-specific lncRNA Morrbid could regulate macrophage differentiation and atherogenesis. We identified that Morrbid was increased in monocytes and arterial walls from atherosclerotic mouse and from patients with atherosclerosis. In cultured monocytes, Morrbid expression was markedly increased during monocyte to M0 macrophage differentiation with an additional increase during M0 macrophage-to-M1 macrophage differentiation. The differentiation stimuli-induced monocyte-macrophage differentiation and the macrophage activity were inhibited by Morrbid knockdown. Moreover, overexpression of Morrbid alone was sufficient to elicit the monocyte-macrophage differentiation. The role of Morrbid in monocyte-macrophage differentiation was also identified in vivo in atherosclerotic mice and was verified in Morrbid knockout mice. We identified that PI3-kinase/Akt was involved in the up-regulation of Morrbid expression, whereas s100a10 was involved in Morrbid-mediated effect on macrophage differentiation. To provide a proof of concept of Morrbid in pathogenesis of monocyte/macrophage-related vascular disease, we applied an acute atherosclerosis model in mice. The results revealed that overexpression of Morrbid enhanced but monocyte/macrophage-specific Morrbid knockout inhibited the monocytes/macrophages recruitment and atherosclerotic lesion formation in mice. The results suggest that Morrbid is a novel biomarker and a modulator of monocyte-macrophage phenotypes, which is involved in atherogenesis.

[A comparative study for the efficacies of transaxillary non-inflatable endoscopic surgery versus traditional surgery for papillary thyroid carcinoma]

Objective: To compare the efficacies between open surgery and axillary non-inflatable endoscopic surgery in papillary thyroid carcinoma (PTC). Methods: A retrospective analysis was performed on 343 patients with unilateral PTC treated by traditional open surgery (201 cases) and transaxillary non-inflating endoscopic surgery (142 cases) from May 2019 to December 2021 in the Head and Neck Surgery of Sichuan Cancer Hospital. Among them, 97 were males and 246 were females, aged 20-69 years. 1∶1 propensity score matching (PSM) was performed on the enrolled patients, and the basic characteristics, perioperative clinical outcomes, postoperative complications, postoperative quality of life (Thyroid Cancer-Specific Quality of Life), aesthetic satisfaction and other aspects of the two groups were compared after successful matching. SPSS 26.0 software was used for statistical analysis. Results: A total of 190 patients were enrolled after PSM, with 95 cases in open group and 95 cases in endoscopic group. Intraoperative blood losses for endoscopic and open groups were [20 (20) ml vs. 20 (10) ml, M (IQR), Z=-2.22], postoperative drainage volumes [170 (70)ml vs. 101 (55)ml, Z=-7.91], operative time [135 (35)min vs. 95 (35)min, Z=-7.34], hospitalization cost [(28 188.7±2 765.1)yuan vs. (25 643.5±2 610.7)yuan, x¯±s, t=0.73], postoperative hospitalization time [(3.1±0.9)days vs. (2.6±0.9)days, t=-3.24], and drainage tube placement time [(2.5±0.8) days vs. (2.0±1.0)days, t=-4.16], with statistically significant differrences (all P<0.05). There was no significant difference in surgical complications (P>0.05). There were significant diffferences between two groups in the postoperative quality of life scores in neuromuscular, psychological, scar and cold sensation (all P<0.05), while there were no statistically significant differences in other quality of life scores (all P>0.05). In terms of aesthetic satisfaction 6 months after surgery, the endoscopic group was better than the open group, with statistically significant difference (χ²=41.47, P<0.05). Conclusion: Endoscopic thyroidectomy by a gasless unilateral axillary approach is a safe and reliable surgical method, which has remarkable cosmetic effect and can improve the postoperative quality of life of patients compared with the traditional thyroidectomy.

The performance of left/right adrenal volume ratio and volume difference in predicting unilateral primary aldosteronism

PURPOSE

The role of computed tomography (CT) in the diagnosis of primary aldosteronism (PA) warrants attention, since the success application of adrenal venous sampling (AVS) remains limited. We aimed to investigate the value of CT-based volumetric indicators, including left-versus-right-adrenal-volume ratio (L/Rv) and left-subtract-right-adrenal-volume difference (L - Rv), in the diagnosis of unilateral primary aldosteronism (UPA).

METHODS

A retrospective case-control study included 153 patients with PA and 1272 controls. AVS was used to classify patients into bilateral disease, left-sided disease, and right-sided disease groups.

RESULTS

Adrenal gland volume on both sides of PA patients was significantly larger than controls. The optimal cutoff values of L/Rv and L - Rv were 1.417 [area under the curve (AUC) 0.864] and 1.185 (AUC 0.827), respectively, for the diagnosis of left-sided PA, and 1.030 (AUC 0.767) and 0.220 (AUC 0.769), respectively, for the diagnosis of right-sided PA. The mean AUC for subsequent cross-validation ranged from 0.77 ± 0.03 to 0.86 ± 0.02. Based on the optimal cutoff values, the combination of L/Rv and L - Rv detected 69.6% of patients with left-sided PA and 74.3% of patients with right-sided PA, with a specificity of 93.5% and 89.0%, respectively. For a better clinical application, we reported the sub-optimal cutoffs corresponding to a specificity of 95%. A L/Rv higher than 1.431 and a L - Rv higher than 3.185 as sub-optimal cutoff values was detected in 26.1% of patients with left-sided PA (specificity: 97.2%). A L/Rv smaller than 0.892 and a L - Rv smaller than -0.640 could detect 48.6% of patients with right-sided PA (specificity: 97.5%).

CONCLUSIONS

CT-based L/Rv and L - Rv performed well in predicting UPA. The combination of L/Rv and L - Rv may serve as a potential indicator for guiding surgical decision making in centers without AVS programs.

Cardiac muscle patches containing four types of cardiac cells derived from human pluripotent stem cells improve recovery from cardiac injury in mice

AIMS

We have shown that human cardiac muscle patches (hCMPs) containing three different types of cardiac cells-cardiomyocytes (CMs), smooth-muscle cells (SMCs), and endothelial cells (ECs), all of which were differentiated from human pluripotent stem cells (hPSCs)-significantly improved cardiac function, infarct size, and hypertrophy in a pig model of myocardial infarction (MI). However, hPSC-CMs are phenotypically immature, which may lead to arrythymogenic concerns; thus, since hPSC-derived cardiac fibroblasts (hPSC-CFs) appear to enhance the maturity of hPSC-CMs, we compared hCMPs containing hPSC-CMs, -SMCs, -ECs, and -CFs (4TCC-hCMPs) with a second hCMP construct that lacked hPSC-CFs but was otherwise identical (3TCC-hCMPs).

METHODS

hCMPs were generated in a fibrin scaffold. MI was induced in SCID mice through permanent coronary artery (LAD) ligation, followed by treatment with cardiac muscle patches. Animal groups included: MI heart treated with 3TCC-hCMP; with 4TCC-hCMP; MI heart treated with no patch (MI group) and sham group. Cardiac function was evaluated via echocardiography, and cell engraftment rate while infarct size was evaluated histologically at four weeks after patch transplantation.

RESULTS

The results from experiments in cultured hCMPs demonstrate that the inclusion of CF in 4TCC-hCMPs had: 1) better organized sarcomeres; 2) abundant structural, metabolic, and ion- channel markers of CM maturation; and 3) greater conduction velocities (31 ± 3.23 cm/s, p<0.005) and action-potential durations (APD50 = 365 ms ± 2.649, P<0.0001; APD = 408 ms ± 2.757, P<0.0001) than those (velocity and AP duration time) in 3TCC-hCMPs. Furthermore, when 4TCC- hCMPs transplantation resulted in better cardiac function (EF = 49.18% ± 0.86, p<0.05), reduced infarct size (22.72% ± 0.98, p<0.05), and better engraftment (15.99% ± 1.56, p<0.05) as compared with 3TCC-hCMPs (EF = 41.55 ± 0.92%, infarct size = 39.23 ± 4.28%, and engraftment = 8.56 ± 1.79%, respectively).

CONCLUSION

Collectively, these observations suggest that the inclusion of hPSC-CFs during hCMP manufacture promotes hPSC-CM maturation and increases the potency of implanted hCMPs for improving cardiac recovery in mice model of MI.

TRANSLATIONAL PERSPECTIVE

Heart transplantation surgery remains the only established treatment for end-stage heart disease, and the supply of donated hearts is far lower than the number of patients in need of treatment. Thus, the goal of cardiac tissue engineering is to replace the scarred region of an injured heart with functional cardiac muscle. The results presented in this report suggest that engineered human cardiac-muscle patches may be more effective for the treatment of heart disease when they are constructed with cardiomyocytes, smooth-muscle cells, endothelial cells, and cardiac fibroblasts than when the cardiac fibroblasts are omitted.

Laparoscopic radical resection for rectal cancer in a patient with uncorrected truncus arteriosus type IV: A case report

Persistent truncus arteriosus is a rare congenital heart malformation which if not corrected, results in the death of about 50% of the patients, while fewer than 20% of the patients survive the first year of life. Here, we report the successful anesthetic management of an adult patient with uncorrected truncus arteriosus who presented for the laparoscopic radical resection of rectal cancer.

Metabolic labeling of cardiomyocyte-derived small extracellular-vesicle (sEV) miRNAs identifies miR-208a in cardiac regulation of lung gene expression

Toxoplasma gondii uracil phosphoribosyltransferase (UPRT) converts 4‐thiouracil (4TUc) into 4‐thiouridine (4TUd), which is incorporated into nascent RNAs and can be biotinylated, then labelled with streptavidin conjugates or isolated via streptavidin‐affinity methods. Here, we generated mice that expressed T. gondii UPRT only in cardiomyocytes (^CMUPRT mice) and tested our hypothesis that CM‐derived miRNAs (^CMmiRs) are transferred into remote organs after myocardial infarction (MI) by small extracellular vesicles (sEV) that are released from the heart into the peripheral blood (^PBsEV). We found that 4TUd was incorporated with high specificity and sensitivity into RNAs isolated from the hearts and ^PBsEV of ^CMUPRT mice 6 h after 4TUc injection. In ^PBsEV, 4TUd was incorporated into CM‐specific/enriched miRs including miR‐208a, but not into miRs with other organ or tissue‐type specificities. 4TUd‐labelled miR208a was also present in lung tissues, especially lung endothelial cells (ECs), and CM‐derived miR‐208a (^CMmiR‐208a) levels peaked 12 h after experimentally induced MI in ^PBsEV and 24 h after MI in the lung. Notably, miR‐208a is expressed from intron 29 of α myosin heavy chain (αMHC), but αMHC transcripts were nearly undetectable in the lung. When ^PBsEV from mice that underwent MI (MI‐^PBsEV) or sham surgery (Sham‐^PBsEV) were injected into intact mice, the expression of Tmbim6 and NLK, which are suppressed by miR‐208a and cooperatively regulate inflammation via the NF‐κB pathway, was lower in the lungs of MI‐^PBsEV–treated animals than the lungs of animals treated with Sham‐^PBsEV or saline. In MI mice, Tmbim6 and NLK were downregulated, whereas endothelial adhesion molecules and pro‐inflammatory cells were upregulated in the lung; these changes were significantly attenuated when the mice were treated with miR‐208a antagomirs prior to MI surgery. Thus, ^CMUPRT mice enables us to track ^PBsEV‐mediated transport of ^CMmiRs and identify an miR‐208a‐mediated mechanism by which myocardial injury alters the expression of genes and inflammatory response in the lung.

Hepatic Sam68 Regulates Systemic Glucose Homeostasis and Insulin Sensitivity

Hepatic glucose production (HGP) is an important component of glucose homeostasis, and deregulated HGP, particularly through gluconeogenesis, contributes to hyperglycemia and pathology of type-2 diabetes (T2D). It has been shown that the gluconeogenic gene expression is governed primarily by the transcription factor cAMP-response element (CRE)-binding protein (CREB) and its coactivator, CREB-regulated transcriptional coactivator 2 (CRTC2). Recently, we have discovered that Sam68, an adaptor protein and Src kinase substrate, potently promotes hepatic gluconeogenesis by promoting CRTC2 stability; however, the detailed mechanisms remain unclear. Here we show that in response to glucagon, Sam68 increases CREB/CRTC2 transactivity by interacting with CRTC2 in the CREB/CRTC2 complex and occupying the CRE motif of promoters, leading to gluconeogenic gene expression and glucose production. In hepatocytes, glucagon promotes Sam68 nuclear import, whereas insulin elicits its nuclear export. Furthermore, ablation of Sam68 in hepatocytes protects mice from high-fat diet (HFD)-induced hyperglycemia and significantly increased hepatic and peripheral insulin sensitivities. Thus, hepatic Sam68 potentiates CREB/CRTC2-mediated glucose production, contributes to the pathogenesis of insulin resistance, and may serve as a therapeutic target for T2D.

[Clinical features and prognoses of re-operated patients for persistent/recurrent papillary thyroid carcinoma]

Objective: To investigate the clinicopathological characteristics and the survival of re-operated patients for persistent/recurrent papillary thyroid carcinoma (PTC) and risk factors for re-recurrence after the second operation. Method: A retrospective analysis of 69 cases underwent re-operation for persistent/recurrent PTC in Sichuan Cancer Hospital from January 2010 to December 2016 was performed. There were 21 males and 48 females, aged 14-85 (44.8) years old. According to the imaging after initial treatment, they were divided into a recurrence group (42 cases) and a persistent disease/residual group (27 cases). The positive rates of ipsilateral paratracheal lymph node metastases at re-operation were calculated and compared by chi-square test. Patients were divided into different subgroups according to potential risk factors for re-recurrence. Kaplan-Meier (K-M) method was used for survival analysis. Results: The positive rate of ipsilateral paratracheal lymph node metastasis in recurrence group (15/42, 35.7%) was significantly lower than that in the persistent disease/residual group (17/27, 63.0%) (χ²=4.91, P<0.05). The follow-up period after re-operation was 60-104 months, with a median of 66 months, and 8 patients were lost to follow-up. Permanent hypoparathyroidism occurred in 2 cases (2.9%) and permanent recurrent laryngeal nerve palsy in 1 case (1.4%). Twenty patients had structural recurrences and/or distant metastases. The 5-year disease-specific survival rate was 92.8% and the 5-year recurrence-free survival rate was 68.1%. Survival analysis was performed on risk factors such as age≥55 years old, recurrent tumor diameter ≥4 cm, number of positive lymph nodes ≥ 10, and obvious extracapsular invasion (ENE). Among them, age and diameter of recurrent tumor had significant influences on recurrence-free survival rate (χ² was 6.36, 8.17, respectively, both P values<0.05). There was a statistically significant difference in recurrence-free survival rates between ENE(+) group and ENE(-) group (χ²=5.52, P<0.05). Conclusion: For the re-operated patients due to persistence/ recurrence PTC, attention should be paid to protecting the parathyroid gland and recurrent laryngeal nerve during re-operation. Timely and effective postoperative follow-up for patients aged ≥ 55 years, with recurrent tumor diameter ≥ 4 cm and ENE(+), can significantly improve their prognoses.

Abstract P1018: Bone Marrow Progenitor Cell-Derived Exosomes Activate Cardiac Fibroblasts Via Mir-21a-5p Mediated Integrin Alpha V Stabilization

Abstract: Heart failure is leading cause of death worldwide, and cardiac fibrosis is the hallmark of heart failure. We previously showed that interleukin-10 (IL10) treatment significantly reduces pressure overload-induced cardiac fibrosis. We also have demonstrated that fibroblast progenitor cells (bone marrow-prominin positive cells; FPCs) play a prominent role in developing cardiac fibrosis, yet the mechanism is largely unknown. Here, we hypothesized that pro-fibrotic miRNAs enriched in exosomes derived from IL10 KO FPCs promote fibroblast activation and cardiac fibrosis in pressure-overloaded myocardium.

Methods: Exosomes were isolated from WT and IL-10KO FPCs. Exosomal miRNAs profiling was performed using fibrosis-associated miRNA profiler kit from Qiagen. To determine the contribution of exosomal miR21 on TAC-induced fibrosis, miR21 level was reduced in FPCs-derived exosomes using miR21 silencer. Modified exosomes were injected into heart immediately after TAC surgery.

Results: FPCs were identified as CD45+/prominin-1 cells using FACS. TGFβ treatment exacerbated fibrotic genes (Col1α, fibronectin, periostin, and αSMA) expression in IL10KO FPCs compared to WT-FPCs. Pathway-based miRNA array revealed that IL10KO FPCs exosomes are enriched with miR-21a-5p and facilitated fibroblasts activation as observed by qPCR (αSMA and Col1α), western (Col1α and TGFβ levels), wound healing, and immunostaining assay (Col1α/DAPI expression) as compared to WT control. Interestingly, miR21 inhibition in IL10KO FPCs exosome using antimiR 21, reduced TGFβ-induced cardiac fibroblast activation. Target prediction database analysis revealed that Integrin Subunit Alpha V (ITGAV) is a strong regulatory target for miRNA21. At molecular level, we found that exosomal miR-21a-5p stabilizes ITGAV, which ultimately enhances fibroblast activation and cardiac fibrosis both in vitro and in vivo.

Conclusions: In conclusion, we report that FPCs derived miR21 packaged in exosomes activates cardiac fibroblasts in IL10-KO mice via miR-21a-5p/ITGAV/Col1α signaling axis and increased cardiac fibrosis. IL10 treatment significantly reduced miR21 exosomal packaging, inhibited fibroblasts activation, and reduced cardiac fibrosis following TAC.

Reporter Systems for Assessments of Extracellular Vesicle Transfer

Extracellular vesicles (EVs) are lipid bilayer particles naturally released from most if not all cell types to mediate inter-cellular exchange of bioactive molecules. Mounting evidence suggest their important role in diverse pathophysiological processes in the development, growth, homeostasis, and disease. Thus, sensitive and reliable assessments of functional EV cargo transfer from donor to acceptor cells are extremely important. Here, we summarize the methods EV are labeled and their functional transfer in acceptor cells are evaluated by various reporter systems.

Yeast culture (Saccharomyces cerevisiae) and its active metabolites affect the cecal microbiome of broilers

Yeast cultures (YCs) are defined as promising feed additives that maintain the health of birds and improve growth performance by modulating gut microbiota. YCs contain effective metabolites such as glycine, fructose, inositol, galactose, and sucrose. This study investigated the effects of YCs and their effective metabolites on carcass traits and cecal microflora in broilers. A total of 280 one-day-old mixed-sex Arbor Acres broilers were randomly allocated to seven groups. The basal diet (control DZ) was supplemented with various proportions of glycine, fructose, inositol, galactose, and sucrose (Groups A, B, and C), 24-hour grown Saccharomyces cerevisiae cultures (Group D) (YC), and a commercial yeast culture product (SZ) at concentrations of 0.1% and 1% (Groups E and F). Bodyweight of broilers was correlated positively with proportions of Proteobacteria in Group C and Lactobacillus and Roseburia in Group B (P <0.05). Broilers fed diets supplemented with YC or its active metabolites had the highest proportions of bacteria involved in nucleotide metabolism, and amino acid and carbohydrate metabolism. These results suggested that the dietary addition of YC could alter the proliferation of beneficial bacteria in broilers.

[Evaluation of the effect of comprehensive prevention and management of diabetes mellitus of two cross-sectional surveys based on community population]

To investigate the prevalence of diabetes mellitus (DM) among residents in Chongchuan district, Nantong city in 2012 and 2018, and evaluate the effectiveness of community comprehensive management of DM. Based on the data of 17 780 and 13 382 residents in the cross-sectional surveys of the " National Demonstration Area for Comprehensive Prevention and Control of Chronic Diseases " project in Chongchuan District of Nantong City, Jiangsu Province in 2012 and 2018, 4 583 and 3 996 DM-related information were obtained. The population of Jiangsu Province in 2012 and 2018 was used as the reference for standardization. The rates of prevalence and management (including awareness, treatment, treatment of patients who knew their diabetic situation, control and control of patients under treatment) of DM in the two surveys were compared using chi-square test. The results showed that in 2012 and 2018, the prevalence rates of DM were 12.0% and 15.7% (χ²=24.25, P<0.05), and the standardized rates were 10.1% and 10.8% (χ²=1.05, P=0.306). The incidence rates were 5.7% and 2.3%, respectively (χ²=55.60, P<0.05). The standardized prevalence rates in the two surveys were 9.7% and 11.6% for males (χ²=3.66, P=0.056) and 10.5% and 9.9% for females (χ²=0.50, P=0.481), 7.2% and 6.5% (χ²=0.85, P=0.357) for people aged 18-59 years old and 20.6% and 21.9% (χ²=0.91, P=0.339) for people aged 60 years and over, respectively. The standardized rates of awareness, treatment, treatment of patients who knew their diabetic situation, control, and control of patients under treatment in 2018 were 84.4%, 80.3%, 95.2%, 58.4%, and 70.2%, respectively, higher than 47.2%, 23.4%, 44.8%, 30.4% and 59.4% in 2012 (χ²=183.33, χ²=380.65, χ²=282.99, χ²=93.24, χ²=6.22, all P<0.05). Among men, the standardized rates of awareness, treatment, treatment of patients who knew their diabetic situation, and control in 2018 were 85.8%, 78.8%, 91.8% and 62.7%, higher than 50.5%, 37.5%, 72.3% and 32.6% in 2012 (χ²=78.40, χ²=96.17, χ²=27.55, χ²=48.96, all P<0.05). Similarly, the standardized management rates in 2018 were 83.0%, 81.7%, 98.5%, 54.1% and 65.1%, higher than 44.0%, 10.0%, 18.3%, 28.2% and 48.8% in 2012 among women (χ²=105.52, χ²=326.36, χ²=317.22, χ²=43.34, χ²=3.87, all P<0.05). The standardized rates of awareness, treatment, treatment of patients who knew their diabetic situation, and control of people aged 18-59 and 60 years and over were 82.9%, 79.7%, 96.1%, 55.0% and 88.0%, 81.8%, 93.0% and 67.2%, higher than 42.6%, 19.8%, 42.2%, 27.5% and 63.9%, 36.8%, 53.9%, 40.8% in 2012 (χ²=44.51, χ²=102.17, χ²=57.78, χ²=21.65, all P<0.05; χ²=71.18, χ²=181.55, χ²=146.26, χ²=59.23, all P<0.05). The comprehensive prevention and control system of chronic diseases, which comprehensively covered the life of community residents, had good management effect on DM, and effectively promoted health education and health promotion.

Recent Progress in in vitro Models for Atherosclerosis Studies

Atherosclerosis is the primary cause of hardening and narrowing arteries, leading to cardiovascular disease accounting for the high mortality in the United States. For developing effective treatments for atherosclerosis, considerable efforts have been devoted to developing in vitro models. Compared to animal models, in vitro models can provide great opportunities to obtain data more efficiently, economically. Therefore, this review discusses the recent progress in in vitro models for atherosclerosis studies, including traditional two-dimensional (2D) systems cultured on the tissue culture plate, 2D cell sheets, and recently emerged microfluidic chip models with 2D culture. In addition, advanced in vitro three-dimensional models such as spheroids, cell-laden hydrogel constructs, tissue-engineered blood vessels, and vessel-on-a-chip will also be covered. Moreover, the functions of these models are also summarized along with model discussion. Lastly, the future perspectives of this field are discussed.

Novel Mechanisms of Exosome-Mediated Phagocytosis of Dead Cells in Injured Heart

[Figure: see text].

[Comparison of three kinds of free flaps used in patients with oral and oropharyngeal tumors]

Objective: To compare the recovery and quality of life of patients with oral and oropharyngeal tumors treated with three kinds of free soft tissue flaps. Methods: The clinical data of 103 patients, including 66 males and 37 females, aged 26-74 years, who underwent primary repair of defects after resection of oral and oropharyngeal tumors in Sichuan Tumor Hospital from July 2014 to August 2020 were analyzed. Anterolateral thigh flap (ALTF) was used in 43 patients, radial forearm free flap (RFFF) in 45 patients, and lateral arm free flap (LAFF) in 15 patients. Postoperative qualities of life of patients were evaluated by the university of Washington quality of life questionnaire and oral health impact scale (HIP-14 Chinese edition). SPSS 23.0 software was used for statistical analysis. Results: The T staging of RFFF or LAFF group was significantly lower than that of ALTF group (P<0.05). There was no significant difference in mean flap areas between ALTF group ((55.87±27.38) cm²) and LAFF group ((49.93±19.44) cm²), while RFFF group had smaller mean flap area ((33.18±6.05) cm²) than ALTF group (t=5.311, P<0.001) and LAFF group (t=3.284, P=0.005). In terms of oral functions including swallowing, mastication, taste and spitmouth, there were no significant differences between LAFF group and RFFF group (P>0.05), but both groups had better oral functions than ALTF group (P<0.05). There was no significant difference in appearance scores between LAFF group (75(75, 75)) and ALTF group (75(75,75) vs.75(75,75),Z=-1.532, P=0.126), and both groups had higher scores than RFFF group (50(50, 75),Z values were -3.447 and -3.005 respectively, P<0.05). RFFF group had higher speech score (100(67, 100)) than LAFF group (67(50, 76),Z=-2.480, P<0.05) and ALTF group (67(33, 67),Z=-5.414, P<0.05). ALTF group had lower mean score of quality of life than RFFF group [72(56,77) vs.79(69, 89),Z=-3.070, P<0.05), but there was no statistical difference in the mean scores of qualities of life between ALTF group and LAFF group (Z=1.754, P=0.079). According to the evaluation of oral health impact scale (HIP-14 Chinese version) 1 year after surgery, individual item scores and the average score of all items in ALTF group were lower than those in RFFF and LAFF groups (P<0.05), with no significant difference between RFFF group and LAFF group (P>0.05). Conclusions: RFFF has unique advantages for small tissue defects, while ALTF is suitable for large tissue defects, such as buccal penetrating defect, whole tongue and near whole tongue defect, and LAFF is a compromise choice between ALTF and RFFF. ALTF is inferior to RFFF and LAFF in oral functional reconstruction, including swallowing, chewing, taste and spittle. ALTF and LAFF are superior to RFFF in postoperative appearance.

Functional Inhibition of Valosin-Containing Protein Induces Cardiac Dilation and Dysfunction in a New Dominant-Negative Transgenic Mouse Model

Valosin-containing protein (VCP) was found to play a vital protective role against cardiac stresses. Genetic mutations of VCP are associated with human dilated cardiomyopathy. However, the essential role of VCP in the heart during the physiological condition remains unknown since the VCP knockout in mice is embryonically lethal. We generated a cardiac-specific dominant-negative VCP transgenic (DN-VCP TG) mouse to determine the effects of impaired VCP activity on the heart. Using echocardiography, we showed that cardiac-specific overexpression of DN-VCP induced a remarkable cardiac dilation and progressively declined cardiac function during the aging transition. Mechanistically, DN-VCP did not affect the endogenous VCP (EN-VCP) expression but significantly reduced cardiac ATPase activity in the DN-VCP TG mouse hearts, indicating a functional inhibition. DN-VCP significantly impaired the aging-related cytoplasmic/nuclear shuffling of EN-VCP and its co-factors in the heart tissues and interrupted the balance of the VCP-cofactors interaction between the activating co-factors, ubiquitin fusion degradation protein 1 (UFD-1)/nuclear protein localization protein 4 (NPL-4) complex, and its inhibiting co-factor P47, leading to the binding preference with the inhibitory co-factor, resulting in functional repression of VCP. This DN-VCP TG mouse provides a unique functional-inactivation model for investigating VCP in the heart in physiological and pathological conditions.

Deletion of PRAK Mitigates the Mitochondria Function and Suppresses Insulin Signaling in C2C12 Myoblasts Exposed to High Glucose

Background: p38 regulated/activated protein kinase (PRAK) plays a crucial role in modulating cell death and survival. However, the role of PRAK in the regulation of metabolic stress remains unclear. We examined the effects of PRAK on cell survival and mitochondrial function in C2C12 myoblasts in response to high glucose stresses.

Methods: PRAK of C2C12 myoblasts was knocked out by using CRISPR/Cas-9 genome editing technology. Both wild type and PRAK^−/− C2C12 cells were exposed to high glucose at the concentration of 30 mmol/L to induce metabolic stress. The effect of irisin, an adipomyokine, on both wild type and PRAK^−/− cells was determined to explore its relationship with RPAK. Cell viability, ATP product, glucose uptake, mitochondrial damage, and insulin signaling were assessed.

Results: PRAK knockout decreased C2C12 viability in response to high glucose stress as evident by MTT assay in association with the reduction of ATP and glucose uptake. PRAK knockout enhanced apoptosis of C2C12 myoblasts in response to high glucose, consistent with an impairment in mitochondrial function, by decreasing mitochondrial membrane potential. PRAK knockout induced impairment of mitochondrial and cell damage were rescued by irisin. PRAK knockout caused decrease in phosphorylated PI3 kinase at Tyr 485, IRS-1 and AMPKα and but did not affect non-phosphorylated PI3 kinase, IRS-1 and AMPKα signaling. High glucose caused the further reduction of phosphorylated PI3 kinase, IRS-1 and AMPKα. Irisin treatment preserved phosphorylated PI3 kinase, IRS-1by rescuing PRAK in high glucose treatment.

Conclusion: Our finding indicates a pivotal role of PRAK in preserving cellular survival, mitochondrial function, and high glucose stress.

Extracellular vesicles in cardiovascular disease: Biological functions and therapeutic implications

Extracellular vesicles (EVs), including exosomes and microvesicles, are lipid bilayer particles naturally released from the cell. While exosomes are formed as intraluminal vesicles (ILVs) of the multivesicular endosomes (MVEs) and released to extracellular space upon MVE-plasma membrane fusion, microvesicles are generated through direct outward budding of the plasma membrane. Exosomes and microvesicles have same membrane orientation, different yet overlapping sizes; their cargo contents are selectively packed and dependent on the source cell type and functional state. Both exosomes and microvesicles can transfer bioactive RNAs, proteins, lipids, and metabolites from donor to recipient cells and influence the biological properties of the latter. Over the last decade, their potential roles as effective inter-tissue communicators in cardiovascular physiology and pathology have been increasingly appreciated. In addition, EVs are attractive sources of biomarkers for the diagnosis and prognosis of diseases, because they acquire their complex cargoes through cellular processes intimately linked to disease pathogenesis. Furthermore, EVs obtained from various stem/progenitor cell populations have been tested as cell-free therapy in various preclinical models of cardiovascular diseases and demonstrate unequivocally encouraging benefits. Here we summarize the findings from recent research on the biological functions of EVs in the ischemic heart disease and heart failure, and their potential as novel diagnostic biomarkers and therapeutic opportunities.

Effects of feed with different protein digestion kinetic profiles on intestinal health of growing pigs

This study evaluated the effects of feed ingredients with different protein digestion kinetic profiles on the intestinal health of growing pigs. Two protein sources were selected, namely casein (CAS) as a rapid release source of amino acids (AAs), and corn gluten meal (CGM) as a slow-release source. Twenty-four crossbred barrows (Duroc × Landrace × Yorkshire) with similar bodyweight (43.27 ± 3.51 kg) were selected and randomly assigned to four treatments with six barrows. These consisted of T1: 13.2% digestible crude protein (CP) with supplemental CAS; T2: 13.2% digestible CP with supplemental CGM; T3: 11.2% digestible CP with supplemental CAS (T3); and T4: 11.2% digestible CP with supplemental CGM. Diets with CGM had increased crypt depth in the duodenum, jejunum, and ileum and reduced villi height in the jejunum in comparison with CAS. They also had increased intestinal permeability, as seen by the high level of serum diamine oxidase (DAO) compared with CAS. The diets with CAS increased health-promoting Lactobacillus and decreased health-threatening Treponema compared with those fed CGM diets. The CAS diets had a positive effect on gut functions with increased villi height, decreased crypt depth and high villi height/crypt depth. Thus, use of CAS in diets for pigs is favoured over CGM.

microRNA-377 Signaling Modulates Anticancer Drug-Induced Cardiotoxicity in Mice

Doxorubicin (DOX, an anthracycline) is a widely used chemotherapy agent against various forms of cancer; however, it is also known to induce dose-dependent cardiotoxicity leading to adverse complications. Investigating the underlying molecular mechanisms and strategies to limit DOX-induced cardiotoxicity might have potential clinical implications. Our previous study has shown that expression of microRNA-377 (miR-377) increases in cardiomyocytes (CMs) after cardiac ischemia-reperfusion injury in mice, but its specific role in DOX-induced cardiotoxicity has not been elucidated. In the present study, we investigated the effect of anti-miR-377 on DOX-induced cardiac cell death, remodeling, and dysfunction. We evaluated the role of miR-377 in CM apoptosis, its target analysis by RNA sequencing, and we tested the effect of AAV9-anti-miR-377 on DOX-induced cardiotoxicity and mortality. DOX administration in mice increases miR-377 expression in the myocardium. miR-377 inhibition in cardiomyocyte cell line protects against DOX-induced cell death and oxidative stress. Furthermore, RNA sequencing and Gene Ontology (GO) analysis revealed alterations in a number of cell death/survival genes. Intriguingly, we observed accelerated mortality and enhanced myocardial remodeling in the mice pretreated with AAV9-anti-miR-377 followed by DOX administration as compared to the AAV9-scrambled-control-pretreated mice. Taken together, our data suggest that in vitro miR-377 inhibition protects against DOX-induced cardiomyocyte cell death. On the contrary, in vivo administration of AAV9-anti-miR-377 increases mortality in DOX-treated mice.

Abstract P374: Functional Impairment Of Cardiac Endothelial Cells In Diabetic Failing Heart Via Dysregulated Exosomal Mirnas

Introduction: Cardiac endothelial cells (ECs) and fibroblasts (FBs) together maintain cardiac homeostasis. Their functional impairment aggravates complications in the heart. In diabetes, acute inflammation leads to cardiac FBs activation, which predisposes the diabetic myocardium to severe fibrosis. Further, inflammation-related vascular dysfunction is a major end-organ complication in diabetics. However, it is not known, whether myofibroblast regulates ECs function in a diseased diabetic heart. Therefore, we hypothesized that “myofibroblast in diabetic heart secretes exosomes packed with antiangiogenic/profibrotic factors, which impede EC function and exaggerate pathological remodelling in pressure-overloaded (PO) myocardium.

Methods: Exosomes were isolated from diabetic mice plasma and FB condition media by ultracentrifugation and characterized by nanosight & electron microscopy. We cultured mouse primary heart ECs in growth media and treated with exosomes derived from FBs (treated with 25mM glucose or 500nM Angiotensin II (AngII) or both) for 48 hr. Mannitol (25mM) served as control.

Results: Ang II and glucose significantly activate FBs as shown by qPCR (fibronectin, collagenase1α1) and western blot (pSmad2, p-p38). Exosomes derived from diabetic Ang II treated FBs significantly impaired ECs function as shown by Matrigel tube formation and Boyden chamber migration assays. Interestingly, ECs markers (eNOS, VEGF, CD31) genes and proteins expression were significantly inhibited in ECs treated with exosomes-derived from glucose and Ang II treated FBs. We, further, checked the effect of diabetic mice plasma exosomes on ECs function and found significantly impaired as shown by tube formation and migration data. Finally, microRNA (miR) array and qPCR analysis revealed that miR-216a-5p, miR-26a-5p and miR7a-5p were highly upregulated in exosomes derived from FBs co-treated with glucose and AngII.

Conclusions: Taken together, this study demonstrates that glucose and AngII co-treated FBs-derived exosomes are enriched in pro-fibrotic factors and can lead to EC dysfunction and promotes cardiac fibrosis in PO myocardium. In future studies, we will modulate the target miRs in diabetic FBs to see whether it rescue reparative function of ECs and inhibits fibrosis in failing heart.

Ablation of Sam68 in adult mice increases thermogenesis and energy expenditure

Genetic deletion of Src associated in mitosis of 68kDa (Sam68), a pleiotropic adaptor protein prevents high-fat diet-induced weight gain and insulin resistance. To clarify the role of Sam68 in energy metabolism in the adult stage, we generated an inducible Sam68 knockout mice. Knockout of Sam68 was induced at the age of 7-10 weeks, and then we examined the metabolic profiles of the mice. Sam68 knockout mice gained less body weight over time and at 34 or 36 weeks old, had smaller fat mass without changes in food intake and absorption efficiency. Deletion of Sam68 in mice elevated thermogenesis, increased energy expenditure, and attenuated core-temperature drop during acute cold exposure. Furthermore, we examined younger Sam68 knockout mice at 11 weeks old before their body weights deviate, and confirmed increased energy expenditure and thermogenic gene program. Thus, Sam68 is essential for the control of adipose thermogenesis and energy homeostasis in the adult.

Ablation of lncRNA Miat attenuates pathological hypertrophy and heart failure

Rationale: The conserved long non-coding RNA (lncRNA) myocardial infarction associate transcript (Miat) was identified for its multiple single-nucleotide polymorphisms that are strongly associated with susceptibility to MI, but its role in cardiovascular biology remains elusive. Here we investigated whether Miat regulates cardiac response to pathological hypertrophic stimuli. Methods: Both an angiotensin II (Ang II) infusion model and a transverse aortic constriction (TAC) model were used in adult WT and Miat-null knockout (Miat-KO) mice to induce pathological cardiac hypertrophy. Heart structure and function were evaluated by echocardiography and histological assessments. Gene expression in the heart was evaluated by RNA sequencing (RNA-seq), quantitative real-time RT-PCR (qRT-PCR), and Western blotting. Primary WT and Miat-KO mouse cardiomyocytes were isolated and used in Ca²⁺ transient and contractility measurements. Results: Continuous Ang II infusion for 4 weeks induced concentric hypertrophy in WT mice, but to a lesser extent in Miat-KO mice. Surgical TAC for 6 weeks resulted in decreased systolic function and heart failure in WT mice but not in Miat-KO mice. In both models, Miat-KO mice displayed reduced heart-weight to tibia-length ratio, cardiomyocyte cross-sectional area, cardiomyocyte apoptosis, and cardiac interstitial fibrosis and a better-preserved capillary density, as compared to WT mice. In addition, Ang II treatment led to significantly reduced mRNA and protein expression of the Ca²⁺ cycling genes Sarcoplasmic/endoplasmic reticulum Ca²⁺ ATPase 2a (SERCA2a) and ryanodine receptor 2 (RyR2) and a dramatic increase in global RNA splicing events in the left ventricle (LV) of WT mice, and these changes were largely blunted in Miat-KO mice. Consistently, cardiomyocytes isolated from Miat-KO mice demonstrated more efficient Ca²⁺ cycling and greater contractility. Conclusions: Ablation of Miat attenuates pathological hypertrophy and heart failure, in part, by enhancing cardiomyocyte contractility.

Sam68 promotes hepatic gluconeogenesis via CRTC2

Hepatic gluconeogenesis is essential for glucose homeostasis and also a therapeutic target for type 2 diabetes, but its mechanism is incompletely understood. Here, we report that Sam68, an RNA-binding adaptor protein and Src kinase substrate, is a novel regulator of hepatic gluconeogenesis. Both global and hepatic deletions of Sam68 significantly reduce blood glucose levels and the glucagon-induced expression of gluconeogenic genes. Protein, but not mRNA, levels of CRTC2, a crucial transcriptional regulator of gluconeogenesis, are >50% lower in Sam68-deficient hepatocytes than in wild-type hepatocytes. Sam68 interacts with CRTC2 and reduces CRTC2 ubiquitination. However, truncated mutants of Sam68 that lack the C- (Sam68^ΔC) or N-terminal (Sam68^ΔN) domains fails to bind CRTC2 or to stabilize CRTC2 protein, respectively, and transgenic Sam68^ΔN mice recapitulate the blood-glucose and gluconeogenesis profile of Sam68-deficient mice. Hepatic Sam68 expression is also upregulated in patients with diabetes and in two diabetic mouse models, while hepatocyte-specific Sam68 deficiencies alleviate diabetic hyperglycemia and improves insulin sensitivity in mice. Thus, our results identify a role for Sam68 in hepatic gluconeogenesis, and Sam68 may represent a therapeutic target for diabetes.

Hepatic gluconeogenesis is important for glucose homeostasis and a therapeutic target for type 2 diabetes. Here, the authors show that the RNA-binding adaptor protein Sam68 promotes the expression level of gluconeogenic genes and increases blood glucose levels by stabilizing the transcriptional coactivator CRTC2, while hepatic Sam68 deletion alleviates hyperglycemia in mice.

MiR-21-5p in macrophage-derived extracellular vesicles affects podocyte pyroptosis in diabetic nephropathy by regulating A20

OBJECTIVES

Podocyte pyroptosis, characterized by inflammasome activation, plays an important role in inflammation-mediated diabetic nephropathy (DN). Our study aimed to investigate whether miR-21-5p in macrophage-derived extracellular vesicles (EVs) could affect podocyte injury in DN.

METHODS

EVs were extracted after the treatment of RAW 264.7 (mouse macrophage line) with high glucose (HG). The podocyte pyroptosis was determined using the flow cytometry and the western blot. After the knockdown of miR-21-5p in HG-induced RAW264.7 cells, we injected the extracted EVs into DN model mice.

RESULTS

The level of miR-21-5p was higher in HG-stimulated macrophage-derived EVs than in normal glucose-cultured macrophage-derived EVs. The co-culture of EVs and podocytes promoted reactive oxygen species (ROS) production and activation of inflammatory in MPC5 cells (mouse podocyte line). However, restraint of miR-21-5p in EVs reduced ROS production and inhibit inflammasome activation in MPC5 cells, thereby reducing podocytes injury. Meanwhile, we found that miR-21-5p inhibited the A20 expression through binding with its 3'-untranslated regions in MPC5 cells. Further studies showed that A20 was also involved in the regulation of miR-21-5p of RAW 264.7-derived EVs on MPC5 injury. At the same time, it was also proved in the DN model mice that miR-21-5p in macrophage-derived EVs could regulate podocyte injury.

CONCLUSION

MiR-21-5p in macrophage-derived EVs can regulate pyroptosis-mediated podocyte injury by A20 in DN.

Visualization and Identification of Bioorthogonally Labeled Exosome Proteins Following Systemic Administration in Mice

Exosomes transport biologically active cargo (e.g., proteins and microRNA) between cells, including many of the paracrine factors that mediate the beneficial effects associated with stem-cell therapy. Stem cell derived exosomes, in particular mesenchymal stem cells (MSCs), have been shown previously to largely replicate the therapeutic activity associated with the cells themselves, which suggests that exosomes may be a useful cell-free alternative for the treatment of cardiovascular disorders. However, the mechanisms that govern how exosomes home to damaged cells and tissues or the uptake and distribution of exosomal cargo are poorly characterized, because techniques for distinguishing between exosomal proteins and proteins in the targeted tissues are lacking. Here, we report the development of an in vivo model that enabled the visualization, tracking, and quantification of proteins from systemically administered MSC exosomes. The model uses bioorthogonal chemistry and cell-selective metabolic labeling to incorporate the non-canonical amino acid azidonorleucine (ANL) into the MSC proteome. ANL incorporation is facilitated via expression of a mutant (L274G) methionyl-tRNA-synthetase (MetRS^∗) and subsequent incubation with ANL-supplemented media; after which ANL can be covalently linked to alkyne-conjugated reagents (e.g., dyes and resins) via click chemistry. Our results demonstrate that when the exosomes produced by ANL-treated, MetRS^∗-expressing MSCs were systemically administered to mice, the ANL-labeled exosomal proteins could be accurately and reliably identified, isolated, and quantified from a variety of mouse organs, and that myocardial infarction (MI) both increased the abundance of exosomal proteins and redistributed a number of them from the membrane fraction of intact hearts to the cytosol of cells in infarcted hearts. Additionally, we found that Desmoglein-1c is enriched in MSC exosomes and taken up by ischemic myocardium. Collectively, our results indicate that this newly developed bioorthogonal system can provide crucial insights into exosome homing, as well as the uptake and biodistribution of exosomal proteins.

Calcium Dobesilate (CaD) Attenuates High Glucose and High Lipid-Induced Impairment of Sarcoplasmic Reticulum Calcium Handling in Cardiomyocytes

Calcium dobesilate (CaD) is used effectively in patients with diabetic microvascular disorder, retinopathy, and nephropathy. Here we sought to determine whether it has an effect on cardiomyocytes calcium mishandling that is characteristic of diabetic cardiomyopathy. Cardiomyocytes were sterile isolated and cultured from 1 to 3 days neonatal rats and treated with vehicle (Control), 25 mM glucose+300 μM Palmitic acid (HG+PA), 100 μM CaD (CaD), or HG+PA+CaD to test the effects on calcium signaling (Ca²⁺ sparks, transients, and SR loads) and reactive oxygen species (ROS) production by confocal imaging. Compared to Control, HG+PA treatment significantly reduced field stimulation-induced calcium transient amplitudes (2.22 ± 0.19 vs. 3.56 ± 0.21, p < 0.01) and the levels of caffeine-induced calcium transients (3.19 ± 0.14 vs. 3.72 ± 0.15, p < 0.01), however significantly increased spontaneous Ca²⁺ sparks firing levels in single cardiomyocytes (spontaneous frequency 2.65 ± 0.23 vs. 1.72 ± 0.12, p < 0.01) and ROS production (67.12 ± 4.4 vs. 47.65 ± 2.12, p < 0.05), which suggest that HG+PA treatment increases the Spontaneity Ca²⁺ spark frequency, and then induced partial reduction of SR Ca²⁺ content and subsequently weaken systolic Ca²⁺ transient in cardiomyocyte. Remarkably, these impairments in calcium signaling and ROS production were largely prevented by pre-treatment of the cells with CaD. Therefore, CaD may contribute to a good protective effect on patients with calcium mishandling and contractile dysfunction in cardiomyocytes associated with diabetic cardiomyopathy.

Novel genomic targets of valosin-containing protein in protecting pathological cardiac hypertrophy

Pressure overload-induced cardiac hypertrophy, such as that caused by hypertension, is a key risk factor for heart failure. However, the underlying molecular mechanisms remain largely unknown. We previously reported that the valosin-containing protein (VCP), an ATPase-associated protein newly identified in the heart, acts as a significant mediator of cardiac protection against pressure overload-induced pathological cardiac hypertrophy. Still, the underlying molecular basis for the protection is unclear. This study used a cardiac-specific VCP transgenic mouse model to understand the transcriptomic alterations induced by VCP under the cardiac stress caused by pressure overload. Using RNA sequencing and comprehensive bioinformatic analysis, we found that overexpression of the VCP in the heart was able to normalize the pressure overload-stimulated hypertrophic signals by activating G protein-coupled receptors, particularly, the olfactory receptor family, and inhibiting the transcription factor controlling cell proliferation and differentiation. Moreover, VCP overexpression restored pro-survival signaling through regulating alternative splicing alterations of mitochondrial genes. Together, our study revealed a novel molecular regulation mediated by VCP under pressure overload that may bring new insight into the mechanisms involved in protecting against hypertensive heart failure.

Analysis of mesenchymal stem cell proteomes in situ in the ischemic heart

Rationale: Cell therapy for myocardial infarction is promising but largely unsuccessful in part due to a lack of mechanistic understanding. Techniques enabling identification of stem cell-specific proteomes in situ in the injured heart may shed light on how the administered cells respond to the injured microenvironment and exert reparative effects.

Objective: To identify the proteomes of the transplanted mesenchymal stem cells (MSCs) in the infarcted myocardium, we sought to target a mutant methionyl-tRNA synthetase (MetRS^L274G) in MSCs, which charges azidonorleucine (ANL), a methionine analogue and non-canonical amino acid, to tRNA and subsequently to nascent proteins, permitting isolation of ANL-labeled MSC proteomes from ischemic hearts by ANL-alkyne based click reaction.

Methods and Results: Murine MSCs were transduced with lentivirus MetRS^L274G and supplemented with ANL; the ANL-tagged nascent proteins were visualized by bio-orthogonal non-canonical amino-acid tagging, spanning all molecular weights and by fluorescent non-canonical amino-acid tagging, displaying strong fluorescent signal. Then, the MetRS^L274G-transduced MSCs were administered to the infarcted or Sham heart in mice receiving ANL treatment. The MSC proteomes were isolated from the left ventricular protein lysates by click reaction at days 1, 3, and 7 after cell administration, identified by LC/MS. Among all identified proteins (in Sham and MI hearts, three time-points each), 648 were shared by all 6 groups, accounting for 82±5% of total proteins in each group, and enriched under mitochondrion, extracellular exosomes, oxidation-reduction process and poly(A) RNA binding. Notably, 26, 110 and 65 proteins were significantly up-regulated and 11, 28 and 19 proteins were down-regulated in the infarcted vs. Sham heart at the three time-points, respectively; these proteins are pronounced in the GO terms of extracellular matrix organization, response to stress and regulation of apoptotic process and in the KEGG pathways of complements and coagulation cascades, apoptosis, and regulators of actin cytoskeleton.

Conclusions: MetRS^L274G expression allows successful identification of MSC-specific nascent proteins in the infarcted hearts, which reflect the functional states, adaptive response, and reparative effects of MSCs that may be leveraged to improve cardiac repair.

Abstract 362: Role of Dysregulated Exosomal MiRNAs in Functional Impairment of Cardiac Endothelial Cells

Objective: Endothelial cells (ECs) play critical role to maintain the normal heart function. It is shown that fibroblast-derived exosomes have the ability to enhance cardiac myocytes hypertrophy in pressure-overloaded myocardium. However, their effect on endothelial cell function has not been studied. Others and we have previously shown that stress-induced chronic inflammation induces cardiac fibroblasts and mediates endothelial cells dysfunction. Here we hypothesized that activated cardiac fibroblasts-derived exosomes (FB-Exo) mediates cardiac ECs dysfunction and leads for cardiac pathology and restoring the altered FB-Exo contents will improve endothelial cells function and biology.

Methods: We cultured mouse primary endothelial cells in EC growth media. Cells were treated with fibroblasts-derived-Exo. Exosomes were isolated from fibroblast condition media by ultracentrifugation and characterized by nanosight & electron microscopy.

Results: Fibroblasts were significantly activated by TGFβ treatment as shown by qPCR and western blot (smad2/3, p-Smad2/3, p38, p-p38) data. Endothelial cells dysfunction as shown by Matrigel assay, real-time Q-PCR and western data (eNOS and Hif1α) data was observed in TGFβ-FB-Exo treatment endothelial cell. MTT, TUNEL and migration assay also followed the same trend as TGFβ-FB-Exo treatment significantly induced endothelial cell death and inhibits its proliferation and migration. Furthermore, microRNA array and PCR analysis revealed dysregulation of miR-132-3p, miR-2001-3p and miR-125b-5p in TGFβ-FB-Exo treated endothelial cells.

Conclusions: Taken together, this study demonstrates that TGFβ treated fibroblasts-derived exosomes are enriched in pro-fibrotic factors and can lead to endothelial dysfunction and promotes cardiac fibrosis in PO myocardium. In future study, we will modulate the target miRs in fibroblasts to see whether it rescue reparative function of endothelial cell and inhibits cardiac fibrosis in failing heart.

Abstract 523: Analysis of Mesenchymal Stem Cell Proteomes In Situ in the Ischemic Heart

Cell therapy for myocardial infarction is promising but largely unsuccessful partially due to a lack of mechanistic understanding. Techniques enabling identification of stem cell-specific proteomes in situ in the injured heart may shed light on how the administered cells respond to the injured microenvironment and exert reparative effects. To identify the proteomes of the transplanted mesenchymal stem cells (MSCs) in the infarcted myocardium, we sought to engineer a mutant methionyl-tRNA synthetase (MetRS L274G ) in MSC, which charges the methionine analogue azidonorleucine (ANL) to tRNA and subsequently to nascent proteins, permitting isolation of ANL-labeled MSC proteomes from ischemic hearts by ANL-alkyne based click reaction. Murine MSCs were transduced with lentivirus MetRS L274G and supplemented with ANL; the ANL-tagged nascent proteins were visualized by bio-orthogonal non-canonical amino-acid tagging, spanning all molecular weights and by fluorescent non-canonical amino-acid tagging, displaying strong fluorescent signal. Then, the MetRS L274G -transduced MSCs were administered to the infarcted or Sham heart in mice receiving ANL treatment. The MSC proteomes were isolated from the left ventricle by click reaction at days 1, 3, and 7 after cell administration, identified by LC/MS. Among all identified proteins (in Sham and MI hearts, three time-points each), 648 were shared by all 6 groups, accounting for 82±5% of total proteins in each group, and their GO terms are enriched under mitochondrion, extracellular exosomes, oxidation-reduction process and poly(A) RNA binding. Notably, 35, 131 and 84 proteins were significantly up-regulated and 12, 38 and 27 proteins were down-regulated in the infarcted vs. Sham heart at the three time-points, respectively; these proteins are pronounced in the GO terms of extracellular microvesicles, inflammatory response and apoptosis and in the KEGG pathways of complements and coagulation cascades, lysosomes, and regulators of actin cytoskeleton. MetRS L274G expression allows successful identification of MSC-specific nascent proteins in the infarcted hearts, which reflect the functional states, adaptive response, and reparative effects of MSCs that may be leveraged to improve cardiac repair.

Genomic characterization reveals novel mechanisms underlying the valosin-containing protein-mediated cardiac protection against heart failure

Chronic hypertension is a key risk factor for heart failure. However, the underlying molecular mechanisms are not fully understood. Our previous studies found that the valosin-containing protein (VCP), an ATPase-associated protein, was significantly decreased in the hypertensive heart tissues. In this study, we tested the hypothesis that restoration of VCP protected the heart against pressure overload-induced heart failure. With a cardiac-specific transgenic (TG) mouse model, we showed that a moderate increase of VCP was able to attenuate chronic pressure overload-induced maladaptive cardiac hypertrophy and dysfunction. RNA sequencing and a comprehensive bioinformatic analysis further demonstrated that overexpression of VCP in the heart normalized the pressure overload-stimulated hypertrophic signals and repressed the stress-induced inflammatory response. In addition, VCP overexpression promoted cell survival by enhancing the mitochondria resistance to the oxidative stress via activating the Rictor-mediated-gene networks. VCP was also found to be involved in the regulation of the alternative splicing and differential isoform expression for some genes that are related to ATP production and protein synthesis by interacting with long no-coding RNAs and histone deacetylases, indicating a novel epigenetic regulation of VCP in integrating coding and noncoding genomic network in the stressed heart. In summary, our study demonstrated that the rescuing of a deficient VCP in the heart could prevent pressure overload-induced heart failure by rectifying cardiac hypertrophic and inflammatory signaling and enhancing the cardiac resistance to oxidative stress, which brought in novel insights into the understanding of the mechanism of VCP in protecting patients from hypertensive heart failure.

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Deficiency of VCP contributes to the pathogenesis of hypertensive heart failure.

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Rescue of VCP prevents stress-induced cardiac remodeling and cell death.

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VCP attenuates stress-induced inflammatory and hypertrophic signaling.

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VCP promotes cardiac resistance to oxidative stress.

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VCP mediates a novel epigenetic integrating regulation in the stressed heart.

Gender and age differences in the association between sleep characteristics and fasting glucose levels in Chinese adults

AIM

The present study examined the associations between night-time sleep duration, midday napping duration and bedtime, and fasting glucose levels, and whether or not such associations are dependent on gender and age.

METHODS

This study was a cross-sectional analysis of 172,901 adults aged≥40 years living in mainland China. Sleep duration was obtained by self-reports of bedtime at night, waking-up time the next morning and average napping duration at midday. Fasting plasma glucose (FPG)≥7.0mmol/L was defined as hyperglycaemia. Independent associations between night-time sleep duration, midday naptime duration and bedtime with hyperglycaemia were evaluated using regression models.

RESULTS

Compared with night-time sleep durations of 6-7.9h, both short (<6h) and long (≥8h) night-time sleep durations were significantly associated with an increased risk of hyperglycaemia in women [odds ratio (OR): 1.12, 95% confidence interval (CI): 1.01-1.29 and OR: 1.14, 95% CI: 1.08-1.21, respectively], and revealed a U-shaped distribution of risk in women and no significant association in men. Long midday nap durations (≥1h) were significantly but weakly associated with hyperglycaemia (OR: 1.04, 95% CI: 1.01-1.09) compared with no napping without interactions from gender or age, whereas the association between bedtime and fasting glucose levels did vary according to gender and age.

CONCLUSION

Night-time sleep duration, midday napping duration and bedtime were all independently associated with the risk of hyperglycaemia, and some of the associations between these sleep characteristics and hyperglycaemia were gender- and age-dependent.

Irisin Improves Myocardial Performance and Attenuates Insulin Resistance in Spontaneous Mutation (Leprdb ) Mice

Background

Irisin, a newly identified peptide, is critical to regulating metabolism, thermogenesis, and reducing oxidative stresses. Our recent works demonstrated that irisin protected the heart against myocardial ischemic injury and preserved the function of mitochondria. However, whether irisin preserves myocardial performance and attenuates insulin resistance in type II diabetes remains unknown.

Objective

Effects of irisin on type II diabetes-induced cardiac dysfty unction and insulin resistance in db/db mice were studied. Methods: Homozygous db/db mice (n=5/each group) for spontaneous mutation (Lepr^db) and heterozygous (heterozygous) mice (n=5/each group) for control were used to assess for cardiac performance and impairment of insulin resistance. Homozygous and heterozygous controls received a treatment with either irisin (100 mg/kg, intraperitoneal injection, every other day) or vehicle control (PBS) for 4 weeks at 16 weeks of age. Insulin tolerance test and glucose tolerance test were employed to determine insulin resistance in mice. Cardiac function was assessed by echocardiography. Metabolic features including hyperglycemia and body growth were also examined. Immunohistochemical analysis was employed to determine myocardial hypertrophy and interstitial fibrosis. Immunoblots were employed to determine the signaling pathway associated with irisin treatment.

Results

Homozygous db/db mice developed an impairment in insulin sensitivity as indicated by Insulin tolerance test (ITT), glucose tolerance test (GTT) (p<0.05 vs non-irisin treatment), hyperglycemia (p<0.05 vs heterozygous control), and hyperinsulinemia (serum insulin: 0.81 ± 0.065 ng/ml in heterozygous control vs. 8.33 ± 0.69 ng/ml in homozygous db/db control, p<0.0001), which were attenuated by the administration of irisin (serum insulin 8.32 ± 0.68 ng/ml in homozygous db/db control vs 6.56 ± 0.38 ng/ml in homozygous db/db irisin treatment, p<0.0001). Furthermore, as compared to heterozygous control, db/db mice manifested a depression in cardiac performance [ejection fraction (EF): 91.9% ± 0.44 in heterozygous control vs 79.1% ± 2.0 in homozygous db/db control, p< 0.001] in associated myocardial remodeling (cardiac fibrosis 1.89% ± 0.09 in heterozygous control vs. 5.39% ± 0.22 in homozygous db/db control, p<0.001). Notably, the depression of cardiac function in EF (79.2% ± 2.0 homozygous db/db control vs. 88.6% ± 1.9 in homozygous db/db + irisin, p<0.01) and fractional shortening (FS) (42.2% ± 1.8 in homozygous db/db control vs. 53.2% ± 2.7 in homozygous db/db+irisin, p<0.01) and remodeling were markedly attenuated by the administration of irisin. Western blotting shows that irisin treatment prevented an approximate two-fold decrease in p38 phosphorylation and increase in histone deacetylase 4 (HDAC4) in the homozygous db/db myocardium (p<0.05 vs homozygous db/db control).

Conclusion

Irisin preserves myocardial performance and insulin resistance in db/db mice, which is related to p38 phosphorylation and HDAC reduction.

Irisin counteracts high glucose and fatty acid-induced cytotoxicity by preserving the AMPK-insulin receptor signaling axis in C2C12 myoblasts

Irisin, a newly identified myokine, is critical to modulating body metabolism and biological homeostasis. However, whether irisin protects the skeletal muscles against metabolic stresses remains unknown. In this study, we determine the effect of irisin on high glucose and fatty acid-induced damages using irisin-overexpressed mouse C2C12 (irisin-C2C12) myoblasts and skeletal muscle from irisin-injected mice. Compared with empty vector-transfected control C2C12 cells, irisin overexpression resulted in a marked increase in cell viability and decrease in apoptosis under high-glucose stress. Progression of the cell cycle into the G2/M phase in the proliferative condition was also observed with irisin overexpression. Furthermore, glucose uptake, glycogen accumulation, and phosphorylation of AMPKα/insulin receptor (IR) β-subunit/Erk1/2 in response to insulin stimulation were enhanced by irisin overexpression. In irisin-C2C12 myoblasts, these responses of phosphorylation were preserved under palmitate treatment, which induced insulin resistance in the control cells. These effects of irisin were reversed by inhibiting AMPK with compound C. In addition, high glucose-induced suppression of the mitochondrial membrane potential was also prevented by irisin. Moreover, suppression of IR in irisin-C2C12 myoblasts by cotransfection of shRNA against IR also mitigated the effects of irisin while not affecting AMPKα phosphorylation. As an in vivo study, soleus muscles from irisin-injected mice showed elevated phosphorylation of AMPKα and Erk1/2 and glycogen contents. Our results indicate that irisin counteracts the stresses generated by high glucose and fatty acid levels and irisin overexpression serves as a novel approach to elicit cellular protection. Furthermore, AMPK activation is a crucial factor that regulates insulin action as a downstream target.

MitoQ regulates redox-related noncoding RNAs to preserve mitochondrial network integrity in pressure-overload heart failure

Evidence suggests that mitochondrial network integrity is impaired in cardiomyocytes from failing hearts. While oxidative stress has been implicated in heart failure (HF)-associated mitochondrial remodeling, the effect of mitochondrial-targeted antioxidants, such as mitoquinone (MitoQ), on the mitochondrial network in a model of HF (e.g., pressure overload) has not been demonstrated. Furthermore, the mechanism of this regulation is not completely understood with an emerging role for posttranscriptional regulation via long noncoding RNAs (lncRNAs). We hypothesized that MitoQ preserves mitochondrial fusion proteins (i.e., mitofusin), likely through redox-sensitive lncRNAs, leading to improved mitochondrial network integrity in failing hearts. To test this hypothesis, 8-wk-old C57BL/6J mice were subjected to ascending aortic constriction (AAC), which caused substantial left ventricular (LV) chamber remodeling and remarkable contractile dysfunction in 1 wk. Transmission electron microscopy and immunostaining revealed defective intermitochondrial and mitochondrial-sarcoplasmic reticulum ultrastructure in AAC mice compared with sham-operated animals, which was accompanied by elevated oxidative stress and suppressed mitofusin (i.e., Mfn1 and Mfn2) expression. MitoQ (1.36 mg·day-1·mouse-1, 7 consecutive days) significantly ameliorated LV dysfunction, attenuated Mfn2 downregulation, improved interorganellar contact, and increased metabolism-related gene expression. Moreover, our data revealed that MitoQ alleviated the dysregulation of an Mfn2-associated lncRNA (i.e., Plscr4). In summary, the present study supports a unique mechanism by which MitoQ improves myocardial intermitochondrial and mitochondrial-sarcoplasmic reticulum (SR) ultrastructural remodeling in HF by maintaining Mfn2 expression via regulation by an lncRNA. These findings underscore the important role of lncRNAs in the pathogenesis of HF and the potential of targeting them for effective HF treatment.NEW & NOTEWORTHY We have shown that MitoQ improves cardiac mitochondrial network integrity and mitochondrial-SR alignment in a pressure-overload mouse heart-failure model. This may be occurring partly through preventing the dysregulation of a redox-sensitive lncRNA-microRNA pair (i.e., Plscr4-miR-214) that results in an increase in mitofusin-2 expression.

Neuroendoscopic lavage for ventriculitis: Case report and literature review

BACKGROUND

Ventriculitis, one of the difficulties in neurosurgical treatment, is a significant cause of death and morbidity in patients with hydrocephalus. Neuroendoscopy is widely used in the treatment of non-communicable hydrocephalus. The advantages of neuroendoscopy may play a decisive role in the treatment of ventriculitis.

CASE REPORT AND METHODS

We report a 34-year-old male patient with refractory fever and rapid progressive disturbance of consciousness due to ventriculitis caused by intraventricle rupture in a left colliculus abscess. He received intravenous (IV) antibiotics and saline neuroendoscopic lavage (NEL) combined with septostomy and endoscopic third ventriculostomy leading to rapid recovery and remission of symptoms. We also reviewed the use of NEL for ventriculitis in PubMed from 1970 to January 20, 2019.

RESULTS

In our review, 93 cases (including the present report) were treated with NEL; 91 cases of infection subsided, and 7 patients died.

CONCLUSION

NEL may be an effective method for the treatment of ventriculitis.

Underlying Causes of Death among Adults in the United States, 2013-2017

BACKGROUND AND OBJECTIVES

Overall mortality among U.S. adults has been stable in past years; however, racial disparity influenced 10 leading causes of death or age-specific mortality in Blacks or African Americans. Unfortunately, the trends in sex- and race-adjusted age-standardized cause-specific mortality are poorly understood.

METHODS

We here aimed to identify the underlying causes of death (UCD) with sex- and race-adjusted, and age-standardized mortality that has changed in recent years. We extracted the data of UCD from the Multiple Cause of Death database of the Centers for Disease Control and Prevention (CDC). Multivariable log-linear regression models were used to estimate trends in sex- and race-adjusted, and age-standardized mortality of UCD during 2013-2017.

RESULTS

A total of 31,029,133 deaths were identified. Among the list of 113 UCDs compiled by the CDC, there were 29 UCDs exhibiting an upward trend, 33 UCDs exhibiting a downward trend and 56 UCDs with no significant trends. The 2 UCDs with the largest annual percent change were both nutrition related (annual percent change [APC] = 17.73, 95% CI [15.13-20.33] for malnutrition, and APC = 17.49, 95% CI [14.94-20.04] for Nutritional deficiencies), followed by accidental poisoning and exposure to noxious substances. The 4 UCDs with the largest decreasing APC were viral hepatitis (APC = -11.71), chronic and unspecified bronchitis (APC = -8.26), emphysema (APC = -7.11) and human immunodeficiency virus disease (APC = -7.10).

CONCLUSIONS

This study thus reports UCDs with changing mortality in recent years after sex- and race-adjustments and age-standardizations. More effort and resources should focus on understanding, preventing and controling the mortality linked to these UCDs. Continuous monitoring of mortality trends is recommended.

Convergences of Life Sciences and Engineering in Understanding and Treating Heart Failure

On March 1 and 2, 2018, the National Institutes of Health 2018 Progenitor Cell Translational Consortium, Cardiovascular Bioengineering Symposium, was held at the University of Alabama at Birmingham. Convergence of life sciences and engineering to advance the understanding and treatment of heart failure was the theme of the meeting. Over 150 attendees were present, and >40 scientists presented their latest work on engineering human functional myocardium for disease modeling, drug development, and heart failure research. The scientists, engineers, and physicians in the field of cardiovascular sciences met and discussed the most recent advances in their work and proposed future strategies for overcoming the major roadblocks of cardiovascular bioengineering and therapy. Particular emphasis was given for manipulation and using of stem/progenitor cells, biomaterials, and methods to provide molecular, chemical, and mechanical cues to cells to influence their identity and fate in vitro and in vivo. Collectively, these works are profoundly impacting and progressing toward deciphering the mechanisms and developing novel treatments for left ventricular dysfunction of failing hearts. Here, we present some important perspectives that emerged from this meeting.

Sam68 impedes the recovery of arterial injury by augmenting inflammatory response

OBJECTIVE

The role of Src-associated-in-mitosis-68-kDa (Sam68) in cardiovascular biology has not been studied. A recent report suggests that Sam68 promotes TNF-α-induced NF-κB activation in fibroblasts. Here we sought to dissect the molecular mechanism by which Sam68 regulates NF-κB signaling and its functional significance in vascular injury.

APPROACH AND RESULTS

The endothelial denudation injury was induced in the carotid artery of Sam68-null (Sam68^-/-) and WT mice. Sam68^-/- mice displayed an accelerated re-endothelialization and attenuated neointima hyperplasia, which was associated with a reduced macrophage infiltration and lowered expression of pro-inflammatory cytokines in the injured vessels. Remarkably, the ameliorated vascular remodeling was recapitulated in WT mice after receiving transplantation of bone marrow (BM) from Sam68^-/- mice, suggesting the effect was attributable to BM-derived inflammatory cells. In cultured Raw264.7 macrophages, knockdown of Sam68 resulted in a significant reduction in the TNF-α-induced expression of TNF-α, IL-1β, and IL-6 and in the level of nuclear phospho-p65, indicating attenuated NF-κB activation; and these results were confirmed in peritoneal and BM-derived macrophages of Sam68^-/- vs. WT mice. Furthermore, co-immunoprecipitation and mass-spectrometry identified Filamin A (FLNA) as a novel Sam68-interacting protein upon TNF-α treatment. Loss- and gain-of-function experiments suggest that Sam68 and FLNA are mutually dependent for NF-κB activation and pro-inflammatory cytokine expression, and that the N-terminus of Sam68 is required for TRAF2-FLNA interaction.

CONCLUSIONS

Sam68 promotes pro-inflammatory response in injured arteries and impedes recovery by interacting with FLNA to stabilize TRAF2 on the cytoskeleton and consequently potentiate NF-κB signaling.

A Defined Combination of Four Active Principles From the Danhong Injection Is Necessary and Sufficient to Accelerate EPC-Mediated Vascular Repair and Local Angiogenesis

Many compounds in Chinese medicine formulae, including Danhong injection (DHI) formulae, are capable of stimulating angiogenesis and promoting vascular repair, but their chemical basis and action mechanisms remain poorly defined. The aim of this study is to determine the minimal native chemical composition of DHI for the pro-angiogenesis activity and to evaluate its contribution from local endothelial cells (ECs) and bone marrow-derived endothelial progenitor cells (EPCs). Our study demonstrated that the action of DHI in accelerating the recovery of hindlimb blood flow in a ischemic rat model was attributable to its local CXCR4-mediated pro-angiogenesis activity in mature endothelial cells, as well as to its ability to promote the proliferation, migration, adhesion, and angiogenesis of EPCs via integrated activation of SDF-1α/CXCR4, VEGF/KDR, and eNOS/MMP-9 signal pathways. Combination experiments narrowed down the angiogenic activity into a few components in DHI. Reconstitution experiment defined that a combination of tanshinol, protocatechuic aldehyde, salvianolic acid B, and salvianolic acid C in their native proportion was necessary and sufficient for DHI's angiogenic activity. Compared with the full DHI, the minimal reconstituted four active principles had the same effects in promoting tube formation in vitro, improving perfusion and recovery of ischemic limb, and enhancing angiogenesis in ischemic mice post-hindlimb ischemia in vivo.

Abstract 288: Mitoq Regulates Redox-related Non-coding Rnas to Improve Mitochondrial Network in Pressure Overload Heart Failure

Background: Previous studies show that mitochondrial network excitability, or the propagation of ROS signals, is impaired in cardiomyocytes from failing hearts. While oxidative stress has been implicated in heart failure (HF)-associated mitochondrial network abnormality, the effect of mitochondrial-targeted antioxidant, such as mitoquinone (MitoQ), on mitochondrial network in pressure overload hearts has not been demonstrated. We hypothesize that MitoQ improves mitochondrial networks in HF via regulation of redox-related cardiac remodeling-associated non-coding RNAs.

Methods and results: To test the hypothesis, C57BL/6J mice were subjected to ascending aortic constriction (AAC) to induce left ventricular (LV) pressure overload, followed by 7 days of MitoQ treatment (2 μmol). Doppler echocardiography revealed severe LV dilation and decreased ejection fraction following AAC, which were attenuated by MitoQ. Electron microscopy and immunostaining showed that inter-mitochondrial and mitochondria-sarcoplasmic reticulum (SR) network structure were altered in HF myocardium, in parallel with reduced expression of mitofusin proteins (e.g., MFN1 and MFN2) compared to sham-operated animals. MitoQ blunted mitofusin protein downregulation and improved mitochondrial networks. Our data also identified a MitoQ-mediated mechanism of mitofusin expression in HF by ameliorating the dysregulation of redox-related cardiac remodeling-associated long non-coding RNAs and microRNAs (i.e. Plscr4-miR-214 axis).

Conclusion: The present study indicates that MitoQ improves inter-mitochondrial and mitochondrial-SR structural organization in pressure overload hearts by attenuating the dysregulation of cardiac remodeling-associated non-coding RNAs.

Danhong injection mobilizes endothelial progenitor cells to repair vascular endothelium injury via upregulating the expression of Akt, eNOS and MMP-9

BACKGROUD

Endothelial progenitor cells (EPCs) have been characterized as one of the key effectors of endothelial healing. The effect of Danhong injection (DHI), the most widely prescribed Chinese medicine for coronary heart disease (CHD), on EPCs mobilization remains unclear.

PURPOSE

We aimed to assess the effect of DHI on EPCs mobilization to repair percutaneous coronary intervention (PCI) induced vascular injury, and to investigate the characteristics and potential mechanism of DHI on EPCs mobilization.

METHOD

Forty-two patients with CHD underwent PCI and received stent implantation were enrolled in a Phase II clinical trials. All patients received routine western medical treatment after PCI, patients of DHI group received DHI in addition. The levels of CECs, cytokines (vWF, IL-6, CRP) and EPCs were analyzed at baseline, post-PCI and after treatment. To investigate the characteristics of DHI on EPCs mobilization, 12 healthy volunteers received intravenous infusion of DHI once and the other 12 received for 7 days. EPCs enumeration were done at a series of time points. At last we tested the effect of DHI and three chemical constituents of DHI (danshensu; lithospermic acid, LA; salvianolic acid D, SaD) on EPCs level and expression of Akt, eNOS and MMP-9 in bone marrow cells of myocardial infarction (MI) mice.

RESULTS

In the DHI group the angina symptoms were improved, the levels of cytokines and CECs were reduced; while EPCs population was increased after treatment. In the phase I clinical trials, EPCs counts reached a plateau phase in 9 h and maintained for more than 10 h after a single dose. After continuous administration, EPCs levels plateaued on the 3rd or 4th day, and maintain till 1 day after the withdrawal, then its levels gradually declined. DHI treatment induced a timely dependent mobilization of EPCs. DHI promoted EPCs mobilization via upregulating the expression of Akt, eNOS and MMP-9 in BM. LA and SaD have played a valuable role in EPCs mobilization.

CONCLUSION

These initial results demonstrated that DHI is effective in alleviating endothelial injury and promoting endothelial repair through enhancing EPCs mobilization and revealed the effect feature and possible mechanisms of DHI in mobilizing EPCs.

The valosin-containing protein protects the heart against pathological Ca2+ overload by modulating Ca2+ uptake proteins

Stress-induced mitochondrial calcium (Ca2+) overload is a key cellular toxic effectors and a trigger of cardiomyocyte death during cardiac ischemic injury through the opening of mitochondrial permeability transition pore (mPTP). We previously found that the valosin-containing protein (VCP), an ATPase-associated protein, protects cardiomyocytes against stress-induced death and also inhibits mPTP opening in vitro. However, the underlying molecular mechanisms are not fully understood. Here, we tested our hypothesis that VCP acts as a novel regulator of mitochondrial Ca2+ uptake proteins and resists cardiac mitochondrial Ca2+ overload by modulating mitochondrial Ca2+ homeostasis. By using a cardiac-specific transgenic (TG) mouse model in which VCP is overexpressed by 3.5 folds in the heart compared to the wild type (WT) mouse, we found that, under the pathological extra-mitochondrial Ca2+ overload, Ca2+ entry into cardiac mitochondria was reduced in VCP TG mice compared to their little-matched WT mice, subsequently preventing mPTP opening and ATP depletion under the Ca2+ challenge. Mechanistically, overexpression of VCP in the heart resulted in post-translational protein degradation of the mitochondrial Ca2+ uptake protein 1 (MICU1), an activator of the mitochondria Ca2+ uniporter (MCU) that is responsible for mitochondrial calcium uptake. Together, our results reveal a new regulatory role of VCP in cardiac mitochondrial Ca2+ homeostasis and unlock the potential mechanism by which VCP confers its cardioprotection.

p38-Regulated/activated protein kinase plays a pivotal role in protecting heart against ischemia-reperfusion injury and preserving cardiac performance

p38-Regulated/activated protein kinase (PRAK) plays a critical role in modulating cellular survival and biological function. However, the function of PRAK in the regulation of myocardial ischemic injury remains unknown. This study is aimed at determining the function of PRAK in modulating myocardial ischemia-reperfusion injury and myocardial remodeling following myocardial infarction. Hearts were isolated from adult male homozygous PRAK^-/- and wild-type mice and subjected to global ischemia-reperfusion injury in Langendorff isolated heart perfusion. PRAK^-/- mice mitigated postischemic ventricular functional recovery and decreased coronary effluent. Moreover, the infarct size in the perfused heart was significantly increased by deletion of PRAK. Western blot showed that deletion of PRAK decreased the phosphorylation of ERK1/2. Furthermore, the effect of deletion of PRAK on myocardial function and remodeling was also examined on infarcted mice in which the left anterior descending artery was ligated. Echocardiography indicated that PRAK^-/- mice had accelerated left ventricular systolic dysfunction, which was associated with increased hypertrophy in the infarcted area. Deletion of PRAK augmented interstitial fibrosis and terminal deoxynucleotidyl transferase nick-end labeling (TUNEL)-positive myocytes. Furthermore, immunostaining analysis shows that CD31-postive vascular density and α-smooth muscle actin capillary staining decreased significantly in PRAK^-/- mice. These results indicate that deletion of PRAK enhances susceptibility to myocardial ischemia-reperfusion injury, attenuates cardiac performance and angiogenesis, and increases interstitial fibrosis and apoptosis in the infarcted hearts.