MI Surgery Research Articles

Transcriptome wide changes in long noncoding RNAs in diabetic ischemic heart disease

More than 10% of adults in the United States have type 2 diabetes mellitus (DM) with a 2–4 times higher prevalence of ischemic heart disease than the non-diabetics. Despite extensive research approaches to limit this life-threatening condition have proven unsuccessful, highlighting the need for understanding underlying molecular mechanisms. Long noncoding RNAs (lncRNAs), which regulate gene expression by acting as signals, decoys, guides, or scaffolds have been implicated in diverse cardiovascular conditions. However, their role in ischemic heart disease in DM remains poorly understood. We provide new insights into the lncRNA expression profile after ischemic heart disease in DM mice. We performed unbiased RNA sequencing of well-characterized type 2 DM model db/db mice or its control db/+ subjected to sham or MI surgery. Computational analysis of the RNA sequencing of these LV tissues identified several differentially expressed lncRNAs between (db/db sham vs. db/db MI) including Gm19522 and Gm8075. lncRNA Gm-19522 may regulate DNA replication via DNA protein kinases, while lncRNA Gm-8075 is associated with cancer gene dysregulation and PI3K/Akt pathways. Thus, the downregulation of lncRNAs Gm19522 and Gm8075 post-MI may serve as potential biomarkers or novel therapeutic targets to improve cardiac repair/recovery in diabetic ischemic heart disease.

RING finger protein 5 protects against acute myocardial infarction by inhibiting ASK1

BackgroundMyocardial infarction (MI) is a major disease with high morbidity and mortality worldwide. However, existing treatments are far from satisfactory, making the exploration of potent molecular targets more imperative. The E3 ubiquitin ligase RING finger protein 5 (RNF5) has been previously reported to be involved in several diseases by regulating ubiquitination-mediated protein degradation. Nevertheless, few reports have focused on its function in cardiovascular diseases, including MI.MethodsIn this study, we established RNF5 knockout mice through precise CRISPR-mediated genome editing and utilized left anterior descending coronary artery ligation in 9-11-week-old male C57BL/6 mice. Subsequently, serum biochemical analysis and histopathological examination of heart tissues were performed. Furthermore, we engineered adenoviruses for modulating RNF5 expression and subjected neonatal rat cardiomyocytes to oxygen-glucose deprivation (OGD) to mimic ischemic conditions, demonstrating the impact of RNF5 manipulation on cellular viability. Gene and protein expression analysis provided insights into the molecular mechanisms. Statistical methods were rigorously employed to assess the significance of experimental findings.ResultsWe found RNF5 was downregulated in infarcted heart tissue of mice and NRCMs subjected to OGD treatment. RNF5 knockout in mice resulted in exacerbated heart dysfunction, more severe inflammatory responses, and increased apoptosis after MI surgery. In vitro, RNF5 knockdown exacerbated the OGD-induced decline in cell activity, increased apoptosis, while RNF5 overexpression had the opposite effect. Mechanistically, it was proven that the kinase cascade initiated by apoptosis signal-regulating kinase 1 (ASK1) activation was closely regulated by RNF5 and mediated RNF5’s protective function during MI.ConclusionsWe demonstrated the protective effect of RNF5 on myocardial infarction and its function was dependent on inhibiting the activation of ASK1, which adds a new regulatory component to the myocardial infarction associated network and promises to enable new therapeutic strategy.

M6A reader YTHDF1 promotes cardiac fibrosis by enhancing AXL translation.

Cardiac fibrosis caused by ventricular remodeling and dysfunction such as post-myocardial infarction (MI) can lead to heart failure. RNA N6-methyladenosine (m6A) methylation has been shown to play a pivotal role in the occurrence and development of many illnesses. In investigating the biological function of the m6A reader YTHDF1 in cardiac fibrosis, adeno-associated virus 9 was used to knock down or overexpress the YTHDF1 gene in mouse hearts, and MI surgery in vivo and transforming growth factor-β (TGF-β)-activated cardiac fibroblasts in vitro were performed to establish fibrosis models. Our results demonstrated that silencing YTHDF1 in mouse hearts can significantly restore impaired cardiac function and attenuate myocardial fibrosis, whereas YTHDF1 overexpression could further enhance cardiac dysfunction and aggravate the occurrence of ventricular pathological remodeling and fibrotic development. Mechanistically, zinc finger BED-type containing 6 mediated the transcriptional function of the YTHDF1 gene promoter. YTHDF1 augmented AXL translation and activated the TGF-β-Smad2/3 signaling pathway, thereby aggravating the occurrence and development of cardiac dysfunction and myocardial fibrosis. Consistently, our data indicated that YTHDF1 was involved in activation, proliferation, and migration to participate in cardiac fibrosis in vitro. Our results revealed that YTHDF1 could serve as a potential therapeutic target for myocardial fibrosis.

LncRNA CCRR Attenuates Postmyocardial Infarction Inflammatory Response by Inhibiting the TLR Signalling Pathway

BackgroundTimely and proper suppression of inflammation can effectively reduce myocardial injury and promote the postmyocardial infarction (post-MI) wound-healing process. We have previously found that cardiac conduction regulatory RNA (CCRR), a long noncoding RNA (lncRNA) transcribed by the gene located on chromosome 9, with abundant expression in the heart, elicits antiarrhythmic effects in heart failure, and this is a continuing study on the role of CCRR in MI. MethodsCCRR was overexpressed in CCRR transgenic mice or after injection of adeno-associated virus-9 (AAV-9). MI surgery was performed, and cardiac function was assessed in vivo by echocardiography, followed by histologic analyses. Western blot analysis and qRT-PCR were performed to investigate the effects of CCRR on macrophages, cardiomyocytes, and cardiomyocytes cocultured with macrophages. Through microarray analysis and RNA-binding protein immunoprecipitation (RIP) and other related techniques were also employed to study the effects of CCRR on Toll-like receptor (TLR)2 and TLR4. ResultsWe found that CCRR level was significantly decreased with increases in proinflammatory cytokines and activation of the TLR signalling pathway in the heart of the 3-day MI mice. CCRR overexpression downregulated TLR2 and TLR4 in MI and effectively inhibited the inflammatory responses in primary cardiomyocytes and macrophages cultured under hypoxic conditions. Downregulation of CCRR induced excessive inflammatory responses by activating the TLR signalling pathway. CCRR acted by suppressing TLR2 and TLR4 to inhibit the secretion of proinflammatory factors to reduce infarct size, thereby improving cardiac function. ConclusionsCCRR protected cardiomyocytes against MI injury by suppressing inflammatory response through targeting the TLR signalling pathway.

Correlation between Heart Rate Recovery & Global Longitudinal Strain in Heart Failure Patients Subjected to Cardiac Rehabilitation

Abstract Background Cardiac rehabilitation is a medically supervised program designed to improve cardiovascular outcomes after MI, heart failure, angioplasty, or heart surgery. It is a complex intervention that involves a variety of therapies, including supervised exercise training, health education and risk factor modification, behavior change, social and psychological support. Objective To study the correlation between heart rate recovery & global longitudinal strain in heart failure patients subjected to cardiac rehabilitation. Patients and Methods This study was conducted in the cardiac rehabilitation (CR) unit in the cardiology department of Ain Shams University hospital between December 2019 and December 2020 to investigate the correlation between heart rate recovery & global longitudinal strain in heart failure patients subjected to cardiac rehabilitation. Results Our study is the first study that investigated the correlation between HRR and GLS in ischemic heart failure patients subjected to cardiac rehabilitation. Conclusion Exercise-based cardiac rehabilitation leads to improvement in the functional capacity of ischemic heart failure patients as reflected by the improvement in HRR and also leads to IMPROVEMENT in LV functions as reflected by the improvement in GLS. Moreover, METs and HR reserve was improved significantly with CR.

Abstract P2005: Mechanosensitive Piezo-1 Channel Aggravates Ischemia Induced Adverse Cardiac Remodeling And Dysfunction

Background: Mechanotransduction is a physiological process through which mechanical forces are sensed and converted to biological responses. It is fundamental for morphogenesis during early development and organ functions during adult life. An injured heart undergoes dynamic phases of structural and functional remodeling, exposing cardiac cells to the fluctuating mechanical environment. Piezo-1 (PZO1) is a recently discovered mechanosensitive ion channel with widespread physiological importance. However, its role in the pathophysiology of heart disease is not fully understood. Methods and Results: The qPCR analysis confirmed that PZO-1 expression increases in cardiomyocytes (CM) post-MI. To evaluate the role of CM-PZO1 in MI-induced adverse cardiac remodeling, conditional CM-specific PZO1 KO mice were generated using tamoxifen-inducible α-MHC promoter driven MerCreMer transgene. At 12 weeks of age, mice were subjected to a well-established tamoxifen diet protocol followed by MI surgery. Cardiac function was monitored by serial echocardiography. In the control group, EF and FS declined from 2 weeks post-MI, indicating systolic dysfunction. These changes were associated with the development of structural remodeling as reflected by a significant increase in LVIDs, HW/TL ratio, CM CSA, and hypertrophy markers (ANP, BNP). Interestingly, all these parameters were essentially normalized in CM-PZO1 KO mice, confirming that CM-specific PZO1 deletion prevents the progression of pathological hypertrophy and systolic dysfunction in MI heart. Moreover, CM-PZO1 KO displayed significant alterations in gene expression of ECM proteins such as connective tissue growth factor (CTGF), latent TGF-β binding protein 2 (LTBP2), cartilage oligomeric matrix protein (COMP), cartilage intermediate layer protein (CILP) while collagen and fibronectin levels were comparable between control and KO groups. These observations indicate a potential role of CM-PZO1 in modulating cardiac ECM and scar properties under pathological conditions. Conclusion: Our findings suggest that PZO1 serves as a key cardiac mechanotransducer under pathological condition and represent a novel therapeutic target for treating heart diseases.

Pancreatic Anastomosis in Robotic-Assisted Pancreaticoduodenectomy: Different Surgical Techniques

Robot-assisted pancreatoduodenectomy (R-PD) may provide challenges but potential benefits for pancreatic-enteric anastomosis fashioning. Despite numerous trials comparing different pancreatic-enteric anastomosis techniques, an ideal method is still missing. This study aims to describe different management strategies and surgical techniques of standardized pancreatic-enteric anastomoses during an R-PD. This study reported the robotic technical steps of the modified end-to-side Blumgart pancreaticojejunostomy, the Cattel-Warren duct-to-mucosa pancreatojejunostomy, with internal or external pancreatic duct stent, and the modified end-to-side, double-layer pancreogastrostomy. A dual-console da Vinci Xi Surgical System® (Intuitive Surgical Xi, Sunnyvale, CA) was used to perform all the R-PD. Different robotic pancreatic-enteric anastomosis techniques can be used during the reconstruction phase, possibly reproducing the open technique. The type of anastomosis and applied mitigation strategies should balance surgical strategy adaptability and operative technique standardization. R-PD should be performed in high-volume centers by surgeons with extensive experience in pancreatic and advanced MI surgery, enabling different but standardized anastomotic techniques based on patients’ risk factors and intraoperative findings. Future studies on robotic pancreatic anastomosis should focus on personalized approaches after adequate risk stratification.

Tunneling of Mesh during Ventral Rectopexy: Technical Aspects and Long-Term Functional Results

Avoiding the extensive damage of pelvic structures during ventral rectopexy could minimize secondary disfunctions. The objective of our observational study is to assess the safety and functional efficacy of a modified ventral rectopexy. In the modified ventral rectopexy, a retroperitoneal tunnel was created along the right side of rectum, connecting two peritoneal mini-incisions at the Douglas pouch and sacral promontory. The proximal edge of a polypropylene mesh, sutured over the ventral rectum, was pulled up through the retroperitoneal tunnel and fixed to the sacral promontory. In all patients, radiopaque clips were placed on the mesh, making it radiographically "visible". Before surgery and at follow up visits, Altomare, Longo, CCSS, PAC-SYM, and CCFI scores were collected. From March 2010 to September 2021, 117 patients underwent VR. Modified ventral rectopexy was performed in 65 patients, while the standard ventral rectopexy was performed in 52 patients. The open approach was used in 97 cases (55 and 42 patients in modified and standard VR, respectively), while MI surgery was used in 20 cases (10 and 10 patients in modified and standard VR, respectively). A slightly shorter operative time and hospital stay were observed following modified ventral rectopexy (though this was not statistically significant). Similar overall complication rates were registered in the modified vs. standard ventral rectopexies (4.6% vs. 5.8%, p = 0.779). At follow-up, the Longo score (14.0 ± 8.6 vs. 11.0 ± 8.2, p = 0.042) and "delta" values of Altomare (9.2 ± 6.1 vs. 5.9 ± 6.3, p = 0.008) and CCSS (8.4 ± 6.3 vs. 6.1 ± 6.1, p = 0.037) scores were significantly improved in the modified ventral rectopexy group. A similar occurrence of symptoms recurrence was diagnosed in the two groups. Radiopaque clips helped to accurately diagnose mesh detachment/dislocation. The proposed modified VR seems to be feasible and safe. Marking the mesh intraoperatively seems useful.

Hysterectomy in benign conditions: a 20-year single-center retrospective on the development of surgical techniques

IntroductionMinimally invasive (MI) surgery has long been established as a standard for hysterectomy in benign conditions. Robotic surgery is generally seen as equivalent to conventional laparoscopy in terms of patient outcome. However, robotics might facilitate an MI approach even in complex patients, rendering laparotomy unnecessary for almost all patients.Materials and methodsWe identified 1939 patients who underwent hysterectomy for benign conditions between 2002 and 2020 at the University Hospital of Essen. Peri- and postoperative data as well as patient characteristics were collected retrospectively.ResultsRobotic surgery, implemented at our institution in 2010, was the most common approach (n = 771; 39.8%). 60.2% of all hysterectomies (1168/1938) were performed using MI techniques. However, there was a significant shift in the methods used for hysterectomy over time. While in 2002 51.4% of all hysterectomies were performed via an open abdominal approach, this percentage dropped to 1.4% in the year 2020. Accordingly, the use of MI approaches increased from 18.9% in 2002 to 98.6% in 2020. The introduction of robotic surgery in 2010 marked a significant shift towards more MI procedures. MI surgery resulted in shorter hospital stay and less postoperative complications compared to laparotomy.On a special note, our cohort includes the largest uterus myomatous uterus in the scientific literature with a specimen weight of 54.8 kg.ConclusionOur data support the hypothesis that the implementation of robotic surgery leads to an improved capability to perform MI surgery and avoid laparotomy in almost all patients. The known benefits of MI surgery could be confirmed.

Dapagliflozin attenuates residual cardiac remodeling after surgical ventricular reconstruction in mice with an enlarged heart after myocardial infarction

BackgroundSevere heart failure refractory to conventional therapy requires alternative treatment modalities. Surgical ventricular reconstruction (SVR) has been used to reverse cardiac remodeling in post-myocardial infarction (MI) patients with large left ventricular (LV) aneurysm, however, residual LV remodeling and dysfunction remain postoperatively. It is unclear whether SVR recovers response to drug treatment and whether the sodium-glucose co-transporter 2 inhibitor dapagliflozin (DAPA) reverses residual LV remodeling after SVR. MethodsAdult male C57 mice were subjected to MI or sham surgery. Four-week later, MI mice with LV aneurysm underwent modified SVR or second open-chest sham operation and were randomized to DAPA or vehicle for four-week. Cardiac remodeling, LV function, and the underlying mechanisms were evaluated by echocardiography, invasive LV hemodynamic measurements, mRNA sequencing, and bioinformatics analysis. ResultsSVR significantly decreased LV volume; increased myocardial strain, LV pressure change rates and end-systolic elastance; and decreased heart-to-body weight ratio and myocardial fibrosis. However, significant residual cardiac remodeling remained. DAPA significantly attenuated residual cardiac remodeling and improved LV function in SVR mice but did not have curative effects in non-SVR mice. Of the 1532 genes differentially expressed in SVR and MI mice, 1037 were associated with cardiac metabolism; Src, Crebbp, Fn1, Grb2, and Mapk14 were the top 5 hub genes. Unlike sham surgery, MI upregulated those 5 genes, and treatment with SVR + DAPA normalized their expression. ConclusionsSVR restores therapeutic response in the post-MI heart with large LV aneurysm, and DAPA attenuates residual cardiac remodeling after SVR by normalizing some cardiac metabolism-related hub genes.

Left ventricular-aortic angle is associated with platelet reactivity in patients with aortic stenosis.

The impact of aortic stenosis on platelet reactivity is unclear. Previous studies reported contradicting results. The reason for this is unknown. It is known that flow alterations enhance platelet reactivity. A steep left ventricular-aortic angle (LV-AO-angle) is associated with turbulent flow in the aorta ascendens. Therefore, in this study, we hypothesized that LV-AO-angle is associated with platelet reactivity in patients with severe aortic stenosis. We included 289 patients with severe aortic stenosis and performed cardiac computertomography to assess the LV-AO-angle. Platelet function was evaluated by light transmission aggregometry. Platelet reactivity was higher in patients with a steep LV-AO-angle (ADP: <160°: 66.99% ± 20.72% vs. ≥160°: 60.66% ± 19.85%, P = 0.009; collagen: <160°: 78.67% ± 13.19% vs. ≥160°: 73.85% ± 14.44%, P = 0.003). Using Spearman correlation, ADP and collagen-induced aggregation was associated with LV-AO-angle (ADP: r = -0.19, P = 0.0009, R2 = 0.022; collagen: r = -0.21, P = 0.0004, R2 = 0.027). Apart from platelet reactivity, body weight, history of myocardial infarction and other factors were associated with steep LV-AO-angle. However, multivariate cox-regression (including body weight, comorbidities, history of MI and cardiac surgery, kidney function and laboratory parameters) revealed that LV-AO angle was a robust predictor of ADP and collagen-induced platelet aggregation. Steep LV-AO-angle is associated with enhanced platelet reactivity in patients with aortic stenosis. This could be the reason of contradicting results regarding platelet function in patients with aortic stenosis in previous studies. In addition, enhanced platelet reactivity in steep LV-AO-angle aortic stenosis patients might be a promising target in pathogenesis of aortic stenosis.

Abstract 14338: Mitochondria-Targeted ROS Scavenger JP4-039 Induces Coronary Angiogenesis in Ischemic Myocardium Resulting in the Improvement of Cardiac Function in Post-MI Animals

Introduction: A reduction of mitochondrial reactive oxygen species (mito-ROS) has been sought as a potential approach for recovering energy supply and improving cardiac function in cardiovascular disease. Here, we evaluated JP4-039, a mito-ROS scavenger, for post-myocardial infarction (MI) recovery. Hypothesis: We hypothesized that mitochondrial antioxidant JP4-039 will induce coronary angiogenesis and improve post-MI cardiac function in mice. Methods: FVB mice (n=8/group) underwent MI surgery and were assigned to either vehicle (sunflower seed oil) or JP4-039 group (1mg/kg, i.p., 3x/week for 4 weeks). A SHAM surgery group received vehicle only. Left ventricle (LV) ejection fraction (EF), fractional shortening (FS), and fractional area change (FAC) were assessed by echocardiography 28 days post-MI. Capillary (CD31 antibody) and arteriole density (α-SMA antibody) were quantified by immunofluorescence of ischemic heart sections 28 days post-MI. Western blot of myocardial homogenates was conducted to evaluate activation of Akt, ERK1/2, and AMPKα. Data were analyzed by One-way ANOVA and Tukey’s post-hoc, and a p value &lt;0.05 was taken as significant. Results: Mice treated with JP4-039 presented with a 35% decrease in infarction size, and a 57% increase in EF compared to the vehicle group (43.6±5.1 vs. 27.8±5.3). FS and FAC of JP4-039-treated mice increased by 65% (21.9±2.9 vs. 13.3±2.6) and 90% (38.0±5.6 vs. 20.0±4.0), respectively. In ischemic myocardium, the JP4-039 group showed an increase in capillary density of 39% in comparison to vehicle (208.6±21.7 vs 149.9±18.0). Interestingly, arteriogenesis was decreased in ischemic myocardium by 31% in JP4-039-treated mice compared to vehicle group (9.0±1.1 vs. 13.1±1.5). Although activation of Akt or ERK1/2 signaling were unchanged, p-AMPKα was decreased by 67% in JP4-039 vs. vehicle (0.39±0.07 vs. 0.65±0.03) in myocardium. Conclusions: The findings suggest that mitochondrial antioxidant JP4-039 improves capillary angiogenesis in ischemic myocardium, resulting in improved cardiac function in post-MI mice. Mechanisms involved in differential levels of capillary and arteriole densities in ischemic myocardium are being examined in human coronary ECs and will be presented at the meeting.

Abstract 10984: The Novel Curcumin Formulation, ASD-Cur Suppressed Myocardial Infarction Induced Heart Failure in Rats

Introduction: Curcumin prevents the development of heart failure, demonstrating that the compound is a potential treatment for the disease. Although curcumin is known to be safe, its therapeutic efficiency is limited due to its low bioavailability. To overcome this problem, we developed ASD-Cur, an amorphous formulation of curcumin. Hypothesis: ASD-Cur have greater therapeutic potency than Theracurmin ® , a colloidal submicron dispersion of curcumin. Methods: Male SD rats were orally administrated with ASD-Cur or Theracurmin ® (10 mg/kg curcumin). The plasma levels of curcumin were measured at 0.25, 0.5, 1, 2, 4 and 6 hours after administration. Twelve healthy volunteers, who had provided written informed consent, were administrated with ASD-Cur or Theracurmin ® containing 30 mg curcumin, and plasma curcumin concentrations were determined at 0.5, 1, 2, 4 and 8 hours. Next, the rats were subjected to MI or sham surgery. One week after surgery, the MI rats were randomly assigned to 4 groups: vehicle, ASD-Cur (0.2 mg/kg curcumin), or Theracurmin ® (0.2 or 0.5 mg/kg curcumin). Daily oral administration of these compounds was repeated for 6 weeks. After echocardiographic examination, myocardial cell diameter, perivascular fibrosis, mRNA levels, and the acetylation of histone H3K9 were measured. Results: After administration, the area under the plasma concentration-time curve (AUC 0-6h ) and the maximum plasma concentration (C max ) of ASD-Cur were 3.7-fold and 9.6-fold higher than those of Theracurmin ® , respectively. The AUC 0-8h and C max of ASD-Cur in humans were 3.4-fold and 5.4-fold higher than those of Theracurmin ® , respectively. Echocardiographic analysis showed that 0.2 mg/kg ASD-Cur and 0.5 mg/kg Theracurmin ® significantly improved both MI-induced reduction in FS and left ventricular hypertrophy to the same extent. Both treatments significantly suppressed MI-induced increases in myocardial cell diameter, perivascular fibrosis, mRNA levels of hypertrophic markers and cardiac fibrosis, and the acetylation of histone H3K9 to the same extent. Conclusions: These findings indicated that ASD-Cur has greater bioavailability than Theracurmin ® , and could have greater therapeutic potency towards MI-induced heart failure at a lower dose.

Abstract P410: A Novel Curcumin Formulation, ASD-cur Suppressed Heart Failure After Myocardial Infarction In Rats

Introduction: Curcumin prevents the development of heart failure and is a potential treatment for heart failure. Although curcumin is known to be safe, its therapeutic efficiency is limited due to its low bioavailability. To overcome this problem, we developed ASD-Cur, an amorphous formulation of curcumin. In this study, we investigated the effect of ASD-Cur and compared it with Theracurmin ® , a colloidal submicron dispersion of curcumin. Methods: Male SD rats were orally administrated with ASD-Cur or Theracurmin ® (10 mg/kg curcumin). The plasma levels of curcumin were measured at 0.25, 0.5, 1, 2, 4 and 6 hours after administration. Twelve healthy volunteers, who had provided written informed consent, were administrated with ASD-Cur and Theracurmin ® containing 30 mg curcumin, and plasma curcumin concentrations were determined at 0.5, 1, 2, 4, and 8 hours. Next, male SD rats were subjected to MI or sham surgery. One week after surgery, the MI rats were randomly assigned to 4 groups: vehicle, ASD-Cur (0.2 mg/kg curcumin) or Theracurmin ® (0.2 or 0.5 mg/kg curcumin). Oral administration of these compounds was repeated for 6 weeks. After echocardiographic examinations, myocardial cell diameter, perivascular fibrosis, mRNA levels, and the acetylation of histone H3K9 were measured. Results: After administration in rats, the area under the plasma concentration-time curve ( AUC 0-6h ) and the maximum plasma concentration ( C max ) of ASD-Cur were 3.7-fold and 9.6-fold higher than those of Theracurmin ® , respectively. The AUC 0-8h and C max of ASD-Cur in humans were 3.4-fold and 5.4-fold higher than those of Theracurmin ® , respectively. Echocardiographic analysis showed that 0.2 mg/kg ASD-Cur and 0.5 mg/kg Theracurmin ® significantly improved the MI-induced deterioration of FS and left ventricular hypertrophy to the same extent. Both treatments significantly suppressed MI-induced increases in myocardial cell diameter, perivascular fibrosis, mRNA levels of hypertrophic markers and cardiac fibrosis, and acetylation of histone H3K9 to the same extent. Conclusion: These findings indicated that ASD-Cur has greater bioavailability than Theracurmin ® , and could exhibit greater therapeutic potency towards for MI-induced heart failure at a lower dose.

Effects of selective TNFR1 inhibition or TNFR2 stimulation, compared to non-selective TNF inhibition, on (neuro)inflammation and behavior after myocardial infarction in male mice

BackgroundMyocardial infarction (MI) coinciding with depression worsens prognosis. Although Tumor Necrosis Factor alpha (TNF) is recognized to play a role in both conditions, the therapeutic potential of TNF inhibition is disappointing. TNF activates two receptors, TNFR1 and TNFR2, associated with opposite effects. Therefore, anti-inflammatory treatment with specific TNF receptor interference was compared to non-specific TNF inhibition regarding effects on heart, (neuro)inflammation, brain and behavior in mice with MI. MethodsMale C57BL/6 mice were subjected to MI or sham surgery. One hour later, MI mice were randomized to either non-specific TNF inhibition by Enbrel, specific TNFR1 antagonist-, or specific TNFR2 agonist treatment until the end of the protocol. Control sham and MI mice received saline. Behavioral evaluation was obtained day 10–14 after surgery. Eighteen days post-surgery, cardiac function was measured and mice were sacrificed. Blood and tissue samples were collected for analyses of (neuro)inflammation. ResultsMI mice displayed left ventricular dysfunction, without heart failure, (neuro) inflammation or depressive-like behavior. Both receptor-specific interventions, but not Enbrel, doubled early post-MI mortality. TNFR2 agonist treatment improved left ventricular function and caused hyper-ramification of microglia, with no effect on depressive-like behavior. In contrast, TNFR1 antagonist treatment was associated with enhanced (neuro)inflammation: more plasma eosinophils and monocytes; increased plasma Lcn2 and hippocampal microglia and astrocyte activation. Moreover, increased baseline heart rate, with reduced beta-adrenergic responsiveness indicated sympathetic activation, and coincided with reduced exploratory behavior in the open field. Enbrel did not affect neuroinflammation nor behavior. ConclusionEarly receptor interventions, but not non-specific TNF inhibition, increased mortality. Apart from this undesired effect, the general beneficial profile after TNFR2 stimulation, rather than the unfavourable effects of TNFR1 inhibition, would render TNFR2 stimulation preferable over non-specific TNF inhibition in MI with comorbid depression. However, follow-up studies regarding optimal timing and dosing are needed.

Adipolin/C1q/Tnf-related protein 12 prevents adverse cardiac remodeling after myocardial infarction.

BackgroundMyocardial infarction (MI) is a leading cause of death worldwide. We previously identified adipolin, also known as C1q/Tnf-related protein 12, as an anti-inflammatory adipokine with protective features against metabolic and vascular disorders. Here, we investigated the effect of adipolin on myocardial remodeling in a mouse model of MI.MethodsMale adipolin-knockout (APL-KO) and wild-type (WT) mice were subjected to the permanent ligation of the left anterior descending coronary artery to create MI.ResultsAPL-KO mice exhibited increased ratios of heart weight/body weight and lung weight/body weight after MI compared with WT mice. APL-KO mice showed increased left ventricular diastolic diameter and decreased fractional shortening after MI compared with WT mice. APL-KO mice exhibited increased expression of pro-inflammatory mediators and enhanced cardiomyocyte apoptosis in the post-MI hearts compared with WT mice. Systemic administration of adenoviral vectors expressing adipolin to WT mice after MI surgery improved left ventricular contractile dysfunction and reduced cardiac expression of pro-inflammatory genes. Treatment of cultured cardiomyocytes with adipolin protein reduced lipopolysaccharide-induced expression of pro-inflammatory mediators and hypoxia-induced apoptosis. Treatment with adipolin protein increased Akt phosphorylation in cardiomyocytes. Inhibition of PI3 kinase/Akt signaling reversed the anti-inflammatory and anti-apoptotic effects of adipolin in cardiomyocytes.ConclusionOur data indicate that adipolin ameliorates pathological remodeling of myocardium after MI, at least in part, by its ability to reduce myocardial inflammatory response and apoptosis.

Abstract 14834: Protective Role of Cardiomyocyte-derived Ddt in Ischemic Cardiomyopathy

Background: D-dopachrome tautomerase (DDT), the only homolog of macrophage migration inhibitory factor (MIF), is a cytokine highly expressed in cardiomyocytes and exerts autocrine-paracrine effects by signaling through the CD74 receptor. Endogenous DDT and MIF prevent acute ischemia-reperfusion injury and pressure overload-induced heart failure in mice. This study investigated whether endogenous cardiomyocyte DDT has a role in ischemic cardiomyopathy (ICM). Methods: LV tissue was obtained from patients with ICM during heart transplantation and from non-transplanted donor hearts. Plasma DDT concentrations were measured in heart failure outpatients with ICM. Cardiomyocyte-specific DDT knockout (cKO) and littermate control (CON) mice underwent MI or sham surgery. Serial echocardiography was performed to assess LV remodeling after MI or sham surgery. Tissue from the non-infarct region was analyzed 3 days and 4 weeks after MI or sham surgery for histology and molecular studies. Results: Cardiac DDT mRNA and protein expression were reduced in LV from patients transplanted for ICM (n=8). Plasma DDT concentrations below the median value were associated with worse survival in ICM outpatients (p&lt;0.05, n=32). In mice, baseline LV function was similar in DDT cKO and CON after sham surgery and 3 days post-MI. However, DDT cKO mice developed more rapid LV dilatation and decreased LV ejection fraction and stroke volume as early as 1-week post-MI (n=4-6/group, all P&lt;0.05). The DDT cKO mice had smaller cardiomyocyte cross-sectional area 4 weeks after MI (p &lt;0.05), as well as early diminished phosphorylation of mTOR and S6-kinase (3 days post-MI). They also showed increased apoptosis 3 days post-MI and an early increase in p38 MAP kinase activation. Conclusion: Cardiomyocyte-derived DDT prevents adverse cardiac remodeling in ICM, potentially through modulating mTOR/S6 kinase (adaptive hypertrophy) and p38 MAP kinase (limiting apoptosis). Down-regulation of DDT in patients with ICM may contribute to the pathogenesis of advanced heart failure.

Abstract 16007: Myeloid-specific Deletion in Lipid Phosphate Phosphatase3 (plpp3) Increases Cardiac Inflammation

Introduction and Hypothesis: Acute myocardial infarction (AMI) is the leading cause of morbidity and mortality worldwide. The innate immune response plays a major role in cardiac remodeling after AMI. Lysophosphatidic acid (LPA), produced by autotaxin (ATX) and degraded by Lipid phosphate phosphatase 3 (LPP3), regulates monocytosis and promotes inflammation. However, the role of LPP3 in post-AMI inflammation is not understood. Here, we investigated the possible role of Myeloid-specific Plpp3 KO mice in cardiac and systemic inflammation and resulting in adverse cardiac remodeling post-MI. Methods and Results: To generate mice with Myeloid-specific Plpp3 deletion , female Plpp3 fl/fl mice were crossed to male Plpp3 mice expressing Cre recombinase under the control of the LysM promoter to generate lysm-plpp3. mice. These mice and their littermate control underwent MI or sham surgery. Inflammatory cell content was assessed using flow cytometry and immunohistochemistry. Cardiac function and scar size were assessed by echocardiography and Mason Trichrome staining, respectively. Increased number of Ly6C hi monocytes (CD45 + /Ly6C/G hi /CD115 hi ) and pro-inflammatory macrophages (CD45 + /F4-80 + /CD11b + ) (CD45 + /F4-80 + /CD86 + ), in cardiac tissue of Cre+LysM mice was observed compared to Cre-fl/fl littermate controls during peak post-MI inflammation, as assessed by flow cytometry ( Fig.1A-C ). This increase in inflammatory cells and inflammation may be the consequence of the significant increase in bone marrow and spleen progenitor cell count and proliferation. Moreover, Cre+LysM mice cardiac functional recovery was also reduced significantly ( Fig. 1D-F ) as assessed by echocardiography. Conclusion: Myeloid-specific Plpp3 deletion increases the deleterious effects of inflammation on the ischemic myocardium and ATX/ LPA signaling could represent a novel therapeutic target for future clinical studies of coronary heart diseases.

HIF-1\u03b1 overexpression in mesenchymal stem cell-derived exosomes mediates cardioprotection in myocardial infarction by enhanced angiogenesis

BackgroundMyocardial infarction (MI) is a severe disease that often associated with dysfunction of angiogenesis. Cell-based therapies for MI using mesenchymal stem cell (MSC)-derived exosomes have been well studied due to their strong proangiogenic effect. Genetic modification is one of the most common methods to enhance exosome therapy. This study investigated the proangiogenic and cardioprotective effect of exosomes derived from hypoxia-inducible factor 1-alpha (HIF-1α)-modified MSCs.MethodsLentivirus containing HIF-1α overexpressing vector was packaged and used to infect MSCs. Exosomes were isolated from MSC-conditioned medium by ultracentrifugation. Human umbilical vein endothelial cells (HUVECs) were treated under hypoxia condition for 48 h co-cultured with PBS, control exosomes, or HIF-1α-overexpressed exosomes, respectively. Then the preconditioned HUVECs were subjected to tube formation assay, Transwell assay, and EdU assay to evaluate the protective effect of exosomes. Meanwhile, mRNA and secretion levels of proangiogenic factors were measured by RT-qPCR and ELISA assays. In vivo assays were conducted using the rat myocardial infarction model. PBS, control exosomes, or HIF-1α-overexpressed exosomes were injected through tail vein after MI surgery. Heart function was assessed by echocardiography at days 3, 14, and 28. At day 7, mRNA and protein expression levels of proangiogenic factors in the peri-infarction area and circulation were evaluated, respectively. At day 28, hearts were collected and subjected to H&E staining, Masson’s trichrome staining, and immunofluorescent staining.ResultsHIF-1α-overexpressed exosomes rescued the impaired angiogenic ability, migratory function, and proliferation of hypoxia-injured HUVECs. Simultaneously, HIF-1α-overexpressed exosomes preserved heart function by promoting neovessel formation and inhibiting fibrosis in the rat MI model. In addition, both in vitro and in vivo proangiogenic factors mRNA and protein expression levels were elevated after HIF-1α-overexpressed exosome application.ConclusionHIF-1α-overexpressed exosomes could rescue the impaired angiogenic ability, migration, and proliferation of hypoxia-pretreated HUVECs in vitro and mediate cardioprotection by upregulating proangiogenic factors and enhancing neovessel formation.

Abstract 486: Chronic Periodontitis Induces Adverse Post-myocardial Wound Healing Through Activation of CD8+ T-cells

Increased risk of adverse cardiac remodeling post-myocardial infarction (MI) has been observed in patients with periodontal disease. Previously, we demonstrated that chronic inflammation induced by periodontal pathogen Porphyromonas gingivalis lipopolysaccharide (LPS) resets cardiac homeostasis, causing acceleration and exacerbation of the macrophage response post-MI. We hypothesize that chronic LPS activates a memory T-cell response resulting in adverse cardiac remodeling post-MI. Analysis of the mouse heart attack research tool (mHART) 1.0 identified 135 mice (5.4 ± 0.1 months of age) associated with the LPS study that had both echo and plasma data collected. Of these 26 mice also had tissue blocks in the mHART tissue bank. Mice were grouped as follows: 1) Saline day 0 unoperated mice (D0), 2) 28 day LPS day 0 unoperated mice (LPS), 3) Saline day 1 MI (MI), and 4) 28 day LPS day 1 MI (LPS+MI). Immunofluorescence of the left ventricle (LV) demonstrated that chronic LPS increased the number of memory CD8+ T-cells (CD3+CD8+CD27+) in the LV and remained elevated in the LPS+MI group compared to D0 and MI controls. Similar to chronic LPS, ligature-induced periodontitis (21 days) also showed upregulation of CD8+ T-cells in the LV along with changes in plasma proteins associated with interleukin, cytokine, chemokine receptor binding, peptide ligand-binding, inflammasome pathway, class A/1 rhodopsin-like receptors, G-protein coupled receptor ligand binding, and RUNX1 and FOXP3 control of Treg development and signaling. To dissect T-cell mediated signaling pathways, we constantly infused an MHC-I blocking antibody (MHCi; 0.2 μg/day; n=3) by osmotic mini-pumps implanted subcutaneously 7 days before (21 days after LPS infusion) and after MI surgery. Interestingly, MHCi attenuated the effector CD8+ T-cell response (CD3+CD8+CD44+) without affecting the memory response. MHCi also attenuated macrophage numbers within the infarct, thereby improving cardiac function at post-MI day 1. Our data showed the recruitment of effector but not memory CD8+ T-cells is regulating macrophage-mediated adverse post-MI remodeling in the setting of chronic periodontitis.