Fractional Shortening Research Articles

Abstract 37: Targeted Deletion of NKCC1 in Vascular Smooth Muscle Cells Lowers Blood Pressure in Normotensive and Hypertensive Mice

Background: Salt plays a major role in blood pressure homeostasis and the pathogenesis of arterial hypertension. While numerous mechanisms have been described by which Na + can influence arterial blood pressure, the role of Cl - in blood pressure regulation is still largely unexplored. The Na + -K + -2Cl - cotransporter NKCC1 is an important Cl - import pathway in vascular smooth muscle cells (VSMC). To investigate the role of NKCC1 in blood pressure regulation, we generated mice with an inducible VSMC-specific disruption of Slc12a2 . Methods: Mean arterial blood pressure and heart rate were measured by radiotelemetry in unrestrained mice lacking vascular NKCC1 (KO) and wildtype littermates (WT). Cardiac function was assessed by echocardiography. Plasma renin activity and aldosterone concentrations were quantified by radioimmunoassay. Protein expression of renal sodium transporters and channels was analyzed by Western blotting. Results: Mean arterial blood pressure was markedly decreased in Nkcc1 -deficient mice 6 weeks after induction of gene disruption (from 116±2 mm Hg to 103±4 mm Hg, n=18, p<0.001, 2-way ANOVA and Bonferroni post-test), while it did not change in WT control animals (n=17). Heart rate, stroke volume, fractional shortening, and ejection fraction remained unchanged compared to non-induced controls. We did not observe a compensatory increase in plasma renin activity or aldosterone levels, and the blood pressure response to ANG II receptor 1 antagonism by losartan treatment for 7 days was similar in both groups (ΔMAP KO -8.8±3.0 mm Hg, n=8, ΔMAP WT -12.4±1.9 mm Hg, n=7; p>0.05, 2-way ANOVA). In the kidney, the relative expression of total NCC (1.5- fold , n=7-8; p=<0.05, Student’s t-test) and pNCCThr53 (1.9- fold , n=7-8; p=<0.05, Student’s t-test) were modestly increased. The hypotensive effect of Nkcc1 disruption was maintained after induction of hypertension by either infusion of ANG II for 10 days (ΔMAP KO 43.8±6.5 mm Hg, n=6, ΔMAP WT 50.2±7.2 mm Hg, n=4; p>0.05, 2-way ANOVA) or a high salt diet for 10 days (ΔMAP KO 21.7±7.0 mm Hg, n=8, ΔMAP WT 34.0±7.3 mm Hg, n=5; p>0.05, 2-way ANOVA). Conclusions: Our findings indicate that NKCC1 in vascular smooth muscle contributes significantly to the maintenance of arterial blood pressure. Inhibition of NKCC1 in VSMC may provide additional blood pressure reduction in resistant hypertension.

P163 EMPAGLIFLOZIN AND ITS CARDIOPROTECTIVE EFFECTS IN THE HEART DURING VOLUME OVERLOAD IN AN EXPERIMENTAL MODEL INDUCED BY AORTOCAVAL FISTULA

Mitral regurgitation causes volume overload of the heart, and due to the deregulation of extracellular matrix proteins, the electrical communication between cardiomyocytes provided by connexin channels is disturbed. The aim of this study was to investigate the effect of cardiac volume overload (VO) on its functional parameters, structural remodeling, and connexin43 (Cx43), a protein ensuring electrical synchronization of the heart, and the cardioprotective effect of empagliflozin. Cardiac VO was induced by surgical aortocaval fistula (ACF) in adult, 6-month-old male Wistar rats. Mitral regurgitation and VO developed within four weeks. Subsequently, empagliflozin was administered daily for five weeks at a dose of 10 mg/kg of body weight. Echocardiographic examination showed increased cardiac output and increased Vmax of the aortic valve, decreased ejection fraction and fractional shortening due to ACF-VO. Echocardiographic parameters showed an increase in the diameter of the left ventricle in both systole and diastole, as well as an increase in the volume of the left ventricle at the end of systole and diastole. Empagliflozin normalized the negative parameters in the ACF-VO group. Myocardial protein Cx43 levels were reduced by ACF-VO but normalized by empagliflozin treatment. In addition, empagliflozin suppressed the ACF-VO-induced increase in interstitial collagen detected by van Gieson staining. These findings were consistent with increased protein expression of MMP-2, which is involved in structural remodeling of the extracellular matrix, and was normalized by empagliflozin. Protein kinase C epsilon levels associated with Cx43 and extracellular matrix modulation were reduced by ACF-VO and normalized by empagliflozin. However, protein levels of pro-apoptotic and pro-hypertrophic protein kinase C delta were increased by ACF-VO and normalized by empagliflozin. Protein expression of transforming growth factor beta as well as fibroblast growth factor 21 was increased by ACF-VO and normalized by empagliflozin. The results indicate a cardioprotective effect of empagliflozin due to suppression of myocardial structural remodeling and preservation of Cx43 in an experimental model simulating volume overload. The research was supported by grants APVV-21-0410,VEGA-2/0006/23,VEGA-2/0133/24,VEGA-2/0002/20

Abstract P119: The Heart Failure with Preserved Ejection Fraction Induced By High-Fat Diet and L-NAME in Mice Does not Induce a Renal Damage

Heart failure with preserved ejection fraction (HFpEF) is a clinical syndrome, without effective therapy, characterized by diastolic dysfunction, a chronic low-grade inflammation and comorbidities such as hypertension. At the present time, few experimental models of HFpEF represent the hallmarks of patients. Recently, it has been described that the administration of a high-fat diet (HFD) in conjunction with an endothelial nitric oxide synthase inhibitor (L-NAME) can adequately reproduce the pathophysiological features of HFpEF. However, the effects on at renal level in HFpEF models have not been fully described. Our goal was to evaluate the kidney damage in a HFpEF model induced by HFD+L-NAME. Male C57BL/6N mice (12 weeks old, n=4-6) were treated with control diet or HFD (60% in fat calories) plus L-NAME (0.65 g/L in drinking water) for 15 weeks. We evaluated cardiac function (echocardiographic analysis), systolic blood pressure (SBP, plethysmography), cardiac and renal hypertrophy (morphometry and histology), plasma creatinine, blood urea nitrogen (BUN), plasma neutrophil gelatinase-associated lipocalin (pNGAL), proteinuria, and kidney immune cells infiltration (flow cytometry). All data are presented by mean±standard deviation. After 15 weeks of HFD+L-NAME we observed diastolic dysfunction (p<0.001), an increased SBP (control=128.0±15.3 vs. HFD+L-NAME=155.7±9.8 mmHg; p<0.01), without changes in ejection fraction and shortening fraction. In addition, we did not observe cardiac or renal hypertrophy, nor apparent histological changes in the renal structure between both groups of animals. No differences were found between groups regarding plasma creatinine, pNGAL or BUN, however, we observed that HFD+L-NAME induced proteinuria in compared to control mice (p<0.05). Finally, when we evaluated the immune cells population in kidney of both groups, we observed no differences in dendritic cells, macrophages, or neutrophils. Nevertheless, the HFD+L-NAME treatment was associated to a significant rising of Ly6G + CD11b - cells population (CD45 + MHC-II - CD11c +/- F4/80 - ) compared to control mice (p<0.05). In conclusion, our results indicate that there is no renal inflammatory damage after 15 weeks of in HFpEF experimental model. However, to our knowledge, an uncharacterized population of Ly6G cells could be participating at this stage which could trigger a long-term renal damage . FONDECYT 1221585 (MPO), 1231604 (JJ), 1231909 (CAA), 11241074 (PA) and FONDAP 15130011(MPO, LG).

O17 THE PROGRESSION OF HYPERTENSION WITH OBESITY AND DIABETES FAVORS CARDIAC PRO-INFLAMMATORY MACROPHAGES AND DIASTOLIC DYSFUNCTION

Background: In most patients, hypertension (HT) is accompanied by obesity and diabetes. Cell-specific mechanisms like accumulation of macrophages, and dysregulation of innate immune pathways play important roles in cardiac remodeling (CR). Macrophages (Mo) exhibit phenotypic heterogeneity in response to tissue micro-environment. It is unknown whether in the heart the subpopulations of pro-inflammatory Mo (CCR2+MHCII+) and resident repair Mo (CCR2-MHCII+ and CCR2-MHCII-) differ in the development of the chronic HT, obesity and diabetes. Objective. To determine in male with HT and or obesity and diabetes, the pro-inflammatory cardiac Mo derived from monocytes (CCR2+MHCII+) and the resident repair Mo (CCR2-MHCII+ and CCR2- MHCII-). Methods: 12-week-old male C57BL/6N mice were assigned to experimental groups: control diet, high-fat diet (HFD, 60% kcal from fat), L-NAME (L,0.65 g/L in drinking water) and HFD+L for 5 and 15 weeks. Body weight (BW), systolic (SBP) and diastolic blood pressure, glucose and exercise capacity (EC), cardiac function and cardiac Mo CCR2+MHCII+, CCR2-MHCII+, CCR2- MHCII- were determined. Results: (mean ± SEM, n=9-12). During 15 weeks, HFD and HFD+L groups showed significantly higher BW and glucose intolerance vs. control and L (p <0.001, F=28.4; p<0.001, F=10.3, respectively). EC as lower in the HFD and HFD+L groups compared to control and L (p<0.059). Echocardiographic parameters showed a significant increase in the size of the left atrium (p<0.001, F=38.9) and diastolic dysfunction in the HFD+L group vs control, HFD and L (p<0.001, F=35.6). No changes in ejection fraction and shortening fraction. The thickness of the septal wall and posterior wall was significantly greater in the HFD+L and HFD groups (p<0.0001, F=10.6 and p<0.0001, F=14.6, respectively). The L hearts showed a significant increase in CCR2-MHCII- (p<0.0001, F=68.6) and a significant decrease in CCR2+ MHCII+ (p<0.001, F=13.7), compared to the control and HFD groups. Conclusion: The progression of HT with obesity and diabetes favors cardiac pro-inflammatory macrophages and diastolic dysfunction.

IDI2-AS1 influences the development of acute myocardial infarction by regulating NR4A2 through microRNA-33b-5p

To explore the effect and correlation of long non-coding RNA (lncRNA) IDI2-AS1/microRNA-33b-5p (miR-33b-5p)/nuclear receptor-associated protein NR4A2 competitive endogenous RNA (ceRNA) regulatory network on acute myocardial infarction (AMI), and to verify whether IDI2-AS1 regulates NR4A2 through miR-33b-5p to affect the occurrence and development of myocardial infarction. The miRNA and mRNA expression chips related to myocardial infarction were obtained from gene expression omnibus (GEO), and the differential expression was analyzed. The upstream regulatory mechanism of NR4A2 was predicted using TargetScan database. Thirty-two male C57/BL6 mice were divided into Sham group, AMI model group, miR-33b-5p mimic group [miR-33b-5p mimic lentivirus (5×107 TU) was injected locally into the heart tissue during ligation] and miR-33b-5p inhibitor group [miR-33b-5p inhibitor lentivirus (5×107 TU) was injected locally into the heart tissue during ligation] according to random number table method, with 8 mice per group. Left ventricular end-diastolic diameter (LVEDD) and left ventricular end-systolic diameter (LVESD) were asseessed by echocardiography, left ventricular fractional shortening (LVFS) and left ventricular ejection fraction (LVEF) were calculated. After the last weighing, the anesthetized mice were sacrificed and the heart tissues were taken. Masson staining of the heart tissues was observed under light microscope, myocardial collagen volume fraction (CVF) and infarct size were calculated. Cardiomyocytes of SPF grade SD rats were collected. They were divided into normal control group (control group), ischemia-hypoxia model group, miR-33b-5p mimic transfection group (miR-33b-5p mimic transfection group before ischemia and hypoxia treatment) and miR-33b-5p inhibitor transfection group (miR-33b-5p inhibitor transfection group before ischemia and hypoxia treatment). The activity of caspase-3/7 in cardiomyocytes was measured. The levels of interleukins (IL-1β, IL-6) and tumor necrosis factor-α (TNF-α) were detected by enzyme-linked immunosorbent assay (ELISA). The levels of malondialdehyde (MDA), superoxide dismutase (SOD), creatine kinase (CK), MB isoenzyme of creatine kinase (CK-MB) and lactate dehydrogenase (LDH) were detected by colorimetry. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of apoptosis-related proteins Bax and Bcl-2, cytochrome C (Cyt C) and IDI2-AS1/miR-33b-5p/NR4A2 regulatory axis genes. The myocardial infarction microarray analysis showed that NR4A2 expression was significantly up-regulated in myocardial infarction, with predicted upstream regulatory mechanisms indicating its possible influence through the IDI2-AS1/miR-33b-5p/NR4A2 regulatory axis. Echocardiographic detection showed that compared with AMI model group and miR-33b-5p inhibitor group, LVEF and LVFS in the heart tissue of mice in miR-33b-5p mimic group were significantly increased, while the levels of LVEDD, LVESD, CK, CK-MB and LDH were significantly decreased, with statistical significance. Light microscope showed myocardial fibrosis and myocardial infarction in AMI model group and miR-33b-5p inhibitor group. In the miR-33b-5p mimic group, the degree of myocardial fibrosis was decreased and the myocardial infarction size was significantly reduced. Compared with AMI model group and miR-33b-5p inhibitor group, the levels of MDA, IL-1β, IL-6, TNF-α and the expressions of Bax and Cyt C in the heart tissue of mice in miR-33b-5p mimic group were significantly decreased, while the levels of SOD and Bcl-2 expression were significantly increased, and the differences were statistically significant. The expressions of IDI2-AS1 and NR4A2 in the heart tissue of mice in miR-33b-5p mimic group were significantly lower than those in AMI model group and miR-33b-5p inhibitor group [IDI2-AS1 (2-ΔΔCt): 1.96±0.08 vs. 2.73±0.08, 3.10±0.05, NR4A2 (2-ΔΔCt): 2.36±0.07 vs. 3.16±0.08, 3.80±0.08, all P < 0.01]. The expression of miR-33b-5p was significantly higher than that of AMI model group and miR-33b-5p inhibitor group (2-ΔΔCt: 0.88±0.07 vs. 0.57±0.07, 0.23±0.01, both P < 0.01). The cell experiment results showed that the caspase-3/7 activity of rat neonatal cardiomyocytes in the miR-33b-5p mimic transfection group was significantly lower than that in the ischemia-hypoxia model group and the miR-33b-5p inhibitor transfection group, suggesting that miR-33b-5p can significantly reduce the apoptosis level of the ischemia-hypoxia model. The levels of peroxidation and inflammation indexes, important genes of apoptosis pathway and the expression of IDI2-AS1/miR-33b-5p/NR4A2 regulatory axis of rat neonatal cardiomyocytes in all groups were consistent with the above. IDI2-AS1 can regulate NR4A2 through miR-33b-5p, thus affecting the occurrence and development of AMI.

Ultrasonographic Evaluation of Masseter Muscle in Patients with Oral Submucous Fibrosis

Purpose: Oral submucous fibrosis (OSF) is a potentially malignant disorder associated with gutkha chewing habit, and India has the greatest number of people affected, worldwide. Constant chewing leads to untoward forces on the masticatory muscles, especially the masseter muscle (MM). Hence, with an interdisciplinary approach, diagnosis and cessation of the habit and treatment will improve the well-being of the patient. Aim: The aim of the study was to assess the changes in the structure and function of the MM in patients with OSF using B-mode and M-mode ultrasonography. Methodology: The study sample was drawn from male patients attending the outpatient department of oral medicine and radiology. Subjects were divided into three groups of 20 subjects each as follows: Group I – 20 consecutive patients with the clinical diagnosis of OSF which constituted the case group; Group II – 20 consecutive patients with a history of areca nut use but no clinical evidence of OSF; and Group III –20 consecutive patients with a negative history of areca nut use and with no clinical evidence of OSF, who reported to the department for some other dental problems. Results: Based on the results of our study, we hypothesize that the reduction of amplitude of contraction and fractional shortening of MM as determined by ultrasonography could be one of the first and significant indicators of declining muscle function in OSF patients. Conclusion: The reduction of amplitude of contraction and fractional shortening of masseter muscle as determined by ultrasonography could be one of the first and significant indicators of declining muscle function in OSF patients.

Effect of Linggui Zhugan Decoction on myocardial fibrosis and Lats1/Yap signaling pathway in mice after myocardial infraction

This study aims to investigate the effects of Linggui Zhugan Decoction(LGZGD) on myocardial fibrosis(MF) and the Lats1/Yap signaling pathway in mice after myocardial infarction(MI), exploring its role and mechanism in inhibiting MF. The MI-induced ischemic mouse model was established by left anterior descending coronary artery ligation, followed by continuous intervention for six weeks. Doppler ultrasound imaging-system of small animals was used to detect left ventricular ejection fraction(LVEF), left ventricular fractional shortening(LVFS), left ventricular internal diameter at end-systole(LVIDs), and left ventricular internal diameter at end-diastole(LVIDd). Pathological changes in myocardial tissue were observed by HE and Masson staining. Serum levels of creatine kinase isoenzyme MB(CK-MB) and lactate dehydrogenase(LDH) were detected by using ELISA. Myocardial tissue mRNA levels of Lats1, Yap, and connective tissue growth factor(CTGF) were determined by RT-qPCR. Protein expression of alpha-smooth muscle actin(α-SMA), collagen Ⅰ(Col Ⅰ), collagen Ⅲ(Col Ⅲ), tissue inhibitor of metal protease 1(TIMP1), matrix metallopeptidase 2(MMP2), Yap, p-Yap, and n-Yap was determined by Western blot. Compared with the sham group, the model group showed significantly decreased LVEF and LVFS levels, increased LVIDd and LVIDs levels(P&lt;0.01), disordered arrangement of myocardial cells, partial fracture of myocardial fibers, and massive deposition of collagen fibers. Moreover, serum levels of CK-MB and LDH were significantly increased(P&lt;0.01), while myocardial tissue mRNA levels of Lats1 were significantly decreased(P&lt;0.01), and mRNA levels of Yap and CTGF were significantly increased(P&lt;0.01). Protein expression of α-SMA, Col Ⅰ, Col Ⅲ, MMP2, Yap, and n-Yap was significantly increased(P&lt;0.01), while protein expression of Lats1, TIMP1, p-Yap, and the ratio of p-Yap/Yap were significantly decreased(P&lt;0.01). Compared with the model group, after intervention with LGZGD(9.36 g·kg~(-1)), mice showed significantly increased LVEF and LVFS levels, decreased LVIDd and LVIDs levels(P&lt;0.01), more orderly arrangement of myocardial cells, significantly reduced myocardial fiber fracture and collagen fiber deposition. Serum levels of CK-MB and LDH were significantly decreased(P&lt;0.01), while myocardial tissue mRNA levels of Lats1 were significantly increased(P&lt;0.01), and mRNA levels of Yap and CTGF were significantly decreased(P&lt;0.01). Protein expression of α-SMA, Col Ⅰ, Col Ⅲ, MMP2, Yap, and n-Yap was significantly decreased(P&lt;0.01), while protein expression of Lats1, TIMP1, p-Yap, and the ratio of p-Yap/Yap were significantly increased(P&lt;0.01). LGZGD can inhibit MF in mice after MI and improve mouse cardiac function, which is closely related to the activation of the Lats1/Yap signaling pathway.

P180 CONTRIBUTION OF AFFERENT RENAL NERVES TO HYPERTENSION AND HYPERTENSIVE HEART FAILURE

Background and Objective: Renal nerves contain efferent and afferent fibers. This study aimed to investigate the contribution of afferent renal nerves to the development of hypertension and hypertensive heart failure in several rat models of hypertension. Methods: Selective afferent renal nerve denervation (ARDN) or sham operation was performed in the following models: (1) SHRSP at 9 weeks; (2) 4% high-salt diet (HS)-fed SHRSP at 8 weeks (HS from 8 weeks); and (3) 8% HS-fed Dahl salt-sensitive rats at 9 weeks (HS from 6 weeks). Dahl rats fed 0.3% low-salt diet were controls for (3). Blood pressure (BP) was measured by telemetry in (1) and (2), and by tail-cuff method in (3). Results: (1) Mean BP was elevated from 9 weeks to 11 weeks in sham-SHRSP (155.2±2.0 vs 144.0±1.9 mmHg, n=10, p&lt;0.05). Mean BP in ARDN-SHRSP (157.8±2.7 mmHg, n=10) did not differ from sham-SHRSP at 11 weeks. (2) Mean BP increased from 8 weeks to 11 weeks in HS-sham-SHRSP (191.5±8.1 vs 126.5±4.0 mmHg, n=6, p&lt;0.05). Mean BP in HS-ARDN-SHRSP (186.0±7.1 mmHg, n=6) did not differ from HS-sham-SHRSP at 11 weeks. (3) Systolic BP increased (243.6±7.0 vs 140.0±2.7 mmHg, n=9 each, p&lt;0.05) and echocardiographic left ventricular (LV) fractional shortening decreased (25.9±1.7 vs 48.8±0.4%, p&lt;0.05) in HS-sham-Dahl rats compared to low-salt controls at 16 weeks (“HFrEF” phase). LV weight, lung weight, and LV fibrosis were significantly increased in HS-sham-Dahl rats compared to controls. ARDN attenuated these changes except for BP. At 12 weeks (pre-HFrEF phase), plasma norepinephrine levels increased in HS-sham-Dahl rats compared to controls and were attenuated by ARDN (controls 188.7±16.5, HS-sham 563.8±82.7, HS-ARDN 327.4±50.2 pg/ml; n=15, 12, 14; p&lt;0.05). Conclusions: Signals from afferent renal nerves contribute to sympathoexcitation and the development of HFrEF without affecting BP in Dahl salt-sensitive hypertensive rats, but not to the development of hypertension in SHRSP and HS-fed SHRSP.

Magnoflorine attenuates Ang II-induced cardiac remodeling via promoting AMPK-regulated autophagy.

Heart failure (HF) remains one of the most common events in the progression of hypertension. Magnoflorine (MNF) has been shown beneficial effects on the cardiovascular system. However, the action of MNF on angiotensin (Ang) II-induced cardiac remodeling and its underlying mechanisms have not yet been characterised. Here, we assessed the action of MNF in the development of hypertension-related HF. C57BL/6 male mice were subjected to Ang II through a micro-osmotic pump infusion continuously for 4 weeks to induce hypertensive HF. MNF (10 and 20 mg/kg) was administered in the final 2 weeks. Ang II content was measured by enzyme-linked immunosorbent assay (ELISA) kit. Values of ejection fraction (EF) and fractional shortening (FS) were detected using an ultrasound diagnostic instrument. The mRNA levels of hypertrophic and fibrotic genes were determined by real-time quantitative polymerase chain reaction (RT-qPCR). Haematoxylin and eosin (H&E), wheat germ agglutinin (WGA), Masson trichrome, and Sirius Red staining were used to analyse pathologic changes in heart tissues. The expression levels of phosphorylated AMP-activated protein kinase (AMPK), light chain 3 microtubule associated protein II (LC3 II) to LC3 I, and p62 were detected by western blot assay. MNF significantly improved cardiac dysfunction and the content of creatine kinase-MB without altering blood pressure in Ang II-challenged mice. MNF obviously corrected the phenotypes of cardiac hypertrophy and fibrosis, including the high mRNA levels of atrial natriuretic peptide (Anp), brain natriuretic peptide (Bnp), collagen1a (Col1a1), transforming growth factor beta (Tgfb1), enlarged myocardial areas, and increased positive areas of Masson trichrome and Sirius Red staining. In addition, MNF alleviated oxidative injury, reflected by the upregulation of glutathione and the downregulation of reactive oxygen species and malondialdehyde. The activation of AMPK was elevated accompanied by an increased level of autophagy by MNF in hypertensive heart tissues. The therapeutic action of MNF was confirmed in Ang II-challenged H9c2 cells. Specifically, the AMPK inhibitor could eliminate the autophagy pathway in which MNF is involved. MNF has benefits in hypertension-induced cardiac remodeling, which was partially associated with the improvement of oxidative stress via the mediation of the AMPK/autophagy axis.

Dehydrocorydaline attenuates myocardial ischemia-reperfusion injury via the FoXO signalling pathway: A multimodal study based on network pharmacology, molecular docking, and experimental study

Ethnopharmacological relevanceDehydrocorydaline (DHC), an active component of Corydalis yanhusuo (Y.H. Chou & Chun C. Hsu) W.T. Wang ex Z.Y. Su & C.Y. Wu (Papaveraceae), exhibits protective and pain-relieving effects on coronary heart disease, but the underlying mechanism still remains unknown. Aim of the studyNetwork pharmacology and experimental validation both in vivo and in vitro were applied to assess whether DHC can treat myocardial ischemia-reperfusion injury (MIRI) by regulating the forkhead box O (FoxO) signalling pathway to inhibit apoptosis. Materials and methodsDHC and MIRI targets were retrieved from various databases. Molecular docking and microscale thermophoresis (MST) determined potential binding affinity. An in vivo mouse model of MIRI was established by ligating the left anterior descending coronary artery. C57BL/6N mice were divided into sham, MIRI, and DHC (intraperitoneal injection of 5 mg/kg DHC) groups. Haematoxylin and eosin, Masson, and immunohistochemical stainings verified DHC treatment effects and the involved signalling pathways. In vitro, H9c2 cells were incubated with DHC and underwent hypoxia/reoxygenation. TUNEL, JC-1, and reactive oxygen species stainings and western blots were used to explore the protective effects of DHC and the underlying mechanisms. ResultsVenny analysis identified 120 common targets from 121 DHC and 23,354 MIRI targets. DHC exhibited high affinity for CCND1, CDK2, and MDM2 (<−7 kcal/mol). In vivo, DHC attenuated decreases in left ventricular ejection fraction and fractional shortening, reduced infarct sizes, and decreased cTnI and lactate dehydrogenase levels. In vitro, DHC alleviated apoptosis and oxidative stress in the hypoxia/reoxygenation model by attenuating ΔΨm disruption; reducing the production of reactive oxygen species; upregulating Bax and CCND1 via the FoxO signalling pathway, as well as cleaved-caspase 8; downregulating the apoptosis-associated proteins Bcl-2, Bid, cleaved-caspase 3, and cleaved-caspase 9; and promoting the phosphorylation of FOXO1A and MDM2. ConclusionBy upregulating the FoxO signaling pathway to inhibit apoptosis, DHC exerts a cardioprotective effect, which could serve as a potential therapeutic option for MIRI.

The Cardioprotective Potential of Herbal Formulas in Myocardial Infarction-Induced Heart Failure through Inhibition of JAK/STAT3 Signaling and Improvement of Cardiac Function.

Myocardial infarction (MI) is a leading cause of heart failure, characterized by adverse cardiac remodeling. This study evaluated the cardioprotective potential of Dohongsamul-tang (DHT), a traditional Korean herbal formula, in a rat model of MI-induced heart failure. Rats underwent left anterior descending (LAD) artery ligation and were treated with either 100 mg/kg or 200 mg/kg of DHT daily for 8 weeks. DHT treatment significantly improved cardiac function, as evidenced by increased ejection fraction (EF) from 62.1% to 70.1% (100 mg/kg) and fractional shortening (FS) from 32.3% to 39.4% (200 mg/kg) compared to the MI control group. Additionally, DHT reduced infarct size by approximately 63.3% (from 60.0% to 22.0%) and heart weight by approximately 16.7% (from 3.6 mg/g to 3.0 mg/g), and significantly decreased levels of heart failure biomarkers: LDH was reduced by 37.6% (from 1409.1 U/L to 879.1 U/L) and CK-MB by 47.6% (from 367.3 U/L to 192.5 U/L). Histological analysis revealed a reduction in left ventricle (LV) fibrosis by approximately 50% (from 24.0% to 12.0%). At the molecular level, DHT inhibited the expression of phospho-JAK by 75% (from 2-fold to 0.5-fold), phospho-STAT3 by 30.8% (from 1.3-fold to 0.9-fold), Bax/Bcl-2 by 56.3% (from 3.2-fold to 1.4-fold), and caspase-3 by 46.3% (from 1.23-fold to 0.66-fold). These results suggest that DHT exerts cardioprotective effects by modulating the JAK/STAT3 signaling pathway, highlighting its potential as a therapeutic option for heart failure.

Respiratory, cardio-metabolic and neurodevelopmental long-term outcomes of moderate to late preterm birth: not just a near term-population. A follow-up study.

Moderate-to-late preterm infants constitute the majority within the preterm infant population. Most research on preterm infants has focused on very preterm children, often treating moderate-to-late preterm infants as similar to full-term infants. Our objective was to compare clinical, respiratory, cardio-metabolic and neurodevelopmental outcomes in adolescents aged 12-15 years born moderate and late preterm with a control group of the same age born full-term. Observational cross-sectional study, comparing moderate-to-late preterm (32-36+6 weeks' gestational age) with full-term adolescents (37-41+6 weeks' gestational age; 75 each group). Perinatal and neonatal history were collected as well as data on respiratory evolution (ISAAC questionnaire for asthma symptoms for adolescents 13-14 years), anthropometric values, learning difficulties, behavioral test (screening questionnaire for high-performance autism spectrum disorder and evaluation test for attention deficit hyperactivity disorder), skin prick test, pulmonary function test, echocardiogram and blood pressure. A blood test with metabolic profile was conducted. Moderate-to-late preterm adolescents had more current asthma [p = 0.008, OR3 (95% CI 1.26-7.14)] and longer duration of combined treatments to control asthma (inhaled corticosteroids and anti-leukotrienes; p = 0.048). Forced vital capacity <80% was detected more often in moderate-to-late preterm patients (p = 0.013). When assessing right ventricle, moderate-to-late preterm adolescents showed better tricuspid annular plane systolic excursion z-score (p = 0.003), shortening fraction (p < 0.001) and E/A ratio z-score (p = 0.002). Regarding left ventricular assessment, moderate-to-late preterm group had smaller ventricle diastolic diameter (p = 0.04) and lower posterior wall z-score values (p = 0.037). They also showed a better S'wave z-score (p = 0.027), E wave (p = 0.005), E/A ratio (p = 0.003) and a higher septal myocardial performance index z-score (p = 0.025). Moderate-to-late preterm adolescents presented lower weight z-score (p = 0.039), body mass index z-score (p = 0.013), Waterlow weight index (p = 0.006) and higher undernutrition index [p = 0.04; OR 1.4 (95% CI 1-1.9)]. Although there were no differences in neurodevelopmental survey or behavioral tests. Our findings underscore the importance of extended follow-up for this predominant group of premature infants to identify potential respiratory, cardiac and anthropometric issues that may emerge in the future.

Fetal heart quantification technique improves the prenatal prediction of coarctation of the aorta: A retrospective analysis.

Coarctation of the aorta (CoA) ranks among the most prevalent congenital heart defects and poses a life-threatening risk if left undiagnosed. Herein, we utilized fetal heart quantification (HQ) technology to improve the prenatal prediction of CoA. A retrospective analysis was conducted on 64 fetal cases with suspected aortic arch constriction, identified through prenatal ultrasound findings between November 2020 and March 2022 at the Department of Ultrasound, Sir Run Run Shaw Hospital, Zhejiang University. According to the follow-up results, these cases were divided into two groups: 35 cases confirmed as CoA by postpartum surgery or induction, and 29 cases initially suspected of CoA prenatally but subsequently ruled out postnatally. Additionally, 88 cases of normal fetuses were randomly selected as the control group. Both conventional M-mode ultrasound techniques and Fetal HQ software were utilized for fetal analysis across all groups. Parameters related to the heart were measured, including fetal 4-CV length, width, Global Spherical Index (GSI), Mitral Annular Plane Systolic Excursion (MAPSE), areas and ratios of the left and right ventricles, as well as lengths and ratios of the left and right ventricles. Functional measurements of the left and right ventricles included ejection fraction (EF), fractional area change (FAC), global longitudinal strain (GLS), fractional shortening (FS), end-diastolic diameter (ED), and sphericity index (SI). Left ventricular (LV)-GLS, LV-FAC, LV-EF, and LV-EF Z-score could potentially differentiate between true CoA and false CoA or normal groups and serve as potential indicators for the clinical diagnosis of CoA. The receiver operating characteristic (ROC) curves indicated that LV-GLS and LV-EF Z-score have the greatest predictive power for CoA diagnosis. The segments 6-12 of FS in the confirmed CoA group were significantly lower than those in the false CoA and normal groups. Fetal HQ technology, by assessing changes in the size and shape of the heart, can provide relatively reliable parameter support for the prenatal diagnosis of fetal aortic coarctation.

Associations of multiple blood metals with cardiac structure and function: A cross-sectional study in a CAD population

Coronary artery disease (CAD) is often accompanied by abnormal cardiac structure and function, leading to an increased prognostic risk. However, less is known about the associations of mixed metals with abnormal cardiac structure and function in CAD patients. Here, we aimed to investigate the associations of exposure to metal mixtures with cardiac structure and function and potential interactions in a CAD population. We conducted a cross-sectional study from Southwest China that included 1555 CAD patients. The blood concentrations of 14 metals were measured via inductively coupled plasma spectrometry. CAD was defined as at least one vessel having stenosis ≥50% the vessel diameter. Echocardiography was used for cardiac structural and functional measurements. Bayesian kernel machine regression was applied to explore the overall effect, metal weight, and dose effect. Linear regression analysis was used to analyze the effects of single metals, metal‒metal interactions and metal‒traditional interactions. Finally, we found that the negative associations of mixed metals with cardiac structure was significant when the levels of all metals were below the 60th percentile. For cardiac function, changes in metals from 50th to 75th were associated with 0.954% and 0.683% decrease in left ventricular ejection fraction and left ventricular fractional shortening, respectively. Negative associations of copper and manganese with cardiac structure and function, whereas positive associations of titanium, selenium and molybdenum with several parameters were found. Antagonistic interactions between copper and tin and between selenium and several metals (manganese, copper and aluminum) (all Pinteraction terms < 0.05) were found. In conclusion, mixed metal exposure was negatively associated with cardiac structure and function in CAD patients. The main metals contributing to this negative associations were copper and manganese. Selenium or tin supplementation may reduce the adverse associations of copper and manganese with cardiac structure and function.

Micropeptide MPM regulates cardiomyocyte proliferation and heart growth via the AKT pathway

The role of micropeptide in cardiomyocyte proliferation remains unknown. We found that MPM (micropeptide in mitochondria) was highly expressed in cardiomyocytes. Compared to MPM+/+ mice, MPM knockout (MPM−/−) mice exhibited reduction in left ventricular (LV) mass, myocardial thickness and LV fractional shortening. RNA-sequencing analysis in H9c2, a rat cardiomyocyte cell line, identified downregulation of cell cycle-promoting genes as the most significant alteration in MPM-silencing cells. Consistently, gain- and loss-of-function analyses in H9c2 cells revealed that cardiomyocyte proliferation was repressed by silencing MPM but was promoted by overexpressing MPM. Moreover, the cardiomyocytes in the hearts of MPM−/− mice displayed reduced proliferation rates. Mechanism investigations disclosed that MPM is crucial for AKT activation in cardiomyocytes. We also identified an interaction between MPM and PTPMT1, and found that silencing PTPMT1 attenuated the effect of MPM in activating the AKT pathway, whereas inhibition of the AKT pathway abrogated the role of MPM in promoting cardiomyocyte proliferation. Collectively, these results indicate that MPM may promote cardiomyocyte proliferation and thus heart growth by interacting with PTPMT1 to activate the AKT pathway. Our findings identify the novel function and regulatory network of MPM and highlight the importance of micropeptides in cardiomyocyte proliferation and heart growth.

Left atrial fractional shortening in cats: a comparison between two echocardiographic views

Introduction/objectivesLeft atrial fractional shortening (LAFS%) is a widely used index of left atrial systolic function in cats that has been shown to predict development of hypertrophic cardiomyopathy (HCM) and cardiac mortality. It can be determined by two methods: from an M-mode right parasternal short-axis view (LAFS%RPSA-MM) or two-dimensional right parasternal long-axis four-chamber view (LAFS%RPLA-2D). We aimed to assess the agreement between LAFS%RPSA-MM and LAFS%RPLA-2D in cats and to evaluate the correlation between LAFS%RPSA-MM and LAFS%RPLA-2D and left ventricular systolic performance. Animals, materials, and methodsOne hundred and seventeen cats were enrolled in the study: 40 control, 41 HCM stage B (asymptomatic), and 36 HCM stage C (symptomatic) cats. This was a retrospective case–control study. Bland–Altman analysis was used to assess agreement between LAFS%RPSA-MM and LAFS%RPLA-2D across the whole cohort and in cats with asymptomatic and symptomatic HCM. Correlation analysis was used to assess associations between LAFS% methods and forward aortic flow, left ventricular fractional shortening, and aortic root motion. ResultsThe LAFS% determined by LAFS%RPSA-MM and LAFS%RPLA-2D was similar (P=0.8), but Bland–Altman analysis showed wide limits of agreement between methods. There was a good correlation between LAFS%RPSA-MM and LAFS%RPLA-2D and aortic root motion (r = 0.78 and r = 0.71, respectively) and a fair correlation with left ventricular fractional shortening (r = 0.31 and r = 0.29, respectively). None of the methods showed a correlation with indices of aortic flow. ConclusionsOur study suggests a poor agreement between LAFS%RPSA-MM and LAFS%RPLA-2D, and thus, these methods should not be used interchangeably. Both echocardiographic methods showed good correlation with aortic root motion.

Anchored PKA synchronizes adrenergic phosphoregulation of cardiac Cav1.2 channels

Adrenergic modulation of voltage gated Ca2+ currents is a context specific process. In the heart Cav1.2 channels initiate excitation-contraction coupling. This requires PKA phosphorylation of the small GTPase Rad (Ras associated with diabetes) and involves direct phosphorylation of the Cav1.2 α1 subunit at Ser1700. A contributing factor is the proximity of PKA to the channel through association with A-kinase anchoring proteins (AKAPs). Disruption of PKA anchoring by the disruptor peptide AKAP-IS prevents upregulation of Cav1.2 currents in tsA-201cells. Biochemical analyses demonstrate that Rad does not function as an AKAP. Electrophysiological recording shows that channel mutants lacking phosphorylation sites (Cav1.2 STAA) lose responsivity to the second messenger cAMP. Measurements in cardiomyocytes isolated from Rad-/- mice show that adrenergic activation of Cav1.2 is attenuated but not completely abolished. Whole animal electrocardiography studies reveal that cardiac selective Rad KO mice exhibited higher baseline left ventricular ejection fraction, greater fractional shortening, and increased heart rate as compared to control animals. Yet, each parameter of cardiac function was slightly elevated when Rad-/- mice were treated with the adrenergic agonist isoproterenol. Thus, phosphorylation of Cav1.2 and dissociation of phospho-Rad from the channel are local cAMP responsive events that act in concert to enhance L-type calcium currents. This convergence of local PKA regulatory events at the cardiac L-type calcium channel may permit maximal β-adrenergic influence on the fight-or-flight response.

Heparanase inhibitor improves clinical study in patients with septic cardiomyopathy.

Septic cardiomyopathy (SCM), a prevalent and critical condition in individuals suffering from sepsis and septic shock, remains elusive in terms of its intricate pathogenesis, thereby lacking definitive diagnostic standards. Current clinical management predominantly revolves around addressing the underlying disease and alleviating symptoms, yet mortality rates persist at elevated levels. This research endeavors to delve into the effects of low molecular weight heparin on Heparanase (HPA) levels in SCM patients, while assessing the clinical significance of HPA as a diagnostic marker in this patient population. A comprehensive cohort of 105 patients diagnosed with SCM was recruited from the Department of Critical Care Medicine at the First Hospital of Lanzhou University, spanning the period from September 2022 to October 2023, serving as the primary research subjects for this investigation. A prospective, randomized controlled trial was undertaken, wherein 53 SCM patients were randomly allocated to a control group receiving standard therapy, while 52 patients were randomly assigned to an intervention group receiving conventional treatment augmented with low molecular weight heparin (LMWH). On the 1st, 3rd, and 7th days post-treatment, the following parameters were measured and documented: HPA levels, syndecan-1 levels, IL-6, TNF-α, CD4+/CD8+ cell ratio, anti-Xa factor, antithrombin III (AT-III) levels, left ventricular ejection fraction (LVEF), fractional shortening (FS), E/e' ratio, stroke volume (SV), cardiac performance index (CPI), global end-diastolic volume index (GEDVI), N-terminal pro-brain natriuretic peptide (NT-proBNP), cardiac troponin I (CTnI), heart-type fatty acid-binding protein (H-FABP), lactate (Lac) levels, central venous oxygen saturation (ScvO2), Sequential Organ Failure Assessment (SOFA) score, Acute Physiology and Chronic Health Evaluation II (APACHE II) score, ICU length of stay, and 28-day mortality rate. In comparison to the control group, the LMWH group demonstrated significantly lower levels of HPA and syndecan-1 (p < 0.05), along with reduced levels of IL-6, TNF-α, E/e', NT-proBNP, CTnI, H-FABP, GEDVI, SOFA score, APACHE II score, ICU length of stay, and 28-day mortality (p < 0.05). Additionally, the LMWH group exhibited increased levels of anti-Xa factor, AT-III, CD4+/CD8+ cell, LVEF, FS, SV, and CPI (p < 0.05). ROC curve analysis indicated that HPA can be combined with NT-proBNP, CTnI and H-FABP to improve the diagnostic efficiency of SCM. In SCM patient management, the integration of LMWH into conventional treatment significantly reduced HPA levels, mitigated syndecan-1 loss, attenuated inflammatory responses, enhanced immune function, improved microcirculation, cardiac systolic and diastolic functions, myocardial contractility, heart index, and end-diastolic volume. These interventions correlated with decreased clinical severity, ICU stays, and 28-day mortality rates in SCM patients. https://www.chictr.org.cn.

Heart Stiffening in Pediatric Dilated Cardiomyopathy: Causes of Severity

Background: Cardiomyopathy, characterized by heart stiffness, can lead to heart failure. This study aimed to investigate aortic stiffness in children with dilated cardiomyopathy (DCM) to better understand its contribution to disease severity. Methods: This case-control study compared 48 children with DCM with 96 healthy children over a 10-year period starting in 2011. Aortic strain, aortic stiffness index, aortic distensibility, and pressure strain elastic modulus were measured. These parameters, along with several echocardiographic measures, were compared between the DCM and control groups. Statistical analyses were performed using SPSS 18, with a significance threshold set at a P value below 0.05. Results: The participants included 57.6% boys, with 58.3% in the DCM group and 57.35% in the control group (χ2=0.014, P=0.905). The age range was 2 to 18 years, with mean ages of 11.08±4.63 years for the DCM group and 10.77±2.82 years for the control group (P=0.691). Significant differences between groups were observed in aortic distensibility (P=0.004), aortic stiffness β index (P=0.001), and pressure strain elastic modulus (P=0.004). Post-treatment analyses based on ejection fraction and fractional shortening cutoffs indicated no changes in elasticity parameters except for the aortic stiffness β index, which varied according to the Ross classification. Conclusion: Children with DCM exhibited reduced aortic strain and aortic distensibility, as well as elevated aortic stiffness β index and pressure strain elastic modulus

Abstract Tu063: Acute sleep deprivation induces cardiac remodeling via activation of AT1R/ERK/GSK-3β signaling

Background: Sleep deprivation (SD) has an adverse effect on cardiovascular system. However, whether acute SD contributes to the morphological and functional changes of the heart remains unclear. Approach and Results: The modified multiple platform method (MMPM) was used to establish the SD model in Sprague-Dawley rats. Acute SD significantly enhanced cardiac ejection fraction and fractional shortening in rats as observed by echocardiography. The elevated ratio of heart weight to body weight (HW/BW) and enlarged cross-section area of cardiomyocytes by WGA staining were detected in SD groups (3, 7,10 days). The upregulation of ANP and BNP was also detected by western blotting. Masson-trichrome staining showed significant fibrosis in the SD groups, which was confirmed by western blotting of the fibrosis markers α-SMA and collagen 1. Furthermore, SD increased the level of angiotensin II (Ang II) and angiotensin type 1 receptor (AT1R) in the heart tissue of SD groups accompanied by the activation of the ERK/GSK-3β pathway. Administration of valsartan and benazepril dramatically ameliorated SD-induced cardiac fibrosis and hypertrophy by downregulating Ang II/AT1R and phosphor-ERK/GSK-3β levels. Conclusion: Our results indicated that cardiac remodeling was induced by the acute and short duration of SD, in which the AT1R/ ERK/GSK3β signal pathway was involved. Our study demonstrates a novel complementary phenomenon induced by SD and provides detailed evidence for the risk of SD on the cardiovascular system.