Dysregulation of cardiac mitochondrial aldehyde dehydrogenase 2: Studies in dogs with chronic heart failure.

Mitochondrial (MITO) dysfunction occurs in the failing heart and contributes to worsening of heart failure (HF). Reduced aldehyde dehydrogenase 2 (ALDH2) in left ventricular (LV) myocardium of diabetic hearts has been implicated in MITO dysfunction through accumulation of toxic aldehydes including and elevated levels of 4-hydroxy-2-nonenal (4HNE). This study examined whether dysregulation of MITO ALDH2 (mALDH2) occurs in mitochondria of the failing LV and is associated with increased levels of 4HNE. LV tissue from 7 HF and 7 normal (NL) dogs was obtained. Protein quantification of total mitochondrial ALDH2 (t-mALDH2), phosphorylated mALDH2 (p-mALDH2), total MITO protein kinase c epsilon (t-mPKCε), phosphorylated mPKCε (p-mPKCε) was performed by Western blotting, and total mALDH2 enzymatic activity was measured. Protein adducts of 4HNE-MITO and 4HNE-mALDH2 were also measured in MITO fraction by Western Blotting. Protein level of t-mALDH2 was decreased in HF compared with NL dogs (0.63 ± 0.07 vs 1.17 ± 0.08, p < 0.05) as did mALDH2 enzymatic activity (51.39 ± 3 vs. 107.66 ± 4 nmol NADH/min/mg, p < 0.05). Phosphorylated-mALDH2 and p-mPKCε were unchanged. 4HNE-MITO proteins adduct levels increased in HF compared with NL (2.45 ± 0.08 vs 1.30 ± 0.03 du, p < 0.05) as did adduct levels of 4HNE-mALDH2 (1.60 ± 0.20 vs 0.39 ± 0.08, p < 0.05). In isolated failing cardiomyocytes (CM) exposure to 4HNE decreased mALDH2 activity, increased ROS and 4HNE-ALDH2 adducts, and worsened MITO function. Stimulation of mALDH2 activity with ALDA-1 in isolated HF CMs compared to NL CMs improved ADP-stimulated respiration and maximal ATP synthesis to a greater extant (+47 % and +89 %, respectively). Down-regulation of mALDH2 protein levels and activity occurs in HF and contributes to MITO dysfunction and is likely caused by accumulation of 4HNE-mALDH2 adduct. Increasing mALDH2 activity (via ALDA-1) improved MITO function in failing CMs.

Maintaining the Mitochondrial Quality Control System Was a Key Event of Tanshinone IIA against Deoxynivalenol-Induced Intestinal Toxicity.

Deoxynivalenol (DON) is the one of the most common mycotoxins, widely detected in various original foods and processed foods. Tanshinone IIA (Tan IIA) is a fat-soluble diterpene quinone extracted from Salvia miltiorrhiza Bunge, which has multi-biological functions and pharmacological effects. However, whether Tan IIA has a protective effect against DON-induced intestinal toxicity is unknown. In this study, the results showed Tan IIA treatment could attenuate DON-induced IPEC-J2 cell death. DON increased oxidation product accumulation, decreased antioxidant ability and disrupted barrier function, while Tan IIA reversed DON-induced barrier function impairment and oxidative stress. Furthermore, Tan IIA dramatically improved mitochondrial function via mitochondrial quality control. Tan IIA could upregulate mitochondrial biogenesis and mitochondrial fusion as well as downregulate mitochondrial fission and mitochondrial unfolded protein response. In addition, Tan IIA significantly attenuated mitophagy caused by DON. Collectively, Tan IIA presented a potential protective effect against DON toxicity and the underlying mechanisms were involved in mitochondrial quality control-mediated mitophagy.

Tanshinone IIA protects intestinal epithelial cells from deoxynivalenol-induced pyroptosis.

Deoxynivalenol (DON) is the most common mycotoxin in food and feed, which can cause undesirable effects, including diarrhea, emesis, weight loss, and growth delay in livestock. Intestinal epithelial cells were the main target of DON, which can cause oxidative stress and inflammatory injury. Tanshinone IIA (Tan IIA) is fat-soluble diterpene quinone, which is the most abundant active ingredient in salvia miltiorrhiza plant with antioxidant and anti-inflammatory characteristics. However, it is not clear whether Tan IIA can protect against or inhibit intestinal oxidative stress and inflammatory injury under DON exposure. This study aimed to explore the protective effect of Tan IIA on DON-induced toxicity in porcine jejunum epithelial cells (IPEC-J2). Cells were exposed to 0, 0.5, 1.0, 2.0 µM DON and/or 45 µg/mL TAN ⅡA to detect oxidative stress indicators. inflammatory cytokines, NF-κB expression, NLRP3 inflammasome and pyroptosis-related factors. In this study, DON exposure caused IPEC-J2 cells oxidative stress by elevating ROS and 8-OHdG content, inhibited GSH-Px activity. Furthermore, DON increased pro-inflammatory factor (TNF-α, IL-1ß, IL-18 and IL-6) expression and decreased the anti-inflammatory factor (IL-10) expression, causing inflammatory response via triggering NF-κB pathway. Interestingly, above changes were alleviated after Tan IIA treatment. In addition, Tan IIA relieved DON-induced pyroptosis by suppressing the expression of pyroptosis-related factors (NLRP3, Caspase-1, GSDMD, IL-1ß, and IL-18). In general, our data suggested that Tan IIA can ameliorate DON-induced intestinal epithelial cells injury associated with suppressing the pyroptosis signaling pathway. Our findings pointed that Tan IIA could be used as the potential therapeutic drugs on DON-induced enterotoxicity.

Hepatic arterial infusion therapy for advanced hepatocellular carcinoma after systemic treatment failure: Multicenter, real-world study.

AIM: The study was conducted to evaluate the feasibility and safety profile of hepatic arterial infusion chemotherapy with oxaliplatin, 5-fluorouracil, and leucovorin (HAIC-FOLFOX) as an alternative therapeutic choice for patients with advanced hepatocellular carcinoma (HCC) that is refractory to systemic treatment including immune checkpoint blockades or molecular targeting agents. METHODS: Two hundred and forty five consecutive patients with advanced HCC who received HAIC-FOLFOX treatment after systemic treatment failure were retrospectively reviewed in six institutions and their survival, tumor response, and tolerance were assessed. RESULTS: The median overall survival (OS) and progression-free survival of the 209 included participants were 10.5 months (95% confidence interval [CI], 8.1-12.9) and 6.0 months (95% CI, 5.1-6.9), respectively. According to Response Evaluation Criteria in Solid Tumors 1.1 criteria, the objective response rate was 21.1%, and the disease control rate was 64.6%. Multivariate analysis of risk factors of OS were albumin-bilirubin grade (2 and 3 vs. 1, hazard ratio [HR] 1.57; 95% CI, 1.05-2.34; p = 0.028), tumor number (>3 vs. 1-3, HR 2.18; 95% CI, 1.10-4.34; p = 0.026), extrahepatic spread (present vs. absent, HR 1.61, 95% CI, 1.06-2.45; p = 0.027), synchronous systemic treatment (present vs. absent, HR 0.55, 95% CI, 0.37-0.83; p = 0.004) and treatment response (responder vs. nonresponder, HR 0.30, 95% CI, 0.17-0.53; p < 0.001). Grade 3-4 adverse events (AEs) occurred in 59 (28.2%) HCC patients. All AEs were manageable, and deaths related to hepatic artery infusion chemotherapy treatment were not observed. CONCLUSIONS: Our findings support the effectiveness and safety of HAIC-FOLFOX treatment for patients with advanced HCC who have failed systemic treatment.

Natural variation of GmRj2/Rfg1 determines symbiont differentiation in soybean.

Symbiotic nitrogen fixation (SNF) provides much of the N utilized by leguminous plants throughout growth and development. Legumes may simultaneously establish symbiosis with different taxa of microbial symbionts. Yet, the mechanisms used to steer associations toward symbionts that are most propitious across variations in soil types remain mysterious. Here, we demonstrate that GmRj2/Rfg1 is responsible for regulating symbiosis with multiple taxa of soybean symbionts. In our experiments, the GmRj2/Rfg1SC haplotype favored association with Bradyrhizobia, which is mostly distributed in acid soils, whereas the GmRj2/Rfg1HH haplotype and knockout mutants of GmRj2/Rfg1SC associated equally with Bradyrhizobia and Sinorhizobium. Association between GmRj2/Rfg1 and NopP, furthermore, appeared to be involved in symbiont selection. Furthermore, geographic distribution analysis of 1,821 soybean accessions showed that GmRj2/Rfg1SC haplotypes were enriched in acidic soils where Bradyrhizobia were the dominant symbionts, whereas GmRj2/Rfg1HH haplotypes were most prevalent in alkaline soils dominated by Sinorhizobium, and neutral soils harbored no apparent predilections toward either haplotype. Taken together, our results suggest that GmRj2/Rfg1 regulates symbiosis with different symbionts and is a strong determinant of soybean adaptability across soil regions. As a consequence, the manipulation of the GmRj2/Rfg1 genotype or application of suitable symbionts according to the haplotype at the GmRj2/Rfg1 locus might be suitable strategies to explore for increasing soybean yield through the management of SNF.

p38 mediates T-2 toxin-induced Leydig cell testosterone synthesis disorder.

T-2 toxin is an unavoidable food and feed contaminant that seriously threatens human and animal health. Exposure to T-2 toxin can cause testosterone synthesis disorder in male animals, but the molecular mechanism is still not completely clear. The MAPK pathway participates in the regulation of testosterone synthesis by Leydig cells, but it is unclear whether the MAPK pathway participates in T-2 toxin-induced testosterone synthesis disorders. In this research, testosterone synthesis capacity, testosterone synthase expression and MAPK pathway activation were examined in male mice and TM3 cells exposed to T-2 toxin. The results showed that T-2 toxin exposure decreased testicular volume and caused pathological changes in the microstructure and ultrastructure of testicular Leydig cells. T-2 toxin exposure also decreased testicular testosterone content and the protein expression of testosterone synthase. In vitro, T-2 toxin inhibited cell viability and decreased the expression of testosterone synthase in TM3 cells, and it decreased the testosterone contents in cell culture supernatants. Moreover, T-2 toxin activated the MAPK pathway by increasing the expression of p38, JNK and ERK as well as the expression of p-p38, p-JNK and p-ERK in testis and TM3 cells. The p38 molecular inhibitor (SB203580) significantly alleviated the T-2 toxin-induced decrease in testosterone synthase expression in TM3 cells and the T-2 toxin-induced reduction in testosterone content in TM3 cell culture supernatants. In summary, p38 mediates T-2 toxin-induced Leydig cell testosterone synthesis disorder.

Transcriptomic profiling of lipopolysaccharide-challenged bovine mammary epithelial cells treated with forsythoside A.

Mastitis is usually caused by a variety of pathogenic bacteria that seriously impact the health and milk-production ability of dairy cows, with consequent, economically detrimental effects on the dairy industry. Forsythoside A (FTA), isolated from the fruit and leaves of Forsythia suspensa (Thunb.) Vahl (Oleaceae), has been reported to have significant antioxidant, anti-inflammatory, and antibacterial effects. However, it is not clear whether FTA exerts a protective effect against lipopolysaccharide (LPS)-induced bovine mastitis and its potential gene signature. In this study, high-throughput sequencing technology was performed to analyze the differences between the mRNA and enrichment pathway of bovine mammary epithelial cells of the control, LPS, and LPS + FTA groups. The results showed that there were 139 differentially expressed genes (DEGs) (p-value < 0.05, |log2FoldChange| > 1, FPKM > 1) in the LPS group compared with the control group, including 121 up-regulated genes and 18 down-regulated genes, which were mainly enriched in the cellular response to lipopolysaccharide, cytokine activity, protein binding, and IL-17 signaling pathway based on Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, respectively. Compared with the control group and LPS + FTA group, there were 349 DEGs, including 322 up-regulated genes and 27 down-regulated genes. They were mainly enriched in protein localization to organelles, centrosomes, binding, and the IL-17 signaling pathway, based on GO and KEGG analysis. Compared to the LPS group, the LPS + FTA group had 272 DEGs, including 259 up-regulated genes and 13 down-regulated genes, which were mainly enriched in RNA processing, IL-6 receptor binding, and the lysosome pathway, based on GO and KEGG analyses. It can be seen that LPS stimulation induced the expression of inflammation-related genes, IL-17 and IL-6, whereas FTA treatment promoted the expression of the spliceosome-, lysosome-, and oxidative stress-related genes HSP70, HSPA8, and PARP2. The study utilized RNA-sequencing analysis of FTA against LPS-challenged bovine mammary epithelial cells to explore key mRNA findings that may be strongly associated with inflammation and oxidative stress, and provides a theoretical reference for further elucidation of molecular mechanisms of bovine mastitis and therapeutic effects of FTA against bovine mastitis.

Multi-step forecast of PM2.5 and PM10 concentrations using convolutional neural network integrated with spatial-temporal attention and residual learning.

Accurate and reliable forecasting of PM2.5 and PM10 concentrations is important to the public to reasonably avoid air pollution and for the governmental policy responses. However, the prediction of PM2.5 and PM10 concentrations has great uncertainty and instability because of the dynamics of atmospheric flows, making it difficult for a single model to efficiently extract the spatial-temporal dependences. This paper reports a robust forecasting system to achieve accurate multi-step ahead forecasting of PM2.5 and PM10 concentrations. First, correlation analysis is adopted to screen the spatial information on pollution and meteorology that may facilitate the prediction of concentrations in a target city. Then, a spatial-temporal attention mechanism is used to assign weights to original inputs from both space and time dimensions to enhance the essential information. Subsequently, the residual-based convolutional neural network with feature extraction capabilities is employed to model the refined inputs. Finally, five accuracy metrics and two additional statistical tests are applied to comprehensively assess the performance of the proposed forecasting system. In addition, experimental studies of three major cities in the Yangtze River Delta urban agglomeration region indicate that the forecasting system outperforms various prevalent baseline models in terms of accuracy and stability. Quantitatively, the proposed STA-ResCNN model reduces root mean square error by 5.595 %-15.247 % and 6.827 %-16.906 % for the average of 1-4 h ahead predictions in three major cities of PM2.5 and PM10, respectively, compared to baseline models. The applicability and generalization of the proposed forecasting system are further verified by the extended applications in the other 23 cities in the entire region. The results prove that the forecasting system is promising in the early warning, regional prevention, and control of air pollution.

Overexpression of GmPHR1 Promotes Soybean Yield through Global Regulation of Nutrient Acquisition and Root Development.

MYB-CC transcription factors (TFs) are essential for plant growth and development. Members of the MYB-CC subfamily with long N terminal domains, such as phosphate starvation response 1 (PHR1) or PHR1-like TFs, have well documented functions, while those with short N terminal domains remain less understood. In this study, we identified a nodule specific MYB-CC transcription factor 1 (GmPHR1) in soybean that is different from other canonical PHR family genes in that GmPHR1 harbors a short N terminal ahead of its MYB-CC domain and was highly induced by rhizobium infection. The overexpression of GmPHR1 dramatically increased the ratio of deformed root hairs, enhanced subsequent soybean nodulation, and promoted soybean growth in pot experiments. The growth promotion effects of GmPHR1 overexpression were further demonstrated in field trails in which two GmPHR1-OE lines yielded 10.78% and 8.19% more than the wild type line. Transcriptome analysis suggested that GmPHR1 overexpression led to global reprogramming, with 749 genes upregulated and 279 genes downregulated, especially for genes involved in MYB transcription factor activities, root growth, and nutrient acquisition. Taken together, we conclude that GmPHR1 is a key gene involved in the global regulation of nodulation, root growth, and nutrient acquisition in soybeans, and is thus a promising candidate gene to target for soybean yield enhancement.

Deoxynivalenol triggers porcine intestinal tight junction disorder: Insights from mitochondrial dynamics and mitophagy.

Deoxynivalenol (DON) is universally detected trichothecene in most cereal commodities, which is considered as a major hazardous material for human and animal health. Intestine is the most vulnerable organ with higher concentration of DON than other organs, owing to the first defense barrier function to exogenous substances. However, the underling mechanisms about DON-induced intestinal toxicity remain poorly understood. Here, DON poisoning models of IPEC-J2 cells was established to explore adverse effect and the potential mechanism of DON-induced enterotoxicity. Results showed that DON exposure destroyed IPEC-J2 cells morphology. Results showed that DON exposure destroyed IPEC-J2 cells morphology. Intestinal epithelial barrier injury was caused by DON with increasing LDH release, decreasing cell viability as well decreasing tight junction protein expressions (Occludin, N-Cad, ZO-1, Claudin-1 and Claudin-3). Moreover, DON caused mitochondrial dysfunction by opening mitochondrial permeability transition pore and eliminating mitochondrial membrane potential. DON exposure upregulated protein and mRNA expression of mitochondrial fission factors (Drp1, Fis1, MIEF1 and MFF) and mitophagy factors (PINK1, Parkin and LC3), downregulated mitochondrial fusion factors (Mfn1, Mfn2, except OPA1), resulting in mitochondrial dynamics imbalance and mitophagy. Overall, these findings suggested that DON induced tight junction dysfunction in IPEC-J2 cells was related to mitochondrial dynamics-mediated mitophagy.

Effects of non-driving related tasks on readiness to take over control in conditionally automated driving.

OBJECTIVE: At conditionally automated driving, the driver can temporarily engage in non-driving related tasks (NDRTs). However, they must safely take over control when the automated driving system reaches its operation limit. Thus, understanding the effects of the NDRTs on driver take-over performance is essential. The present work investigates the effects of various NDRTs on motor readiness in take-over scenarios during conditionally automated driving. METHODS: Three driving simulator studies were conducted. 48, 49, and 22 participants were recruited in three experiments, respectively. The participants were distracted by different NDRTs (everyday task in Experiment 1, arrow task in Experiment 2, and SuRT in Experiment 3) on a tablet mounted in the vehicle. The everyday task included reading the news and watching a video, and the arrow task included a set of arrow matrices presented to the participants in sequence. The time budgets in Experiment 1 included 3 s, 4 s, and 5 s, and the time budgets in Experiment 2 and 3 included 5 s and 7 s. A take-over request (TOR) warning was issued in the automated driving condition when the participants encountered a broken-down car in front. The participants must regain control of the vehicle with the given time budget. The hands-on time was evaluated, measuring the time from the TOR until the hands touch the steering wheel. RESULTS: The task (arrow task and SuRT), time budget (5 s and 7 s), and gender did not affect the hands-on time. However, the hands-on time for the drivers with the everyday task was significantly shorter than that for the drivers with the arrow task in the 5 s time budget. CONCLUSIONS: In conditionally automated driving, the arrow task and SuRT imposed a similar workload on readiness to take over control. Compared to the everyday task, the engagement in the arrow tasks consumed more workload on readiness to take over control.

Functional assembly of root-associated microbial consortia improves nutrient efficiency and yield in soybean.

Root-associated microbes are critical for plant growth and nutrient acquisition. However, scant information exists on optimizing communities of beneficial root-associated microbes or the mechanisms underlying their interactions with host plants. In this report, we demonstrate that root-associated microbes are critical influencers of host plant growth and nutrient acquisition. Three synthetic communities (SynComs) were constructed based on functional screening of 1,893 microbial strains isolated from root-associated compartments of soybean plants. Functional assemblage of SynComs promoted significant plant growth and nutrient acquisition under both N/P nutrient deficiency and sufficiency conditions. Field trials further revealed that application of SynComs stably and significantly promoted plant growth, facilitated N and P acquisition, and subsequently increased soybean yield. Among the tested communities, SynCom1 exhibited the greatest promotion effect, with yield increases of up to 36.1% observed in two field sites. Further RNA-seq implied that SynCom application systemically regulates N and P signaling networks at the transcriptional level, which leads to increased representation of important growth pathways, especially those related to auxin responses. Overall, this study details a promising strategy for constructing SynComs based on functional screening, which are capable of enhancing nutrient acquisition and crop yield through the activities of beneficial root-associated microbes.

Intravenous Infusion of the ß3-Adrenergic Receptor Antagonist APD418 Improves Left Ventricular Systolic Function in Dogs With Systolic Heart Failure.

BACKGROUND: Unlike ß1- and ß2-adrenergic receptors (ARs), ß3-AR stimulation inhibits cardiac contractility and relaxation. In the failing left ventricular (LV) myocardium, ß3-ARs are upregulated, and can be maladaptive in the setting of decompensation by contributing to LV dysfunction. This study examined the effects of intravenous infusions of the ß3-AR antagonist APD418 on cardiovascular function and safety in dogs with systolic heart failure (HF). METHODS AND RESULTS: Three separate studies were performed in 21 dogs with coronary microembolization-induced HF (LV ejection fraction [LVEF] of approximately 35%). Studies 1 and 2 (n = 7 dogs each) were APD418 dose escalation studies (dosing range, 0.35-15.00 mg/kg/h) designed to identify an effective dose of APD418 to be used in study 3. Study 3, the sustained efficacy study, (n = 7 dogs) was a 6-hour constant intravenous infusion of APD418 at a dose of 4.224 mg/kg (0.70 mg/kg/h) measuring key hemodynamic endpoints (e.g., EF, cardiac output, the time velocity integral of the mitral inflow velocity waveform representing early filling to time-velocity integral representing left atrial contraction [Ei/Ai]). Studies 1 and 2 showed a dose-dependent increase of LVEF and Ei/Ai, the latter being an index of LV diastolic function. In study 3, infusion of APD418 over 6 hours increased LVEF from 31 ± 1% to 38 ± 1% (P < .05) and increased Ei/Ai from 3.4 ± 0.4 to 4.9 ± 0.5 (P < .05). Vehicle had no effect on the LVEF or Ei/Ai. In study 3, APD418 had no significant effects on the HR or the systemic blood pressure. CONCLUSIONS: Intravenous infusions of APD418 in dogs with systolic HF elicit significant positive inotropic and lusitropic effects. These findings support the development of APD418 for the in-hospital treatment of patients with an acute exacerbation of chronic HF.

Functional Investigation of Plant Growth Promoting Rhizobacterial Communities in Sugarcane.

Plant microbiota are of great importance for host nutrition and health. As a C4 plant species with a high carbon fixation capacity, sugarcane also associates with beneficial microbes, though mechanisms underlying sugarcane root-associated community development remain unclear. Here, we identify microbes that are specifically enriched around sugarcane roots and report results of functional testing of potentially beneficial microbes propagating with sugarcane plants. First, we analyzed recruitment of microbes through analysis of 16S rDNA enrichment in greenhouse cultured sugarcane seedlings growing in field soil. Then, plant-associated microbes were isolated and assayed for beneficial activity, first in greenhouse experiments, followed by field trials for selected microbial strains. The promising beneficial microbe SRB-109, which quickly colonized both roots and shoots of sugarcane plants, significantly promoted sugarcane growth in field trials, nitrogen and potassium acquisition increasing by 35.68 and 28.35%, respectively. Taken together, this report demonstrates successful identification and utilization of beneficial plant-associated microbes in sugarcane production. Further development might facilitate incorporation of such growth-promoting microbial applications in large-scale sugarcane production, which may not only increase yields but also reduce fertilizer costs and runoff.

miR169c-NFYA-C-ENOD40 modulates nitrogen inhibitory effects in soybean nodulation.

Legume crops contribute a great portion of clean nitrogen (N) to agro-ecosystems through symbiotic N2 fixation in the nodule; however, the nodulation is always inhibited by high N availability which is known as the N inhibitory effect through largely unknown mechanisms. We functionally investigated miR169c-GmNFYA-C-GmENOD40 under multiple N conditions in soybean (Glycine max) (ENOD, Early Nodulin; NFYA, Nuclear Factor-Y Subunit A). We elucidated their regulatory roles in soybean nodulation through analyzing expression patterns, micro-messenger RNA (miRNA-mRNA) interactions, phenotypes of transgenic soybean plants and genetic interactions. We found that miR169c expression was induced by high N, whereas its target GmNFYA-C was preferentially expressed in nodules and induced by rhizobium inoculation. Overexpression of miR169c inhibited nodulation through targeting 3'-UTR of GmNFYA-C, whereas knockout miR169c through CRISPR-cas9 promoted nodulation. However, overexpression of GmNFYA-C promoted soybean nodulation through facilitating rhizobium infection and increasing the expression of symbiotic signaling gene GmENOD40. Besides, GmNFYA-C directly induced the expression of GmENOD40. In addition, overexpression of GmNFYA-C without the target site of miR169c partially attenuated the inhibitory effect of high N on soybean nodulation. We discovered a new regulatory pathway involving the miR169c-NFYA-C-ENOD40 module that regulates soybean nodulation in response to N availability. This pathway provides substantial new insights into the mechanisms underlying the N inhibitory effect on nodulation.

Effects of Angiotensin-Neprilysin Inhibition in Canines with Experimentally Induced Cardiorenal Syndrome.

BACKGROUND: Sacubitril/valsartan (Sac/Val), a combined angiotensin-II receptor blocker (Val) and neprilysin inhibitor (Sac) in a 1:1 molar ratio, was shown to decrease the risk of cardiovascular death or heart failure (HF) hospitalization in patients with HF and reduced left ventricular (LV) ejection fraction. This study examined the effects of Sac/Val on LV structure, function, and bioenergetics, and on biomarkers of kidney injury and kidney function in dogs with experimental cardiorenal syndrome. METHODS AND RESULTS: Fourteen dogs with cardiorenal syndrome (coronary microembolization-induced HF and renal dysfunction) were randomized to 3 months Sac/Val therapy (100 mg once daily, n = 7) or no therapy (control, n = 7). LV ejection fraction and troponin-I, as well as biomarkers of kidney injury/function including serum creatinine and urinary kidney injury molecule-1 were measured before and at end of therapy and the change (treatment effect change) calculated. Mitochondrial function measures, including the maximum rate of adenosine triphosphate synthesis, were measured in isolated cardiomyocytes at end of therapy. In Sac/Val dogs, the change in ejection fraction increased compared with controls, 6.9 ± 1.4 vs 0.7 ± 0.6%, P < .002, whereas change in troponin I decreased, -0.16 ± 0.03 vs -0.03 ± 0.02 ng/mL, P < .001. Urinary change in kidney injury molecule 1 decreased in Sac/Val-treated dogs compared with controls, -17.2 ± 7.9 vs 7.7 ± 3.0 mg/mL, P < .007, whereas the change in serum creatinine was not significantly different. Treatment with Sac/Val increased adenosine triphosphate synthesis compared with controls, 3240 ± 121 vs 986 ± 84 RLU/µg protein, P < .05. CONCLUSIONS: In dogs with cardiorenal syndrome, Sac/Val improves LV systolic function, improves mitochondrial function and decreases biomarkers of heart and kidney injury. The results offer mechanistic insights into the benefits of Sac/Val in HF with compromised renal function.

Effects of Intravenous Infusion of Vepoloxamer on Left Ventricular Function in Dogs with Advanced Heart Failure.

PURPOSE: Vepoloxamer (VEPO), a rheologic agent, repairs damaged cell membranes, thus inhibiting unregulated Ca2+ entry into cardiomyocytes. This study examined the effects of i.v. infusion of VEPO on LV function in dogs with coronary microembolization-induced heart failure (HF) (LV ejection fraction, EF ~ 30%). METHODS: Thirty-five HF dogs were studied. Study 1: 21 of 35 dogs were randomized to 2-h infusion of VEPO at dose of 450 mg/kg (n = 7) or VEPO at 225 mg/kg (n = 7) or normal saline (control, n = 7). Hemodynamics were measured at 2 h, 24 h, 1 week, and 2 weeks after infusion. Study 2: 14 HF dogs were randomized to 2-h infusions of VEPO (450 mg/kg, n = 7) or normal saline (control, n = 7). Each dog received 2 infusions of VEPO or saline (pulsed therapy) 3 weeks apart and hemodynamics measured at 24 h, and 1, 2, and 3 weeks after each infusion. In both studies, the change between pre-infusion measures and measures at other time points (treatment effect, Δ) was calculated. RESULTS: Study 1: compared to pre-infusion, high dose VEPO increased LVEF by 11 ± 2% at 2 h, 8 ± 2% at 24 h (p < 0.05), 8 ± 2% at 1 week (p < 0.05), and 4 ± 2% at 2 weeks. LV EF also increased with low-dose VEPO but not with saline. Study 2: VEPO but not saline significantly increased LVEF by 6.0 ± 0.7% at 2 h (p < 0.05); 7.0 ± 0.7%% at 1 week (p < 0.05); 1.0 ± 0.6% at 3 weeks; 6.0 ± 1.3% at 4 weeks (p < 0.05); and 5.9 ± 1.3% at 6 weeks (p < 0.05). CONCLUSIONS: Intravenous VEPO improves LV function for at least 1 week after infusion. The benefits can be extended with pulsed VEPO therapy. The results support development of VEPO for treating patients with acute on chronic HF.

A New Method for Refining the GNSS-Derived Precipitable Water Vapor Map.

Abstract: The objective of the study was to put forth an interpolation method (the LZ method) for refining the GNSS-derived precipitable water vapor (PWV) map. We established a regional weighted mean temperature (Tm) model for this experiment, which introduced a minor difference into the resultant GNSS-derived PWV compared to the previous Tm models. The kernel of the LZ method consists of increasing the sample density via the virtual sample points. These virtual sample points originated from the digital elevation model (DEM) were constructed on the basis of the statistically significant correlation between PWV and geographical location (i.e., geographical coordinates and elevation). The LZ method was validated and compared to the conventional interpolation approach only accounting for the original sample points. The results reflect that the PWV maps generated by the LZ method showed more details than through conventional one. In addition, the prediction performance of the LZ method was better than that of the conventional method by using cross-validation.

Effects of elamipretide on skeletal muscle in dogs with experimentally induced heart failure.

AIMS: Elamipretide (ELAM), an aromatic-cationic tetrapeptide, interacts with cardiolipin and normalizes dysfunctional mitochondria of cardiomyocytes. This study examined the effects of ELAM on skeletal muscle mitochondria function in dogs with chronic heart failure (HF). METHODS AND RESULTS: Studies were performed in skeletal muscle biopsy specimens obtained from normal dogs (n = 7) and dogs with chronic intracoronary microembolization-induced HF (n = 14) treated with subcutaneous ELAM 0.5 mg/kg (HF + ELAM, n = 7) or vehicle (normal saline control, HF-CON, n = 7). After 3 months of therapy, triceps skeletal muscle samples were obtained from all dogs, and the proportion of type 1 and type 2 fibres was assessed. Mitochondria isolated from myofibrils of the vastus lateralis skeletal muscle exposed in vitro to ELAM for 1 h were used to assess mitochondrial function. The proportion of skeletal muscle type 1 fibres was lower in HF-CON dogs compared with normal dogs (23 ± 4 vs. 32 ± 5%, P < 0.05). Treatment with ELAM restored a near-normal fibre-type composition (31 ± 7%, P < 0.05 vs. HF-CON). Skeletal muscle mitochondria showed significantly lower levels of adenosine diphosphate-dependent mitochondrial respiration (100 ± 9 vs. 164 ± 15 natom O/min/mg protein, P < 0.05), mitochondrial membrane potential (0.17 ± 0.03 vs. 0.53 ± 0.03 red/green fluorescence ratio, P < 0.05), mitochondrial permeability transition pore (38 ± 3 vs. 62 ± 2 relative light units, P < 0.05), maximum rate of adenosine triphosphate synthesis (3284 ± 418 vs. 8835 ± 423 RLU/µg protein, P < 0.05), and cytochrome c oxidase activity (1390 ± 108 vs. 2459 ± 210 natom O/min/mg protein, P < 0.05) compared with normal dogs. Exposure of skeletal muscle myofibrillar mitochondria from HF dogs to ELAM showed a dose-dependent improvement/normalization of all measures of mitochondrial function. In mitochondria from skeletal muscle of HF dogs exposed to 0.10 µM ELAM, adenosine diphosphate-dependent mitochondrial respiration increased to 183 ± 18 natom O/min/mg protein, membrane potential increased to 0.30 ± 0.03 red/green fluorescence ratio, mitochondrial permeability transition pore increased to 54 ± 4 RLU, maximum rate of adenosine triphosphate synthesis increased to 4423 ± 414, and cytochrome c oxidase activity increased to 2033 ± 191 natom O/min/mg protein. Exposure of skeletal muscle myofibrillar mitochondria from normal dogs to ELAM had no effect on mitochondrial function parameters. CONCLUSIONS: The results indicate that ELAM, previously shown to positively influence mitochondrial function of the failing heart, can also positively impact mitochondrial function of skeletal muscle and potentially help restore skeletal muscle function and improve exercise tolerance.

Intravenous Infusion of the Novel HNO Donor BMS-986231 Is Associated With Beneficial Inotropic, Lusitropic, and Vasodilatory Properties in 2 Canine Models of Heart Failure.

The effects of the nitroxyl donor BMS-986231 on hemodynamics, left ventricular (LV) function, and pro-arrhythmic potential were assessed using canine heart failure models. BMS-986231 significantly (p < 0.05) increased LV end-systolic elastance, pre-load-recruitable stroke work, ejection fraction, stroke volume, cardiac output, ratio of early-to-late filling time integrals, and early mitral valve inflow velocity deceleration time. BMS-986231 significantly decreased LV filling pressures, end-diastolic stiffness, the time-constant of relaxation, end-diastolic wall stress, systemic vascular resistance, and myocardial oxygen consumption. BMS-986231 had little effect on heart rate and did not induce de novo arrhythmias. Thus, BMS-986231 has beneficial inotropic, lusitropic, and vasodilatory effects.