Research on the Cell Wall Breaking and Subcritical Extraction of Astaxanthin from Phaffia rhodozyma.

This study focused on developing an effective cell wall-breaking method for Phaffia rhodozyma, followed by utilizing subcritical fluid extraction to isolate, extract, and concentrate astaxanthin from the complex fermentation products of P. rhodozyma. A comprehensive comparison of seven distinct methods for disrupting cell walls, including dimethyl sulfoxide treatment, lactic acid treatment, sodium hydroxide treatment, ß-glucanase enzymatic digestion, ß-mannanase enzymatic digestion, and a combined enzymatic treatment involving both ß-mannanase and ß-glucanase was conducted. The results identified the lactic acid method as the most effective in disrupting the cell walls of P. rhodozyma. The software, Design Expert, was used in the process of extracting astaxanthin from cell lysates using a subcritical extraction method. Through fitting analysis and response surface optimization analysis by Design Expert, the optimal extraction conditions were determined as follows: an extraction temperature of 41 °C, extraction frequency of two times, and extraction time of 46 min. These parameters facilitated the efficient extraction, concentration, and enrichment of astaxanthin from P. rhodozyma, resulting in an astaxanthin concentration of 540.00 mg/L. This result can establish the foundation for its high-value applications.

Iron and atrial fibrillation: A review.

Atrial fibrillation (AF), one of the most common arrhythmias in clinical practice, is classified into paroxysmal, persistent, and permanent AF according to its duration. The development of AF is associated with increased cardiovascular morbidity and mortality. However, the exact etiology of this disease remains poorly understood. Recent studies found disorders of iron metabolism might be involved in the progression of AF. Abnormal iron metabolism in cardiomyocytes provides arrhythmogenic substrates through a variety of mechanisms, including calcium mishandling, ion channel remodeling, and oxidative stress overaction. Interestingly, in AF patients with iron overload, interventions on iron metabolism, such as iron chelators and ferroptosis inhibitors, has been shown to prevent AF via reducing ferroptosis. Herein, we review the possible mechanisms, consequences, and therapeutic implications of altered atrial iron handling for AF pathophysiology.

Effect of SH2B1 on glucose metabolism during pressure overload-induced cardiac hypertrophy and cardiac dysfunction.

This study mainly explored the effect and mechanism of Src homology 2 (SH2) B adaptor protein 1 (SH2B1) on cardiac glucose metabolism during pressure overload-induced cardiac hypertrophy and dysfunction. A pressure-overloaded cardiac hypertrophy model was constructed, and SH2B1-siRNA was injected through the tail vein. Haematoxylin and eosin (H&E) staining was used to detect myocardial morphology. ANP, BNP, ß-MHC and the diameter of myocardial fibres were quantitatively measured to evaluate the degree of cardiac hypertrophy, respectively. GLUT1, GLUT4, and IR were detected to assess cardiac glucose metabolism. Cardiac function was determined by echocardiography. Then, glucose oxidation and uptake, glycolysis and fatty acid metabolism were assessed in Langendorff perfusion of hearts. Finally, PI3K/AKT activator was used to further explore the relevant mechanism. The results showed that during cardiac pressure overload, with the aggravation of cardiac hypertrophy and dysfunction, cardiac glucose metabolism and glycolysis increased, and fatty acid metabolism decreased. After SH2B1-siRNA transfection, cardiac SH2B1 expression was knocked down, and the degree of cardiac hypertrophy and dysfunction was alleviated compared with the Control-siRNA transfected group. Simultaneously, cardiac glucose metabolism and glycolysis were reduced, and fatty acid metabolism was enhanced. The SH2B1 expression knockdown mitigated the cardiac hypertrophy and dysfunction by reducing cardiac glucose metabolism. After using PI3K/AKT activator, the effect of SH2B1 expression knockdown on cardiac glucose metabolism was reversed during cardiac hypertrophy and dysfunction. Collectively, SH2B1 regulated cardiac glucose metabolism by activating the PI3K/AKT pathway during pressure overload-induced cardiac hypertrophy and cardiac dysfunction.

Exploiting synthetic biology platforms for enhanced biosynthesis of natural products in Yarrowia lipolytica.

With the rapid development of synthetic biology, researchers can design, modify, or even synthesize microorganisms de novo, and microorganisms endowed with unnatural functions can be considered "artificial life" and facilitate the development of functional products. Based on this concept, researchers can solve critical problems related to the insufficient supply of natural products, such as low yields, long production cycles, and cumbersome procedures. Due to its superior performance and unique physiological and biochemical characteristics, Yarrowia lipolytica is a favorable chassis cell used for green biomanufacturing by numerous researchers. This paper mainly reviews the development of synthetic biology techniques for Y. lipolytica and summarizes the recent research progress on the synthesis of natural products in Y. lipolytica. This review will promote the continued innovative development of Y. lipolytica by providing theoretical guidance for research on the biosynthesis of natural products.

Condensed tannin improves growth and alleviates intestinal inflammation of juvenile largemouth bass (Micropterus salmoides) fed with high cottonseed protein concentrate diet.

The objective of this study was to examine the potential of condensed tannin (CT) in mitigating the adverse effects on growth and intestinal health induced by high cottonseed concentrate protein (CPC) diets in juvenile largemouth bass (Micropterus salmoides). Largemouth bass were respectively fed with the basic diet, the high CPC diet, and the CPC + CT diet (incorporated 3.75 g/kg CT into the high CPC diet) for a duration of 8 weeks. Results indicated that the high CPC diet resulted in decreased growth performance and compromised intestinal health. Dietary CT enhanced the growth of fish, improved intestinal function, and optimized intestinal microbiota. Additionally, intestinal transcriptome analysis revealed that dietary CT might mitigate intestinal inflammation by downregulating the related gene expression in the cell adhesion molecule pathway. Furthermore, the gene expression of cd22 and mhc2 was positively correlated with the relative abundance of the Geodermatophilus, an indicator species of intestinal microbiota in high CPC treatment. Our research suggests that the inclusion of CT (3.75 g/kg) in the high CPC diet of largemouth bass can stimulate growth and alleviate negative impacts on intestinal health, indicating that CT can be utilized to enhance the utilization of CPC in fish nutrition.

Efficient conversion of distillers grains as feed ingredient by synergy of probiotics and enzymes.

The direct feeding value of distillers grains is low due to the presence of higher cellulose, lignin and anti-nutritional factors such as mannan and xylan. In this study, complex enzymes and probiotic flora based on "probiotic enzyme synergy" technology were used to produce fermented distillers grains. The optimal substrate ratio, moisture content, fermentation time and temperature were determined. Subsequently, scale-up experiments were conducted to determine the performance of fermented feed. The results showed that multi-probiotic (Lactobacillus casei, Bacillus subtilis, Saccharomyces cerevisiae, and Aspergillus oryzae) cooperated with complex enzymes (glucanase, mannanase, xylanase) showed excellent fermentation effect, crude protein, trichloroacetic acid soluble protein and fat increased by 31.25, 36.68, and 49.11% respectively, while crude fiber, acidic fiber and neutral fiber decreased by 34.24, 26.91, and 33.20%, respectively. The anti-nutritional factors mannan and arabinoxylan were reduced by 26.96 and 40.87%, respectively. Lactic acid, acetic acid, and propionic acid in the fermented organic acids increased by 240.93, 76.77, and 89.47%, respectively. Butyric acid increased significantly from scratch, and the mycotoxin degradation effect was not significant. This study provides a potential approach for high-value utilization of distillers grains.

Hydrolysable tannin improves growth performance and liver health of largemouth bass (Micropterus salmoides) fed high soybean meal diets.

This study provided evidence that the inclusion of hydrolysable tannin (HT) in high soybean meal (SBM) diets improved growth performance and glycolipid metabolism of largemouth bass (Micropterus salmoides). In vivo, various levels of HT were added to high SBM diets and fed to largemouth bass (initial weight: 6.00 ± 0.03 g) for 56 days. Results showed that a high level of SBM led to the reduction in growth performance, as evidenced by decreased weight gain rate and impaired hepatic function. Dietary supplementation with HT (1.0 g/kg) improved growth performance of largemouth bass, accompanied by the enhancements in hepatic antioxidant capacity and glycolipid metabolism. In vitro, HT facilitated glucose utilization in hepatocytes and positively influenced the modulation of crucial genes within the PI3K/Akt signaling pathway. Conversely, administration of LY294002 (a PI3K inhibitor) reversed the detrimental effects observed in hepatocytes exposed to high glucose levels. Overall, incorporating HT (1.0 g/kg) into the diet enhanced liver health and improved the absorption and utilization of SBM in largemouth bass, potentially achieved through modulation of the PI3K/Akt signaling pathway.

Alterations of Myocardial Mitochondrial Morphology and Function in a Canine Model of Premature Ventricular Contractions-Induced Cardiomyopathy.

AIMS: Changes in myocardial mitochondrial morphology and function in premature ventricular contractions (PVCs)-induced cardiomyopathy (PVCCM) remain poorly studied. Here, we investigated the effects of PVCs with different coupling intervals (CIs) on myocardial mitochondrial remodelling in a canine model of PVCCM. METHODS AND RESULTS: Twenty-one beagles underwent pacemaker implantation and were randomised into the sham (n = 7), short-coupled PVCs (SCP, n = 7), and long-coupled PVCs (LCP, n = 7) groups. Right ventricular (RV) apical bigeminy was produced for 12-week to induce PVCCM in the SCP (CI, 250 ms) and LCP (CI, 350 ms) groups. Echocardiography was performed at baseline and biweekly thereafter to evaluate cardiac function. Masson's trichrome staining measured ventricular interstitial fibrosis. The ultrastructural morphology of the myocardial mitochondria was analysed using transmission electron microscopy. Mitochondrial Ca2+ concentration, reactive oxygen species (ROS) levels, adenosine triphosphate (ATP) content, membrane potential, and electron transport chain (ETC) complex activity were measured to assess myocardial mitochondrial function. Twelve-week-PVCs led to left ventricular (LV) enlargement with systolic dysfunction, disrupted mitochondrial morphology, increased mitochondrial Ca2+ concentration and ROS levels, decreased mitochondrial ATP content and membrane potential, and impaired ETC complex activity in both the SCP and LCP groups (all p < 0.01 vs the sham group). Ventricular fibrosis was observed only in canines with LCP. Worse cardiac function and more pronounced abnormalities in mitochondrial morphology and function were observed in the LCP group than to the SCP group (all p < 0.05). CONCLUSION: We demonstrated myocardial mitochondrial abnormalities in dogs with PVCCM, characterised by abnormal mitochondrial morphology, mitochondrial Ca2+ overload, oxidative stress, and impaired mitochondrial energy metabolism. Compared to SCP, long-term LCP exposure resulted in more severe mitochondrial remodelling and cardiac dysfunction in dogs.

Serinc2 deficiency exacerbates sepsis-induced cardiomyopathy by enhancing necroptosis and apoptosis.

In critical care medicine, sepsis is a potentially fatal syndrome characterized by multi-organ dysfunction and eventual failure. Sepsis-induced cardiomyopathy (SIC) is characterized by decreased venstricular contractility. Serine incorporator 2 (Serinc2) is a protein involved in phosphatidylserine biosynthesis and membrane incorporation. It may also be a protective factor in septic lung injury. However, it is unknown whether Serinc2 influences SIC onset or progression. In the present study, we found that Serinc2 was downregulated in the cardiomyocytes of cecal ligation and puncture (CLP)-induced SIC and in neonatal rat cardiomyocytes (NRCMs) exposed to lipopolysaccharides (LPS). Serinc2 knockout (KO) exacerbated sepsis-induced myocardial inflammation, necroptosis, apoptosis, myocardial damage, and contractility impairment. Furthermore, the lack of Serinc2 in cardiomyocytes aggravated LPS-induced cardiomyopathic inflammation, necroptosis, and apoptosis. An adenovirus overexpressing Serinc2 inhibited the inflammatory response and favored cardiomyocyte survival. A mechanistic analysis revealed that Serinc2 deficiency exacerbated LPS-induced cardiac dysfunction by inhibiting the protein kinase B (Akt)/glycogen synthase kinase 3 beta (GSK-3ß) signaling pathway that regulates necrotic complex formation and apoptotic pathways in cardiomyopathy. The findings of the present work demonstrated that Serinc2 plays an essential role in SIC and is, therefore, promising as a prophylactic and therapeutic target for this condition.

Carnosic acid protects against doxorubicin-induced cardiotoxicity through enhancing the Nrf2/HO-1 pathway.

Doxorubicin (DOX) is used extensively in anticancer therapy, but its clinical application is limited due to its cardiotoxicity. Carnosic acid (CA) is a bioactive compound found in rosemary. It has been shown to reduce inflammation and reactive oxygen species. The purpose of this study was to investigate the potential cardioprotective effects of CA in response to DOX-induced cardiotoxicity. Here, C57BL/6 mice were administered an intraperitoneal injection of DOX (5 mg kg-1, ip) once a week for three consecutive weeks and treated with CA (40 mg kg-1, ig) for a three-week experimental period. For in vitro study, neonatal rat ventricular cardiomyocytes were used to validate the protective effects of CA (20 µM) in response to DOX-induced cardiotoxicity. CA markedly suppressed oxidative stress, apoptosis, and pyroptosis responses in the mouse hearts, eventually improving cardiac function. CA showed its antioxidant effect by activating nuclear factor erythroid 2-related factor (Nrf2) and its downstream heme oxygenase-1 (HO-1); CA also reduced oxidative stress by lowering the MDA and lipid ROS levels and raising the SOD and GSH-px levels. Additionally, CA treatment significantly increased Bcl-2 and inhibited Bax and Caspase-3 cleavage in DOX-induced cardiotoxicity. Moreover, CA suppressed the NOD-like receptor protein 3 (NLRP3) pathway to mitigate pyroptosis, as evidenced by lowered caspase1, interleukin-18, and interleukin-1ß. Consistently, the transfection of Nrf2-siRNA eliminated the protective effects of CA on cardiomyocytes. Altogether, our findings demonstrated that CA inhibited NLRP3 inflammasomes via activating the Nrf2-related cytoprotective system and protected the heart from oxidative damage, apoptosis, and pyroptosis, implying that the use of CA could be a potential therapeutic strategy in the prevention of DOX-associated myocardiopathy.

Three-stage fermentation of the feed and the application on weaned piglets.

Numerous studies have demonstrated that soybean meal (SBM) contains high levels of anti-nutritional factors, which interrupt gastrointestinal homeostasis or metabolism normally of the weaned piglets. Here, the mixed probiotics, including Bacillus licheniformis (B. licheniformis, CGMCC 8147), Saccharomyces cerevisiae H11 (S. cerevisiae H11) and Lactobacillus casei (L. casei, CGMCC 8149) were applied to the three-stage fermentation of functional feed. Our research investigated the optimum ratio of inoculation, optimal time of inoculation, combination of substrates, and nutritional value of the fermented feed. The optimal microbial combination was B. licheniformis: S. cerevisiae: L. casei = 2:2:1, inoculating at 0, 12 and 24 h, respectively. The results revealed that crude protein and acid-soluble protein were remarkably improved and had lower pH. Trypsin inhibitor, glycine and ß-glycine were reduced by 79.86, 77.18, and 69.29%, respectively. Moreover, animal trials further evaluated the growth-promoting effects of the fermented feed. It was noted that the average daily gain of weaned piglets was significantly higher, and the ratio of feed with weight, diarrhea incidence and mortality were lower significantly. The concentrations of serum immunoglobulin G(IgG), IgA, IgM, Complement C3 and interferon-γ (IFN-γ), and lysozyme activity were all increased. The relative abundance of fecal microbiota improved, especially lactobacillus, which increased the abundance of fecal dominant probiotics. Overall, the fermented feed may be conducive to the growth and health of weaned piglets by improving nutritional value, immunity properties, relative abundance of fecal microflora, and decreasing anti-nutritional factors of feed, thereby making them viable and usable feedstuffs for potential use in livestock industries.

Corrigendum: Three-stage fermentation of the feed and the application on weaned piglets.

[This corrects the article DOI: 10.3389/fvets.2023.1123563.].