Adipose transplantation improves metabolism and atherosclerosis but not perivascular adipose tissue abnormality or vascular dysfunction in lipodystrophic Seipin/Apoe null mice.

Adipose dysfunction in lipodystrophic SEIPIN deficiency is associated with multiple metabolic disorders and increased risks of developing cardiovascular diseases, such as atherosclerosis, cardiac hypertrophy, and heart failure. Recently, adipose transplantation has been found to correct adipose dysfunction and metabolic disorders in lipodystrophic Seipin knockout mice; however, whether adipose transplantation could improve lipodystrophy-associated cardiovascular consequences is still unclear. Here, we aimed to explore the effects of adipose transplantation on lipodystrophy-associated metabolic cardiovascular diseases in Seipin knockout mice crossed into atherosclerosis-prone apolipoprotein E (Apoe) knockout background. At 2 months of age, lipodystrophic Seipin/Apoe double knockout mice and nonlipodystrophic Apoe knockout controls were subjected to adipose transplantation or sham operation. Seven months later, mice were euthanized. Our data showed that although adipose transplantation had no significant impact on endogenous adipose atrophy or gene expression, it remarkably increased plasma leptin but not adiponectin concentration in Seipin/Apoe double knockout mice. This led to significantly reduced hyperlipidemia, hepatic steatosis, and insulin resistance in Seipin/Apoe double knockout mice. Consequently, atherosclerosis burden, intraplaque macrophage infiltration, and aortic inflammatory gene expression were all attenuated in Seipin/Apoe double knockout mice with adipose transplantation. However, adipocyte morphology, macrophage infiltration, or fibrosis of the perivascular adipose tissue was not altered in Seipin/Apoe double knockout mice with adipose transplantation, followed by no significant improvement of vasoconstriction or relaxation. In conclusion, we demonstrate that adipose transplantation could alleviate lipodystrophy-associated metabolic disorders and atherosclerosis but has an almost null impact on perivascular adipose abnormality or vascular dysfunction in lipodystrophic Seipin/Apoe double knockout mice.NEW & NOTEWORTHY Adipose transplantation (AT) reverses multiply metabolic derangements in lipodystrophy, but whether it could improve lipodystrophy-related cardiovascular consequences is unknown. Here, using Seipin/Apoe double knockout mice as a lipodystrophy disease model, we showed that AT partially restored adipose functionality, which translated into significantly reduced atherosclerosis. However, AT was incapable of reversing perivascular adipose abnormality or vascular dysfunction. The current study provides preliminary experimental evidence on the therapeutic potential of AT on lipodystrophy-related metabolic cardiovascular diseases.

Treating High COD Dyeing Wastewater via a Regenerative Sorption-Oxidation Process Using a Nano-Pored Activated Carbon.

Nowadays, the structural complexity of dyes used in the textile industry and the widely adopted water-saving strategy in the dyeing processes often fail plants' biological wastewater treatment units due to chemical oxygen demand (COD) overload. To alleviate this problems, this study investigated a regenerable adsorption-oxidation process to treat dyeing wastewater with COD around 10,000 mg/dm3 using a highly nano-pored activated carbon (AC) as a COD adsorbent, followed by its regeneration using hydrogen peroxide as an oxidizing reagent. In addition to studying AC's COD adsorption and oxidation performance, its operational treatment conditions in terms of temperature and pH were assessed. The results firstly demonstrated that about 50-60% of the COD was consistently adsorbed during the repeated adsorption operation before reaching AC's maximum adsorption capacity (qmax) of 0.165 g-COD/g-AC. The optimal pH and temperature during adsorption were 4.7 and 25 °C, respectively. Secondly, AC regeneration was accomplished by using an initial peroxide concentration of 2.5% (by wt %) and EDTA-Fe of 2.12 mmole/dm3. The reuse of the regenerated ACs was doable. Surprisingly, after the first AC regeneration, the COD adsorption capacity of the regenerated AC even increased by ~7% with respect to the virgin AC. Thirdly, the results of a five-consecutive adsorption-regeneration operation showed that a total of 0.3625 g COD was removed by the 5 g AC used, which was equivalent to an adsorption capacity (q) of 0.0725 (= 0.3625/5) g-COD/g-AC during each adsorption stage. Based on the obtained results, a regenerable COD adsorption-oxidation process using a nano-pored AC to treat the high-textile-COD wastewater looks promising. Thus, a conceptual treatment unit was proposed, and its potential benefits and limitations were addressed.

Immunoproteasome subunit ß5i regulates diet-induced atherosclerosis through altering MERTK-mediated efferocytosis in Apoe knockout mice.

The immunoproteasome contains three catalytic subunits (ß1i, ß2i and ß5i) that are important modulators of immune cell homeostasis. A previous study showed a correlation between ß5i and human atherosclerotic plaque instability; however, the causative role of ß5i in atherosclerosis and the underlying mechanisms remain unknown. Here we explored this issue in apolipoprotein E (Apoe) knockout (eKO) mice with genetic deletion or pharmacological inhibition of ß5i. We found that ß5i expression was upregulated in lesional macrophages after an atherogenic diet (ATD). ß5i/Apoe double KO (dKO) mice fed on the ATD had a significant decrease in both lesion area and necrotic core area, compared with eKO controls. Moreover, dKO mice had less caspase-3+ apoptotic cell accumulation but enhanced efferocytosis of apoptotic cells and increased expression of Mer receptor tyrosine kinase (MERTK). Consistently, similar phenotypes were observed in eKO mice transplanted with dKO bone marrow or treated with ß5i-specific inhibitor PR-957. Mechanistic studies in vitro revealed that ß5i deletion reduced IκBα degradation and inhibited NF-κB activation, promoting Mertk transcription and efferocytosis, thereby attenuating apoptotic cell accumulation. In conclusion, we demonstrate that ß5i plays an important role in diet-induced atherosclerosis by altering MERTK-mediated efferocytosis. ß5i might be a potential pharmaceutical target against atherosclerosis. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Doxorubicin contributes to thrombus formation and vascular injury by interfering with platelet function.

In clinical studies, platelet aggregation and risk of thrombosis are increased in patients after doxorubicin treatment. However, the exact role of doxorubicin in platelet functions and thrombus formation in vivo remain unclear. The present study is to investigate the role of doxorubicin in platelet function in relation to thrombus formation and vascular toxicity, as well as the efficacy of antiplatelet therapy. Mice were treated with doxorubicin or vehicle (5 mg/kg iv, 4 wk), and the following parameters were determined: platelet count and size, platelet surface adhesive receptors by flow cytometry, density of granules by electron microscopy, platelet aggregation and degranulation at resting or agonist-stimulated state, platelet adhesion on fibrinogen or endothelial cells, and thrombus formation on collagen matrix. The efficacy of clopidogrel (15 mg·kg-1·day-1, followed by 5 mg·kg-1·day-1) on doxorubicin-induced changes in the aforementioned parameters as well as vascular injury were also determined. Whereas platelet count and size were similar between doxorubicin-treated and vehicle-treated mice, doxorubicin promoted thrombus formation evidenced by greater platelet aggregation, degranulation, and adhesion to endothelial cells evoked by agonists. Clopidogrel treatment attenuated the enhanced platelet activity and thrombus formation by doxorubicin, as well as vascular platelet infiltration and reactive oxygen species generation. Collectively, this study demonstrates that platelet functions are enhanced after long-term doxorubicin administration, which leads to thrombus formation and vascular toxicity, and that doxorubicin-induced changes in the functionality of platelets can be effectively inhibited by antiplatelet drugs.NEW & NOTEWORTHY Doxorubicin therapy in mice (antitumor dosage) markedly enhanced platelet functions measured as agonist-induced platelet aggregation, degranulation, and adhesion to endothelial cells, actions leading to thrombus formation and thrombosis-independent vascular injury. Clopidogrel treatment ameliorated thrombus formation and vascular toxicity induced by doxorubicin via inhibiting platelet activity.

Reversal of adipose tissue loss by probucol in mice with deficiency of both scavenger receptor class B type 1 and LDL receptor on high fat diet.

Scavenger receptor class B type 1(SR-B1) and low density lipoprotein receptor (LDLR) play vital roles in cholesterol homeostasis. Previous studies indicated a strong link between cholesterol and adipose tissue (AT). In this study, adult male SR-B1 and LDLR double knockout (DKO) mice were fed with high fat diet (HFD) for 3 months. Interestingly, we found severe loss of AT in DKO mice fed with HFD. To reverse the AT loss in DKO mice, 1% probucol was added in HFD. In DKO mice on HFD, plasma total cholesterol (TC) and free cholesterol (FC) levels were increased 6 and 15 folds respectively compared with wild type (WT) mice. We found severe loss of AT in whole body of DKO mice compared with WT or single KO mice. In AT of DKO mice, histology showed the very small size of adipocytes and infiltration of inflammatory cells; Genes expressions related to fatty acid uptake, lipogenesis and adipogenesis were decreased; TUNEL analysis and related genes expressions of endoplasmic reticulum (ER) stress and inflammation were significantly higher than those of WT or single KO mice. Probucol could reduce increased TC and FC levels, and reverse the loss of fat and apoptosis of AT in DKO mice. AT loss in DKO mice with HFD was probably due to high levels of FC which led to apoptosis induced by ER stress and inflammation of AT. This study provided a novel utility of probucol in rescue of fat loss in DKO mice.

Adipose tissue deficiency results in severe hyperlipidemia and atherosclerosis in the low-density lipoprotein receptor knockout mice.

Adipose tissue can store over 50% of whole-body cholesterol; however, the physiological role of adipose tissue in cholesterol metabolism and atherogenesis has not been directly assessed. Here, we examined lipoprotein metabolism and atherogenesis in a unique mouse model of severe lipodystrophy: the Seipin(-/-) mice, and also in mice deficient in both low-density lipoprotein receptor (Ldlr) and Seipin: the Ldlr(-/-)Seipin(-/-) mice. Plasma cholesterol was moderately increased in the Seipin(-/-) mice when fed an atherogenic diet. Strikingly, plasma cholesterol reached ~6000 mg/dl in the Seipin(-/-)Ldlr(-/-) mice on an atherogenic diet, as compared to ~1000 mg/dl in the Ldlr(-/-) mice on the same diet. The Seipin(-/-)Ldlr(-/-) mice also developed spontaneous atherosclerosis on chow diet and severe atherosclerosis on an atherogenic diet. Rosiglitazone treatment significantly reduced the hypercholesterolemia of the Seipin(-/-)Ldlr(-/-) mice, and also alleviated the severity of atherosclerosis. Our results provide direct evidence, for the first time, that the adipose tissue plays a critical role in the clearance of plasma cholesterol. Our results also reveal a previously unappreciated strong link between adipose tissue and LDLR in plasma cholesterol metabolism.

Lack of seipin in neurons results in anxiety- and depression-like behaviors via down regulation of PPARγ.

The Seipin gene was originally found to be responsible for type 2 congenital lipodystrophy and involved in lipid droplet formation. Seipin is highly expressed in the central nervous system as well. Seipin mutations have been identified in motor neuron diseases such as Silver syndrome and spastic paraplegia. In this study, we generated neuron-specific seipin knockout mice (seipin-nKO) to investigate the influence of seipin deficiency on locomotion and affective behaviors. In comparison with control mice, 8-week-old male seipin-nKO mice, but not female mice, displayed anxiety- and depression-like behaviors as assessed by open-field, elevated plus-maze, forced swim and tail suspension tests. However, neither male nor female seipin-nKO mice showed locomotion deficits in swimming tank and rotarod tests. Interestingly, the mRNA and protein levels of peroxisome proliferator-activated receptor gamma (PPARγ) in the hippocampus and cortex were lower in male seipin-nKO mice, but not female mice, than controls. In seipin-nKO mice, plasma levels of sex hormones including 17ß-estradiol (E2) in females and testosterone in males as well as corticosterone were not altered compared with controls. The treatment of male seipin-nKO mice with E2 ameliorated the anxiety- and depression-like behaviors and remarkably increased PPARγ levels. The PPARγ agonist rosiglitazone alleviated affective disorders in male seipin-nKO mice. Notably, anxiety- and depression-like behaviors appeared in female seipin-nKO mice after ovariectomy, which was associated with low PPARγ expression. Collectively, these results indicate that neuronal seipin deficiency causing reduced PPARγ levels leads to affective disorders in male mice that are rescued by E2-increased PPARγ expression.

Spontaneous and diet-aggravated hemolysis and its correction by probucol in SR-BI knockout mice with LDL-R deficiency.

BACKGROUND: High density lipoprotein receptor SR-BI plays a vital role in cholesterol homeostasis. Depletion of SR-BI causes plasma free cholesterol (FC) accumulation, which disrupts erythrocytes membrane and might induce hemolytic anemia. Here we explored the effects of hypercholesteremia, induced by depletion of low density lipoprotein receptor (LDL-R) and high fat diet (HFD) feeding, on plasma FC and possible hemolysis in SR-BI knockout (KO) mice, and the therapeutic effects of a lipid-lowering drug probucol. METHODS AND RESULTS: To determine the effects of LDL-R depletion, SR-BI KO mice were cross-bred with LDL-R KO mice to generate SR-BI/LDL-R double KO (dKO) mice. Compared to control wild type (WT), SR-BI KO and LDL-R KO mice fed normal chow diet (NCD), dKO mice fed NCD had increased plasma FC and developed macrocytic anemia, splenomegaly, jaundice and renal tubular hemosiderin deposition, indicating spontaneous hemolysis. To determine the effects of HFD feeding and probucol therapy, dKO and LDL-R KO mice were fed HFD containing 0.5% cholesterol and 20% fat with or without 1% probucol. HFD further increased plasma FC and aggravated hemolysis while probucol almost normalized plasma FC and corrected hemolysis in dKO mice. CONCLUSION: We demonstrated that in SR-BI KO mice, hypercholesteremia due to LDL-R deficiency significantly increased plasma FC and induced spontaneous hemolysis, which could be further exacerbated by HFD feeding. Probucol almost normalized plasma FC and corrected diet-aggravated hemolysis in SR-BI KO mice with LDL-R deficiency.

Dysfunction of lipid metabolism in lipodystrophic Seipin-deficient mice.

Congenital generalized lipodystrophy (CGL) is characterized by a complete loss of body adipose tissue accompanying dyslipidemia, severe hepatic steatosis and insulin resistance. However, the mechanisms of dyslipidemia and hepatic steatosis are unclear. Here using the lipodystrophic Seipin-deficient mouse (Seipin(-/-)) model, we found Seipin(-/-) mice were unable to respond appropriately to a long time fasting and developed postprandial hypertriglyceridemia. Impaired very low density lipoprotein (VLDL) secretion and enhanced triglyceride-rich lipoproteins (TRL) clearance were also observed in our Seipin(-/-) mice. To identify the association between upregulation of hepatic LDL receptor and enhanced TRL clearance, we crossed Seipin(-/-) mice with Ldlr(-/-) mice to generate Seipin(-/-)Ldlr(-/-) mice. Seipin(-/-)Ldlr(-/-) mice displayed increased TRL clearance only after 24 h-fast rather 6 h-fast. In contrast to Seipin(-/-) mice, Seipin(-/-)Ldlr(-/-) mice displayed hypertriglyceridemia as observed in human CGL patients. Furthermore, in this study, we demonstrated hepatic steatosis in lipodystrophy Seipin(-/-) mice is a metabolic adaptation of dysfunctional adipose tissue. This study using lipodystrophic model established the importance of adipose tissue in energy homeostasis and lipid metabolism.

Expression of seipin in adipose tissue rescues lipodystrophy, hepatic steatosis and insulin resistance in seipin null mice.

OBJECTIVES: Gene mutations in an ER protein seipin result in congenital generalized lipodystrophy (CGL) in humans, accompanied with hepatic steatosis and insulin resistance. Seipin gene is highly expressed in the brain, testis and adipose tissue. Seipin globally deficient mice (SKO) displayed similar phenotypes as human counterparts. It has been demonstrated that adipose-specific seipin knockout mice at elder age were indistinguishable from SKO mice. Due to the large mass of adipose tissue in the body, we hypothesized that seipin in adipose tissue might be responsible for the multiple metabolism-related abnormalities in SKO mice. METHODS AND RESULTS: Transgenic mice with adipose-specific expression of human seipin gene driven by aP2 promoter were generated and crossed with SKO mice to obtain adipose-specific seipin reconstitute (Seipin-RE) mice. In comparison with wild-type (WT) and SKO mice, the Seipin-RE mice exhibited normal plasma triglyceride and non-esterified fatty acids upon fasting, recovered adipose tissue mass, restored epididymal and subcutaneous fat pads morphology and partially recovered plasma leptin and adiponectin levels. Moreover, hepatic steatosis and insulin resistance was also absent in these mice. CONCLUSION: Our study demonstrates that expression of seipin in adipose tissue alone could rescue dyslipidemia, lipodystrophy, hepatic steatosis and insulin resistance in SKO mice.

Dual COF functionalized magnetic MXene composite for enhancing magnetic solid phase extraction of thiophene compounds from oilfield produced waters prior to GC-MS/MS analysis.

In this study, a novel COFTABT@COFTATp modified magnetic MXene composite (CoFe2O4 @Ti3C2 @COFTABT@COFTATp) was synthesized by Schiff base reaction and irre-versible enol-keto tautomerization, and employed to establish a sensitive monitoring method for six thiophene compounds in oilfield produced water samples based on magnetic solid-phase extraction (MSPE) prior to gas chromatography coupled with a triple quadruple mass spectrometer (GC-MS/MS). The designed magnetic materials exhibited unexpected enrichment ability to target thiophene compounds and achieved good extraction efficiencies ranging from 83 % to 98 %. The developed MSPE/GC-MS/MS method exhibited good linearity in the range of 0.001-100 µg L-1, and obtained lower limits of detection ranging from 0.39 to 1.9 ng L-1. The spiked recoveries of thiophene compounds obtained in three oilfield produced water samples were over the range of 96.26 %-99.54 % with relative standard deviations (RSDs) less than 3.7 %. Notably, benzothiophene, 4-methyldibenzothiophene and 4,6-dimethyldibenzothiophene were detected in three oilfield-produced water samples. Furthermore, the material still kept favorable stability after six recycling experiments. The adsorption kinetics, adsorption isotherms as well as adsorption thermodynamics of thiophene compounds were investigated in detail to provide insight into the mechanisms. Overall, the present work contributed a promising strategy for designing and synthesizing new functionalized materials for the enrichment and detection of typical pollutants in the environment.

Taxonomic identification and life cycle comparison of two populations of the monostromatic green algae Monostroma nitidum.

Monostroma nitidum, a monostromatic green algae (MGA) with high economic value, is distributed worldwide. Life cycle often serves as a fundamental criterion for taxonomic classification. Most researchers consider the life cycle of M. nitidum to involve dimorphic alternation of generations, although the possibility of a monomorphic asexual life cycle remains unclear. In this study, tufA and 18S rDNA sequences were employed as molecular markers, complemented by morphological analysis, to classify and identify MGA in two distinct habitats: Hailing Island reefs (YJ) and Naozhou Island reefs (ZJ). The results of tufA and 18S rDNA sequence analysis revealed that all samples from YJ and ZJ clustered to the same branch (M. nitidum clade) with high bootstrap support and genetic distances of less than 0.000 and 0.005, respectively. However, morphological observations indicated significant differences in the external morphology of the YJ and ZJ samples, although both initially exhibited a filament-blade form during early development. The life cycle of the ZJ samples exhibited typical dimorphic alternation of generations, whereas the YJ samples only produced biflagellate asexual gametes with negative phototaxis. Gametes of the YJ samples directly developed into new gametophytes without undergoing the sporophyte stage. Consequently, the YJ and ZJ samples were classified as monomorphic asexual and dimorphic sexual M. nitidum, respectively. These findings provide evidence supporting the monomorphic asexual life cycle of M. nitidum for the classification of MGA.

Magnetic solid extraction of PCBs in the fruit juices based on polyaniline-modified CoFe2O4@Ti3C2 composite.

Polychlorinated biphenyls (PCBs) have been known pollutants, which are ubiquitous in various matrix, even in some food products and beverages like fruit juices. It is of great importance to develop efficient and simple method to detect them in such matrix. In this work, an effective magnetic composite integrating the advantages of the magnism of CoFe2O4, hydrophilicity and multisites of Ti3C2 and high adsorption properties of polyaniline (CoFe2O4@Ti3C2@PANI) was designed and synthesized. CoFe2O4@Ti3C2@PANI-based magnetic solid-phase extraction coupled with gas chromatography-tandem mass spectrometry was established for determination of nine PCBs in fruit juices. The developed method achieved low detection limits of 0.4-0.8 ng L-1. The established method was validated with three beverages and achieved good spiked recoveries ranging from 77.2 % to 104.7 %. These findings exhibited that the established method was very simple, efficient, and credible for the analysis of PCBs in food, environmental, and other fields.

Gradient-Pattern Micro-Grooved Wicks Fabricated by the Ultraviolet Nanosecond Laser Method and Their Enhanced Capillary Performance.

Capillary-gradient wicks can achieve fast or directional liquid transport, but they face fabrication challenges by traditional methods in terms of precise patterns. Laser processing is a potential solution due to its high pattern accuracy, but there are a few studies on laser-processed capillary-gradient wicks. In this paper, capillary step-gradient micro-grooved wicks (CSMWs) were fabricated by an ultraviolet nanosecond pulsed laser, and their capillary performance was studied experimentally. The CSMWs could be divided into three regions with a decreasing capillary radius. The equilibrium rising height of the CSMWs was enhanced by 124% compared to the non-gradient parallel wick. Different from the classical Lucas-Washburn model describing a uniform non-gradient wick, secondary capillary acceleration was observed in the negative gradient direction of the CSMWs. With the increase in laser power and the decrease in scanning speed, the capillary performance was promoted, and the optimal laser processing parameters were 4 W-10 mm/s. The laser-enhanced capillary performance was attributed to the improved hydrophilicity and reduced capillary radius, which resulted from the increased surface roughness, protrusion morphology, and deep-narrow V-shaped grooves induced by the high energy density of the laser. Our study demonstrates that ultraviolet pulsed laser processing is a highly efficient and low-cost method for fabricating high-performance capillary gradient wicks.

Covalent organic framework-functionalized magnetic MXene nanocomposite for efficient pre-concentration and detection of organophosphorus and organochlorine pesticides in tea samples before gas chromatography-triple quadrupole mass spectrometry analysis.

In this study, a hydrophobic covalent organic framework-functionalized magnetic composite (CoFe2O4@Ti3C2@TAPB-TFTA) with a high specific area with 1,3,5-tris(4-aminophenyl)benzene (TAPB) and 2,3,5,6-tetrafluoroterephthalaldehyde (TFTA) was designed and synthesized through Schiff base reaction. An efficient magnetic solid-phase extraction method was established and combined with gas chromatography-triple quadrupole mass spectrometry to sensitively determine 10 organochlorine and organophosphorus pesticides in tea samples. The established method exhibited good linearity in the range of 0.05-120 µg/L and had low limits of detection (0.013-0.018 µg/L). The method was evaluated with tea samples, and the spiked recoveries of pesticides in different tea samples reached satisfactory values of 85.7-96.8%. Moreover, the adsorption of pesticides was spontaneous and followed Redlich-Peterson isotherm and pseudo-second-order kinetic models. These results demonstrate the sensitivity, effectiveness, and reliability of the proposed method for monitoring organochlorine and organophosphorus pesticides in tea samples, providing a preliminary basis for researchers to reasonably design adsorbents for the efficient extraction of pesticides.

Research Advances of Engineered Exosomes as Drug Delivery Carrier.

Exosomes are nanoscale vesicles secreted by living cells that have similar membrane composition to parental cells and carry a variety of proteins, lipids, and nucleic acids. Therefore, exosomes have certain biological activities and play an important role in intercellular communication. On the basis of its potential as a carrier for drug delivery systems, exosomes have been engineered to compensate for the shortage of natural exosomes through various engineering strategies for improving drug delivery efficiency, enhancing targeting to tissues and organs, and extending the circulating half-life of exosomes. This review focuses on the engineered exosomes loading drugs through different strategies, discussions on exosome surface modification strategies, and summarizes the advantages and disadvantages of different strategies. In addition, this review provides an overview of the recent applications of engineered exosomes in a number of refractory and relapsable diseases. This review has the potential to provide a reference for further research and development of engineered exosomes.

Hyperhomocysteinaemia Promotes Doxorubicin-Induced Cardiotoxicity in Mice.

Doxorubicin, a widely used chemotherapeutic drug in clinical oncology, causes a series of cardiac side effects referred to as doxorubicin-induced cardiotoxicity. Hyperhomocysteinaemia is an independent risk factor for multiple cardiovascular diseases. However, whether hyperhomocysteinaemia contributes to doxorubicin-induced cardiotoxicity is currently unknown. In this study, we explored the pathogenic effects of hyperhomocysteinaemia induced by dietary methionine supplementation (2% wt/wt in rodent chow) in a mouse model of doxorubicin-induced cardiotoxicity. Our data showed that methionine supplementation doubled serum homocysteine levels, inducing mild hyperhomocysteinaemia. Doxorubicin at a cumulative dosage of 25 mg/kg body weight led to significant weight loss and severe cardiac dysfunction, which were further exacerbated by methionine-induced mild hyperhomocysteinaemia. Doxorubicin-induced cardiac atrophy, cytoplasmic vacuolisation, myofibrillar disarray and loss, as well as cardiac fibrosis, were also exacerbated by methionine-induced mild hyperhomocysteinaemia. Additional folic acid supplementation (0.006% wt/wt) prevented methionine-induced hyperhomocysteinaemia and inhibited hyperhomocysteinaemia-aggravated cardiac dysfunction and cardiomyopathy. In particular, hyperhomocysteinaemia increased both serum and cardiac oxidative stress, which could all be inhibited by folic acid supplementation. Therefore, we demonstrated for the first time that hyperhomocysteinaemia could exacerbate doxorubicin-induced cardiotoxicity in mice, and the pathogenic effects of hyperhomocysteinaemia might at least partially correlate with increased oxidative stress and could be prevented by folic acid supplementation. Our study provides preliminary experimental evidence for the assessment of hyperhomocysteinaemia as a potential risk factor for chemotherapy-induced cardiotoxicity in cancer patients.

Transcriptome analysis reveals the molecular mechanisms of adaptation to high temperatures in Gracilaria bailinae.

Global warming causes great thermal stress to macroalgae and those species that can adapt to it are thought to be better able to cope with warmer oceans. Gracilaria bailinae, a macroalgae with high economic and ecological values, can survive through the hot summer in the South China Sea, but the molecular mechanisms underlying its adaptation to high temperatures are unclear. To address this issue, the present study analyzed the growth and transcriptome of G. bailinae after a 7-day exposure to 15°C (LT: low temperature), 25°C (MT: middle temperature), and 35°C (HT: high temperature). Growth analysis showed that the HT group had the highest relative growth rate (RGR = 2.1%) with the maximum photochemical quantum yield of PSII (F v/F m = 0.62) remaining within the normal range. Transcriptome analysis showed more differentially expressed genes (DEGs) in the comparison between MT and HT groups than in that between MT and LT, and most of these DEGs tended to be downregulated at higher temperatures. The KEGG pathway enrichment analysis showed that the DEGs were mainly enriched in the carbohydrate, energy, and lipid metabolisms. In addition, the genes involved in NADPH and ATP synthesis, which are associated with photosynthesis, the Calvin cycle, pyruvate metabolism, and the citrate cycle, were downregulated. Downregulation was also observed in genes that encode enzymes involved in fatty acid desaturation and alpha-linolenic acid metabolism. In summary, G. bailinae regulated the synthesis of NADPH and ATP, which are involved in the above-mentioned processes, to reduce unnecessary energy consumption, and limited the synthesis of enzymes in the metabolism of unsaturated fatty acids and alpha-linolenic acid to adapt to high environmental temperatures. The results of this study improve our understanding of the molecular mechanisms underlying the adaptation of G. bailinae to high temperatures.

Severe hypertriglyceridemia caused by Gpihbp1 deficiency facilitates vascular remodeling through increasing endothelial activation and oxidative stress.

Hypertriglyceridemia (HTG) is an independent risk factor for atherosclerosis. However, its impact on non-atherosclerotic cardiovascular diseases remains largely unknown. Glycosylphosphatidylinositol anchored high-density lipoprotein binding protein 1 (GPIHBP1) is essential for the hydrolysis of circulating triglycerides and loss of functional GPIHBP1 causes severe HTG. In this study, we used Gpihbp1 knockout (GKO) mice to investigate the potential effects of HTG on non-atherosclerotic vascular remodeling. We compared the aortic morphology and gene expressions between three-month-old and ten-month-old GKO mice and their age-matched wild-type controls. We also conducted similar comparisons between GKO mice and wild-type controls in an angiotensin II (AngII)-induced vascular remodeling model. Our data showed that the intima-media wall of ten-month-old GKO mice but not three-month-olds was significantly thickened compared to wild-type controls. Moreover, ten-month-old GKO mice but not three-month-olds had increased aortic macrophage infiltration and perivascular fibrosis, along with increased endothelial activation and oxidative stress. Similarly, the AngII-induced vascular remodeling, as well as endothelial activation and oxidative stress, were also exacerbated in the GKO mice compared to wild-type controls. In conclusion, we demonstrated that severe HTG caused by Gpihbp1 deficiency could facilitate the onset and progression of non-atherosclerotic vascular remodeling through endothelial activation and oxidative stress in mice.

Ferritinophagy activation and sideroflexin1-dependent mitochondrial iron overload contribute to patulin-induced cardiac inflammation and fibrosis.

Patulin (PAT) is a mycotoxin that is commonly present throughout the ecosystem where fungi grow and mainly contaminates food, soil, and water. PAT was found to be cardiotoxic in previous studies. However, the detailed mechanism has not been fully elucidated. The present study aimed to explore the role and underlying mechanism of ferroptosis in PAT-induced cardiac injury. Here, we confirmed in vivo and in vitro that ferroptosis is involved in PAT-induced myocardial inflammation and fibrosis. Mice exposed to PAT (1 and 2 mg/kg body weight/day for 14 days) exhibited myocardial inflammation and fibrosis along with disrupted iron homeostasis, elevated lipid peroxidation, depletion of glutathione peroxidase 4, and abnormal mitochondrial morphology. When primary neonatal rat cardiomyocytes (NRCMs) and H9c2 cells were exposed to PAT, ferroptosis was initiated in a dose-dependent manner, and this process could be significantly attenuated by ferrostatin-1. Mechanistically, we found that nuclear receptor coactivator (NCOA) 4, a master regulator of ferritinophagy, bound to and degraded ferritin in response to PAT treatment, thereby releasing large amounts of ferrous iron and further leading to sideroflexin (SFXN) 1-dependent mitochondrial iron overload. Conversely, knockdown of NCOA4 or SFXN1 with small interfering RNAs could effectively ameliorate ferroptotic cell death, cellular or mitochondrial iron overload and lipid peroxides accumulation. Furthermore, myocardial inflammation and fibrosis in PAT-exposed mice was alleviated by the mitochondrial iron chelator deferiprone. Overall, our findings underscore that ferritinophagy activation and SFXN1-dependent mitochondrial iron overload play critical roles in PAT-induced myocardial ferroptosis and consequent cardiotoxicity.