Curcumin nicotinate increases LDL cholesterol uptake in hepatocytes through IDOL/LDL-R pathway regulation.

BACKGROUND: Curcumin nicotinate (Curtn), derived from curcumin and niacin, reduces serum LDL-C levels, partly due to its influence on PCSK9. This study investigates IDOL's role in Curtn's lipid-lowering effects. OBJECTIVE: To elucidate Curtn's regulation of the IDOL/LDLR pathway and potential molecular mechanisms in hepatocytes. METHODS: Differential metabolites in Curtn-treated HepG2 cells were identified via LC-MS. Molecular docking assessed Curtn's affinity with IDOL. Cholesterol content and LDLR expression effects were studied in high-fat diet Wistar rats. In vitro evaluations determined Curtn's influence on IDOL overexpression's LDL-C uptake and LDLR expression in hepatocytes. RESULTS: Lipids were the main differential metabolites in Curtn-treated HepG2 cells. Docking showed Curtn's higher affinity to IDOL's FERM domain compared to curcumin, suggesting potential competitive inhibition of IDOL's binding to LDLR. Curtn decreased liver cholesterol in Wistar rats and elevated LDLR expression. During in vitro experiments, Curtn significantly enhanced the effects of IDOL overexpression in HepG2 cells, leading to increased LDL-C uptake and elevated expression of LDL receptors. CONCLUSION: Curtn modulates the IDOL/LDLR pathway, enhancing LDL cholesterol uptake in hepatocytes. Combined with its PCSK9 influence, Curtn emerges as a potential hyperlipidemia therapy.

Curcumin nicotinate decreases serum LDL cholesterol through LDL receptor-mediated mechanism.

Curcumin nicotinate (Curtn) is a synthesized ester derivative of curcumin and niacin. Our previous study has shown that Curtn lowers serum low-density lipoprotein cholesterol (LDL-C) levels in apoE-/- mice and promotes LDL-C uptake into HepG2 cells in vitro. The present study was to test the hypothesis that Curtn decreases serum LDL-C levels through decreased expression of pro-protein convertase subtilisin/kexin type 9 (PCSK9) and subsequent increase in LDL receptor expression. Male Wistar rats on high-fat diet (HFD) were treated with Curtn or rosuvastatin. Curtn or rosuvastatin treatment significantly decreased serum levels of total cholesterol (TC) and LDL-C in rats on HFD with increased liver LDL receptor expression. LDL-C-lowering effect of Curtn was not observed in LDL receptor deficient (LDLR-/-) mice on HFD, while rosuvastatin still decreased serum lipid levels in LDLR-/- mice, indicating that the reduction of serum LDL-C levels by Curtn treatment was LDL receptor-dependent. Curtn treatment also significantly decreased the protein expression of PCSK9 in Wistar rats and LDLR-/- mice. In HepG2 cells with overexpression of human PCSK9, Curtn treatment significantly increased LDL-C uptakes into hepatocytes, and increased LDL receptor distribution on cell surface in association with decreased PCSK9 protein expression. RNAi-LDLR significantly attenuated the effect of Curtn on LDLR distribution on cell surface. These data indicates that Curtn would decrease serum LDL-C level at least partially through inhibition of PCSK9 expression, and subsequent increase in LDL receptor expression and distribution in hepatocytes, serving as a potential novel compound to treat hyperlipidemia.

Curcumin improves the function of umbilical vein endothelial cells by inhibiting H2O2­induced pyroptosis.

Endothelial cell (EC) dysfunction is one of the initiating factors of atherosclerosis. EC dysfunction is primarily caused by oxidative damage and inflammation. As a classic non­specific antioxidant and anti­inflammatory drug, curcumin has been widely used in studies of lipid metabolism disorders. However, whether curcumin is able to alleviate H2O2­induced EC damage and its related mechanisms has remained to be elucidated. The present study confirmed the protective effects of curcumin on human umbilical vein endothelial cells (HUVECs). A HUVEC injury model was established using H2O2 and the optimal concentrations and time of curcumin to achieve therapeutic effects were explored. Curcumin was observed to inhibit H2O2­induced pyroptosis by inhibiting the activation of NOD­, LRR­ and pyrin domain­containing protein 3. In addition, curcumin improved HUVEC function by restoring αvß3 and reducing endothelin­1 expression. In conclusion, the results of the present study revealed the mechanism through which curcumin inhibits pyroptosis and indicated that curcumin may have a potential utility in treating diseases of EC dysfunction.

Apolipoprotein-AI and AIBP synergetic anti-inflammation as vascular diseases therapy: the new perspective.

Vascular diseases (VDs) including pulmonary arterial hypertension (PAH), atherosclerosis (AS) and coronary arterial diseases (CADs) contribute to the higher morbidity and mortality worldwide. Apolipoprotein A-I (Apo A-I) binding protein (AIBP) and Apo-AI negatively correlate with VDs. However, the mechanism by which AIBP and apo-AI regulate VDs still remains unexplained. Here, we provide an overview of the role of AIBP and apo-AI regulation of vascular diseases molecular mechanisms such as vascular energy homeostasis imbalance, oxidative and endoplasmic reticulum stress and inflammation in VDs. In addition, the role of AIBP and apo-AI in endothelial cells (ECs), vascular smooth muscle (VSMCs) and immune cells activation in the pathogenesis of VDs are explained. The in-depth understanding of AIBP and apo-AI function in the vascular system may lead to the discovery of VDs therapy.

Anti-nociceptive effect of Portulaca oleracea L. ethanol extracts attenuated zymosan-induced mouse joint inflammation via inhibition of Nrf2 expression.

The aim of this study was to explore the effects of ethanol extracts from Portulaca oleracea L. (ePO) on joint inflammation and to explain the underlying mechanisms. A joint inflammation mouse model was constructed by injecting zymosan, and the Von Frey method was employed and the joint thickness measured. The numbers of leukocytes, neutrophils, and monocytes were counted in the joint cavity and the infiltration of inflammatory cells was assessed by joint histopathological analysis. The mRNA levels of inflammatory cytokines were determined by quantitative RT-PCR and their secretion levels were determined by specific ELISAs. Pre-treatment with ePO inhibited articular mechanical hyperalgesia and edema and ameliorated the recruitment of mononuclear neutrophils and leukocytes. In addition, pre-treatment with ePO improved pathological alternations in the joint tissues by reducing the number of inflammatory cells. Pre-treatment with ePO regulated the nuclear factor erythroid 2-related factor 2 (Nrf2)-related proteins and thereby inhibited oxidative stress. In addition, ePO inhibited NLR family pyrin domain containing 3 (NLRP3) inflammasome-related genes (NLRP3, ASC, pro-caspase-1 and pro-IL-1ß), modulated inflammatory cytokines and the activation of NF-κB. ePO attenuated zymosan-induced joint inflammation by regulating oxidative stress, NLRP3 inflammasome, and NF-κB.

Enhancing Matured Stem-Cardiac Cell Generation and Transplantation: A Novel Strategy for Heart Failure Therapy.

Heart failure (HF) remains one of the major causes of morbidity and mortality worldwide. Recent studies have shown that stem cells (SCs) including bone marrow mesenchymal stem (BMSC), embryonic bodies (EB), embryonic stem (ESC), human induced pluripotent stem (hiPSC)-derived cardiac cells generation, and transplantation treated myocardial infarction (MI) in vivo and in human. However, the immature phenotypes compromise their clinical application requiring immediate intervention to improve stem-derived cardiac cell (S-CCs) maturation. Recently, an unbiased multi-omic analysis involving genomics, transcriptomics, epigenomics, proteomics, and metabolomics identified specific strategies for the generation of matured S-CCs that may enhance patients' recovery processes upon transplantation. However, these strategies still remain undisclosed. Here, we summarize the recently discovered strategies for the matured S-CC generation. In addition, cardiac patch formation and transplantation that accelerated HF recuperation in clinical trials are discussed. A better understanding of this work may lead to efficient generation of matured S-CCs for regenerative medicine. Graphical abstract.

Influence of CETP on High-Density Lipoprotein Subclasses in Patients with Coronary Heart Disease.

BACKGROUND: Inhibition of plasma cholesteryl ester transfer protein (CETP) can effectively reduce the risk of ath-erosclerotic cardiovascular disease by increasing high-density lipoprotein cholesterol (HDL-C) levels, but the effect of CETP on the distributions of HDL subclasses in patients with coronary heart disease (CHD) is still elusive. METHODS: To investigate the correlation between the level of CETP and the distributions of HDL subclasses, 121 healthy controls and 139 patients with CHD were selected as study subjects. The plasma levels of CETP and each HDL subclass were respectively determined by enzyme-linked immunosorbent assay and two-dimensional gel electrophoresis associated with the immunodetection method. At the same time, blood biochemical data from all subjects were collected, including the levels of triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), HDL-C, apoA1, and apoB100. Correlation analysis and multiple regression analysis among the plasma HDL subclass values and biochemical parameters in subjects with CHD were conducted. RESULTS: As the plasma level of CETP increases, the contents of TC, TG, and apoB100/A1 were obviously elevated, while the levels of HDL-C and apoA1 decreased significantly. For distributions of HDL subclasses, large-sized HDL2a and HDL2b were markedly decreased in the middle CETP group (p < 0.05) and the high CETP group (p < 0.001) compared to the low CETP group, while the small-sized preß1-HDL was obviously increased. Intriguingly, when the plasma concentration of TC or TG in patients with CHD was higher, the elevated preß1-HDL and reduced HDL2a were more dependent on the increase in CETP. Furthermore, correlation analysis and multiple regression analysis also confirmed that plasma CETP was positively correlated with preß1-HDL levels and negatively correlated with HDL2b levels. CONCLUSIONS: The distributions of HDL subclasses were associated with CETP in patients with CHD, especially in those with high levels of TC and TG. CETP levels were associated with an increase in small-sized preß1-HDL and a decrease in large-sized HDL subclasses, which indicated that CETP might be a limiter of reverse cholesterol transport and HDL maturation.

Impaired lipophagy in endothelial cells with prolonged exposure to oxidized low­density lipoprotein.

Oxidative stress induces the formation of oxidized low­density lipoprotein (ox­LDL), which accelerates the development of atherosclerosis and the rupture of atherosclerotic plaques by promoting lipid accumulation and inhibiting autophagy in vascular cells. Lipophagy is known to be involved in maintaining the balance of neutral lipid metabolism; however, the phenomenon of lipophagy deficiency in ox­LDL­treated endothelial cells (ECs) remains to be elucidated. It has been demonstrated that lipid accumulation caused by ox­LDL inhibits autophagy, which promotes apoptosis in ECs. The aim of the present study was to investigate the association between decreased autophagy and lipid accumulation in ECs treated with ox­LDL. Electron microscopy demonstrated that the formation of autolipophagosomes was decreased in ox­LDL­treated human umbilical vein ECs compared with that in the LDL­treated group and was accompanied by a decrease in the autophagy­associated proteins via western blotting analysis. Using laser focal colocalization detection, decreased lipid processing was observed in the lysosomes of ox­LDL­treated ECs, which indicated that lipophagy may be attenuated and subsequently result in lipid accumulation in ox­LDL­treated ECs.

The Correlation between Blood HbA1c and HDL Subclasses in Patients with Metabolic Syndrome.

BACKGROUND: Metabolic syndrome (MS) is characterized by a constellation of metabolic disorders. Hyperglycemia and dyslipidemia are the major risk factors of MS. Here we performed a study to explore the association between glycated hemoglobin A1c (HbA1c) and high-density lipoprotein (HDL) subclasses in patients with MS. METHODS: We included 101 MS patients and 77 healthy subjects in this study. Blood tests were executed to assess the blood glucose and lipid indicators, including HbA1c, fasting plasma glucose (FPG), triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), apolipoprotein B100 (apoB100), preß1-HDL, HDL3b, apoB100/AI, apolipoprotein AI (apoAI), HDL2b and HDL2a. Multivariate linear regression was used to explore potential relationship between HDL subclasses and HbA1c. RESULTS: Compared with control group, the levels of HbA1c, FPG, TG, TC, LDL-C, apoB100, preß1-HDL, HDL3b, apoB100/AI and LDL-C/HDL-C were significantly increased in MS subjects (p < 0.01), while plasma concentrations of HDL-C, apoAI, HDL2b and HDL2a were significantly decreased in MS subjects (p < 0.01). With the increase of whole blood HbA1c levels in MS subjects, preß1-HDL was elevated gradually, while HDL2a was decreased gradually. CONCLUSIONS: Blood HbA1c level is associated with the changes in HDL subclass distribution in patients with MS.

PX Domain-Containing Kinesin KIF16B and Microtubule-Dependent Intracellular Movements.

As a member of the kinesin-3 family, kinesin family member 16B (KIF16B) has a characteristic PhoX homology (PX) domain that binds to membranes containing phosphatidylinositol-3-phosphate (PI(3)P) and moves along microtubule filaments to the plus end via a process regulated by coiled coils in the stalk region in various cell types. The physiological function of KIF16B supports the transport of intracellular cargo and the formation of endosomal tubules. Ras-related protein (Rab) coordinates many steps of membrane transport and are involved in the regulation of KIF16B-mediated vesicle trafficking. Data obtained from clinical research suggest that KIF16B has a potential effect on the disease processes in intellectual disability, abnormal lipid metabolism, and tumor brain metastasis. In this review, we summarize recent advances in the structural and physiological characteristics of KIF16B as well as diseases associated with KIF16B disorders, and speculating its role as a potential adaptor for intracellular cholesterol trafficking.

MMP-12 as a potential biomarker to forecast ischemic stroke in obese patients.

Human health is threatened by obesity which causes the increasing incidence of various diseases, especially stroke. Ischemic stroke (IS) is mostly caused by the rupture of arterial plaque, whose instability is positively associated with matrix metalloproteinases (MMPs) that degrades extracellular matrix components. Studies have shown that matrix metalloproteinase-12 (MMP-12) may be involved in the pathogenesis of IS. Because of the higher incidence of stroke in obese patients than that in normal weight people, it is urgent for obesity to forecast stroke early. Considering high levels MMP-12 in obesity, we put forward that MMP-12 may be a potential biomarker for IS in obese patients.

Cholesterol in LDL receptor recycling and degradation.

The SREBP2/LDLR pathway is sensitive to cholesterol content in the endoplasmic reticulum (ER), while membrane low-density lipoprotein receptor (LDLR) is influenced by sterol response element binding protein 2 (SREBP2), pro-protein convertase subtilisin/kexin type 9 (PCSK9) and inducible degrader of LDLR (IDOL). LDL-C, one of the risk factors in cardiovascular disease, is cleared through endocytosis recycling of LDLR. Therefore, we propose that a balance between LDLR endocytosis recycling and PCSK9-mediated and IDOL-mediated lysosomal LDLR degradation is responsible for cholesterol homeostasis in the ER. For statins that decrease serum LDL-C levels via cholesterol synthesis inhibition, the mechanism by which the statins increase the membrane LDLR may be regulated by cholesterol homeostasis in the ER.

Role of Adiponectin in prostate cancer

ABSTRACT Obesity is defined as a chronic and excessive growth of adipose tissue. It has been associated with a high risk for development and progression of obesity-associated malignancies, while adipokines may mediate this association. Adiponectin is an adipose tissue-derived adipokines, with significant anti-diabetic, anti-inflammatory, anti-atherosclerotic and anti-proliferative properties. Plasma adiponectin levels are decreased in obese individuals, and this feature is closely correlated with development of several metabolic, immunological and neoplastic diseases. Recent studies have shown that prostate cancer patients have lower serum adiponectin levels and decreased expression of adiponectin receptors in tumor tissues, which suggests plasma adiponectin level is a risk factor for prostate cancer. Furthermore, exogenous adiponectin has exhibited therapeutic potential in animal models. In this review, we focus on the potential role of adiponectin and the underlying mechanism of adiponectin in the development and progression of prostate cancer. Exploring the signaling pathways linking adiponectin with tumorigenesis might provide a potential target for therapy.

Role of Adiponectin in prostate cancer.

Obesity is defined as a chronic and excessive growth of adipose tissue. It has been associated with a high risk for development and progression of obesity-associated malignancies, while adipokines may mediate this association. Adiponectin is an adipose tissue-derived adipokines, with significant anti-diabetic, anti-inflammatory, anti-atherosclerotic and anti-proliferative properties. Plasma adiponectin levels are decreased in obese individuals, and this feature is closely correlated with development of several metabolic, immunological and neoplastic diseases. Recent studies have shown that prostate cancer patients have lower serum adiponectin levels and decreased expression of adiponectin receptors in tumor tissues, which suggests plasma adiponectin level is a risk factor for prostate cancer. Furthermore, exogenous adiponectin has exhibited therapeutic potential in animal models. In this review, we focus on the potential role of adiponectin and the underlying mechanism of adiponectin in the development and progression of prostate cancer. Exploring the signaling pathways linking adiponectin with tumorigenesis might provide a potential target for therapy.

Molecular mechanisms and genetic regulation in atherosclerosis.

Atherosclerosis (AS) manifested by lipid accumulation, extracellular matrix protein deposition, and calcification in the intima and media of the large to medium size arteries promoting arterial stiffness and reduction of elasticity. It has been accepted that AS leads to increased morbidity and mortality worldwide. Recent studies indicated that genetic abnormalities play an important role in the development of AS. Specific genetic mutation and histone modification have been found to induce AS formation. Furthermore, specific RNAs such as microRNAs and circular RNAs have been identified to play a crucial role in the progression of AS. Nevertheless, the mechanisms by which genetic mutation, DNA and histone modification, microRNAs and circular RNA induce AS still remain elusive. This review describes specific mechanisms and pathways through which genetic mutation, DNA and histone modification, microRNAs and circular RNA instigate AS. This review further provides a therapeutic strategic direction for the treatment of AS targeting genetic mechanisms.

A new anthraquinone and a new naphthoquinone from the whole plant of Spermacoce latifolia.

A phytochemical study on the whole plant of Spermacoce latifolia led to the isolation of a new anthraquinone, 1,2,6-trihydroxy-5-methoxy-9,10-anthraquinone (1), and a new naphthoquinone, (2R)-6-hydroxy-7-methoxy-dehydroiso-α-lapachone (2), together with three known anthraquinones (3-5). Their structures were established on the basis of detailed spectroscopic analysis, including one- and two-dimensional NMR, ESI-MS, and HR-ESI-MS techniques. All the compounds were isolated from S. latifolia for the first time. Compounds 1, 2, 4, and 5 showed significant antibacterial activity toward Bacillus subtilis with MIC values ranging from 0.9 to 31.2 µg/ml, and compound 4 aslo exhibited antibacterial activity against Bacillus cereus with a MIC value 62.5 µg/ml. Compound 1 was further revealed to show significant in vitro α-glucosidase inhibitory activity with IC50 value of 0.653 mM.

Removal of B-cell epitopes for decreasing immunogenicity in recombinant immunotoxin against B-cell malignancies.

Recombinant immunotoxin HA22, composed of an anti- CD22 Fv fragment fused to PE38, a truncated portion of Pseudomonas Exotoxin A (PE), has been developed for targeted treatment of various B-cell malignancies. As a foreign, internalized macromolecule, PE38 often induces lysosomal degradation and neutralizing antibodies to limit the efficacy of treating B-cell malignancies. The region of PE38 containing lysosomal protease cleavage sites deleted, leaving only furin processing site. The resulting immunotoxin HA22-LR (lysosome resistant) retains excellent biologic activity and removes immunogenic epitopes as an additional benefit. Another approach for avoiding immunogenicity is to identify B-cell epitopes and remove them by mutagenesis. Previously, to determine B-cell epitopes on PE38, murine Ab as a model, 7 major mouse-specific B-cell epitope groups with 13 subgroups were identified and located through a series of point mutations. Two new mutants, HA22-8X and HA22-LR-8X, were prepared, containing 8 epitope-silencing mutations which greatly reduced immunogenicity in mice. Later, by phage-display assay, human Fvs against PE toxin were isolated and human-specific B-cell epitopes were located by alanine scanning mutagenesis. HA22-LR as a scaffold, HA22-LR-LO10 with 7 point mutations was constructed, has low reactivity with human antisera, yet has high cytotoxic and antitumor activity. In this review, theoretical aspects and experimental evidence for the removal of B-cell epitope is discussed.

Relationship between the distribution of plasma HDL subclasses and the polymorphisms of APOA5 in hypertriglyceridemia.

AIMS: This study aims to examine the possible associations between high density lipoprotein (HDL) subclass distribution and APOA5-1131T>C polymorphism in hypertriglyceridemia. METHODS: The distribution of HDL subclasses was quantified by 2-dimensional electrophoresis in conjunction with immunodetection method. The APOA5-1131T>C polymorphism was identified in 95 hypertriglyceridemic (HTG) patients and 102 healthy subjects by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). RESULTS: The APOA5-1131C (C) allele frequency was higher in the HTG group than in the control group. Plasma triglycerides (TG) were significantly higher and apoA5 was significantly lower in patients with the C allele when compared to patients with the APOA5-1131T (T) allele, even more dramatically so in the APOA5-1131CC homozygote. In both the HTG group and the control group, the frequency of the C allele was positively correlated with levels of TG, total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) and apolipoprotein B100 (apoB100), and negatively correlated with levels of high density lipoprotein cholesterol (HDL-C), apolipoprotein A1 (apoA1) and apolipoprotein A5 (apoA5) (P<0.001). In all subjects, the frequency of the C allele was positively correlated with the level of small-sized HDL (preß(1)-HDL and HDL(3a)), and negatively correlated with levels of HDL(2a) and HDL(2b). CONCLUSION: Changes in HDL subclass distributions in HTG may be related to the APOA5-1131T>C polymorphism. This polymorphism leads to a general shift towards smaller-sized HDL.

Statin treatment improves plasma lipid levels but not HDL subclass distribution in patients undergoing percutaneous coronary intervention.

Despite the established efficacy of statin therapy, the risk of cardiovascular events remains high in many patients. We examined high-density lipoprotein (HDL) subclass distribution profiles among statin-treated coronary heart disease (CHD) patients undergoing percutaneous coronary intervention (PCI). Plasma HDL subclasses were measured in 85 patients with established CHD and quantified by two-dimensional gel electrophoresis and immunoblotting. In CHD patients with statin treatment, the mean value of total cholesterol (TC) reached the desirable level and the triacylglycerol level (TAG) was borderline high. Moreover, low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), apolipoproteinA-I, and apolipoproteinB-100 levels in these patients resembled those in normolipidemic healthy subjects. The HDL subclass did not show a normal distribution and was characterized by the lower large-sized HDL(2b) contents and higher contents of small-sized preß1-HDL in CHD patients, compared to those in normolipidemic control subjects. Multiple stepwise regression analysis revealed that the severity of coronary stenosis, determined by the Gensini Score, was significantly and independently predicted by HDL(2b) and HDL(3b). Statin therapy was effective in modifying plasma lipids levels, but not adequate as a monotherapy to normalize the HDL subclass distribution phenotype of patients with CHD undergoing PCI. The HDL subclass distribution may aid in risk stratification, especially in patients with CHD and therapeutic LDL-C and HDL-C levels.