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.

New Dawn for Atherosclerosis: Vascular Endothelial Cell Senescence and Death

Endothelial cells (ECs) form the inner linings of blood vessels, and are directly exposed to endogenous hazard signals and metabolites in the circulatory system. The senescence and death of ECs are not only adverse outcomes, but also causal contributors to endothelial dysfunction, an early risk marker of atherosclerosis. The pathophysiological process of EC senescence involves both structural and functional changes and has been linked to various factors, including oxidative stress, dysregulated cell cycle, hyperuricemia, vascular inflammation, and aberrant metabolite sensing and signaling. Multiple forms of EC death have been documented in atherosclerosis, including autophagic cell death, apoptosis, pyroptosis, NETosis, necroptosis, and ferroptosis. Despite this, the molecular mechanisms underlying EC senescence or death in atherogenesis are not fully understood. To provide a comprehensive update on the subject, this review examines the historic and latest findings on the molecular mechanisms and functional alterations associated with EC senescence and death in different stages of atherosclerosis.

Quantitative analysis of a posterior fossa teratomas with unusual CT and MR Characteristics--illustrative case

BACKGROUND

Intracranial teratomas or other cystic lesions with atypical imaging manifestations can still be frequently seen clinically. The specific reasons for unusual imaging manifestations need to be further explored.

OBSERVATIONS

A case of adult teratoma in the posterior fossa with unusual imaging manifestations was reported. The chemical composition of its cystic fluid was quantitatively detected, and in vitro imaging simulation experiments were performed on some fluid substances with similar cystic fluid properties to explore the reasons for special imaging manifestations. The content of inorganic substances and protein in the cystic fluid were both low, with no melanin detected. In vitro experiments revealed that MR T1 signals could increase with protein content rising and changes in MR T2 signals presented no obvious correlation with it. CT values increased gradually with protein concentration rising. The substances with similar viscosity had similar CT values, whereas substance viscosity showed no significant correlation with changes in MR signals.

CONCLUSION

The abnormality of imaging manifestations cannot be confirmed as the result of "high protein content", nor can it be simply attributed to bleeding. Further research is required for the impact of the combination of paramagnetic particles and biofluid on imaging.

[Quality analysis of Rosae Radix et Rhizoma]

Rosae Radix et Rhizoma is a herbal medicine in a variety of famous Chinese patent medicines, while the quality standard for this medicine remains to be developed due to the insufficient research on the quality of Rosae Radix et Rhizoma from different sources. Therefore, this study comprehensively analyzed the components in Rosae Radix et Rhizoma of different sources from the aspects of extract, component category content, identification based on thin-lay chromatography, active component content determination, and fingerprint, so as to improve the quality control. The results showed that the content of chemical components varied in the samples of different sources, while there was little difference in the chemical composition among the samples. The content of components in the roots of Rosa laevigata was higher than that in the other two species, and the content of components in the roots was higher than that in the stems. The fingerprints of triterpenoids and non-triterpenoids were established, and the content of five main triterpenoids including multiflorin, rosamultin, myrianthic acid, rosolic acid, and tormentic acid in Rosae Radix et Rhizoma was determined. The results were consistent with those of major component categories. In conclusion, the quality of Rosae Radix et Rhizoma is associated with the plant species, producing area, and medicinal parts. The method established in this study lays a foundation for improving the quality standard of Rosae Radix et Rhizoma and provides data support for the rational use of the stem.

Cholesterol homeostasis and cancer: a new perspective on the low-density lipoprotein receptor

BACKGROUND

Disturbance of cholesterol homeostasis is considered as one of the manifestations of cancer. Cholesterol plays an essential role in the pleiotropic functions of cancer cells, including mediating membrane trafficking, intracellular signal transduction, and production of hormones and steroids. As a single transmembrane receptor, the low-density lipoprotein receptor (LDLR) can participate in intracellular cholesterol uptake and regulate cholesterol homeostasis. It has recently been found that LDLR is aberrantly expressed in a broad range of cancers, including colon cancer, prostate cancer, lung cancer, breast cancer and liver cancer. LDLR has also been found to be involved in various signaling pathways, such as the MAPK, NF-κB and PI3K/Akt signaling pathways, which affect cancer cells and their surrounding microenvironment. Moreover, LDLR may serve as an independent prognostic factor for lung cancer, breast cancer and pancreatic cancer, and is closely related to the survival of cancer patients. However, the role of LDLR in some cancers, such as prostate cancer, remains controversial. This may be due to the lack of normal feedback regulation of LDLR expression in cancer cells and the severe imbalance between LDLR-mediated cholesterol uptake and de novo biosynthesis of cholesterol.

CONCLUSIONS

The imbalance of cholesterol homeostasis caused by abnormal LDLR expression provides new therapeutic opportunities for cancer. LDLR interferes with the occurrence and development of cancer by modulating cholesterol homeostasis and may become a novel target for the development of anti-cancer drugs. Herein, we systematically review the contribution of LDLR to cancer progression, especially its dysregulation and underlying mechanism in various malignancies. Besides, potential targeting and immunotherapeutic options are proposed.

Ezetimibe and Cancer: Is There a Connection?

The high level of serum cholesterol caused by the excessive absorption of cholesterol can lead to hypercholesteremia, thus promoting the occurrence and development of cancer. Ezetimibe is a drug that reduces cholesterol absorption and has been widely used for the treatment of patients with high circulating cholesterol levels for many years. Mechanistically, ezetimibe works by binding to NPC1L1, which is a key mediator of cholesterol absorption. Accumulating data from preclinical models have shown that ezetimibe alone could inhibit the development and progression of cancer through a variety of mechanisms, including anti-angiogenesis, stem cell suppression, anti-inflammation, immune enhancement and anti-proliferation. In the past decade, there has been heated discussion on whether ezetimibe combined with statins will increase the risk of cancer. At present, more and more evidence shows that ezetimibe does not increase the risk of cancers, which supports the role of ezetimibe in anti-cancer. In this review, we discussed the latest progress in the anti-cancer properties of ezetimibe and elucidated its underlying molecular mechanisms. Finally, we highlighted the potential of ezetimibe as a therapeutic agent in future cancer treatment and prevention.

Crosstalk between Lipid Rafts and Aging: New Frontiers for Delaying Aging

With the rapid aging in the global population, delay of aging has become a hot research topic. Lipid rafts (LRs) are microdomains in the plasma membrane that contain sphingolipids and cholesterol. Emerging evidence indicates an interesting interplay between LRs and aging. LRs and their components are altered with aging. Further, the aging process is strongly influenced by LRs. In recent years, LRs and their component signaling molecules have been recognized to affect aging by interfering with its hallmarks. Therefore, targeting LRs is a promising strategy to delay aging.

Involvement of LDL and ox-LDL in Cancer Development and Its Therapeutical Potential

Lipid metabolism disorder is related to an increased risk of tumorigenesis and is involved in the rapid growth of cancer cells as well as the formation of metastatic lesions. Epidemiological studies have demonstrated that low-density lipoprotein (LDL) and oxidized low-density lipoprotein (ox-LDL) are closely associated with breast cancer, colorectal cancer, pancreatic cancer, and other malignancies, suggesting that LDL and ox-LDL play important roles during the occurrence and development of cancers. LDL can deliver cholesterol into cancer cells after binding to LDL receptor (LDLR). Activation of PI3K/Akt/mTOR signaling pathway induces transcription of the sterol regulatory element-binding proteins (SREBPs), which subsequently promotes cholesterol uptake and synthesis to meet the demand of cancer cells. Ox-LDL binds to the lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) and cluster of differentiation 36 (CD36) to induce mutations, resulting in inflammation, cell proliferation, and metastasis of cancer. Classic lipid-lowering drugs, statins, have been shown to reduce LDL levels in certain types of cancer. As LDL and ox-LDL play complicated roles in cancers, the potential therapeutic effect of targeting lipid metabolism in cancer therapy warrants more investigation.

Metabolomics and pharmacodynamic analysis reveal the therapeutic role of Prunella vulgaris oil on intrauterine adhesion rats

Metabolomics is applied to explore the curative effect of complex systems, such as Chinese medicine. Intrauterine adhesion (IUA) harms the reproductive system and affects fertility, and hence is a significant public health concern. Prunella vulgaris oil (PVO) protects the reproductive system and exerts anti-inflammatory effects, but its effect on IUA and the underlying mechanism is unclear. In this study, we established a serum metabolomics method based on GC-TOF-MS to evaluate the mechanism of PVO in the IUA rat model established by mechanical injury and infection. Animal experiments showed that PVO improves the inflammatory response in the uterus of IUA model rats and reduces the content of inflammatory factors to improve the microenvironment of the reproductive system. It also regulates the expression of TGF-β1 and Smad-related mRNA and protein to inhibit fibrosis. Metabolomics indicated a significant abnormality in serum metabolism in IUA rats, and a total of 51 differential markers were screened and identified. After PVO treatment, these metabolic abnormalities improved significantly. The metabolic pathway analysis revealed that PVO affects glyoxylate and dicarboxylate metabolism, and β-alanine metabolism pathways. This study showed that PVO significantly improves inflammation and fibrosis in IUA rats combined with the pharmacological results. The primary mechanism is related to regulating the metabolism of amino acids and their derivatives to balance the associated disorders and control energy metabolism.

[Research progress of tannins in traditional Chinese medicines in recent ten years]

In this paper, the newly isolated tannins were sorted after a review of the literature concerning tannins in recent 10 years, and their research progress was summarized in terms of extraction, isolation, pharmacological activity and metabolism. Hydrolysable tannins and condensed tannins are the main structural types. Modern research shows that tannins have many pharmacological effects, such as bacteriostasis, antioxidation, antitumor, antivirus and blood glucose reduction, and have broad development prospects. They are usually extracted by water, ethanol and acetone and isolated and purified by macroporous resin and gel column chromatography. The packings commonly adopted for the column chromatography mainly included Sephadex LH-20, Diaion HP-20, MCI-gel CHP-20 and Toyopearl HW-40. Modern analytical techniques such as nuclear magnetic resonance spectroscopy(NMR), fast atom bombardment mass spectrometry(FAB-MS) and circular dichroism(CD) are generally used for the structural identification of tannins. Howe-ver, their isolation, purification and structural identification are still challenging. It is necessary to use a variety of high-throughput screening methods to explore their pharmacological activities and to explore the material basis responsible for their functions through experiments in vivo.

Curcumin Acetylsalicylate Extends the Lifespan of Caenorhabditis elegans

Aspirin and curcumin have been reported to be beneficial to anti-aging in a variety of biological models. Here, we synthesized a novel compound, curcumin acetylsalicylate (CA), by combining aspirin and curcumin. We characterized how CA affects the lifespan of Caenorhabditis elegans (C. elegans) worms. Our results demonstrated that CA extended the lifespan of worms in a dose-dependent manner and reached its highest anti-aging effect at the concentration of 20 μM. In addition, CA reduced the deposition of lipofuscin or "age pigment" without affecting the reproductivity of worms. CA also caused a rightward shift of C. elegans lifespan curves in the presence of paraquat-induced (5 mM) oxidative stress or 37 °C acute heat shock. Additionally, CA treatment decreased the reactive oxygen species (ROS) level in C. elegans and increased the expression of downstream genes superoxide dismutase (sod)-3, glutathione S-transferase (gst)-4, heat shock protein (hsp)-16.2, and catalase-1 (ctl-1). Notably, CA treatment resulted in nuclear translocation of the DAF-16 transcription factor, which is known to stimulate the expression of SOD-3, GST-4, HSP-16, and CTL-1. CA did not produce a longevity effect in daf-16 mutants. In sum, our data indicate that CA delayed the aging of C. elegans without affecting reproductivity, and this effect may be mediated by its activation of DAF-16 and subsequent expression of antioxidative genes, such as sod-3 and gst-4. Our study suggests that novel anti-aging drugs may be developed by combining two individual drugs.

Celastrol induces lipophagy via the LXRα/ABCA1 pathway in clear cell renal cell carcinoma

Celastrol is a triterpene derived from the traditional Chinese medicine Tripterygium wilfordii Hook f, which displays potential anticancer activity. In the present study, we investigated the anticancer effects of celastrol against clear cell renal cell carcinoma (ccRCC) and the underlying mechanisms. Using Cancer Genome Atlas (TCGA) database and genotype-tissue expression (GTEx) database we conducted a bioinformatics analysis, which showed that the mRNA levels of liver-X receptors α (LXRα) and ATP-binding cassette transporter A1 (ABCA1) in ccRCC tissues were significantly lower than those in adjacent normal tissues. This result was confirmed by immunoblotting analysis of 4 ccRCC clinical specimens, which showed that the protein expression of LXRα and ABCA1 was downregulated. Similar results were obtained in a panel of ccRCC cell lines (786-O, A498, SN12C, and OS-RC-2). In 786-O and SN12C cells, treatment with celastrol (0.25-2.0 μM) concentration-dependently inhibited the cell proliferation, migration, and invasion as well as the epithelial-mesenchymal transition (EMT) process. Furthermore, we demonstrated that celastrol inhibited the invasion of 786-O cells through reducing lipid accumulation; celastrol concentration-dependently promoted autophagy to reduce lipid storage. Moreover, we revealed that celastrol dramatically activated LXRα signaling, and degraded lipid droplets by inducing lipophagy in 786-O cells. Finally, celastrol promoted cholesterol efflux from 786-O cells via ABCA1. In high-fat diet-promoted ccRCC cell line 786-O xenograft model, administration of celastrol (0.25, 0.5, 1.0 mg·kg-1·d-1, for 4 weeks, i.p.) dose-dependently inhibited the tumor growth with upregulated LXRα and ABCA1 protein in tumor tissue. In conclusion, this study reveals that celastrol triggers lipophagy in ccRCC by activating LXRα, promotes ABCA1-mediated cholesterol efflux, suppresses EMT progress, and ultimately inhibits cell proliferation, migration, and invasion as well as tumor growth. Thus, our study provides evidence that celastrol can be used as a lipid metabolism-based anticancer therapeutic approach.

Celastrol ameliorates vascular neointimal hyperplasia through Wnt5a-involved autophagy

Neointimal hyperplasia caused by the excessive proliferation of vascular smooth muscle cells (VSMCs) is the pathological basis of restenosis. However, there are few effective strategies to prevent restenosis. Celastrol, a pentacyclic triterpene, has been recently documented to be beneficial to certain cardiovascular diseases. Based on its significant effect on autophagy, we proposed that celastrol could attenuate restenosis through enhancing autophagy of VSMCs. In the present study, we found that celastrol effectively inhibited the intimal hyperplasia and hyperproliferation of VSMCs by inducing autophagy. It was revealed that autophagy promoted by celastrol could induce the lysosomal degradation of c-MYC, which might be a possible mechanism contributing to the reduction of VSMCs proliferation. The Wnt5a/PKC/mTOR signaling pathway was found to be an underlying mechanism for celastrol to induce autophagy and inhibit the VSMCs proliferation. These observations indicate that celastrol may be a novel drug with a great potential to prevent restenosis.

Targeting HDL in tumor microenvironment: New hope for cancer therapy

Epidemiological studies have shown that plasma HDL-C levels are closely related to the risk of prostate cancer, breast cancer, and other malignancies. As one of the key carriers of cholesterol regulation, high-density lipoprotein (HDL) plays an important role in tumorigenesis and cancer development through anti-inflammation, antioxidation, immune-modulation, and mediating cholesterol transportation in cancer cells and noncancer cells. In addition, the occurrence and progression of cancer are closely related to the alteration of the tumor microenvironment (TME). Cancer cells synthesize and secrete a variety of cytokines and other factors to promote the reprogramming of surrounding cells and shape the microenvironment suitable for cancer survival. By analyzing the effect of HDL on the infiltrating immune cells in the TME, as well as the relationship between HDL and tumor-associated angiogenesis, it is suggested that a moderate increase in the level of HDL in vivo with consequent improvement of the function of HDL in the TME and induction of intracellular cholesterol efflux may be a promising strategy for cancer therapy.

[Metabolic mechanism of Prunella vulgaris in treatment of ethanol-induced oxidative stress in rats based on metabonomics]

Prunella vulgaris(PV) is an edible and traditional medicinal herb which has a wide range application in fighting inflammation and oxidative stress, and protecting liver. Now it has been used to treat various types of liver diseases and has significant clinical efficacy. This study aims to investigate the effects of PV on ethanol-induced oxidative stress injury in rats and its metabolic mechanism. The rats were divided into control group, model group, PV group, and VC group. The liver protection of PV was identified by measuring pharmacological indexes such as antioxidant and anti-inflammatory activity. The metabolic mechanism of long-term ethanol exposure and the metabolic regulation mechanism of PV treatment were studied by LS-MS metabonomics. The pharmacological investigation indicated that ethanol could significantly decrease the contents of SOD, GSH-Px, CAT and other antioxidant enzymes in liver and increase the content of MDA. At the same time, PV could significantly reduce the contents of inflammatory factors(TNF-α, IL-6 and IL-1β) and liver function markers(ALT, AST, ALP) in serum. What's more, long-term ethanol exposure could significantly cause liver injury, while PV could protect liver. Metabolomics based on multiple statistical analyses showed that long-term ethanol exposure could cause significant metabolic disorder, and fatty acids, phospholipids, carnitines and sterols were the main biomarkers. Meanwhile, pathway analysis and enrichment analysis showed that the β oxidation of branched fatty acids was the main influencing pathway. Also, PV could improve metabolic disorder of liver injury induced by ethanol, and amino acids, fatty acids, and phospholi-pids were the main biomarkers in PV treatment. Metabolic pathway analysis showed that PV mainly regulated metabolic disorder of ethanol-induced liver injury through phenylalanine, tyrosine and tryptophan biosynthetic pathways. This study could provide a new perspective on the hepatoprotective effect of natural medicines, such as PV.

Celastrol Attenuates Lipid Accumulation and Stemness of Clear Cell Renal Cell Carcinoma via CAV-1/LOX-1 Pathway

Clear cell renal cell carcinoma (ccRCC) is characterized by abnormal lipid accumulation. Celastrol is a pentacyclic triterpene extracted from Tripterygium wilfordii Hook F with anti-cancer activity. In the present study, the anticancer effects of celastrol on ccRCC and the underlying mechanisms were studied. Patients with reduced high density lipoprotein (HDL) and elevated levels of triglyceride (TG), total cholesterol (TC), low density lipoprotein (LDL) was found to have higher risk of ccRCC. In ccRCC clinical samples and cell lines, caveolin-1 (CAV-1) was highly expressed. CAV-1 was identified as a potential prognostic biomarker for ccRCC. Celastrol inhibited tumor growth and decreased lipid deposition promoted by high-fat diet in vivo. Celastrol reduced lipid accumulation and caveolae abundance, inhibited the binding of CAV-1 and lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) in ccRCC cells. Furthermore, celastrol attenuated stemness through blocking Wnt/β-catenin pathway after knockdown of CAV-1 and LOX-1. Therefore, the findings suggest that celastrol may be a promising active ingredient from traditional Chinese medicine for anti-cancer therapy.

Nicotinate-curcumin inhibits AngII-induced vascular smooth muscle cell phenotype switching by upregulating Daxx expression

Phenotypic switching is the main cause of the abnormal proliferation and migration of vascular smooth muscle cells (VSMCs). We previously showed that Daxx exerted negative regulatory effect on AngII-induced VSMC proliferation and migration. However, the function of Daxx in VSMC phenotype switching remained unknown. Nicotinate-curcumin (NC) is an esterification derivative of niacin and curcumin that can prevent the formation of atherosclerosis. We found that NC significantly decreased AngII-induced VSMC phenotype switching. Furthermore, NC significantly inhibited AngII-induced cell proliferation and migration. Moreover, NC upregulated Daxx expression and regulated the PTEN/Akt signaling pathway. We concluded that NC inhibited AngII-induced VSMC phenotype switching by regulating the PTEN/Akt pathway, and through a mechanism that might be associated with the upregulation of Daxx expression.

Investigation of the idiosyncratic hepatotoxicity of Polygonum multiflorum Thunb. through metabolomics using GC-MS

BACKGROUND

The idiosyncratic hepatotoxicity of Polygonum multiflorum (PM) has attracted considerable interest, but the idiosyncratically hepatotoxic components and endogenous metabolite changes resulting from idiosyncratic hepatotoxicity of PM are not well understood. The aim of this study was to identify the idiosyncratically hepatotoxic components and potential endogenous metabolic biomarkers for PM-induced liver injury.

METHODS

Serum biochemical indicators and hematoxylin and eosin (H&E) staining were evaluated to identify pathological changes. Gas chromatography/mass spectrometry (GC-MS) was performed to identify changes in metabolic biomarkers. Orthogonal projection to latent structures discriminant analysis (OPLS-DA) was applied to determine group clustering trends and differential metabolites.

RESULTS

The results for the liver index, the liver function index and liver pathology showed that Polygonum multiflorum ethanol extract (PME), 50% ethanol elution fractions and tetrahydroxystilbene glucoside (TSG) from PME can induce idiosyncratic hepatotoxicity. TSG was the main idiosyncratically hepatotoxic component. Forty endogenous metabolites were identified in the rat liver. Six biomarkers, including lower levels of L-valine and higher levels of 3-hydroxybutyric acid, hexadecanoic acid, ribose, phosphoric acid and oxalic acid, were related to PM-induced liver injury. These differential biomarkers led to disruptions in amino acid, fatty acid, oxalate, energy and glucose metabolism. A total of 32 types of endogenous metabolites were identified in rat serum. Ten biomarkers were related to the liver injury induced by TSG, including lower levels of L-valine and L-proline and higher levels of urea, caproic acid, DL-malic acid, D-mannose, 3-hydroxybutyric acid, D-galactose, octadecane and hexadecanoic acid. These differential biomarkers led to disruptions in amino acid, glucose and fat metabolism. The mechanism of idiosyncratic hepatotoxicity in PM involves TSG-induced disruptions in amino acid metabolism, lipid metabolism, energy metabolism and glucose metabolism.

CONCLUSIONS

These findings reflect the material basis and metabolic mechanism of idiosyncratic PM hepatotoxicity.

Impaired Barrier Function and Immunity in the Colon of Aldo-Keto Reductase 1B8 Deficient Mice

Aldo-keto reductase 1B10 (AKR1B10) is downregulated in human ulcerative colitis (UC) and colorectal cancer, being a potential pathogenic factor of these diseases. Aldo-keto reductase 1B8 (AKR1B8) is the ortholog in mice of human AKR1B10. Targeted AKR1B8 deficiency disrupts homeostasis of epithelial self-renewal and leads to susceptibility to colitis and carcinogenesis. In this study, we found that in AKR1B8 deficient mice, Muc2 expression in colon was diminished, and permeability of colonic epithelium increased. Within 24 h, orally administered FITC-dextran penetrated into mesenteric lymph nodes (MLN) and liver in AKR1B8 deficient mice, but not in wild type controls. In the colon of AKR1B8 deficient mice, neutrophils and mast cells were markedly infiltrated, γδT cells were numerically and functionally impaired, and dendritic cell development was altered. Furthermore, Th1, Th2, and Th17 cells decreased, but Treg and CD8T cells increased in the colon and MLN of AKR1B8 deficient mice. In colonic epithelial cells of AKR1B8 deficient mice, p-AKT (T308 and S473), p-ERK1/2, p-IKBα, p-p65 (S536), and IKKα expression decreased, accompanied with downregulation of IL18 and CCL20 and upregulation of IL1β and CCL8. These data suggest AKR1B8 deficiency leads to abnormalities of intestinal epithelial barrier and immunity in colon.

Human torpor: translating insights from nature into manned deep space expedition

During a long-duration manned spaceflight mission, such as flying to Mars and beyond, all crew members will spend a long period in an independent spacecraft with closed-loop bioregenerative life-support systems. Saving resources and reducing medical risks, particularly in mental heath, are key technology gaps hampering human expedition into deep space. In the 1960s, several scientists proposed that an induced state of suppressed metabolism in humans, which mimics 'hibernation', could be an ideal solution to cope with many issues during spaceflight. In recent years, with the introduction of specific methods, it is becoming more feasible to induce an artificial hibernation-like state (synthetic torpor) in non-hibernating species. Natural torpor is a fascinating, yet enigmatic, physiological process in which metabolic rate (MR), body core temperature (T_b ) and behavioural activity are reduced to save energy during harsh seasonal conditions. It employs a complex central neural network to orchestrate a homeostatic state of hypometabolism, hypothermia and hypoactivity in response to environmental challenges. The anatomical and functional connections within the central nervous system (CNS) lie at the heart of controlling synthetic torpor. Although progress has been made, the precise mechanisms underlying the active regulation of the torpor-arousal transition, and their profound influence on neural function and behaviour, which are critical concerns for safe and reversible human torpor, remain poorly understood. In this review, we place particular emphasis on elaborating the central nervous mechanism orchestrating the torpor-arousal transition in both non-flying hibernating mammals and non-hibernating species, and aim to provide translational insights into long-duration manned spaceflight. In addition, identifying difficulties and challenges ahead will underscore important concerns in engineering synthetic torpor in humans. We believe that synthetic torpor may not be the only option for manned long-duration spaceflight, but it is the most achievable solution in the foreseeable future. Translating the available knowledge from natural torpor research will not only benefit manned spaceflight, but also many clinical settings attempting to manipulate energy metabolism and neurobehavioural functions.

PVAT targets VSMCs to regulate vascular remodelling: angel or demon

Vascular remodelling refers to abnormal changes in the structure and function of blood vessel walls caused by injury, and is the main pathological basis of cardiovascular diseases such as atherosclerosis, hypertension, and pulmonary hypertension. Among them, the neointimal hyperplasia caused by abnormal proliferation of vascular smooth muscle cells (VSMCs) plays a key role in the pathogenesis of vascular remodelling. Perivascular adipose tissue (PVAT) can release vasoactive substances to target VSMCs and regulate the pathological process of vascular remodelling. Specifically, PVAT can promote the conversion of VSMCs phenotype from contraction to synthesis by secreting visfatin, leptin, and resistin, and participate in the development of vascular remodelling-related diseases. Conversely, it can also inhibit the growth of VSMCs by secreting adiponectin and omentin to prevent neointimal hyperplasia and alleviate vascular remodelling. Therefore, exploring and developing new drugs or other treatments that facilitate the beneficial effects of PVAT on VSMCs is a potential strategy for prevention or treatment of vascular remodelling-related cardiovascular diseases.

Pyroptotic cell-derived microparticle: An atherogenic factor in infectious diseases

Chronic infection is considered a risk factor for atherosclerosis. The link between infectious agents and atherosclerosis is manifested by the presence of infection-induced pyroptotic cells in atherosclerotic lesions. Pyroptosis is an inflammatory form of programmed cell death that occurs most frequently upon infection. However, inflammation is not the only cause by which pyroptosis involved in atherosclerosis. During pyroptosis, a large amount of microparticles are released from pyroptotic cells, which not only transfer inflammatory mediators to arterial vessel, but also mediate the interaction between a variety of cells, leading to endothelial injury, macrophage infiltration, vascular smooth muscle cell migration and proliferation, thereby accelerating atherosclerosis. Thus, we proposed hypothesis that pyroptotic cell-derived microparticle is an atherogenic factor in infectious diseases.

Targeting neuroinflammation: The therapeutic potential of ω-3 PUFAs in substance abuse

Substance abuse is a chronic relapsing disorder that results in serious health and socioeconomic issues worldwide. Addictive drugs induce long-lasting morphologic and functional changes in brain circuits and account for the formation of compulsive drug-seeking and drug-taking behaviors. Yet, there remains a lack of reliable therapy. In recent years, accumulating evidence indicated that neuroinflammation was implicated in the development of drug addiction. Findings from both our and other laboratories suggest that ω-3 polyunsaturated fatty acids (PUFAs) are effective in treating neuroinflammation-related mental diseases, and indicate that they could exert positive effects in treating drug addiction. Thus, in the present review, we summarized and evaluated recently published articles reporting the neuroinflammation mechanism in drug addiction and the immune regulatory ability of ω-3 PUFAs. We also sought to identify some of the challenges ahead in the translation of ω-3 PUFAs into addiction treatment.

The crosstalk: exosomes and lipid metabolism

Exosomes have been considered as novel and potent vehicles of intercellular communication, instead of "cell dust". Exosomes are consistent with anucleate cells, and organelles with lipid bilayer consisting of the proteins and abundant lipid, enhancing their "rigidity" and "flexibility". Neighboring cells or distant cells are capable of exchanging genetic or metabolic information via exosomes binding to recipient cell and releasing bioactive molecules, such as lipids, proteins, and nucleic acids. Of note, exosomes exert the remarkable effects on lipid metabolism, including the synthesis, transportation and degradation of the lipid. The disorder of lipid metabolism mediated by exosomes leads to the occurrence and progression of diseases, such as atherosclerosis, cancer, non-alcoholic fatty liver disease (NAFLD), obesity and Alzheimer's diseases and so on. More importantly, lipid metabolism can also affect the production and secretion of exosomes, as well as interactions with the recipient cells. Therefore, exosomes may be applied as effective targets for diagnosis and treatment of diseases. Video abstract.

Direct Interaction of Daxx and Androgen Receptor Is Required for Their Regulatory Activity in Cholesterol Biosynthesis

INTRODUCTION

Homeostasis of cholesterol is crucial for cellular function, and dysregulated cholesterol biosynthesis is a metabolic event that can lead to hepatic and cardiovascular abnormalities.

OBJECTIVE

The aim of this study was to investigate the effects and mechanisms of domain-associated protein (Daxx) and androgen receptor (AR) on intracellular cholesterol synthesis.

METHODS

HepG2 cells were transfected with pCDNA3.1(+)/Daxx plasmid or treated with testosterone propionate to observe the effects of Daxx and AR on intracellular cholesterol levels. Co-immunoprecipitation experiments were performed to identify the interaction between Daxx and AR and to explore the regulatory effects of this interaction on cholesterol synthesis.

RESULTS

Our experiments showed that AR promoted cholesterol synthesis and accumulation by activating sterol-regulatory element-binding protein isoform 2. AR-induced cholesterol synthesis was inhibited by Daxx; however, the expression of AR was not affected. Further studies demonstrated the existence of direct binding between Daxx and AR and this interaction was required to suppress AR activity.

CONCLUSIONS

The Daxx-mediated antagonism of AR depicts a more complete picture as to how Daxx regulates intracellular cholesterol level and provides a new target for treatment of atherosclerosis.