Laminaria japonica Polysaccharide Suppresses Atherosclerosis via Regulating Autophagy-Mediated Macrophage Polarization

Macrophages in CRSwNP: Do they deserve more attention?

Chronic rhinosinusitis (CRS) represents a heterogeneous disorder primarily characterized by the persistent inflammation of the nasal cavity and paranasal sinuses. The subtype known as chronic rhinosinusitis with nasal polyposis (CRSwNP) is distinguished by a significantly elevated recurrence rate and augmented challenges in the management of nasal polyps. The pathogenesis underlying this subtype remains incompletely understood. Macrophages play a crucial role in mediating the immune system's response to inflammatory stimuli. These cells exhibit remarkable plasticity and heterogeneity, differentiating into either the pro-inflammatory M1 phenotype or the anti-inflammatory and reparative M2 phenotype depending on the surrounding microenvironment. In CRSwNP, macrophages demonstrate reduced production of Interleukin 10 (IL-10), compromised phagocytic activity, and decreased autophagy. Dysregulation of pro-resolving mediators may occur during the inflammatory resolution process, which could potentially hinder the adequate functioning of anti-inflammatory macrophages in facilitating resolution. Collectively, these factors may contribute to the prolonged inflammation observed in CRSwNP. Additionally, macrophages may enhance fibrin cross-linking through the release of factor XIII-A (FAXIII), promoting fibrin deposition and plasma protein retention. Macrophages also modulate vascular permeability by releasing Vascular endothelial growth factor (VEGF). Moreover, they may disrupt the balance between Matrix Metalloproteinases (MMPs) and Tissue Inhibitors of Metalloproteinases (TIMPs), which favors extracellular matrix (ECM) degradation, edema formation, and pseudocyst development. Accumulating evidence suggests a close association between macrophage infiltration and CRSwNP; however, the precise mechanisms underlying this relationship warrant further investigation. In different subtypes of CRSwNP, different macrophage phenotypic aggregations trigger different types of inflammatory features. Increasing evidence suggests that macrophage infiltration is closely associated with CRSwNP, but the mechanism and the relationship between macrophage typing and CRSwNP endophenotyping remain to be further explored. This review discusses the role of different types of macrophages in the pathogenesis of different types of CRSwNP and their contribution to polyp formation, in the hope that a better understanding of the role of macrophages in specific CRSwNP will contribute to a precise and individualized understanding of the disease.

Tea Polysaccharide Ameliorates High-Fat Diet-Induced Renal Tubular Ectopic Lipid Deposition via Regulating the Dynamic Balance of Lipogenesis and Lipolysis

Renal tubular ectopic lipid deposition (ELD) plays a significant role in the development of chronic kidney disease, posing a great threat to human health. The present work aimed to explore the intervention effect and potential molecular mechanism of a purified tea polysaccharide (TPS3A) on renal tubular ELD. The results demonstrated that TPS3A effectively improved kidney function and slowed the progression of tubulointerstitial fibrosis in high-fat-diet (HFD)-exposed ApoE-/- mice. Additionally, TPS3A notably suppressed lipogenesis and enhanced lipolysis, as shown by the downregulation of lipogenesis markers (SREBP-1 and FAS) and the upregulation of lipolysis markers (HSL and ATGL), thereby reducing renal tubular ELD in HFD-fed ApoE-/- mice and palmitic-acid-stimulated HK-2 cells. The AMPK-SIRT1-FoxO1 axis is a core signal pathway in regulating lipid deposition. Consistently, TPS3A significantly increased the levels of phosphorylated-AMPK, SIRT1, and deacetylation of Ac-FoxO1. However, these effects of TPS3A on lipogenesis and lipolysis were abolished by AMPK siRNA, SIRT1 siRNA, and FoxO1 inhibitor, resulting in exacerbated lipid deposition. Taken together, TPS3A shows promise in ameliorating renal tubular ELD by inhibiting lipogenesis and promoting lipolysis through the AMPK-SIRT1-FoxO1 signaling pathway.

Extraction, purification, structural characterization and pharmacological activities of polysaccharides from sea buckthorn (Hippophae rhamnoides L.): A review

ETHNOPHARMACOLOGICAL RELEVANCE

Sea buckthorn (Hippophae rhamnoides L.) is an edible fruit with a long history in China as a medicinal plant. The fruits of H. rhamnoides are rich in a variety of nutrients and pharmacological active compounds. As one of the most important active ingredients in sea buckthorn, polysaccharides have attracted the attention of researchers due to their antioxidant, anti-fatigue, and liver protective qualities.

AIM OF THE REVIEW

This review summarizes recent studies on extraction, purification, structural characterization and pharmacological activities of polysaccharides from sea buckthorn. In addition, the relationship between the structure and the activities of sea buckthorn polysaccharides (SBPS) were discussed. This review would provide important research bases and up-to-date information for the future in-depth development and application of sea buckthorn polysaccharides in the field of pharmaceuticals and functional foods.

MATERIALS AND METHODS

By inputting the search term "Sea buckthorn polysaccharides", relevant research information was obtained from databases such as Web of Science, Google Scholar, PubMed, China Knowledge Network (CNKI), China Master Theses Full-text Database, and China Doctoral Dissertations Full-text Database.

RESULTS

The main extraction methods of SBPS include hot water extraction (HWE), ultrasonic assisted extraction (UAE), microwave-assisted extraction (MAE), flash extraction (FE), and ethanol extraction. More than 20 polysaccharides have been isolated from sea buckthorn fruits. The chemical structures of sea buckthorn polysaccharides obtained by different extraction, isolation, and purification methods are diverse. Polysaccharides from sea buckthorn display a variety of pharmacological properties, including antioxidant, anti-fatigue, liver protection, anti-obesity, regulation of intestinal flora, immunoregulation, anti-tumor, anti-inflammatory, and hypoglycemic activities.

CONCLUSIONS

Sea buckthorn has a long medicinal history and characteristics of an ethnic medicine and food. Polysaccharides are one of the main active components of sea buckthorn, and they have received increasing attention from researchers. Sea buckthorn polysaccharides have remarkable pharmacological activities, health benefits, and broad application prospects. In addition, further exploration of the chemical structure of SBPS, in-depth study of their pharmacological activities, identification of their material basis, characterization of disease resistance mechanisms, and potential health functions are still directions of future research. With the accumulation of research on the extraction and purification processes, chemical structure, pharmacological effects, molecular mechanisms, and structure-activity relationships, sea buckthorn polysaccharides derived from natural resources will ultimately make significant contributions to human health.

Puerarin Induces Macrophage M2 Polarization to Exert Antinonalcoholic Steatohepatitis Pharmacological Activity via the Activation of Autophagy

To determine the protective mechanism of puerarin against nonalcoholic steatohepatitis (NASH), the pharmacodynamic effects of puerarin on NASH were evaluated by using zebrafish, cells, and mice. Western blotting, flow cytometry, immunofluorescence, and qRT-PCR were used to detect the effects of puerarin on RAW264.7 autophagy and polarization. Key target interactions between autophagy and polarization were detected using immunoprecipitation. Puerarin regulated the M1/M2 ratio of RAW 264.7 cells induced by LPS + INF-γ. Transcriptomics revealed that PAI-1 is a key target of puerarin in regulating macrophage polarization. PAI-1 knockout reduced the number of M1-type macrophages and increased the number of M2-type macrophages. Puerarin regulated PAI-1 and was associated with macrophage autophagy. It increased p-ULK1 expression in macrophages and activated autophagic flux, reducing the level of PAI-1 expression. Stat3/Hif-1α and PI3K/AKT signaling pathways regulated the number of macrophage polarization phenotypes, reducing liver lipid droplet formation, alleviating liver structural abnormalities, decreasing the number of cytoplasmic vacuoles, and decreasing the area of blue collagen in NASH mice. Puerarin is a promising dietary component for NASH alleviation.

Fructus lycii oligosaccharide alleviates acute liver injury via PI3K/Akt/mTOR pathway

Regulating the immune-environment is essential for treating acute liver injury (ALI). However, the deficiency of an effective immune balancer restricted progress. Herein, we reported an oligosaccharide from Fructus lycii oligosaccharide (FLO). To investigate the effects of FLO, we adopted primary macrophages and LO2 for experiments in vitro. In vivo, we assessed the influence of FLO in ALI with histochemical staining and enzyme indicators detection. Following that, we clarified the underlying mechanisms using western blotting and immunofluorescence. Our results indicated that FLO (100 μg/mL) showed apparent inflammatory reversal effects by shifting the phenotype of macrophages from M1 to M2 without causing any cytotoxicity. Furthermore, CCl4-induced mice were significantly improved by FLO intragastric administration. Meanwhile, PI3K/AKT/mTOR pathway was confirmed for the up-regulation of IL-10 via M2 polarization of macrophages. Collectively, our findings highlight the beneficial effects of FLO on ALI therapy via M1 to M2 macrophage conversion.

Gypenoside XVII inhibits ox-LDL-induced macrophage inflammatory responses and promotes cholesterol efflux through activating the miR-182-5p/HDAC9 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

The deposition of lipids in macrophages and the subsequent formation of foam cells significantly increase the risk of developing atherosclerosis (As). Targeting ATP-binding cassette transporter A1/G1 (ABCA1/ABCG1)-mediated reverse cholesterol transport is crucial for regulating foam cell formation. Therefore, the search for natural chemical components with the ability to regulate ABCA1/G1 is a potential drug target to combat the development of atherosclerosis. Gypenoside XVII (GP-17), a gypenoside monomer extracted from gynostemma pentaphyllum, presents an efficient anti-atherosclerosis function. However, the suppressed formation mechanism of foam cells by GP-17 remains elusive.

AIM OF STUDY

To explore the protective activities of GP-17 in ox-LDL-induced THP-1 macrophage-derived foam cells through modulating the promotion of cholesterol efflux and alleviation of inflammation.

MATERIALS AND METHODS

MTT was used to detect cell viability. Bodipy493/503 and oil red O staining were performed to measure cell lipid deposition. Enzymatic assay was used to measure intracellular cholesterol measurement. Cholesterol efflux/uptake were determined by cholesterol efflux assay and Dil-ox-LDL uptake assay. Inflammatory cytokines were measured by ELISA. Bioinformatics prediction and dual luciferase reporter assay were performed to validate miR-182-5p targeting HDAC9. Relative protein levels were evaluated by immunoblotting and relative gene levels were determined by quantitative real-time PCR.

RESULTS

Our results showed that GP-17 upregulated the expression of ABCA1, ABCG1 and miR-182-5p, but reduced HDAC9 expression levels in lipid-loaded macrophages, which promoted cholesterol efflux and inhibited lipid deposition. Additionally, GP-17 promoted the M2 phenotype of the macrophage and suppressed the inflammatory response in THP-1 macrophage-derived foam cells. Overexpression of HDAC9 or suppression of miR-182-5p eliminated the effects of ABCA1/G1 expression, lipid deposition and pro-inflammatory response.

CONCLUSION

These findings suggest that GP-17 exerts a beneficial effect on macrophage lipid deposition and inflammation responses through activating the miR-182-5p/HDAC9 signaling pathway.

Purification, structural characteristics and anti-atherosclerosis activity of a novel green tea polysaccharide

A new homogeneous polysaccharide (TPS3A) was isolated and purified from Tianzhu Xianyue fried green tea by DEAE-52 cellulose and Sephacryl S-500 column chromatography. Structural characterization indicated that TPS3A mainly consisted of arabinose, galactose, galacturonic acid and rhamnose in a molar ratio of 5.84: 4.15: 2.06: 1, with an average molecular weight of 1.596 × 104 kDa. The structure of TPS3A was characterized as a repeating unit consisting of 1,3-Galp, 1,4-Galp, 1,3,6-Galp, 1,3-Araf, 1,5-Araf, 1,2,4-Rhap and 1-GalpA, with two branches on the C6 of 1,3,6-Galp and C2 of 1,2,4-Rhap, respectively. To investigate the preventive effects of TPS3A on atherosclerosis, TPS3A was administered orally to ApoE-deficient (ApoE-/-) mice. Results revealed that TPS3A intervention could effectively delay the atherosclerotic plaque progression, modulate dyslipidemia, and reduce the transformation of vascular smooth muscle cells (VSMCs) from contractile phenotype to synthetic phenotype by activating the expression of contractile marker alpha-smooth muscle actin (α-SMA) and inhibiting the expression of synthetic marker osteopontin (OPN) in high-fat diet-induced ApoE-/- mice. Our findings suggested that TPS3A markedly alleviated atherosclerosis by regulating dyslipidemia and phenotypic transition of VSMCs, and might be used as a novel functional ingredient to promote cardiovascular health.

Comprehensive view of macrophage autophagy and its application in cardiovascular diseases

Cardiovascular diseases (CVDs) are the primary drivers of the growing public health epidemic and the leading cause of premature mortality and economic burden worldwide. With decades of research, CVDs have been proven to be associated with the dysregulation of the inflammatory response, with macrophages playing imperative roles in influencing the prognosis of CVDs. Autophagy is a conserved pathway that maintains cellular functions. Emerging evidence has revealed an intrinsic connection between autophagy and macrophage functions. This review focuses on the role and underlying mechanisms of autophagy-mediated regulation of macrophage plasticity in polarization, inflammasome activation, cytokine secretion, metabolism, phagocytosis, and the number of macrophages. In addition, autophagy has been shown to connect macrophages and heart cells. It is attributed to specific substrate degradation or signalling pathway activation by autophagy-related proteins. Referring to the latest reports, applications targeting macrophage autophagy have been discussed in CVDs, such as atherosclerosis, myocardial infarction, heart failure, and myocarditis. This review describes a novel approach for future CVD therapies.

Laminarin Reduces Cholesterol Uptake and NPC1L1 Protein Expression in High-Fat Diet (HFD)-Fed Mice

Aberrantly high dietary cholesterol intake and intestinal cholesterol uptake lead to dyslipidemia, one of the risk factors for cardiovascular diseases (CVDs). Based on previous studies, laminarin, a polysaccharide found in brown algae, has hypolipidemic activity, but its underlying mechanism has not been elucidated. In this study, we investigated the effect of laminarin on intestinal cholesterol uptake in vitro, as well as the lipid and morphological parameters in an in vivo model of high-fat diet (HFD)-fed mice, and addressed the question of whether Niemann-Pick C1-like 1 protein (NPC1L1), a key transporter mediating dietary cholesterol uptake, is involved in the mechanistic action of laminarin. In in vitro studies, BODIPY-cholesterol-labeled Caco-2 cells were examined using confocal microscopy and a fluorescence reader. The results demonstrated that laminarin inhibited cholesterol uptake into Caco-2 cells in a concentration-dependent manner (EC50 = 20.69 μM). In HFD-fed C57BL/6J mice, laminarin significantly reduced the serum levels of total cholesterol (TC), total triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C). It also decreased hepatic levels of TC, TG, and total bile acids (TBA) while promoting the excretion of fecal cholesterol. Furthermore, laminarin significantly reduced local villous damage in the jejunum of HFD mice. Mechanistic studies revealed that laminarin significantly downregulated NPC1L1 protein expression in the jejunum of HFD-fed mice. The siRNA-mediated knockdown of NPC1L1 attenuated the laminarin-mediated inhibition of cholesterol uptake in Caco-2 cells. This study suggests that laminarin significantly improves dyslipidemia in HFD-fed mice, likely by reducing cholesterol uptake through a mechanism that involves the downregulation of NPC1L1 expression.

First transcriptomic insight into the reprogramming of human macrophages by levan-type fructans

Based on stimuli in the biological milieu, macrophages can undergo classical activation into the M1 pro-inflammatory (anti-cancer) phenotype or to the alternatively activated M2 anti-inflammatory one. Drug-free biomaterials have emerged as a new therapeutic strategy to modulate macrophage phenotype. Among them, polysaccharides polarize macrophages to M1 or M2 phenotypes based on the surface receptors they bind. Levan, a fructan, has been proposed as a novel biomaterial though its interaction with macrophages has been scarcely explored. In this study, we investigate the interaction of non-hydrolyzed and hydrolyzed Halomonas levan and its sulfated derivative with human macrophages in vitro. Viability studies show that these levans are cell compatible. In addition, RNA-sequencing analysis reveals the upregulation of pro-inflammatory pathways. These results are in good agreement with real time-quantitative polymerase chain reaction that indicates higher expression levels of C-X-C Motif Chemokine Ligand 8 and interleukin-6 genes and the M2-to-M1 reprogramming of these cells upon levan treatment. Finally, cytokine release studies confirm that hydrolyzed levans increase the secretion of pro-inflammatory cytokines and reprogram IL-4-polarized macrophages to the M1 state. Overall findings indicate that Halomonas levans trigger a classical macrophage activation and pave the way for their application in therapeutic interventions requiring a pro-inflammatory phenotype.

Sulforaphene Inhibits Periodontitis through Regulating Macrophage Polarization via Upregulating Dendritic Cell Immunoreceptor

Periodontitis is one of the most prevalent chronic inflammatory diseases that may eventually lead to the loss of teeth. Macrophage polarization plays an important role in the development of periodontitis, and several naturally occurring food compounds have recently been reported to regulate macrophage polarization. In this study, we aimed to investigate the therapeutic potential of sulforaphene (SFE) in macrophage polarization and its impact on periodontitis. Through in vitro and in vivo experiments, our study demonstrated that SFE effectively inhibits M1 polarization while promoting M2 polarization, ultimately leading to the suppression of periodontitis. Transcriptome sequencing showed that SFE significantly upregulated the expression of dendritic cell immunoreceptor (DCIR, also known as CLEC4A2). We further validated the crucial role of DCIR in macrophage polarization through knockdown and overexpression experiments and demonstrated that SFE regulates macrophage polarization by upregulating DCIR expression. In summary, the results of this study suggest that SFE can regulate macrophage polarization and inhibit periodontitis. Moreover, this research identified DCIR (dendritic cell immunoreceptor) as a potential novel target for regulating macrophage polarization. These findings provide new insights into the treatment of periodontitis and other immune-related diseases.

Naringenin ameliorates collagen-induced arthritis through activating AMPK-mediated autophagy in macrophages

BACKGROUND

Naringenin is widely recognized for its notable attributes, including anti-inflammatory, anti-cancer, and immunomodulatory activities. However, its specific implications for rheumatoid arthritis (RA) and the underlying mechanisms remain to be explored. This study aimed to investigate the therapeutic efficacy and pharmacological mechanism of Naringenin in the treatment of collagen-induced arthritis (CIA).

METHODS

A CIA model was established in DBA/1 mice, and various doses of Naringenin were administered orally to assess its impact on RA. The study also involved lipopolysaccharides (LPS)-induced RAW264.7 cells to further evaluate the effects of Naringenin. Mechanistic studies were conducted to elucidate the signaling pathways involved in Naringenin's actions.

RESULTS

Naringenin significantly alleviated foot inflammation in DBA/1 CIA mice and attenuated the levels of pro-inflammatory cytokines in serum. It also enhanced antioxidant capacity in the CIA model. In vitro studies with LPS-induced RAW264.7 cells demonstrated that Naringenin attenuated pro-inflammatory cytokines and reactive oxygen species (ROS) levels. Mechanistic studies confirmed that Naringenin activated autophagy and increased autophagic flux. Blocking autophagy, either by silencing Atg5 or inhibiting autophagolysosome using chloroquine, effectively counteracted the impact of Naringenin on pro-inflammatory cytokines. Further exploration revealed that Naringenin activated the AMPK/ULK1 signaling pathway, and inhibition of AMPK reversed the initiation of autophagy and reduced pro-inflammatory cytokine secretion induced by Naringenin.

CONCLUSIONS

This study unveils a novel mechanism by which Naringenin may be used to treat RA. It demonstrates the therapeutic efficacy of Naringenin in a CIA model by reducing inflammation, modulating cytokine levels, and enhancing antioxidant capacity. Moreover, the activation of autophagy through the AMPK/ULK1 signaling pathway appears to play a critical role in Naringenin's anti-inflammatory effects. These findings suggest potential strategies for the development of anti-rheumatic medications based on Naringenin.

Macrophage autophagy contributes to immune liver injury in trichloroethylene sensitized mice: Critical role of TNF-α mediating mTOR pathway

Trichloroethylene (TCE) induces occupational medicamentosa-like dermatitis due to TCE (OMDT) with immune liver injury, and TNF-α plays an important role in macrophage polarization and liver injury. However, TNF-α regulating macrophage polarization in liver injury induced by TCE is still unknown. Thus, on the basis of our previous research, we established the TCE-sensitized BALB/c mouse model with R7050, a specific inhibitor of TNFR1. Then, we observed significant decreases in autophagy related protein and gene levels in M1 macrophage in TCE positive group, and R7050 can relieve M1 macrophage autophagy. We also found the phosphorylated form of mammalian target of Rapamycin (mTOR) was activated and the expression of p-mTOR protein increased induce by TCE. In vitro, we found TNFR1 and CD11c were increased in RAW264.7 cell line with TNF-α. And then we use Zafirlukast (Zaf), an TNFR1 antagonist, CD11c and TNFR1 reduced significantly, we also found p-mTOR expression increased after TNF-α treatment, but decreased in TNF-α + Zaf group. Further, we used Rapamycin (RAP), a mTOR-specific inhibitor, to establish a TCE-sensitized mice model and found the expression levels of p62 and p-mTOR proteins increased and LC3B decreased in the TCE positive group, while RAP treatment reversed the trends of all of these proteins. Rapamycin prevented the TNF-α-induced p-mTOR increase and dramatically downregulated IL-1β expression in the RAW264.7 cell line with TNF-α treatment. The results uncover a novel role for TNF-α/TNFR1, which promotes M1 polarization of macrophage and suppresses macrophage autophagy via the mTOR pathway.

Oxidized low-density lipoprotein regulates macrophage polarization in atherosclerosis

Atherosclerosis is the pathological basis of acute cardiovascular and cerebrovascular diseases. Oxidized LDL has been recognized as a major atherogenic factor in the vessel wall for decades. A growing body of evidence suggests that oxidized LDL modulates macrophage phenotypes in atherosclerosis. This article reviews the research progress on the regulation of macrophage polarization by oxidized LDL. Mechanistically, oxidized LDL induces macrophage polarization via cell signaling, metabolic reprogramming, epigenetic regulation, and intercellular regulation. This review is expected to provide new targets for the treatment of atherosclerosis.

Inhibition of Ca2+-calpain signaling is a new mechanism using Laminaria japonica polysaccharide to prevent macrophage foam cell formation and atherosclerosis

The Ca2+-calpain signaling plays a pivotal role in regulating the upstream signaling pathway of cellular autophagy. The aim of the current work was to investigate the role of Ca2+-calpain signaling in the regulation of macrophage autophagy by a Laminaria japonica polysaccharide (LJP61A) in Ox-LDL induced macrophages and high fat diet fed atherosclerotic mice. Results revealed that the LJP61A markedly decreased the levels of intracellular Ca2+, calpain1, calpain2 and their downstream effectors (Gsα, cAMP and IP3), and simultaneously enhanced autophagy activity and lipid metabolism, thereby reducing lipid accumulation in the Ox-LDL stimulated macrophages and lipid-laden plaques in atherosclerotic mice. Moreover, BAPTA-AM (a Ca2+ chelator) and calpeptin (a calpain inhibitor) synergistically strengthened the beneficial effects of LJP61A on autophagy and lipid metabolism by decreasing the levels of intracellular Ca2+, calpain1, calpain2, and their downstream effectors (Gsα, cAMP and IP3) induced by Ox-LDL. These findings suggested that the LJP61A suppressed macrophage derived foam cell formation and atherosclerosis by modulating the Ca2+-calpain-mediated autophagy.

Polygonatum cyrtonema Hua Polysaccharide Alleviates Fatigue by Modulating Osteocalcin-Mediated Crosstalk between Bones and Muscles

Osteocalcin was reported to regulate muscle energy metabolism, thus fighting fatigue during exercise. The current work aimed to investigate the anti-fatigue effect and the underlying mechanism of a homogeneous polysaccharide (PCPY-1) from Polgonatum cyrtonema after structure characterization. In the exhaustive swimming mouse model and the co-culture system of BMSCs/C2C12 cells, PCPY-1 significantly stimulated BMSC differentiation into osteoblasts as determined by ALP activity, matrix mineralization, and the protein expressions of osteogenic markers BMP-2, phosphor-Smad1, RUNX2, and osteocalcin. Meanwhile, PCPY-1 remarkably enhanced myoblast energy metabolism by upregulating osteocalcin release and GPRC6A protein expression; the phosphorylation levels of CREB and HSL; the mRNA levels of GLUT4, CD36, FATP1, and CPT1B; and ATP production in vitro and in vivo. Accordingly, PCPY-1 exhibited good anti-fatigue capacity in mice as confirmed by fatigue-related indicators. Our findings indicated PCPY-1 could enhance osteocalcin-mediated communication between bones and muscles, which was conducive to muscle energy metabolism and ATP generation, thus alleviating fatigue in exhausted swimming mice.

N-desulfated and reacetylated modification of heparin modulates macrophage polarization

Heparin as a widely used anticoagulant drug has potent anti-inflammatory effects, which have been rarely reported to be involved in macrophage polarization. Furthermore, the effects of structural modifications of heparin on the plasticity of macrophage functions have not been clearly understood. In this study, the N-desulfated reacetylated derivative of heparin (NDeSAcH) was prepared and its immunoregulatory effects of macrophage polarization were evaluated. The findings indicated that NDeSAcH could effectively promote the release of more nitric oxide (NO), interleukin (IL)-6 and tumor necrosis factor-α (TNF-α) in RAW264.7 cells than heparin. Moreover, the production of NO, IL-6 and TNF-α was significantly inhibited by NDeSAcH in LPS-induced RAW264.7 cells, while the secretion of transforming growth factor-β (TGF-β) was suppressed in M2 macrophages. The N-desulfated and reacetylated group of heparin was proved to have two-side adjusting effects on the polarization of macrophages. This study suggested that NDeSAcH might be a promising candidate for modulating macrophage polarization and treating inflammation-related diseases.

Structural Characterization and Macrophage Polarization-Modulating Activity of a Novel Polysaccharide from Large Yellow Tea

A novel homogeneous polysaccharide (LYP-S3) that promotes the M2 polarization of macrophages was obtained from large yellow tea by a bioactivity-guided sequential isolation procedure and activity evaluation in the present study. Structural characterization revealed that LYP-S3 has an average molecular weight of 28.6 kDa and is composed of rhamnose, arabinose, galactose, glucose, and galacturonic acid at the molar ratio of 8.08:11.66:11.77:3.96:58.02. The main backbone of LYP-S3 consists of →4)-α-d-GalpA-6-OMe-(1→, β-d-GalpA-(1→, →4)-β-d-Galp-(→1, and →β-d-Galp-(1→, and the branches are composed of α-l-Araf-(→1, →5)-α-l-Araf-(1→, →2,4)-β-l-Rhap-(1→, →2)-β-l-Rhap-(1→, and →4)-β-d-Glcp-(1→. An in vitro bioactivity evaluation assay showed that LYP-S3 remarkably reduced the expression of M1 macrophage markers and increased the expression of M2 macrophage markers. In addition, LYP-S3 inhibited adipocyte differentiation and adipogenesis in 3T3-L1 adipocytes and blocked macrophage migration toward 3T3-L1 adipocytes in the cocultures of bone-marrow-derived monocytes and 3T3-L1 adipocytes. Furthermore, LYP-S3 promoted the M2 polarization of macrophages in cocultures. These findings suggested that LYP-S3 has a potential function in preventing inflammation and obesity.

Chemical Characterization and Atherosclerosis Alleviation Effects of Gypenosides from Gynostemma pentaphyllum through Ameliorating Endothelial Dysfunction via the PCSK9/LOX-1 Pathway

Dietary saponins have the potential to ameliorate atherosclerosis (AS). Gypenosides of Gynostemma pentaphyllum (GPs) have been used as functional foods to exhibit antiatherosclerotic activity. The present study aimed to explore the protective effect, underlying mechanism and active substances of GPs on AS in vivo and in vitro. Results demonstrated GPs administration reduced the serum concentrations of TC and LDL-C, upregulated the plasma HDL-C content, inhibited the secretion of ICAM-1, VCAM-1, and MCP-1, and alleviated vascular lesions in VitD₃ plus high cholesterol diet-induced AS rats as well as reduced adhesion factors levels in ox-LDL-stimulated HUVECs, which was potentially associated with suppressing PCSK9/LOX-1 pathway. Further activity-guided phytochemical investigation of GPs led to the identification of five new dammarane-type glycosides (1-5) and ten known analogs (6-15). Bioassay evaluation showed compounds 1, 6, 7, 12, 13, and 14 observably reduced the expressions of PCSK9 and LOX-1, as well as the secretion of adhesion factors in injured HUVECs. Molecular docking experiments suggested that the active saponins of GPs might bind to the allosteric pocket of PCSK9 located at the catalytic and C-terminal domains, and 2α-OH-protopanaxadiol-type gypenosides might exert a higher affinity for an allosteric binding site on PCSK9 by hydrogen-bond interaction with ARG-458. These findings provide new insights into the potential nutraceutical application of GPs and their bioactive compounds in the prevention and discovery of novel therapeutic strategies for AS.

Progress in preclinical studies of macrophage autophagy in the regulation of ALI/ARDS

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is a critical clinical syndrome with high morbidity and mortality that poses a major challenge in critical care medicine. The development of ALI/ARDS involves excessive inflammatory response, and macrophage autophagy plays an important role in regulating the inflammatory response in ALI/ARDS. In this paper, we review the effects of autophagy in regulating macrophage function, discuss the roles of macrophage autophagy in ALI/ARDS, and highlight drugs and other interventions that can modulate macrophage autophagy in ALI/ARDS to improve the understanding of the mechanism of macrophage autophagy in ALI/ARDS and provide new ideas and further research directions for the treatment of ALI/ARDS.

Study on the regulatory effect of leech peptide HE-D on macrophages in atherosclerosis by transcriptome sequencing

ETHNOPHARMACOLOGICAL RELEVANCE

The incidence of atherosclerotic cardiovascular disease is a serious threat to human health. Leeches are used in traditional Chinese medicine to treat cardiovascular diseases. HE-D is an active peptide extracted and isolated from leeches, which can inhibit the migration of RAW264.7 macrophages.

AIM

This study shows the effects of HE-D on macrophages in atherosclerosis and the mechanism of inhibition on the migration of macrophages based on transcriptome sequencing (RNA-Seq).

MATERIALS AND METHODS

The transwell method was used to detect the activity of HE-D in inhibiting the migration of macrophages. Macrophages were divided into control group, lipopolysaccharide group, and HE-D group. Samples were collected and RNA-Seq performed. The DEseq2 method detected significantly differentially expressed genes (DEGs), GO and KEGG Pathway databases were used to analyze the functions and pathway enrichment of DEGs. Finally, qRT-PCR and Western blotting were used to verify the genes screened by RNA-Seq analyses.

RESULTS

Cell experiments showed that HE-D can inhibit the migration of RAW264.7 macrophages induced by LPS. DEseq2 analyses showed that there were 363 DEGs after HE-D administration in the result of RNA-Seq. The GO function of DEGs was significantly enriched in cell migration and inflammation, and the DEGs related to cell migration were significantly enriched in the NF-κB signaling pathway. qRT-PCR and Western blot analyses, showed that when compared with the LPS group, the related genes IKKα, IKKγ, TRAF6, TLR4, and TRAF5 in the NF-κB pathway were significantly down-regulated in the HE-D group. In addition, it was found that the inflammatory factors iNOS and TNF-α were significantly down-regulated, and Arg-1 and IL-10 were up-regulated.

CONCLUSION

HE-D can inhibit the migration of macrophages by inhibiting IKKα and IKKγ in the NF-κB signaling pathway, and promote the transformation of macrophages from M1to M2 subtypes. Therefore, HE-D can potentially be used as a drug for the treatment of atherosclerosis.