Natural product celastrol suppressed macrophage M1 polarization against inflammation in diet-induced obese mice via regulating Nrf2/HO-1, MAP kinase and NF-κB pathways

Targeted liposomes for macrophages-mediated pulmonary fibrosis therapy

Pulmonary fibrosis (PF) is a horrible lung disease that causes pulmonary ventilation dysfunction and respiratory failure, severely impacting sufferers' physical and mental health. Existing drugs can only partially control the condition and are prone to toxic side effects. Anti-inflammatory treatment is the committed step to alleviate PF. Celastrol (CLT) has significant anti-inflammatory effects and can reverse M1-type transformation of macrophages. In this study, we have developed liposomes loaded with CLT, modified with folate (FA), designated FA-CLT-Lips, which facilitate drug delivery by targeting macrophages. FA-CLT-Lips were shown to be more readily absorbed by macrophages in vitro and to encourage the transition of M1 macrophages into M2 macrophages. In addition, FA-CLT-Lips can inhibit the phosphorylation of Smad2/3, effectively reducing the deposition of extracellular matrix (ECM) and the production of inflammatory factors. This showed that FA-CLT-Lips can ameliorate early lung fibrosis by lowering inflammation. In vivo studies have shown that FA-CLT-Lips accumulate in lung tissue to better attenuate lung injury and collagen deposition, with less toxicity compared to free CLT. In summary, FA receptor-targeting liposomes loaded with CLT provide a secure and reliable PF therapy.

Curcumin Alleviates Microglia-Mediated Neuroinflammation and Neuronal Ferroptosis Following Experimental Subarachnoid Hemorrhage by Modulating the Nrf2/HO-1 Signaling Pathway

Early brain injury caused by subarachnoid hemorrhage (SAH) is associated with inflammatory response and ferroptosis. Curcumin alleviates neuroinflammation and oxidative stress by as yet unknown neuroprotective mechanisms. The objective of this study was to investigate the impact of curcumin on neuronal ferroptosis and microglia-induced neuroinflammation following SAH. By examining Nrf2/HO-1 expression levels and ferroptosis biomarkers expression both in vitro and in vivo, it was demonstrated that curcumin effectively suppressed ferroptosis in neurons after SAH through modulation of the Nrf2/HO-1 signaling pathway. Furthermore, by analyzing the expression levels of Nrf2, HO-1, p-p65, and inflammation-related genes, it was confirmed that curcumin could prevent the upregulation of pro-inflammatory factors following SAH by regulating the Nrf2/HO-1/NF-κB signaling pathway in microglia. The ability of curcumin to reduce neuronal damage and cerebral edemas after SAH in mice was validated using TUNEL staining, Nissl staining, and measurement of brain tissue water content. Additionally, through implementation of the modified Garcia test, open field test, and Y-maze test, it was established that curcumin ameliorated neurobehavioral impairments in mice post-SAH. Taken together, these data suggest that curcumin may offer a promising therapeutic approach for improving outcomes following SAH by concurrently attenuating neuronal ferroptosis and reducing neuroinflammation.

Albiflorin alleviates neuroinflammation of rats after MCAO via PGK1/Nrf2/HO-1 signaling pathway

Ischemic stroke is acknowledged as one of the most frequent causes of death and disability, in which neuroinflammation plays a critical role. Emerging evidence supports that the PGK1/Nrf2/HO-1 signaling can modulate inflammation and oxidative injury. Albiflorin (ALB), a main component of Radix paeoniae Alba, possesses anti-inflammatory and antioxidative properties. However, how it exerts a protective role still needs further exploration. In our study, the middle cerebral artery occlusion (MCAO) model was established, and the Longa score was applied to investigate the degree of neurological impairment. Dihydroethidium (DHE) staining and Malondialdehyde (MDA) assay were used to detect the level of lipid peroxidation. 2, 3, 5-Triphenyltetrazolium chloride (TTC) staining was used to measure the infarct area. Evans blue staining was employed to observe the integrality of the blood-brain barrier (BBB). The injury of brain tissue in each group was observed via HE staining. Immunofluorescence staining, enzyme-linked immunosorbent assay (ELISA) and western blot assay were used for the measurement of inflammatory factors and protein levels. We finally observed that ALB relieved cerebral infarction symptoms, attenuated oxidative damage in brain tissues, and reduced neuroinflammation and cell injury in MCAO rats. The overexpression of PGK1 abrogated the protective effect of ALB after experimental cerebral infarction. ALB promoted PGK1 degradation and induced Nrf2 signaling cascade activation for subsequent anti-inflammatory and antioxidant damage. Generally speaking, ALB exerted a protective role in treating cerebral ischemia, and it might target at PGK1/Nrf2/HO-1 signaling. Thus, ALB might be a potential therapeutic agent to alleviate neuroinflammation and protect brain cells after cerebral infarction.

Uptake of Cyclodextrin Nanoparticles by Macrophages is Dependent on Particle Size and Receptor-Mediated Interactions

Physiochemical properties of nanoparticles, such as their size and chemical composition, dictate their interaction with professional phagocytes of the innate immune system. Macrophages, in particular, are key regulators of the immune microenvironment that heavily influence particle biodistribution as a result of their uptake. This attribute enables macrophage-targeted delivery, including for phenotypic modulation. Saccharide-based materials, including polyglucose polymers and nanoparticles, are efficient vehicles for macrophage-targeted delivery. Here, we investigate the influence of particle size on cyclodextrin nanoparticle (CDNP) uptake by macrophages and further examine the receptor-mediated interactions that drive macrophage-targeted delivery. We designed and synthesized CDNPs ranging in size from 25 nm to >100 nm in diameter. Increasing particle size was correlated with greater uptake by macrophages in vitro. Both scavenger receptor A1 and mannose receptor were critical mediators of macrophage-targeted delivery, inhibition of which reduced the extent of uptake. Finally, we investigated the cellular bioavailability of drug-loaded CDNPs using a model anti-inflammatory drug, celastrol, which demonstrated that drug bioactivity is improved by CDNP loading relative to free drug alone. This study thus elucidates the interactions between the polyglucose nanoparticles and macrophages, thereby facilitating their application in macrophage-targeted drug delivery that has applications in the context of tissue injury and repair.

Nesfatin-1 inhibits cerebral aneurysms by activating Nrf2 and inhibiting NF-κB signaling

AIMS

Cerebral aneurysm (CA) has been considered one of the most common cerebrovascular diseases, affecting millions of people worldwide. A therapeutic agent is currently missing for the treatment of CA. Nesfatin-1 (Nes-1) is an 82-amino acid adipokine which possesses a wide range of biological functions. However, the physiological function of Nes-1 in CA is still unknown. Here, we aimed to assess the preventive effects of Nes-1 in the pathological development of CA and elucidate the mechanisms behind this.

METHODS

We used an elastase-induced CA model, accompanied by a high-salt diet to induce hypertension. Additionally, diverse experimental techniques, including Verhoeff-Van Gieson staining, real time PCR, enzyme-linked immuno sorbent assay (ELISA), and immunofluorescence staining, were employed to assess CA formation, gene and protein expression, as well as the macrophage infiltration.

RESULTS

Our results indicate that administration of Nes-1 significantly decreased the aneurysm size. Additionally, Nes-1 prevented inflammatory response by inhibiting the expression of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and monocyte chemoattractant protein 1 (MCP-1) at both the mRNA and protein levels in the Circle of Willis (COW) region. Also, the increased levels of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) in the COW region were reduced by Nes-1. We found that Nes-1 administration suppressed the invasion of macrophages. Mechanistically, Nes-1 activated Nrf-2 by promoting its nuclear translocation but prevented the activation of the IκBα/NF-κB signaling pathway.

CONCLUSION

These findings suggest that Nes-1 might be used as a promising agent for the prevention of CA.

Exosomes from circRNA-Ptpn4 can modify ADSC treatment and repair nerve damage caused by cerebral infarction by shifting microglial M1/M2 polarization

Adipose-derived stem cells (ADSCs) have been demonstrated to improve the microenvironment after a stroke. Increasing studies have confirmed that hypoxia pretreatment of ADSCs resulted in a better therapeutic effect, but the mechanism of treatment is unclear. We isolated ADSCs and exosomes. Then, constructed a middle cerebral artery occlusion (MCAO) mice model. High-throughput sequencing was used to identify the differential expression of circRNA. Immunofluorescence and ELISAs were used to detect the therapeutic effects of ADSC exosomes on MCAO. The luciferase reporter assay was used to detect the interaction relationships among circRNA-Ptpn4, miR-153-3p, and Nrf2. This study showed that exosomes from hypoxia pretreatment of ADSCs had significant effects in promoting functional recovery following in vivo MCAO, through suppressed inflammatory factor expression, and shifting the microglial from M1 to M2 polarization activation. The results showed that circRNA-Ptpn4 was highly expressed during hypoxia pretreatment of ADSCs exosomes. Exosomes from circ-Ptpn4-modified ADSCs had a greater ability to promote functional recovery. The circ-Ptpn4 delivered from ADSC exosomes induced microglia/macrophage polarization from M1 to M2 by suppressing miR-153-3p and enhancing Nrf2 expressions. Taken together, the results showed that exosomes from circRNA-Ptpn4 modified ADSC treatment repaired nerve damage caused by cerebral infarction by inducing microglial M1/M2 polarization.

Regulation of macrophage polarization by targeted metabolic reprogramming for the treatment of lupus nephritis

Lupus nephritis (LN) is a severe and common manifestation of systemic lupus erythematosus (SLE) that is frequently identified with a poor prognosis. Macrophages play an important role in its pathogenesis. Different macrophage subtypes have different effects on lupus-affected kidneys. Based on their origin, macrophages can be divided into monocyte-derived macrophages (MoMacs) and tissue-resident macrophages (TrMacs). During nephritis, TrMacs develop a hybrid pro-inflammatory and anti-inflammatory functional phenotype, as they do not secrete arginase or nitric oxide (NO) when stimulated by cytokines. The infiltration of these mixed-phenotype macrophages is related to the continuous damage caused by immune complexes and exposure to circulating inflammatory mediators, which is an indication of the failure to resolve inflammation. On the other hand, MoMacs differentiate into M1 or M2 cells under cytokine stimulation. M1 macrophages are pro-inflammatory and secrete pro-inflammatory cytokines, while the M2 main phenotype is essentially anti-inflammatory and promotes tissue repair. Conversely, MoMacs undergo differentiation into M1 or M2 cells in response to cytokine stimulation. M1 macrophages are considered pro-inflammatory cells and secrete pro-inflammatory mediators, whereas the M2 main phenotype is primarily anti-inflammatory and promotes tissue repair. Moreover, based on cytokine expression, M2 macrophages can be further divided into M2a, M2b, and M2c phenotypes. M2a and M2c have anti-inflammatory effects and participate in tissue repair, while M2b cells have immunoregulatory and pro-inflammatory properties. Further, memory macrophages also have a role in the advancement of LN. Studies have demonstrated that the polarization of macrophages is controlled by multiple metabolic pathways, such as glycolysis, the pentose phosphate pathway, fatty acid oxidation, sphingolipid metabolism, the tricarboxylic acid cycle, and arginine metabolism. The changes in these metabolic pathways can be regulated by substances such as fish oil, polyenylphosphatidylcholine, taurine, fumaric acid, metformin, and salbutamol, which inhibit M1 polarization of macrophages and promote M2 polarization, thereby alleviating LN.

Liensinine alleviates sepsis-induced acute liver injury by inhibiting the NF-κB and MAPK pathways in an Nrf2-dependent manner

Sepsis remains a serious public health issue that needs to be addressed globally. Severe liver injury caused by sepsis increases the risk of death in patients with sepsis. Liensinine (Lie) is one of the primary active components in Plumula nelumbinis and has anti-inflammatory and antioxidant effects. Nevertheless, the effects of Lie on septic liver injury are unclear. This research investigated the protective effect of Lie (10, 20 and 40 mg/kg) on liver damage via intraperitoneal administration of LPS (10 mg/kg) to C57BL/6 mice. Lie was given through intraperitoneal injection once a day for five days. Mice were treated with LPS intraperitoneally for 6 h at 1 h after Lie administration on the last day. The results suggested that Lie could decrease AST and ALT levels in serum, ameliorate histopathological changes and inhibit cell apoptosis in mice with LPS-induced septic liver injury. In addition, Lie inhibited increases in the mRNA levels of TNF-α, IL-1β, iNOS and IL-6. Lie also increased the mRNA level of IL-10. Lie reduced the content of MDA, a marker of lipid peroxidation, and increased the activity of the antioxidant enzymes GSH-Px, CAT and SOD. Our results also showed that Lie could suppress the LPS-activated MAPK and NF-κB pathways and trigger the Nrf2 signaling pathway both in vitro and in vivo. Additionally, an Nrf2 inhibitor (ML385) weakened the suppressive effect of Lie on the MAPK and NF-κB pathways. Our results demonstrated that the suppressive effect of Lie on the MAPK and NF-κB pathways was partially reliant on activation of the Nrf2 pathway. In summary, these results indicate that Lie can improve inflammation and oxidative stress by activating Nrf2, which is a prospective therapeutic drug for alleviating septic liver injury.

Fatsia japonica extract exerts antioxidant and anti-neuroinflammatory effects on neuronal cells and a zebrafish model

ETHNOPHARMACOLOGICAL RELEVANCE

Fatsia japonica is a traditional medicine used to treat various diseases, including inflammation-related disorders. However, its antineuroinflammatory and neuroprotective effects remain unclear.

AIM OF THE STUDY

We aimed to evaluate the anti-neuroinflammatory and neuroprotective effects of F. japonica extract to identify the underlying mechanisms.

MATERIALS AND METHODS

The components of F. japonica extract were profiled using ultra-high-performance liquid chromatography-mass spectrometry. The effects of F. japonica extract were investigated in BV2 microglia and HT22 hippocampal cells. Furthermore, in vivo effects of F. japonica extract were assessed using zebrafish models treated with H2O2 and LPS to evaluate the effects of in vivo.

RESULTS

We identified 27 compounds in the F. japonica extract. F. japonica extract demonstrated anti-inflammatory properties by suppressing LPS-induced inflammatory responses in both BV2 cells and zebrafish, along with inhibiting the activation of the nuclear factor (NF)-κB (p65) pathway. The protective effects of this extract were also observed on glutamate-treated HT22 cells and in H2O2-induced zebrafish. Furthermore, F. japonica extract upregulated nuclear factor E2-related (Nrf) 2/heme oxygenase (HO)-1 expression in BV2 and HT22 cells.

CONCLUSIONS

F. japonica extract exerted anti-neuroinflammatory and neuroprotective effects through Nrf2/HO-1 and the NF-κB pathway.

Search progress of pyruvate kinase M2 (PKM2) in organ fibrosis

Fibrosis is characterized by abnormal deposition of the extracellular matrix (ECM), leading to organ structural remodeling and loss of function. The principal cellular effector in fibrosis is activated myofibroblasts, which serve as the main source of matrix proteins. Metabolic reprogramming, transitioning from mitochondrial oxidative phosphorylation to aerobic glycolysis, is widely observed in rapidly dividing cells such as tumor cells and activated myofibroblasts and is increasingly recognized as a fundamental pathogenic basis in organ fibrosis. Targeting metabolism represents a promising strategy to mitigate fibrosis. PKM2, a key enzyme in glycolysis, plays a pivotal role in metabolic reprogramming through allosteric regulation, impacting both metabolic and non-metabolic pathways. Therefore, metabolic reprogramming induced by PKM2 activation is involved in the occurrence and development of fibrosis in various organs. A comprehensive understanding of the role of PKM2 in fibrotic diseases is crucial for seeking new anti-fibrotic therapeutic targets. In this context, we summarize PKM2's role in glycolysis, mediating the intricate mechanisms underlying fibrosis in multiple organs, and discuss the potential value of PKM2 inhibitors and allosteric activators in future clinical treatments, aiming to identify novel therapeutic targets for proliferative fibrotic diseases.

Chondroitin Sulfate-Derived Micelles for Adipose Tissue-Targeted Delivery of Celastrol and Phenformin to Enhance Obesity Treatment

Adipose tissue macrophages (ATMs) are crucial in maintaining a low-grade inflammatory microenvironment in adipose tissues (ATs). Modulating ATM polarization to attenuate inflammation represents a potential strategy for treating obesity with insulin resistance. This study develops a combination therapy of celastrol (CLT) and phenformin (PHE) using chondroitin sulfate-derived micelles. Specifically, CLT-loaded 4-aminophenylboronic acid pinacol ester-modified chondroitin sulfate micelle (CS-PBE/CLT) and chondroitin sulfate-phenformin conjugate micelles (CS-PHE) were synthesized, which were shown to actively target ATs through CD44-mediated pathways. Furthermore, the dual micellar systems significantly reduced inflammation and lipid accumulation via protein quantification and Oil Red O staining. In preliminary in vivo studies, we performed H&E staining, immunohistochemical staining, insulin tolerance test, and glucose tolerance test, and the results showed that the combination therapy using CS-PBE/CLT and CS-PHE micelles significantly reduced the average body weight, white adipose tissue mass, and liver mass of high-fat diet-fed mice while improving their systemic glucose homeostasis. Overall, this combination therapy presents a promising alternative to current treatment options for diet-induced obesity.

Therapeutic Role of Chinese Medicine Targeting Nrf2/HO-1 Signaling Pathway in Myocardial Ischemia/Reperfusion Injury

Acute myocardial infarction (AMI), characterized by high incidence and mortality rates, poses a significant public health threat. Reperfusion therapy, though the preferred treatment for AMI, often exacerbates cardiac damage, leading to myocardial ischemia/reperfusion injury (MI/RI). Consequently, the development of strategies to reduce MI/RI is an urgent priority in cardiovascular therapy. Chinese medicine, recognized for its multi-component, multi-pathway, and multi-target capabilities, provides a novel approach for alleviating MI/RI. A key area of interest is the nuclear factor E2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway. This pathway is instrumental in regulating inflammatory responses, oxidative stress, apoptosis, endoplasmic reticulum stress, and ferroptosis in MI/RI. This paper presents a comprehensive overview of the Nrf2/HO-1 signaling pathway's structure and its influence on MI/RI. Additionally, it reviews the latest research on leveraging Chinese medicine to modulate the Nrf2/HO-1 pathway in MI/RI treatment.

Natural compounds as obesity pharmacotherapies

Obesity has become a serious global public health problem, affecting over 988 million people worldwide. Nevertheless, current pharmacotherapies have proven inadequate. Natural compounds have garnered significant attention due to their potential antiobesity effects. Over the past three decades, ca. 50 natural compounds have been evaluated for the preventive and/or therapeutic effects on obesity in animals and humans. However, variations in the antiobesity efficacies among these natural compounds have been substantial, owing to differences in experimental designs, including variations in animal models, dosages, treatment durations, and administration methods. The feasibility of employing these natural compounds as pharmacotherapies for obesity remained uncertain. In this review, we systematically summarized the antiobesity efficacy and mechanisms of action of each natural compound in animal models. This comprehensive review furnishes valuable insights for the development of antiobesity medications based on natural compounds.

Capsicum annuum var. abbreviatum Induces a Macrophage M2-Like Phenotype Mediated by Nrf2/HO-1 in LPS-Stimulated Macrophages

Capsicum annuum var. abbreviatum (CAAE), which is in the genus Capsicum L. (Solanaceae), was found to be richer in polyphenols and flavonoids than other prevalent peppers of Capsicum annuum var. angulosum and Capsicum annuum. L. Yet, it is still unclear how CAAE reduces inflammation. In this study, we used the lipopolysaccharide-stimulated RAW264.7 macrophage cell line and bone marrow-derived macrophages to assess its anti-inflammatory activities. Initially, we discovered that CAAE decreased the levels of nitric oxide and inducible nitric oxide synthase. In addition, CAAE decreased the intracellular reactive oxygen species levels and increased the nuclear factor-erythroid 2-related factor 2 and heme oxygenase-1 compared with the phenotype of M2 macrophages. CAAE inhibited the activation of mitogen-activated protein kinases (MAPKs), including extracellular signal-regulated kinases, c-Jun N-terminal kinases, and p38 MAPKs. CAAE also inhibited the translocation of nuclear factor kappa B into nuclear, hence preventing the production of proinflammatory cytokines. Therefore, we suggest that CAAE might have potential as a candidate therapeutic agent for inflammatory diseases.

Oral delivery of pH-sensitive nanoparticles loaded Celastrol targeting the inflammatory colons to treat ulcerative colitis

The incidence of ulcerative colitis (UC) is rapidly rising worldwide. Oral drug delivery system is a promising approach for treating UC, but it often fails to accumulate to the inflammatory lesions, thus, it is impressive to develop a colon-targeted oral delivery system for preventing systemic toxicity and maintaining UC therapeutics. Here, a negative-charged PLGA nanoparticle system was designed to encapsulate celastrol (Cel), and then chitosan and mannose were coated on the surface of the nanoparticles (MC@Cel-NPs) to endow these nanoparticles with the mucosal adsorption and macrophage targeting abilities. MC@Cel-NPs demonstrate excellent resist decomposition ability against the strong acidic gastrointestinal environment, and accumulates in the specific inflammatory sites through the affinity of electrostatic reaction. After releasing the payload, MC@Cel-NPs could remarkably alleviate the colon inflammation, which was evidenced by the decrease in pro-inflammatory cytokines TNF-α, IL-1β, and IL-6 in both blood and colon sections, and scavenging reactive oxygen species (ROS) in colon cells, including macrophage, neutrophil, T cell, and B cell. This nanoparticle system provided a new approach for treating UC through a Chinese herbal ingredient-related oral delivery manner.

Celastrol as a candidate drug for silicosis: From bioinformatics and network pharmacology to experimental validation

Silicosis, a highly lethal occupational respiratory disease characterized by irreversible pulmonary fibrosis, remains challenging to treat due to its unclear pathogenesis. In this study, bioinformatics, network pharmacology, and experimental validation were combined to explore potential mechanisms and therapeutic drugs for silicosis. First, the differentially expressed genes（DEGs）and pathway enrichment in pulmonary fibrosis were identified by GO and KEGG analysis. Next, the differential genes were submitted to cMap database for drug prediction and celastrol stood out as the most promising candidate drug. Then, network pharmacology analysis identified pharmacological targets of celastrol and demonstrated that celastrol could regulate JAK-STAT, MAPK, and Toll-like receptor signaling pathways. Finally, we verified the therapeutic role and mechanism of celastrol on silicosis. In vivo, celastrol significantly ameliorated CS-induced inflammation and fibrosis in silicosis mice, including inflammatory cell infiltration, collagen fiber and extracellular matrix deposition, fibroblast activation and related factor expression. Moreover, it dramatically improved lung respiratory function of silicosis mice. In vitro, celastrol suppressed CS-induced cytokine expression, apoptosis of macrophages and activation of Stat3 and Erk1/2 signals. Overall, our research identified and verified celastrol as a novel and promising candidate drug for silicosis.

Protective effects of Emblica officinalis polysaccharide against lead induced liver injury in mice model

Heavy metal contamination especially lead (Pb) causes a serious threat to global public health. In the current study, we explored the protective and regulating effects of Emblica officinalis polysaccharide (EOP) in the liver against Pb-induced toxicity. According to our findings, EOP decreased the Pb-induced pathological lesions of liver and overall weight index in mice (p < 0.05). Following treatment with EOP, the levels of biological biomarkers for liver hepatic function (i.e., ALT and AST) were significantly decreased (p < 0.01) in a dose-dependent manner, consisted with histopathological changes. The key proteins involved in hepatic oxidative stress and apoptosis, including Nrf2, HO-1, Bcl-2, and Bax were quantified, which indicated EOP as an effective approach in protecting against the liver injury. Moreover, EOP treatment ameliorated the negative changes of liver metabolic profile (i.e., metabolites concentrations and metabolic patterns). In conclusion, EOP could protect the liver against oxidative stress and apoptosis induced by Pb poisoning, associated with the efficacy of ameliorating the negative changes in liver metabolic profile. Hence, the current findings recommend EOP as an efficient way for alleviating liver injury in lead poisoning.

Insulin-like growth factor 1 in heat stress-induced neuroinflammation: novel perspective about the neuroprotective role of chromium

Heat stress (HS) can cause a series of stress responses, resulting in numerous negative effects on the body, such as the diminished food intake, carcass quality and reproductive capacity. In addition to the negative effects on the peripheral system, HS leads to central nervous system (CNS) disorders given its toll on neuroinflammation. This neuroinflammatory process is mainly mediated by microglia and astrocytes, which are involved in the activation of glial cells and the secretion of cytokines. While the regulation of inflammatory signaling has a close relationship with the expression of heat shock protein 70 (Hsp70), HS-induced neuroinflammation is closely related to the activation of the TLR4/NF-κB pathway. Moreover, oxidative stress and endoplasmic reticulum (ER) stress are key players in the development of neuroinflammation. Chromium (Cr) has been widely shown to have neuroprotective effects in both humans and animals, despite the lack of mechanistic evidence. Evidence has shown that Cr supplementation can increase the levels of insulin-like growth factor 1 (IGF-1), a major neurotrophic factor with anti-inflammatory and antioxidant effects. This review highlights recent advances in the attenuating effects and potential mechanisms of Cr-mediated IGF-1 actions on HS-induced neuroinflammation, providing presently existing evidence supporting the neuroprotective role of Cr.

Five-Aminolevulinic Acid (5-ALA) Induces Heme Oxygenase-1 and Ameliorates Palmitic Acid-Induced Endoplasmic Reticulum Stress in Renal Tubules

Steatosis, or ectopic lipid deposition, is the fundamental pathophysiology of non-alcoholic steatohepatitis and chronic kidney disease. Steatosis in the renal tubule causes endoplasmic reticulum (ER) stress, leading to kidney injury. Thus, ER stress could be a therapeutic target in steatonephropathy. Five-aminolevulinic acid (5-ALA) is a natural product that induces heme oxygenase (HO)-1, which acts as an antioxidant. This study aimed to investigate the therapeutic potential of 5-ALA in lipotoxicity-induced ER stress in human primary renal proximal tubule epithelial cells. Cells were stimulated with palmitic acid (PA) to induce ER stress. Cellular apoptotic signals and expression of genes involved in the ER stress cascade and heme biosynthesis pathway were analyzed. The expression of glucose-regulated protein 78 (GRP78), a master regulator of ER stress, increased significantly, followed by increased cellular apoptosis. Administration of 5-ALA induced a remarkable increase in HO-1 expression, thus ameliorating PA-induced GRP78 expression and apoptotic signals. BTB and CNC homology 1 (BACH1), a transcriptional repressor of HO-1, was significantly downregulated by 5-ALA treatment. HO-1 induction attenuates PA-induced renal tubular injury by suppressing ER stress. This study demonstrates the therapeutic potential of 5-ALA against lipotoxicity through redox pathway.

Downregulated PGK1 attenuates cerebral ischemia-reperfusion injury by reversing neuroinflammation and oxidative stress through the Nrf2/ARE pathway

Understanding the role and mechanism of astrocytes in inflammation and oxidative response is crucial for developing therapeutic strategies to reduce inflammation and oxidative injury in cerebral ischemia-reperfusion injury (CIRI). In this study, we investigated the regulatory effects of phosphoglycerate kinase 1 (PGK1) on inflammation and oxidative response after CIRI in male adult Sprague-Dawley (SD) rats and using primary astrocytes obtained from neonatal SD rats, and explored its related mechanisms. We established a rat model of middle cerebral artery occlusion-reperfusion (MCAO/R) by suture occlusion, and an oxygen-glucose deprivation/reoxygenation model of astrocytes using oxygen-free, glucose-free, and serum-free cultures. AAV8-PGK1-GFP was injected into the left ventricle 24 h before modeling. Real-time quantitative polymerase chain reaction, enzyme-linked immunosorbent assay, co-immunoprecipitation (CoIP) assay, fluorescence in situ hybridization (FISH), and western blotting were used to elucidate the in-depth mechanisms of PGK1 in CIRI. PGK1 overexpression significantly exacerbated neurological deficits, increased cerebral infarct volume, and aggravated nerve cell injury in rats after MCAO/R. Using FISH and CoIP assays, we verified the localization of PGK1 and Nrf2 in primary astrocytes. Further rescue experiments showed that Nrf2 knockdown eliminated the protective effect of CBR-470-1 (a PGK1 inhibitor) on CIRI. Lastly, we confirmed that PGK1 aggravates CIRI by inhibiting the Nrf2/ARE pathway. In conclusion, our findings suggest that inhibiting PGK1 attenuates CIRI by reducing the release of inflammatory and oxidative factors from astrocytes by activating the Nrf2/ARE signaling pathway.

Brucella abortus modulates macrophage polarization and inflammatory response by targeting glutaminases through the NF-κB signaling pathway

Objectives

The mechanism of Brucella infection regulating macrophage phenotype has not been completely elucidated until now. This study aimed to determine the mechanism of Brucella abortus in the modulation of macrophage phenotype using RAW264.7 cells as a model.

Materials and methods

RT-qPCR, ELISA and flow cytometry were used to detect the inflammatory factor production and phenotype conversion associated with M1/M2 polarization of macrophages by Brucella abortus infection. Western blot and immunofluorescence were used to analyze the role of nuclear factor kappa B (NF-κB) signaling pathway in regulation of Brucella abortus-induced macrophage polarization. Chromatin immunoprecipitation sequencing (Chip-seq), bioinformatics analysis and luciferase reporter assay were used to screen and validate NF-κB target genes associated with macrophage polarization and further verify its function.

Results

The results demonstrate that B. abortus induces a macrophage phenotypic switch and inflammatory response in a time-dependent manner. With the increase of infection time, B. abortus infection-induced M1-type increased first, peaked at 12 h, and then decreased, whereas the M2-type decreased first, trough at 12 h, and then increased. The trend of intracellular survival of B. abortus was consistent with that of M2 type. When NF-κB was inhibited, M1-type polarization was inhibited and M2-type was promoted, and the intracellular survival of B. abortus increased significantly. Chip-seq and luciferase reporter assay results showed that NF-κB binds to the glutaminase gene (Gls). Gls expression was down-regulated when NF-κB was inhibited. Furthermore, when Gls was inhibited, M1-type polarization was inhibited and M2-type was promoted, the intracellular survival of B. abortus increased significantly. Our data further suggest that NF-κB and its key target gene Gls play an important role in controlling macrophage phenotypic transformation.

Conclusions

Taken together, our study demonstrates that B. abortus infection can induce dynamic transformation of M1/M2 phenotype in macrophages. Highlighting NF-κB as a central pathway that regulates M1/M2 phenotypic transition. This is the first to elucidate the molecular mechanism of B. abortus regulation of macrophage phenotype switch and inflammatory response by regulating the key gene Gls, which is regulated by the transcription factor NF-κB.

Association of nanoparticles and Nrf2 with various oxidative stress-mediated diseases

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that regultes the cellular antioxidant defense system at the posttranscriptional level. During oxidative stress, Nrf2 is released from its negative regulator Kelch-like ECH-associated protein 1 (Keap1) and binds to antioxidant response element (ARE) to transcribe antioxidative metabolizing/detoxifying genes. Various transcription factors like aryl hydrocarbon receptor (AhR) and nuclear factor kappa light chain enhancer of activated B cells (NF-kB) and epigenetic modification including DNA methylation and histone methylation might also regulate the expression of Nrf2. Despite its protective role, Keap1/Nrf2/ARE signaling is considered as a pharmacological target due to its involvement in various pathophysiological conditions such as diabetes, cardiovascular disease, cancer, neurodegenerative diseases, hepatotoxicity and kidney disorders. Recently, nanomaterials have received a lot of attention due to their unique physiochemical properties and are also used in various biological applications, for example, biosensors, drug delivery systems, cancer therapy, etc. In this review, we will be discussing the functions of nanoparticles and Nrf2 as a combined therapy or sensitizing agent and their significance in various diseases such as diabetes, cancer and oxidative stress-mediated diseases.

Adipose Tissue Macrophage-Mediated Inflammation in Obesity: A Link to Posttranslational Modification

Adipose tissue macrophages (ATM) are an essential type of immune cells in adipose tissue. Obesity induces the inflammation of adipose tissues, as expressed by ATM accumulation, that is more likely to become a source of systemic metabolic diseases, including insulin resistance. The process is characterized by the transcriptional regulation of inflammatory pathways by virtue of signaling molecules such as cytokines and free fatty acids. Notably, posttranslational modification (PTM) is a key link for these signaling molecules to trigger the proinflammatory or anti-inflammatory phenotype of ATMs. This review focuses on summarizing the functions and molecular mechanisms of ATMs regulating inflammation in obese adipose tissue. Furthermore, the role of PTM is elaborated, hoping to identify new horizons of treatment and prevention for obesity-mediated metabolic disease.

Celastrol-loaded biomimetic nanodrug ameliorates APAP-induced liver injury through modulating macrophage polarization

Drug-induced liver injury (DILI) is a major concern in clinical treatment as well as postmarketing surveillance, showing an urgent requirement for the development of protective medications. Celastrol (Cel), a highly active natural product extracted from the roots of Tripterygium wilfordii, has a potential liver protective activity due to its antioxidant and anti-inflammatory effects. However, the further application of Cel to DILI remains a challenge because of its short half-life, low solubility, and toxic side effects. Herein, we developed a Cel-loaded biomimetic nanodrug based on erythrocyte membrane vesicles (EMV) for protecting the liver from acetaminophen (APAP)-induced liver injury. The Cel-loaded EMV (C-EMV) with lower cytotoxicity had a well-sustained release effect and exhibited excellent ability for liver accumulation under physiological and pathological conditions. By suppressing the inflammatory response of pro-inflammatory macrophage M1 polarization while stimulating anti-inflammatory macrophage M2 polarization, C-EMV could significantly alleviate the primary pathological manifestations related to liver injury, including aberrant elevation of biochemical indicators, histopathological alterations, neutrophil infiltration as well as hepatocyte DNA fragmentation. The macrophage depletion experiment further demonstrated that the protective effect of C-EMV on APAP-induced liver injury appeared to be dependent on hepatic macrophages. Therefore, C-EMV as a biomimetic nanodrug exhibits great potential for attenuating the progress of DILI, providing a new approach to protecting the liver from DILI as well as other liver inflammatory diseases through a targeted nanodelivery system. KEY MESSAGES: EMV biomimetic nanocarrier has good monodispersity and sustained-release property. EMV biomimetic nanocarrier displays excellent liver-targeting capability under physiological and pathological conditions. C-EMV biomimetic nanodrug with lower cytotoxicity regulates macrophage polarization in vitro and in vivo. C-EMV biomimetic nanodrug can significantly alleviate APAP-induced liver injury. The protective effect of C-EMV on APAP-induced liver injury is dependent on hepatic macrophages.

LncRNA MEG3 alleviates interstitial cystitis in rats by upregulating Nrf2 and inhibiting the p38/NF-κB pathway

PURPOSE

Interstitial cystitis (IC), a chronic pain syndrome characterized by urinary frequency, urgency, and bladder or pelvic floor pain, severely affects the quality of life of patients. The aim of this study was to investigate the role and mechanism of long noncoding RNA Maternally Expressed Gene3 (lncRNA MEG3) in IC.

METHODS

An IC rat model was established by intraperitoneal injection of cyclophosphamide combined with bladder perfusion of fisetin and tumor necrosis factor-α (TNF-α) to mimic IC. An in vitro model was established using TNF-α-induced rat bladder epithelium cells. H&E staining was used to assess bladder tissue damage and ELISA was used to measure inflammatory cytokine levels. Western blot analysis was used to examine Nrf2, Bax, Bcl-2, cleaved caspase-3, p-p38, p38, p-NF-κB and NF-κB protein expression levels. RNA immunoprecipitation and RNA pull-down assays were used to examine the interaction between MEG3 and Nrf2.

RESULTS

MEG3 levels were upregulated in IC tissues and bladder epithelial cells, whereas Nrf2 expression was found to be downregulated. Knockdown of MEG3 reduced bladder tissue injury, inflammation, oxidative stress and apoptosis. MEG3 was negatively correlated with Nrf2. Downregulation of MEG3 alleviated IC inflammation and injury by upregulating Nrf2 and inhibiting the p38/NF-κB pathway.

CONCLUSION

Downregulation of MEG3 alleviated inflammation and injury in IC rats by upregulating Nrf2 and inhibiting the p38/NF-κB pathway.

N-Trimethylated chitosan coating white adipose tissue vascular-targeting oral nano-system for the enhanced anti-obesity effects of celastrol

Oral nanoparticles (NPs) are more suitable for obesity control compared to NPs administered intravenously, as their convenience increases patient compliance. Herein, we developed an oral nano-system to improve the anti-obesity efficacy of celastrol (Cel). The observed enhanced efficacy was mediated by zein core NPs decorated with adipose-homing peptides that were coated with N-trimethylated chitosan. The optimized Cel/AHP-NPs@TMC exhibited spherical morphology by TEM, as well as narrow size distribution (221.76 ± 6.73 nm) and adequate stability in a gastrointestinal environment. Based on the combined delivery advantages of AHP-NPs@TMC - i.e., improved cellular internalization within Caco-2 cells and enhanced white adipose tissue (WAT) vascular targeting - Cel/AHP-NPs@TMC significantly reduced the body weight, blood lipid levels, adipose inflammation, and WAT distribution in diet-induced obese mice without side-effects. In short, this study provides clear evidence that TMC-based oral NPs can effectively improve celastrol for obesity treatment.

Celastrol confers ferroptosis resistance via AKT/GSK3β signaling in high-fat diet-induced cardiac injury

Obesity-induced cardiac dysfunction is a severe global disease associated with high dietary fat intake, and its pathogenesis includes inflammation, oxidative stress, and ferroptosis. Celastrol (Cel) is a bioactive compound isolated from the herb Tripterygium wilfordii, which has a protective influence on cardiovascular diseases. In this study, the role of Cel in obesity-induced ferroptosis and cardiac injury was investigated. We found that Cel alleviated ferroptosis induced by Palmitic acid (PA), exhibiting a decrease in the LDH, CK-MB, Ptgs2, and Lipid Peroxidation levels. After cardiomyocytes were treated with additional LY294002 and LiCl, Cel exerted its protective effect through increased AKT/GSK3β phosphorylation and decreased level of lipid peroxidation and Mitochondrial ROS. The systolic left ventricle (LV) dysfunction of obese mice was alleviated via ferroptosis inhibition by elevated p-GSK3β and decreased Mitochondrial ROS under Cel treatment. Moreover, mitochondrial anomalies included swelling and distortion in the myocardium which was relieved with Cel. In conclusion, our results demonstrate that ferroptosis resistance with Cel under HFD conditions targets AKT/GSK3β signaling, which provides novel therapeutic strategies in obesity-induced cardiac injury.

New Insights into Baicalein's Effect on Chlorpyrifos-Induced Liver Injury in Carp: Involving Macrophage Polarization and Pyropto sis

Chlorpyrifos (CPF) is widely used in agriculture, plants, and buildings to kill pests and worms. Excessive environmental residues of CPF will result in soil and ecological contamination and toxicity to animals and humans. Baicalein (Bai), derived from the root of natural Scutellaria baicalensis, is a potent anti-inflammatory, antioxidant, and antitumor agent. The objective of this paper is to investigate the molecular mechanism by which Bai prevents CPF-induced hepatotoxic injury. Carp were kept in water containing CPF (23.2 μg/L) and/or fed diets containing Bai (0.15 g/kg). We found that Bai attenuated liver tissue damage and vacuolization caused by CPF. We confirmed that CPF causes M1/M2 polarization imbalance in macrophages and hepatocyte pyroptosis, which ultimately leads to liver injury. Further exploration of the internal mechanism shows that CPF participates in liver toxicity damage by destroying the AMPK/SIRT1/pGC-1α pathway and causing mitochondrial biogenesis and mitochondrial dynamics imbalance. Notably, Bai significantly attenuated CPF-induced inhibition of the AMPK/SIRT1/pGC-1α pathway. In summary, our results suggest that Bai alleviates CPF exposure-induced inhibition of the AMPK/SIRT1/pGC-1α pathway, thereby attenuating macrophage M1 hyperpolarization and pyroptosis by inhibiting the NF-κB pathway. These results may provide new insights into the detoxification mechanism of Bai on the same type of organophosphorus pesticides.

The markers to delineate different phenotypes of macrophages related to metabolic disorders

Macrophages have a wide variety of roles in physiological and pathological conditions, making them promising diagnostic and therapeutic targets in diseases, especially metabolic disorders, which have attracted considerable attention in recent years. Owing to their heterogeneity and polarization, the phenotypes and functions of macrophages related to metabolic disorders are diverse and complicated. In the past three decades, the rapid progress of macrophage research has benefited from the emergence of specific molecular markers to delineate different phenotypes of macrophages and elucidate their role in metabolic disorders. In this review, we analyze the functions and applications of commonly used and novel markers of macrophages related to metabolic disorders, facilitating the better use of these macrophage markers in metabolic disorder research.

Celastrol Treatment Ameliorated Acute Ischemic Stroke-Induced Brain Injury by Microglial Injury Inhibition and Nrf2/HO-1 Pathway Activations

Background

Stroke is the third main reason of mortality, which is the leading reason for adult disability in the globe. Poststroke inflammation is well known to cause acute ischemic stroke- (AIS-) induced brain injury (BI) exacerbation. Celastrol (CL) has exhibited anti-inflammatory activities in various inflammatory traits though underlying mechanisms remain unknown. So, the present investigation is aimed at studying CL protective mechanism against AIS-induced BI.

Methods

A mouse model regarding middle cerebral artery occlusion and an oxygen-glucose deprivation (OGD) cell model with or not CL treatment were constructed to study CL protective effects. NF-E2-related factor 2 (Nrf2) was then silenced in BV2 microglia cells (BV2) to study Nrf2 role regarding CL-mediated neuroprotection.

Results

The results showed that CL treatment suppressed AIS-induced BI by inhibiting NLRP3/caspase-1 pathway activations and induction of apoptosis and pyroptosis in vivo and in vitro. NLRP3/caspase-1 pathway blocking activation suppressed OGD-induced cell pyroptosis and apoptosis. Also, CL treatment reversed OGD-induced microglial injury by promoting Nrf2/heme oxygenase-1 (HO-1) pathway activations. Nrf2 downregulation reversed CL protective effects against OGD-induced microglial injury, pyroptosis, and apoptosis.

Conclusion

The findings advise that CL treatment ameliorated AIS-induced BI by inhibiting microglial injury and activating the Nrf2/HO-1 pathway.

Perfluorooctane sulfonate promotes atherosclerosis by modulating M1 polarization of macrophages through the NF-κB pathway

Perfluorooctane sulfonate (PFOS) is a widely used and distributed perfluorinated compounds and is reported to be harmful to cardiovascular health; however, the direct association between PFOS exposure and atherosclerosis and the underlying mechanisms remain unknown. Therefore, this study aimed to investigate the effects of PFOS exposure on the atherosclerosis progression and the underlying mechanisms. PFOS was administered through oral gavage to apolipoprotein E-deficient (ApoE^-/-) mice for 12 weeks. PFOS exposure significantly increased pulse wave velocity (PWV) and intima-media thickness (IMT), increased aortic plaque burden and vulnerability, and elevated serum lipid and inflammatory cytokine levels. PFOS promoted aortic and RAW264.7 M1 macrophage polarization, which increased the secretion of nitric oxide synthase (iNOS) and pro-inflammatory factors (tumor necrosis factor-α [TNF-α], interleukin-6 [IL-6], and interleukin-1β [IL-1β]), and suppressed M2 macrophage polarization, which decreased the expression of CD206, arginine I (Arg-1), and interleukin-10 (IL-10). Moreover, PFOS activated nuclear factor-kappa B (NF-κB) in the aorta and macrophages. BAY11-7082 was used to inhibit NF-κB-alleviated M1 macrophage polarization and the inflammatory response induced by PFOS in RAW264.7 macrophages. Our results are the first to reveal the acceleratory effect of PFOS on the atherosclerosis progression in ApoE^-/- mice, which is associated with the NF-κB activation of macrophages to M1 polarization to induce inflammation.

Therapeutic delivery of microRNA-125a-5p oligonucleotides improves recovery from myocardial ischemia/reperfusion injury in mice and swine

Rationale: Clinical application of mesenchymal stem cells (MSCs) and MSC-derived exosomes (MSC-Exos) to alleviate myocardial ischemia/reperfusion (I/R) injury is compromised by the low cell engraftment rate and uncontrolled exosomal content. As one of their active ingredients, single-component microRNA therapy may have more inherent advantages. We sought to find an ideal microRNA candidate and determine whether it could reproduce the cardioprotective effects of MSCs and MSC-Exos. Methods: Cardiac function and myocardial remodeling in MSC, MSC-Exo, or microRNA oligonucleotide-treated mouse hearts were investigated after I/R injury. The effects of microRNA oligonucleotides on cardiac cells (macrophages, cardiomyocytes, fibroblasts, and endothelial cells) and their downstream mechanisms were confirmed. Large animals were also employed to investigate the safety of microRNA therapy. Results: The results showed that microRNA-125a-5p (miR-125a-5p) is enriched in MSC-Exos, and intramyocardial delivery of their modified oligonucleotides (agomir) in mouse I/R myocardium, as well as MSCs or MSC-Exos, exerted obvious cardioprotection by increasing cardiac function and limiting adverse remodeling. In addition, miR-125a-5p agomir treatment increased M2 macrophage polarization, promoted angiogenesis, and attenuated fibroblast proliferation and activation, which subsequently contributed to the improvements in cardiomyocyte apoptosis and inflammation. Mechanistically, Klf13, Tgfbr1, and Daam1 are considered the targets of miR-125a-5p for regulating the function of macrophages, fibroblasts, and endothelial cells, respectively. Similar results were observed following miR-125a-5p agomir treatment in a porcine model, with no increase in the risk of arrhythmia or hepatic, renal, or cardiac toxicity. Conclusions: This targeted microRNA delivery presents an effective and safe strategy as a stem cell and exosomal therapy in I/R cardiac repair.

Celastrol-regulated gut microbiota and bile acid metabolism alleviate hepatocellular carcinoma proliferation by regulating the interaction between FXR and RXRα in vivo and in vitro

Celastrol, a triterpene derived from Thunder God Vine (Tripterygium wilfordii Hook f; Celastraceae), a traditional Chinese herb, has promising anticancer activity. The present study aimed to elucidate an indirect mechanism of celastrol-mediated alleviation of hepatocellular carcinoma (HCC) via gut microbiota-regulated bile acid metabolism and downstream signaling. Here, we constructed a rat model of orthotopic HCC and performed 16S rDNA sequencing and UPLC-MS analysis. The results showed that celastrol could regulate gut bacteria; suppress the abundance of Bacteroides fragilis; raise the levels of glycoursodeoxycholic acid (GUDCA), a bile acid; and alleviate HCC. We found that GUDCA suppressed cellular proliferation and induced the arrest of mTOR/S6K1 pathway-associated cell cycle G0/G1 phase in HepG2 cells. Further analyses using molecular simulations, Co-IP, and immunofluorescence assays revealed that GUDCA binds to farnesoid X receptor (FXR) and regulates the interaction of FXR with retinoid X receptor a (RXRα). Transfection experiments using the FXR mutant confirmed that FXR is essential for GUCDA-mediated suppression of HCC cellular proliferation. Finally, animal experiments showed that the treatment with the combination of celastrol/GUDCA alleviated the adverse effects of celastrol alone treatment on body weight loss and improved survival in rats with HCC. In conclusion, the findings of this study suggest that celastrol exerts an alleviating effect on HCC, in part via regulation of the B. fragilis-GUDCA-FXR/RXRα-mTOR axis.

Anti-Inflammatory Mechanisms of Dietary Flavones: Tapping into Nature to Control Chronic Inflammation in Obesity and Cancer

Flavones are natural phytochemicals broadly distributed in our diet. Their anti-inflammatory properties provide unique opportunities to control the innate immune system and inflammation. Here, we review the role of flavones in chronic inflammation with an emphasis on their impact on the molecular mechanisms underlying inflammatory diseases including obesity and cancer. Flavones can influence the innate immune cell repertoire restoring the immune landscape. Flavones impinge on NF-κB, STAT, COX-2, or NLRP3 inflammasome pathways reestablishing immune homeostasis. Devoid of adverse side effects, flavones could present alternative opportunities for the treatment and prevention of chronic inflammation that contributes to obesity and cancer.

Repeated Episodes of Ischemia/Reperfusion Induce Heme-Oxygenase-1 (HO-1) and Anti-Inflammatory Responses and Protects against Chronic Kidney Disease

Preconditioning episodes of ischemia/reperfusion (IR) induce protection against acute kidney injury (AKI), however their long-term effect still unknown. We evaluated AKI to chronic kidney disease (CKD) transition, after three-mild or three-severe episodes of IR. AKI was induced by single bilateral IR (1IR), or three episodes of IR separated by 10-day intervals (3IR) of mild (20 min) or severe (45 min) ischemia. Sham-operated rats served as controls. During 9-months, the 1IR group (20 or 45 min) developed CKD evidenced by progressive proteinuria and renal fibrosis. In contrast, the long-term adverse effects of AKI were markedly ameliorated in the 3IR group. The acute response in 3IR, contrasted with the 1IR group, that was characterized by an increment in heme oxygenase-1 (HO-1) and an anti-inflammatory response mediated by a NFkB-p65 phosphorylation and IL-6 decrease, together with an increase in TGF-β, and IL-10 expression, as well as in M2-macrophages. In addition, three episodes of IR downregulated endoplasmic reticulum (ER) stress markers expression, CHOP and BiP. Thus, repeated episodes of IR with 10-day intervals induced long-term renal protection accompanied with HO-1 overexpression and M2-macrophages increase.

Wound Healing versus Metastasis: Role of Oxidative Stress

Many signaling pathways, molecular and cellular actors which are critical for wound healing have been implicated in cancer metastasis. These two conditions are a complex succession of cellular biological events and accurate regulation of these events is essential. Apart from inflammation, macrophages-released ROS arise as major regulators of these processes. But, whatever the pathology concerned, oxidative stress is a complicated phenomenon to control and requires a finely tuned balance over the different stages and responding cells. This review provides an overview of the pivotal role of oxidative stress in both wound healing and metastasis, encompassing the contribution of macrophages. Indeed, macrophages are major ROS producers but also appear as their targets since ROS interfere with their differentiation and function. Elucidating ROS functions in wound healing and metastatic spread may allow the development of innovative therapeutic strategies involving redox modulators.

Human Umbilical Cord Mesenchymal Stem Cell-Derived Exosomes Attenuate Myocardial Infarction Injury via miR-24-3p-Promoted M2 Macrophage Polarization

Exosomes derived from human umbilical cord mesenchymal stem cells (UMSC-Exos) have shown encouraging effects in regulating inflammation and attenuating myocardial injury. Macrophages are regulated dynamically in response to environmental cues. However, the underlying mechanisms by which UMSC-Exos regulate macrophage polarization are still not well understood. Herein, it is aimed to explore the effects of UMSC-Exos on macrophage polarization and their roles in cardiac repair after myocardial infarction (MI). These results show that UMSC-Exos improve cardiac function by increasing M2 macrophage polarization and reducing excessive inflammation. RNA-sequencing results identify Plcb3 as a key gene involved in UMSC-Exo-facilitated M2 macrophage polarization. Further bioinformatic analysis identifies exosomal miR-24-3p as a potential effector mediating Plcb3 downregulation in macrophages. Increasing miR-24-3p expression in macrophages effectively enhances M2 macrophage polarization by suppressing Plcb3 expression and NF-κB pathway activation in the inflammatory environment. Furthermore, reducing miR-24-3p expression in UMSC-Exos attenuates the effects of UMSC-Exos on M2 macrophage polarization. This study demonstrates that the cardiac therapeutic effects of UMSC-Exos are at least partially through promoting M2 macrophage polarization in an inflammatory microenvironment. Mechanistically, exosomal miR-24-3p is found to inhibit Plcb3 expression and NF-κB pathway activation to promote M2 macrophage polarization.

Total Sesquiterpenoids of Loquat Leaves Alleviated High-Fat Diet-Induced Obesity by Targeting Fecal Metabolic Profiling and Gut Microbiota Composition

In the present study, we demonstrated that whether the gut microbiota and related metabolites contribute to the therapeutic effect of total sesquiterpenoids (TSs) from loquat leaves on obesity. A 4-week high fat diet was used to induce obesity which was then treated with TSs for another 4 weeks. TSs remarkedly reduced the weight of body and white adipose and the levels of total cholesterol (TC) and triglyceride (TG) in serum. We also found that TSs restored the diversity and richness of gut microbiota. In addition, TSs administration affected the relative abundance of seven key genera. Meanwhile, TSs were determined to affect the metabolism of the host through detecting the metabolites in feces. By applying KEGG and the correlation analysis with gut microbiota, 10 differential metabolites were identified to be the key. The results in this work proved that TSs inhibited obesity by remodeling gut microbiota and related metabolites.

Neuroprotective effects of celastrol on sciatic nerve transection model in male Wistar rats

Objectives

Celastrol is an herbal compound with neuroprotective properties. Our research aimed to assess the neuroprotective properties of celastrol on sciatic nerve transection in rats.

Materials and Methods

The rats' left sciatic nerve was cut and sutured directly. The animals were then given 1 or 2 mg/kg celastrol intraperitoneally for two weeks. The sensory and locomotor behaviors of the animals were then evaluated for 16 weeks. Immunohistochemistry, ELISA, and real-time PCR were also utilized to evaluate macrophage polarization, cytokine secretion, and neurotrophin expression in injured nerves.

Results

Results showed that both doses of celastrol significantly accelerated nerve regeneration and improved sensorimotor functional recovery when compared with controls. Nevertheless, administration of 2 mg/kg of celastrol significantly outperforms treatment with a dose of 1 mg/kg. Celastrol treatment-induced M2 polarization in macrophages decreased proinflammatory cytokines at the injury site. It also increased the expression of BDNF mRNA.

Conclusion

These findings suggest that a two-week treatment with celastrol had neuroprotective effects in a rat sciatic nerve transection model, most likely by inducing macrophage M2 polarization and anti-inflammatory effects.

Tryptamine, a Microbial Metabolite in Fermented Rice Bran Suppressed Lipopolysaccharide-Induced Inflammation in a Murine Macrophage Model

Fermentation is thought to alter the composition and bioavailability of bioactive compounds in rice bran. However, how this process affects the anti-inflammatory effects of rice bran and the bioactive compounds that might participate in this function is yet to be elucidated. This study aimed to isolate bioactive compounds in fermented rice bran that play a key role in its anti-inflammatory function. The fermented rice bran was fractionated using a succession of solvent and solid-phase extractions. The fermented rice bran fractions were then applied to lipopolysaccharide (LPS)-activated murine macrophages to evaluate their anti-inflammatory activity. The hot water fractions (FRBA), 50% ethanol fractions (FRBB), and n-hexane fractions (FRBC) were all shown to be able to suppress the pro-inflammatory cytokine expression from LPS-stimulated RAW 264.7 cells. Subsequent fractions from the hot water fraction (FRBF and FRBE) were also able to reduce the inflammatory response of these cells to LPS. Further investigation revealed that tryptamine, a bacterial metabolite of tryptophan, was abundantly present in these extracts. These results indicate that tryptamine may play an important role in the anti-inflammatory effects of fermented rice bran. Furthermore, the anti-inflammatory effects of FRBE and tryptamine may depend on the activity of the aryl hydrocarbon receptor.

Ameliorating Inflammation in Insulin-resistant Rat Adipose Tissue with Abdominal Massage Regulates SIRT1/NF-κB Signaling

It was the aim of this study to determine whether abdominal massage reverses high-fat diet-induced insulin resistance compared with RSV treatment. A total of sixty male Sprague-Dawley rats were randomly placed in one of four groups:the non-fat diet (NFD), the high-fat diet (HFD), the HFD with abdominal massage (HFD+ AM), and the HFD plus resveratrol (HFD+ RSV). For eight weeks, rats were fed high-fat diets to create insulin resistance, followed by six weeks of either AM or RSV. Molecular mechanisms of adipogenesis and cytokine production in rats with high-fat diets were investigated. The model rat adipose tissue showed significant improvements in obesity, glucose intolerance, and the accumulation of lipid in the body [the total cholesterol level (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C)], metabolic effects of glucose [The fasting blood glucose (FBG), Fasting insulin levels (FINS)], inflammatory status [interleukin-6 (IL-6) and tumor necrosis factor (TNF)-α, C-reactive protein (CRP)], and macrophage polarization after AM or RSV treatment. Further, AM increased SIRT1/NF-κB signaling in rat adipose tissue. Accordingly, in rat adipose tissue, our results indicate that AM regulates the secretion of proinflammatory cytokines, blood sugar levels, and related signaling pathways, contributing to improvement of IR, which may serves as a new therapeutic approach for the treatment for IR.

The Role of Diet in Regulation of Macrophages Functioning

The great importance of diet for health and high life-expectancy is established. The impact of nutrients on immune system is a point of growing research interest. Recent studies have found pro- and anti-inflammatory properties of some diet patterns and nutrients that can be used from the bench to the bedside for chronic low-grade inflammatory status correction. In this regard, the assessment of potential effects of nutrition on macrophage differentiation, proliferation, and functioning in health and disease is highly demanded. In this review, we present current data on the effects of nutrients on the macrophage functioning.

Celastrol: A Promising Agent Fighting against Cardiovascular Diseases

Cardiovascular diseases (CVD) are leading causes of morbidity and mortality worldwide; therefore, seeking effective therapeutics to reduce the global burden of CVD has become increasingly urgent. Celastrol, a bioactive compound isolated from the roots of the plant Tripterygium wilfordii (TW), has been attracting increasing research attention in recent years, as it exerts cardiovascular treatment benefits targeting both CVD and their associated risk factors. Substantial evidence has revealed a protective role of celastrol against a broad spectrum of CVD including obesity, diabetes, atherosclerosis, cerebrovascular injury, calcific aortic valve disease and heart failure through complicated and interlinked mechanisms such as direct protection against cardiomyocyte hypertrophy and death, and indirect action on oxidation and inflammation. This review will mainly summarize the beneficial effects of celastrol against CVD, largely based on in vitro and in vivo preclinical studies, and the potential underlying mechanisms. We will also briefly discuss celastrol’s pharmacokinetic limitations, which hamper its further clinical applications, and prospective future directions.

(9S,13R)-12-oxo-phytodienoic acid attenuates inflammation by inhibiting mPGES-1 and modulating macrophage polarization via NF-κB and Nrf2/HO-1 pathways

Non-steroidal anti-inflammatory drugs (NSAIDs) relieve inflammation by suppressing prostaglandin E₂/cyclooxygenase 2 (PGE₂/COX-2) with cardiovascular and gastrointestinal bleeding risk. Theoretically, suppressing PGE₂ through inhibiting the terminal synthase microsomal prostaglandin E₂ synthase-1 (mPGES-1) instead of upstream COX-2 is ideal for inflammation. Here, (9S,13R)-12-oxo-phytodienoic acid (AA-24) extracted from Artemisia anomala was first screened as an anti-inflammatory candidate and decreased inducible nitric oxide synthase (iNOS), nitric oxide (NO), mPGES-1, and PGE₂ without affecting COX-1/2, thromboxane A₂ (TXA₂) and prostaglandin I₂ (PGI₂). Besides, AA-24 suppressed the differentiation of M0 macrophages to M1 phenotype but enhanced it to M2 phenotype, blocked the activation of NF-κB pathway, and increased the activation of Nrf2 and heme oxygenase-1 (HO-1). Moreover, AA-24 selectively inhibited mPGES-1 and reduced inflamed paw edema in carrageenan-induced mice. In conclusion, AA-24 attenuates inflammation by inhibiting mPGES-1 and modulating macrophage polarization via the NF-κB and Nrf2/HO-1 pathways and could be a promising candidate for developing anti-inflammatory drugs.

Modulation of Inflammation-Related Lipid Mediator Pathways by Celastrol During Human Macrophage Polarization

Background and Purpose

Celastrol (CS) is a major active ingredient of the Chinese/Asian herb Tripterygium wilfordii that is frequently used as phytomedicine to treat inflammation and autoimmune diseases. We showed before that short-term exposure to CS (1 µM) favorably impacts the biosynthesis of inflammation-related lipid mediators (LM) in human polarized macrophages by modulating the activities of different lipoxygenases (LOXs). However, whether CS regulates the expression of LOXs and other related LM-biosynthetic enzymes during macrophage polarization is unknown. Here, we investigated how CS affects LM-biosynthetic enzyme expression on the protein level and studied concomitant LM signature profiles during polarization of human monocyte-derived macrophages (MDM) towards M1- and M2-like phenotypes.

Methods and Results

We used LM metabololipidomics to study the long-term effects of CS on LM profile signatures after manipulation of human monocyte-derived macrophages (MDM) during polarization. Exposure of MDM to low concentrations of CS (ie, 0.2 µM) during polarization to an inflammatory M1 phenotype potently suppressed the formation of pro-inflammatory cyclooxygenase (COX)- and 5-LOX-derived LM, especially prostaglandin (PG)E₂. Notably, gene and enzyme expression of COX-2 and microsomal PGE₂ synthase (mPGES)-1 as well as M1 markers were strongly decreased by CS during M1-MDM polarization, along with impaired activation of nuclear factor-κB and p38 mitogen-activated protein kinase. During IL-4-induced M2 polarization, CS decreased the capacity of the resulting M2-MDM to generate pro-inflammatory COX and 5-LOX products as well but it also reduced the formation of 12/15-LOX products and specialized pro-resolving mediators, without affecting the levels of liberated fatty acid substrates.

Conclusion

Depending on the timing and concentration, CS not only favorably affects LOX activities in macrophages but also the expression of LM-biosynthetic enzymes during macrophage polarization connected to changes of inflammation-related LM which might be of relevance for potential application of CS to treat inflammatory disorders.

Neuroprotective Effects of Celastrol in Neurodegenerative Diseases-Unscramble Its Major Mechanisms of Action and Targets

There are rarely new therapeutic breakthroughs present for neurodegenerative diseases in the last decades. Thus, new effective drugs are urgently needed for millions of patients with neurodegenerative diseases. Celastrol, a pentacyclic triterpenoid compound, is one of the main active ingredients isolated from Tripterygium wilfordii Hook. f. that has multiple biological activities. Recently, amount evidence indicates that celastrol exerts neuroprotective effects and holds therapeutic potential to serve as a novel agent for neurodegenerative diseases. This review focuses on the therapeutic efficacy and major regulatory mechanisms of celastrol to rescue damaged neurons, restore normal cognitive and sensory motor functions in neurodegenerative diseases. Importantly, we highlight recent progress regarding identification of the drug targets of celastrol by using advanced quantitative chemical proteomics technology. Overall, this review provides novel insights into the pharmacological activities and therapeutic potential of celastrol for incurable neurodegenerative diseases.

Perinatal Treatment with Leptin, but Not Celastrol, Protects from Metabolically Obese, Normal-Weight Phenotype in Rats

Perinatal nutrition has a well-known influence on obesity susceptibility. We previously demonstrated the protective anti-obesity effects of perinatal leptin administration. Celastrol is a natural compound acting as a leptin sensitizer with anti-obesity effects when administered in adult animals. Here, we aimed to determine if perinatal treatment with leptin, celastrol, or their combination was able to improve metabolic health in animals fed an isocaloric high-fat (HF) diet. Leptin and/or celastrol or their vehicle were administered orally to rats during the suckling period. After weaning, animals were chronically pair-fed with an HF diet provided isocaloric to the intake of a normal-fat diet by control animals to avoid obesity. Isocaloric HF feeding in vehicle-treated animals resulted in metabolic features characteristic of the metabolically obese, normal-weight (MONW) phenotype, i.e., obesity-related disturbances without increased body weight. Leptin treatment prevented liver fat deposition and insulin resistance, induced greater insulin and leptin signaling capacity, decreased gene expression of orexigenic signals at the hypothalamic level, and induced browning in retroperitoneal adipose tissue. However, celastrol treatment did not provide any protective effect and resulted in greater size of the retroperitoneal adipose depot, higher circulating glucose and insulin levels, and decreased leptin sensitivity capacity in adipose tissue. The co-administration of leptin ameliorated the negative effects of celastrol on the retroperitoneal depot, inducing browning and decreasing its size. In conclusion, the perinatal administration of leptin, but not celastrol, provided protection against the consequences of dietary unbalances leading to an MONW phenotype in adulthood.

Celastrol mitigates inflammation in sepsis by inhibiting the PKM2-dependent Warburg effect

BACKGROUND

Sepsis involves life-threatening organ dysfunction and is caused by a dysregulated host response to infection. No specific therapies against sepsis have been reported. Celastrol (Cel) is a natural anti-inflammatory compound that shows potential against systemic inflammatory diseases. This study aimed to investigate the pharmacological activity and molecular mechanism of Cel in models of endotoxemia and sepsis.

METHODS

We evaluated the anti-inflammatory efficacy of Cel against endotoxemia and sepsis in mice and macrophage cultures treated with lipopolysaccharide (LPS). We screened for potential protein targets of Cel using activity-based protein profiling (ABPP). Potential targets were validated using biophysical methods such as cellular thermal shift assays (CETSA) and surface plasmon resonance (SPR). Residues involved in Cel binding to target proteins were identified through point mutagenesis, and the functional effects of such binding were explored through gene knockdown.

RESULTS

Cel protected mice from lethal endotoxemia and improved their survival with sepsis, and it significantly decreased the levels of pro-inflammatory cytokines in mice and macrophages treated with LPS (P < 0.05). Cel bound to Cys424 of pyruvate kinase M2 (PKM2), inhibiting the enzyme and thereby suppressing aerobic glycolysis (Warburg effect). Cel also bound to Cys106 in high mobility group box 1 (HMGB1) protein, reducing the secretion of inflammatory cytokine interleukin (IL)-1β. Cel bound to the Cys residues in lactate dehydrogenase A (LDHA).

CONCLUSION

Cel inhibits inflammation and the Warburg effect in sepsis via targeting PKM2 and HMGB1 protein.