Anti-inflammatory effects of Ang-(1-7) via TLR4-mediated inhibition of the JNK/FoxO1 pathway in lipopolysaccharide-stimulated RAW264.7 cells

The GLP-1 agonist semaglutide ameliorates cognitive regression in P301S tauopathy mice model via autophagy/ACE2/SIRT1/FOXO1-Mediated Microglia Polarization

Tau hyper-phosphorylation has been recognized as an essential contributor to neurodegeneration in Alzheimer's disease (AD) and related tauopathies. In the last decade, tau hyper-phosphorylation has gained considerable concern in AD therapeutic development. Tauopathies are manifested with a broad spectrum of symptoms, from dementia to cognitive decline and motor impairments. Tau undergoes conformational changes and abnormal phosphorylation that mediate its detaching from microtubules, forming neurofibrillary tangles (NFTs). In the current study, a widely used P301S transgenic mice model of tauopathy was employed to evaluate the possible neuroprotective effects of semaglutide as an autophagy regulator through modifications of the brain renin-angiotensin system (RAS). Mice were divided into two groups according to their genotypes (wild type (Wt) and P301S), which were further subdivided to receive either vehicle (saline) or semaglutide (25 nmol/kg, i. p.), once every 2 days for 28 days. Current data suggest that semaglutide ameliorated the hyperactive pattern and alleviated the cognitive decline of P301S mice. It also hastened the autophagic flux through augmenting angiotensin-converting enzyme 2/sirtuin 1/forkhead box protein O1 signaling. Semaglutide also hindered the expression of phosphorylated adenosine monophosphate-activated protein kinase and phosphorylated glycogen synthase kinase-3 beta at serine 9, reducing the propagation of neuroinflammatory cytokines and oxidative reactions. Finally, semaglutide protected against hippocampal degeneration and reduced the immunoreactivity for total tau and ionized calcium-binding adapter molecule. Semaglutide showed promising neuroprotective implications in alleviating tauopathy-related AD's molecular and behavioral deficits through controlling autophagy and brain RAS.

Gestationally administered RAS modulators reprogram endotoxic cardiovascular and inflammatory profiles in adult male offspring of preeclamptic rats

Previous studies showed that preeclampsia (PE) amplifies cardiovascular dysfunction induced by endotoxemia in adult male, but not female, offspring. Here, we asked if such aggravated endotoxic insult could be nullified by modulators of the renin-angiotensin system (RAS). PE was induced by gestational administration of Nω-nitro-L-arginine methyl ester(L-NAME, a nitric oxide synthase inhibitor). Adult male offspring of PE mothers treated gestationally with angiotensin 1-7 (Ang1-7, angiotensin II-derived vasodilator), losartan (AT1 receptor antagonist), pioglitazone (peroxisome proliferator-activated receptor gamma, PPARγ, agonist), or combined losartan/pioglitazone were instrumented with femoral indwelling catheters and challenged intravenously with a 5-mg/kg dose of lipopolysaccharides (LPS, 5 mg/kg). LPS caused significant decreases in blood pressure (BP) and spectral index of overall heart rate variability and increases in heart rate and left ventricular contractility (dP/dtmax). These effects were mostly reduced to similar magnitudes by individual drug therapies. In offspring born to Ang1-7-treated dams, the spectral index of cardiac sympathovagal balance showed elevated sympathetic dominance in response to LPS. Immunohistochemistry revealed that Ang1-7, but not losartan/pioglitazone, abolished the exaggerated increases in toll-like receptor 4 (TLR-4) expression caused by PE/LPS in heart tissues and neuronal circuits of brainstem rostral ventrolateral medulla (RVLM). By contrast, the losartan/pioglitazone regimen, but not Ang1-7, decreased and increased angiotensin converting enzyme (ACE) and ACE2 expression, respectively. Together, gestational fetal reprogramming of Ang II (depression) and Ang1-7 (activation) arms of RAS effectively counterbalance worsened endotoxic cardiovascular and inflammatory profiles in adult male offspring of PE rats.

Alamandine treatment prevents LPS-induced acute renal and systemic dysfunction with multi-organ injury in rats via inhibiting iNOS expression

Sepsis is defined as the dysregulated immune response leading to multi-organ dysfunction and injury. Sepsis-induced acute kidney injury is a significant contributor to morbidity and mortality. Alamandine (ALA) is a novel endogenous peptide of the renin-angiotensin-aldosterone system. It is known for its anti-inflammatory and anti-apoptotic effects, but its functional and vascular effects on sepsis remain unclear. We aimed to investigate the effects of ALA, as a pre- and post-treatment agent, on lipopolysaccharide (LPS)-induced systemic and renal dysfunction and injury in the LPS-induced endotoxemia model in rats via functional, hemodynamic, vascular, molecular, biochemical, and histopathological evaluation. 10 mg/kg intraperitoneal LPS injection caused both hepatic and renal injury, decreased blood flow in several organs, and renal dysfunction at 20 h in Sprague-Dawley rats. Our results showed that ALA treatment ameliorated systemic and renal inflammation, reduced inflammatory cytokines, prevented the enhancement of the mortality rate, reversed vascular dysfunction, corrected decreased blood flows in several organs, and reduced renal and hepatic injury via inhibiting iNOS (inducible nitric oxide synthase) and caspase expressions in the kidney. In addition, expressions of different ALA-related receptors showed alterations in this model, and ALA treatment reversed these alterations. These data suggest that ALA's systemic and renal protective effects are achieved through its anti-inflammatory, anti-pyroptotic, and anti-apoptotic effects on hemodynamic and vascular functions via reduced iNOS expression.

The Essential Role of FoxO1 in the Regulation of Macrophage Function

Macrophages are widely distributed in various tissues and organs. They not only participate in the regulation of innate and adaptive immune response, but also play an important role in tissue homeostasis. Dysregulation of macrophage function is closely related to the initiation, development and prognosis of multiple diseases, including infection and tumorigenesis. Forkhead box transcription factor O1 (FoxO1) is an important member among the forkhead box transcription factor family. Through directly binding to the promoter regions of downstream target genes, FoxO1 is implicated in cell proliferation, apoptosis, metabolic activities and other biological processes. In this review, we summarized the regulatory role of FoxO1 in macrophage phagocytosis, migration, differentiation and inflammatory activation. We also emphasized that macrophage reciprocally modulated FoxO1 activity via a post-translational modification (PTM) dominant manner.

Angiotensin-(1-7) ameliorates high glucose-induced vascular endothelial injury through suppressing chloride channel 3

Diabetes Mellitus (DM) is a significant risk factor for cardiovascular disease (CVD), which is leading cause of deaths in DM patients. However, there are limited effective medical therapies for diabetic CVD. Vascular endothelial injury caused by DM is a critical risk factor for diabetic CVD. Previous study has indicated that Angiotensin-(1-7) (Ang-(1-7)) may prevent diabetic CVD, whereas it is not clear that Ang-(1-7) whether attenuates diabetic CVD through suppressing vascular endothelial injury. In this study, we found that Ang-(1-7) alleviated high glucose (HG)-induced endothelial injury in bEnd3 cells. Moreover, Ang-(1-7) ameliorated HG-induced endothelial injury through downregulating chloride channel 3 (CIC-3) via Mas receptor. Furthermore, HG-induced CIC-3 enhanced reactive oxygen species (ROS) and cytokine production and reduced the level of nitric oxide (NO), while Ang-(1-7) preserved the impact of HG-induced CIC-3 on productions of ROS, cytokine and NO through inhibiting CIC-3 via Mas receptor. Summarily, the present study revealed that Ang-(1-7) alleviated HG-induced vascular endothelial injury through the inhibition of CIC-3, suggested that Ang-(1-7) may preserve diabetic CVD through suppressing HG-induced vascular endothelial injury.

Genetic and Functional Evaluation of the Role of FOXO1 in Antituberculosis Drug-Induced Hepatotoxicity

Background

The accumulation of the hepatotoxic substance protoporphyrin IX (PPIX) induced by aminolevulinate synthase 1 (ALAS1) activation is one of the important mechanisms of antituberculosis drug-induced hepatotoxicity (ATDH). Forkhead box protein O1 (FOXO1) may activate ALAS1 transcription. However, little is known about their roles in ATDH; we performed a study to determine the association between polymorphisms in the two genes and ATDH susceptibility. Then, we verified this possible association by cellular functional experiments.

Materials and Methods

Tag single-nucleotide polymorphisms (TagSNPs) in the two genes were genotyped in 746 tuberculosis patients. The frequencies of the alleles, genotypes, genetic models, and haplotype distribution of the variants were compared between the case and control groups. L-02 cells and HepG2 cells were incubated with the indicated concentration of isoniazid (INH) and rifampicin (RIF) for the desired times, and then the expression levels of ALAS1 and FOXO1 mRNAs and proteins were detected. HepG2 cells were transiently transfected with FOXO1 siRNA to observe the effect of changes in the FOXO1 expression on the cell survival rate and ALAS1 expression.

Results

The C allele at rs2755237 and the T allele at rs4435111 in the FOXO1 gene were associated with a decreased risk of ATDH. The expression of ALAS1 in both L-02 cells and HepG2 cells was increased by the coadministration of INH/RIF (600/200 μM) for 24 h. Although FOXO1 expression was reduced slightly by the same treatment, its content in the nucleus was significantly increased. However, the cell survival rate and ALAS1 expression level were not significantly altered by the downregulation of FOXO1 in HepG2 cells.

Conclusions

Variants of the rs4435111 and rs2755237 loci in the FOXO1 gene were associated with susceptibility to ATDH. Coadministration of INH/RIF promoted the transfer of FOXO1 from the cytoplasm to the nucleus, but the functional significance of its nuclear translocation requires further verification.

Regulation of Monocytes/Macrophages by the Renin-Angiotensin System in Diabetic Nephropathy: State of the Art and Results of a Pilot Study

Diabetic nephropathy (DN) is characterized by albuminuria, loss of renal function, renal fibrosis and infiltration of macrophages originating from peripheral monocytes inside kidneys. DN is also associated with intrarenal overactivation of the renin-angiotensin system (RAS), an enzymatic cascade which is expressed and controlled at the cell and/or tissue levels. All members of the RAS are present in the kidneys and most of them are also expressed in monocytes/macrophages. This review focuses on the control of monocyte recruitment and the modulation of macrophage polarization by the RAS in the context of DN. The local RAS favors the adhesion of monocytes on renal endothelial cells and increases the production of monocyte chemotactic protein-1 and of osteopontin in tubular cells, driving monocytes into the kidneys. There, proinflammatory cytokines and the RAS promote the differentiation of macrophages into the M1 proinflammatory phenotype, largely contributing to renal lesions of DN. Finally, resolution of the inflammatory process is associated with a phenotype switch of macrophages into the M2 anti-inflammatory subset, which protects against DN. The pharmacologic interruption of the RAS reduces albuminuria, improves the trajectory of the renal function, decreases macrophage infiltration in the kidneys and promotes the switch of the macrophage phenotype from M1 to M2.

The ACE2-Ang-(1‑7)-Mas Axis Modulates M1/M2 Macrophage Polarization to Relieve CLP-Induced Inflammation via TLR4-Mediated NF-кb and MAPK Pathways

PURPOSE

Angiotensin 1-7 [Ang-(1-7)] has been identified as an important anti-inflammatory and anti-fibrotic factor. This study determined how the ACE2-Ang-(1-7)-Mas axis affected M1/M2 macrophage polarization and thus contributed to anti-inflammatory processes in the cecal ligation and puncture (CLP)-induced inflammation model.

MATERIALS AND METHODS

ELISA, western blotting, and qRT-PCR were used to verify that Ang-(1-7) decreased the expression of pro-inflammatory cytokines and increased anti-inflammatory cytokines. The differentiation of M1/M2 macrophages was assessed by flow cytometry for assessing the cell-surface markers, CD86 and CD206. The related key receptors and pathways were analyzed by Western blotting, qRT-PCR, and immunofluorescence. CLP-induced inflammatory mice models were used for in vivo studies. Hematoxylin and eosin and immunohistochemical and immunofluorescence staining protocols were used to analyze histological changes in the spleen, and the related key pathway proteins were analyzed by western blotting.

RESULTS

Ang-(1-7) decreased the expressions of the TNF-α and IL-6 pro-inflammatory cytokines and increased the expressions of the IL-4 and IL-10 anti-inflammatory cytokines. INOS and TNF-α, which represented M1 macrophage polarization, were decreased by Ang-(1-7). ARG1 and CD163, which represented M2 macrophage polarization, were increased by Ang-(1-7). Both Mas receptor and ACE2 are expressed on macrophages. Furthermore, the ACE2-Ang-(1-7)-MAS axis modulated macrophage polarization by ameliorating TLR4 expression and regulating the NF-кB and MAPK pathways. In addition, splenomegaly and macrophage infiltration were observed in the spleen of the CLP-induced mouse models and macrophages in the spleen suspension of CLP models were shifted to M1 phenotype and were effectively inhibited by Ang-(1-7) via the TLR4-mediated NF-кB and MAPK pathways, which could be partially rescued by A-779.

CONCLUSION

Ang-(1-7) inhibited inflammatory responses in vivo and in vitro, and repressed macrophage polarization toward the M1 phenotype and promoted it toward the M2 phenotype, which provided new evidence for the anti-inflammation activity of the ACE2-Ang-(1-7)-MAS axis.

Characteristics of Ang-(1-7)/Mas-Mediated Amelioration of Joint Inflammation and Cardiac Complications in Mice With Collagen-Induced Arthritis

Objectives

Rheumatoid arthritis (RA) is a disabling disease with a high incidence that is regularly accompanied by cardiovascular complications. Several studies have suggested that renin–angiotensin–aldosterone system (RAAS) is closely associated with RA. The aim of this study was to investigate the mechanisms underlying Angiotensin-(1–7) [Ang-(1–7)] and its Mas receptor agonist (AVE0991) on joint inflammation and cardiac complications in a collagen-induced arthritis (CIA) model.

Methods

Collagen type II was injected into DBA/1 mice to construct an arthritis model. CIA mice were treated with Ang-(1–7) (2.0 mg/kg intraperitoneally) and AVE0991 (3.0 mg/kg intraperitoneally). The serum levels of inflammatory cytokines [tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1 β, IL-6, and C-reactive protein (CRP)] were determined by ELISA. The mitogen-activated protein kinase (MAPK) and nuclear factor-kappaB (NF-κB) signaling pathways in joint tissues and the transforming growth factor (TGF)-β/Smad pathway and levels of α-Smooth muscle action (SMA) and β-myosin heavy chain (MHC) protein expression in cardiac tissues were assessed by western blots. The levels of TGF-β/Smad pathway, α-SMA, and β-MHC RNA in cardiac tissues were analyzed by real time-PCR. The levels of receptor activator of nuclear factor kappa ligand (RANKL) and promoting matrix metalloproteinase (MMP)-3 expression in the ankle joints were detected by immunohistochemistry and real time-PCR.

Results

Ang-(1–7) and AVE0991 reduced the levels of inflammatory cytokines and inhibited the MAPKs and NF-κB signaling pathways in ankle joint tissues, reduced RANKL and MMP3 expression, and ameliorated local joint inflammation and bone destruction compared with the control group. In addition, Ang-(1–7) and AVE0991 attenuated the TGF-β/Smad signaling pathway, reduced the levels of α-SMA and β-MHC expression, and diminished inflammatory cell infiltration into the myocardial interstitium and myocardial interstitial fibrosis in the hearts of CIA mice.

Conclusions

Ang-(1–7) alleviated joint damage caused by inflammation likely through the attenuation of NF-κB and MAPK pathways and ameliorated inflammation-induced cardiac fibrosis and activation of the TGF-β/Smad pathway. Moreover, Ang-(1–7) was likely mediated through the Mas receptor. This study provides theoretical evidence for exploring novel clinical therapeutic approaches for RA and its cardiac complications.

Novel Interactions Involving the Mas Receptor Show Potential of the Renin-Angiotensin system in the Regulation of Microglia Activation: Altered Expression in Parkinsonism and Dyskinesia

The renin-angiotensin system (RAS) not only plays an important role in controlling blood pressure but also participates in almost every process to maintain homeostasis in mammals. Interest has recently increased because SARS viruses use one RAS component (ACE2) as a target-cell receptor. The occurrence of RAS in the basal ganglia suggests that the system may be targeted to improve the therapy of neurodegenerative diseases. RAS-related data led to the hypothesis that RAS receptors may interact with each other. The aim of this paper was to find heteromers formed by Mas and angiotensin receptors and to address their functionality in neurons and microglia. Novel interactions were discovered by using resonance energy transfer techniques. The functionality of individual and interacting receptors was assayed by measuring levels of the second messengers cAMP and Ca2+ in transfected human embryonic kidney cells (HEK-293T) and primary cultures of striatal cells. Receptor complex expression was assayed by in situ proximity ligation assay. Functionality and expression were assayed in parallel in primary cultures of microglia treated or not with lipopolysaccharide and interferon-γ (IFN-γ). The proximity ligation assay was used to assess heteromer expression in parkinsonian and dyskinetic conditions. Complexes formed by Mas and the angiotensin AT1 or AT2 receptors were identified in both a heterologous expression system and in neural primary cultures. In the heterologous system, we showed that the three receptors-MasR, AT1R, and AT2R-can interact to form heterotrimers. The expression of receptor dimers (AT1R-MasR or AT2R-MasR) was higher in microglia than in neurons and was differentially affected upon microglial activation with lipopolysaccharide and IFN-γ. In all cases, agonist-induced signaling was reduced upon coactivation, and in some cases just by coexpression. Also, the blockade of signaling of two receptors in a complex by the action of a given (selective) receptor antagonist (cross-antagonism) was often observed. Differential expression of the complexes was observed in the striatum under parkinsonian conditions and especially in animals rendered dyskinetic by levodopa treatment. The negative modulation of calcium mobilization (mediated by AT1R activation), the multiplicity of possibilities on RAS affecting the MAPK pathway, and the disbalanced expression of heteromers in dyskinesia yield new insight into the operation of the RAS system, how it becomes unbalanced, and how a disbalanced RAS can be rebalanced. Furthermore, RAS components in activated microglia warrant attention in drug-development approaches to address neurodegeneration.

Unravelling the Dermatological Potential of the Brown Seaweed Carpomitra costata

The ever-increasing interest in keeping a young appearance and healthy skin has leveraged the skincare industry. This, coupled together with the increased concern regarding the safety of synthetic products, has boosted the demand for new and safer natural ingredients. Accordingly, the aim of this study was to evaluate the dermatological potential of the brown seaweed Carpomitra costata. The antioxidant, anti-enzymatic, antimicrobial, photoprotective and anti-inflammatory properties of five C. costata fractions (F1-F5) were evaluated. The ethyl acetate fraction (F3) demonstrated the most promising results, with the best ability to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals (EC50 of 140.1 µg/mL) and the capacity to reduce reactive oxygen species (ROS) production promoted by UVA and UVB radiation in 3T3 cells, revealing its antioxidant and photoprotective potential. This fraction also exhibited the highest anti-enzymatic capacity, inhibiting the activities of collagenase, elastase and tyrosinase (IC50 of 7.2, 4.8 and 85.9 µg/mL, respectively). Moreover, F3 showed anti-inflammatory potential, reducing TNF-α and IL-6 release induced by LPS treatment in RAW 264.7 cells. These bioactivities may be related to the presence of phenolic compounds, such as phlorotannins, as demonstrated by NMR analysis. The results highlight the potential of C. costata as a source of bioactive ingredients for further dermatological applications.

Unravelling the Dermatological Potential of the Brown Seaweed Carpomitra costata

The ever-increasing interest in keeping a young appearance and healthy skin has leveraged the skincare industry. This, coupled together with the increased concern regarding the safety of synthetic products, has boosted the demand for new and safer natural ingredients. Accordingly, the aim of this study was to evaluate the dermatological potential of the brown seaweed Carpomitra costata. The antioxidant, anti-enzymatic, antimicrobial, photoprotective and anti-inflammatory properties of five C. costata fractions (F1–F5) were evaluated. The ethyl acetate fraction (F3) demonstrated the most promising results, with the best ability to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals (EC50 of 140.1 µg/mL) and the capacity to reduce reactive oxygen species (ROS) production promoted by UVA and UVB radiation in 3T3 cells, revealing its antioxidant and photoprotective potential. This fraction also exhibited the highest anti-enzymatic capacity, inhibiting the activities of collagenase, elastase and tyrosinase (IC50 of 7.2, 4.8 and 85.9 µg/mL, respectively). Moreover, F3 showed anti-inflammatory potential, reducing TNF-α and IL-6 release induced by LPS treatment in RAW 264.7 cells. These bioactivities may be related to the presence of phenolic compounds, such as phlorotannins, as demonstrated by NMR analysis. The results highlight the potential of C. costata as a source of bioactive ingredients for further dermatological applications.

Mas receptor activation attenuates allergic airway inflammation via inhibiting JNK/CCL2-induced macrophage recruitment

BACKGROUND

Defective absorption of acute allergic airway inflammation is involved in the initiation and development of chronic asthma. After allergen exposure, there is a rapid recruitment of macrophages around the airways, which promote acute inflammatory responses. The Ang-(1-7)/Mas receptor axis reportedly plays protective roles in various tissue inflammation and remodeling processes in vivo. However, the exact role of Mas receptor and their underlying mechanisms during the pathology of acute allergic airway inflammation remains unclear.

OBJECTIVE

We investigated the role of Mas receptor in acute allergic asthma and explored its underlying mechanisms in vitro, aiming to find critical molecules and signal pathways.

METHODS

Mas receptor expression was assessed in ovalbumin (OVA)-induced acute asthmatic murine model. Then we estimated the anti-inflammatory role of Mas receptor in vivo and explored expressions of several known inflammatory cytokines as well as phosphorylation levels of MAPK pathways. Mas receptor functions and underlying mechanisms were studied further in the human bronchial epithelial cell line (16HBE).

RESULTS

Mas receptor expression decreased in acute allergic airway inflammation. Multiplex immunofluorescence co-localized Mas receptor and EpCAM, indicated that Mas receptor may function in the bronchial epithelium. Activating Mas receptor through AVE0991 significantly alleviated macrophage infiltration in airway inflammation, accompanied with down-regulation of CCL2 and phosphorylation levels of MAPK pathways. Further studies in 16HBE showed that AVE0991 pre-treatment inhibited LPS-induced or anisomycin-induced CCL2 increase and THP-1 macrophages migration via JNK pathways.

CONCLUSION

Our findings suggested that Mas receptor activation significantly attenuated CCL2 dependent macrophage recruitments in acute allergic airway inflammation through JNK pathways, which indicated that Mas receptor, CCL2 and phospho-JNK could be potential targets against allergic airway inflammation.

Angiotensin-(1-7) treatment blocks lipopolysaccharide-induced organ damage, platelet dysfunction, and IL-6 and nitric oxide production in rats

Sepsis can lead to shock, multiple organ failure, and even death. Platelets play an active role in the pathogenesis of sepsis-induced multiple organ failure. Angiotensin (Ang)-(1–7), a biologically active peptide, counteracts various effects of Ang II and attenuates inflammatory responses, reactive oxygen species production, and apoptosis. We evaluated the effects of Ang-(1–7) on organ injury and platelet dysfunction in rats with endotoxaemia. We treated male Wistar rats with saline or lipopolysaccharide (LPS, 10 mg, intravenously) then Ang-(1–7) (1 mg/kg, intravenous infusion for 3 h beginning 30 min after LPS administration). We analysed several haemodynamic, biochemical, and inflammatory parameters, as well as platelet counts and aggregation. Ang-(1–7) improved hypotension and organ dysfunction, and attenuated plasma interleukin-6, chemokines and nitric oxide production in rats after LPS administration. The LPS-induced reduction in platelet aggregation, but not the decreased platelet count, was restored after Ang-(1–7) treatment. The protein expression of iNOS and IκB, but not phosphorylated ERK1/2 and p38, was diminished in Ang-(1–7)-treated LPS rats. The histological changes in liver and lung were significantly attenuated in Ang-(1–7)-treated LPS rats. Our results suggest that Ang-(1–7) ameliorates endotoxaemic-induced organ injury and platelet dysfunction, likely through the inhibition of the inflammatory response and nitric oxide production.

Angiotensin-(1-7) attenuates collagen-induced arthritis via inhibiting oxidative stress in rats

The present study was designed to investigate the anti-rheumatic effects and the mechanism of angiotensin (Ang)-(1-7) in rat models with collagen-induced arthritis (CIA). The CIA model was established using male Wistar rats by intradermal injection of bovine collagen-II in complete Freund's adjuvant at the base of the tail. The levels of angiotensin converting enzyme 2 (ACE2)/Ang-(1-7)/Mas receptor (MasR) were reduced in CIA rats. The attenuation of paw swelling and arthritis scores and improvement of indexes of spleen and thymus were done by Ang-(1-7) injection in CIA rats. The increased levels of inflammatory cytokines, such as interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ in the serum and hind paw were blocked by Ang-(1-7) administration. In addition, enhanced NADPH oxidase (Nox) activity, increased levels of superoxide anions and malondialdehyde (MDA), and weakened superoxide dismutase (SOD) activity, were all reversed by treatment with Ang-(1-7). Nox1 overexpression reversed the suppressing effects of Ang-(1-7) on paw swelling and arthritis scores in CIA rats. The Ang-(1-7)-induced improvement in spleen and thymus indexes in CIA rats was abolished by Nox1 overexpression. Nox1 overexpression reversed the inhibitory effects of Ang-(1-7) by increasing IL-1β, IL-6, TNF-α, and IFN-γ levels in the serum and hind paw of CIA rats. These results demonstrated that Nox1 increased the oxidative stress in arthritis, and Ang-(1-7) improved rheumatism in arthritis via inhibiting oxidative stress.

FoxO1 regulates TLR4/MyD88/MD2-NF-κB inflammatory signalling in mucosal barrier injury of inflammatory bowel disease

In this study, FoxO1 transgenic mice (transgenic, FoxO1-Tg) and C57BL/6 wild-type (wild-type, FoxO1-WT) mice were used to establish chronic colitis by drinking water containing dextran sulphate sodium (DSS). Afterwards, we observed the life changes in mice and assessed the pathological changes by H&E tissue staining. In addition, the TLR4/MyD88/MD2-NF-κB inflammatory signals were detected. As a result, under DSS treatment, the activation level of TLR4/MyD88/MD2-NF-κB inflammatory signal was higher in FoxO1-Tg mice than that in FoxO1-WT mice. Meanwhile, the intestinal mucosal tissue damage was more severe, the down-regulation of tight junction protein level was more significant and the life quality was decreased to a higher degree in FoxO1-Tg mice compared with those in FoxO1-WT mice. Caco-2 cells were used to mimic the intestinal mucosal barrier model for in vitro assays. In addition, lentiviral packaging FoxO1 overexpressing plasmid was transfected into Caco-2 cells for FoxO1 overexpression. TNF-α intervention was performed for intestinal mucosal inflammatory response model. Consequently, the down-regulation of FoxO1 inhibited the activation of TLR4/MyD88/MD2-NF-κB inflammatory signal, decreased the mucosal barrier permeability and up-regulated the expression of tight junction protein. By contrast, the overexpression of FoxO1 increased the mucosal barrier permeability and down-regulated the level of tight junction protein.

Anti-inflammatory activity of a water-soluble polysaccharide from the roots of purple sweet potato

In this study, a water-soluble polysaccharide was isolated from purple sweet potato roots. The in vitro and in vivo anti-inflammatory effects of the polysaccharide were evaluated by lipopolysaccharide (LPS)-induced inflammatory RAW264.7 macrophages and mice, respectively. The in vitro anti-inflammatory assay showed that the polysaccharide could effectively inhibit the overproduction of nitric oxide and pro-inflammatory cytokines (TNF-α, IL-1β, IL-6) while increasing the secretion of anti-inflammatory cytokine (IL-10). The in vivo anti-inflammatory assay revealed that mice administered with the polysaccharide showed higher IL-10, SOD, and T-AOC levels but lower TNF-α, IL-1β, IL-6 and MDA levels as compared to the LPS-treated model. Meanwhile, mice administered with the polysaccharide showed increased abundance of Lachnospiraceae, Lactobacillales and Parabacteroides but decreased amounts of Psychrobacter and Staphylococcus as compared to the LPS model group. Moreover, mice administered with polysaccharide showed enhanced production of short chain fatty acids by gut microbiota in the lipopolysaccharide-induced inflammatory mice. Our results suggested that the water-soluble polysaccharide from purple sweet potato roots could be utilized as a novel anti-inflammatory agent.

A water-soluble polysaccharide from purple sweet potato roots played anti-inflammatory roles by regulating inflammatory cytokines, gut microbiota and antioxidant defense system.

Renin-angiotensin system in osteoarthritis: A new potential therapy

Osteoarthritis (OA) is one of the most common chronic joint diseases. However, the mechanism remains unclear. The traditional renin-angiotensin system (RAS) is an important system for regulating homeostasis and controlling balance. In recent years, RAS-related components have played an important role in the occurrence of OA. The purpose of this review is to summarize the research results of RAS-related components that are associated with OA. This study systematically searched e-medical databases such as PubMed, Embase, Medline, and Web of Science. The search targets included English publications describing the effects of RAS-related components in OA, including the role of renin, angiotensin-converting enzyme (ACE), Angiotensin II (Ang II), and angiotensin receptor (ATR). Additionally, this study summarizes the potential pathways for RAS-related components to intervene in OA. This study found that RAS-related components including renin, ACE, Ang II, AT1R and AT2R are involved in inflammation and chondrocyte hypertrophy in OA. RAS is involved in signaling pathways including the NF-κB, JNK, VEGFR/Tie-2, and the Axna2/Axna2R axis ones, which may be potential targets for the treatment of OA. Although there are few studies on RAS in the field of OA, the pathogenic effect of RAS-related components is still an important topic in OA treatment, and great progress may be made in this aspect in future studies.