Anti-inflammatory Effect of Isaria sinclairii Glycosaminoglycan in an Adjuvant-treated Arthritis Rat Model

Soluble syndecan-3 binds chemokines, reduces leukocyte migration in vitro and ameliorates disease severity in models of rheumatoid arthritis

Background

Syndecans are heparan sulfate proteoglycans that occur in membrane-bound or soluble forms. Syndecan-3, the least well-characterised of the syndecan family, is highly expressed on synovial endothelial cells in rheumatoid arthritis patients. Here, it binds pro-inflammatory chemokines with evidence for a role in chemokine presentation and leukocyte trafficking into the joint, promoting the inflammatory response. In this study, we explored the role of soluble syndecan-3 as a binder of chemokines and as an anti-inflammatory and therapeutic molecule.

Methods

A human monocytic cell line and CD14+ PBMCs were utilised in both Boyden chamber and trans-endothelial migration assays. Soluble syndecan-3 was tested in antigen-induced and collagen-induced in vivo arthritis models in mice. ELISA and isothermal fluorescence titration assays assessed the binding affinities. Syndecan-3 expression was identified by flow cytometry and PCR, and levels of shedding by ELISA.

Results

Using in vitro and in vivo models, soluble syndecan-3 inhibited leukocyte migration in vitro in response to CCL7 and its administration in murine models of rheumatoid arthritis reduced histological disease severity. Using isothermal fluorescence titration, the binding affinity of soluble syndecan-3 to inflammatory chemokines CCL2, CCL7 and CXCL8 was determined, revealing little difference, with K_ds in the low nM range. TNFα increased cell surface expression and shedding of syndecan-3 from cultured human endothelial cells. Furthermore, soluble syndecan-3 occurred naturally in the sera of patients with rheumatoid arthritis and periodontitis, and its levels correlated with syndecan-1.

Conclusions

This study shows that the addition of soluble syndecan-3 may represent an alternative therapeutic approach in inflammatory disease.

Electronic supplementary material

The online version of this article (10.1186/s13075-019-1939-2) contains supplementary material, which is available to authorized users.

Diphlorethohydroxycarmalol Attenuates Fine Particulate Matter-Induced Subcellular Skin Dysfunction

The skin, the largest organ in humans, is exposed to major sources of outdoor air pollution, such as fine particulate matter with a diameter ≤ 2.5 µm (PM_2.5). Diphlorethohydroxycarmalol (DPHC), a marine-based compound, possesses multiple activities including antioxidant effect. In the present study, we evaluated the protective effect of DPHC on PM_2.5-induced skin cell damage and elucidated the underlying mechanisms in vitro and in vivo. The results showed that DPHC blocked PM_2.5-induced reactive oxygen species generation in human keratinocytes. In addition, DPHC protected cells against PM_2.5-induced DNA damage, endoplasmic reticulum stress, and autophagy. HR-1 hairless mice exposed to PM_2.5 showed lipid peroxidation, protein carbonylation, and increased epidermal height, which were inhibited by DPHC. Moreover, PM_2.5 induced apoptosis and mitogen-activated protein kinase (MAPK) protein expression; however, these changes were attenuated by DPHC. MAPK inhibitors were used to elucidate the molecular mechanisms underlying these actions, and the results demonstrated that MAPK signaling pathway may play a key role in PM_2.5-induced skin damage.

Cow-to-mouse fecal transplantations suggest intestinal microbiome as one cause of mastitis

BACKGROUND

Mastitis, which affects nearly all lactating mammals including human, is generally thought to be caused by local infection of the mammary glands. For treatment, antibiotics are commonly prescribed, which however are of concern in both treatment efficacy and neonate safety. Here, using bovine mastitis which is the most costly disease in the dairy industry as a model, we showed that intestinal microbiota alone can lead to mastitis.

RESULTS

Fecal microbiota transplantation (FMT) from mastitis, but not healthy cows, to germ-free (GF) mice resulted in mastitis symptoms in mammary gland and inflammations in serum, spleen, and colon. Probiotic intake in parallel with FMT from diseased cows led to relieved mastitis symptoms in mice, by shifting the murine intestinal microbiota to a state that is functionally distinct from either healthy or diseased microbiota yet structurally similar to the latter. Despite conservation in mastitis symptoms, diseased cows and mice shared few mastitis-associated bacterial organismal or functional markers, suggesting striking divergence in mastitis-associated intestinal microbiota among lactating mammals. Moreover, an "amplification effect" of disease-health distinction in both microbiota structure and function was apparent during the cow-to-mouse FMT.

CONCLUSIONS

Hence, dysbiosis of intestinal microbiota may be one cause of mastitis, and probiotics that restore intestinal microbiota function are an effective and safe strategy to treat mastitis.

Anti-Obesity Effect of Bombus ignitus Queen Glycosaminoglycans in Rats on a High-Fat Diet

The mechanism of functional insect glycosaminoglycan (GAG) on obesity caused a high fat diet has not yet been elucidated. Therefore, insect glycosaminoglycans derived from Isaria sinclairii, Bombus ignitus (a type of bumblebee) queen, and Gryllus bimaculatus were purified and investigated as a potential functional food. 14-week old male Wistar rats were fed a high-fat diet (HFD) for 6 weeks. There were five groups that received daily intraperitoneal administration of phosphate buffered saline (PBS, control), GbG (GAG from Gryllus bimaculatus) 10 mg/kg, ISG (GAG from Isaria sinclairii) 10 mg/kg, IQG (GAG from Bombus ignites) 10 mg/kg, or Pravastatin (2 mg/kg). All treatments were performed for one month. IQG produced a potential anti-inflammatory effect with the inhibition of c-reactive protein and sero-biochemical parameters of phospholipids and free fatty acids indicative of an anti-hyperlipidemic effect. Abdominal and epididymidal fat weight were reduced in conjunction with a mild increase in body weight. The level of laminin in HMVEC-C cells or fibronectin in HFD rat hepatocytes was significantly affected by these GAG treatments, which regulated adipogenesis and adipocyte function. Compared to the control rats, IQG-treated rats displayed up-regulation of 87 genes (test:control ratio >2.0) including fatty acid synthase and 3-hydroxy-3-methylglutaryl-coenzyme A reductase, with the down-regulation of 47 genes including the uridine diphosphate (UDP) glycosyltransferase 2 families, polypeptidase B, and insulin-like growth factor binding protein 1. The data suggest that IQG could potentially prevent or treat fatty liver or hyperlipidemia.

Heme oxygenase 1-mediated novel anti-inflammatory activities of Salvia plebeia and its active components

ETHNOPHARMACOLOGICAL RELEVANCE

Salvia plebeia R. Br. (SP) has been widely used as a traditional folk medicine for the treatment of infectious diseases and pain. An anti-inflammatory potential of SP has remains largely unknown.

AIM OF THE STUDY

We tried to elucidate the principle mechanism and the active ingredients underlying the anti-inflammatory activities of SP.

MATERIALS AND METHODS

We investigated the protective activities of SP methanolic extract (SPME) and seven representative ingredients against inflammation. Quantitative analysis using HPLC-DAD-ESI/MS was conducted to determine the relative amounts of these seven active ingredients in SPME. Both in vitro murine macrophages and in vivo mouse models were employed to elucidate SP- and active ingredient-mediated anti-inflammatory effects.

RESULTS

SPME significantly reduced inflammatory processes both in vivo in a TPA-induced ear edema model and in vitro in lipopolysaccharide (LPS)-activated macrophages. SPME decreased the release of nitric oxide (NO) and prostaglandin E2 (PGE2) and expression of inducible nitric oxide synthase (iNOS). Seven active components (luteoloside (C1), nepitrin (C2), homoplantagenin (C3), luteolin (C4), nepetin (C5), hispidulin (C6), and eupatorin (C7)) of SPME were analyzed and their relative concentrations were determined, demonstrating that C2, C3, C5 and C6 were present in higher amounts than were C1, C4, and C7. These major compounds inhibited NO and PGE2 production, and iNOS and COX-II protein expression through heme oxygenase-1 (HO-1) induction via activation of nuclear factor erythroid 2-related factor2 (Nrf2).

CONCLUSION

Our data demonstrate that SPME possesses potent in vitro and in vivo anti-inflammatory activities. Nepetin and hispidulin, and their glycosides are the major active compounds in SPME, and their effects are mediated by Nrf2/HO-1 signaling. Taken together, we propose that SPME and its active ingredients may serve as novel therapeutic candidates for diseases associated with excessive inflammation.

FTY720 induces autophagy-related apoptosis and necroptosis in human glioblastoma cells

FTY720 is a potent immunosuppressant which has preclinical antitumor efficacy in various cancer models. However, its role in glioblastoma remains unclear. In the present study, we found that FTY720 induced extrinsic apoptosis, necroptosis and autophagy in human glioblastoma cells. Inhibition of autophagy by either RNA interference or chemical inhibitors attenuated FTY720-induced apoptosis and necrosis. Furthermore, autophagy, apoptosis and necrosis induction were dependent on reactive oxygen species-c-Jun N-terminal kinase-protein 53 (ROS-JNK-p53) loop mediated phosphatidylinositide 3-kinases/protein kinase B/mammalian target of rapamycin/p70S6 kinase (PI3K/AKT/mTOR/p70S6K) pathway. In addition, receptor-interacting protein 1 and 3 (RIP1 and RIP3) served as an upstream of ROS-JNK-p53 loop. However, the phosphorylation form of FTY720 induced autophagy but not apoptosis and necroptosis. Finally, the in vitro results were validated in vivo in xenograft mouse of glioblastoma cells. In conclusion, the current study provided novel insights into understanding the mechanisms and functions of FTY720-induced apoptosis, necroptosis and autophagy in human glioblastoma cells.

Antioxidant and angiostatic effect of Spirulina platensis suspension in complete Freund's adjuvant-induced arthritis in rats

Background

Currently, natural products have built a well-recognized role in the management of many degenerative diseases, mainly rheumatoid arthritis. Recent studies suggest that Spirulina, a unicellular blue-green alga, may have a variety of health benefits and curative properties and is also competent of acting as an anti-inflammatory, antioxidant and recently anti-angiogenic agent. In the present study, the antioxidant and the immunomodulatory effect of Spirulina platensis as well as its anti-angiogenic effect against complete Freund's adjuvant-induced arthritis (AIA) in rat model were tested.

Results

We found that the development of arthritis was concealed; moreover it successfully inhibited the development of macroscopic as well as microscopic and histopathological lesions in AIA rats when compared to control. Spirulina treated group showed a higher survival rate and moreover, it reduced the clinical score of RA in a dose dependent manner. Furthermore, Spirulina decreased serum levels of COX-2, TNF-α, IL-6, TBARS, VEGF and increased serum levels of GSH compared to the RA non-treated group.

Conclusions

The present study concluded that Spirulina is able to restrain the changes produced through adjuvant-induced arthritis. The suppressing effect of Spirulina could be attributed, at least in part, to anti-inflammatory, antioxidant and anti-angiogenic properties.