AhR activation promotes Treg cell generation by enhancing Lkb1-mediated fatty acid oxidation via the Skp2/K63-ubiquitination pathway.

Several aryl hydrocarbon receptor (AhR) agonists have been reported to promote the generation of regulatory T cells (Treg cells), and the action mechanisms need to be identified. In this study, we addressed the underlying mechanism of AhR activation to induce the generation of Treg cells in the view of cellular metabolism. Naïve CD4+ T cells were purified with mouse CD4+ CD62L+ T Cells Isolation Kits. The proportions of Treg cells were detected by flow cytometry. The value of oxygen consumption rate (OCR) of CD4+ T cells was detected by the Seahorse XFe 96 analyzer. The activation of fatty acid oxidation (FAO)-related metabolic pathways was detected by Western blotting. Intracellular localization of Lkb1 was detected by immunofluorescence. The Strad-Mo25-Lkb1 complex formation and K63 chain ubiquitination modification of Lkb1 were detected by co-immunoprecipitation. The binding of AhR to the Skp2 promoter was detected by constructing luciferase reporter gene. AhR or carnitine palmitoyltransferases 1 was knockdown in dextran sulphate sodium (DSS)-induced colitis or collagen-induced arthritis (CIA) mice by infecting mice with adeno-associated virus via the tail vein injection. Compared to the control group, exogenous and endogenous AhR agonists 3,3'-diindolylmethane (DIM) and 2-(1'H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE) were shown to preferentially upregulate the mRNA expression of FAO-related enzymes and the value of OCR. Consistently, pharmacological or genetic inhibition of FAO markedly diminished the induction of DIM and ITE on the differentiation of Treg cells. DIM and ITE functioned mainly through activating the liver kinase B1 (Lkb1)-AMPK pathway via promotion of Lkb1-Strad-Mo25 complex formation and Lkb1 K63 ubiquitination. DIM and ITE were also shown to upregulate the mRNA expression of Skp2, a ubiquitination-related enzyme, and facilitate the binding of AhR to the xenobiotic responsive element of Skp2 promoter region by luciferase reporter gene assay. Furthermore, the contribution of Skp2/K63 ubiquitination/Lkb1/FAO axis was verified in (DSS)-induced colitis or CIA mice. In summary, these findings indicate that AhR activation promotes Treg cell generation by enhancing Lkb1-mediated FAO via the Skp2/K63-ubiquitination pathway, and AhR agonists may be used as inducers of Treg cells to prevent and treat autoimmune diseases.

Norisoboldine induces the development of Treg cells by promoting fatty acid oxidation-mediated H3K27 acetylation of Foxp3.

Norisoboldine (NOR), an alkaloid isolated from Radix Lindera, was previously reported to promote the differentiation of regulatory T cells (Treg cells), an important subtype of lymphocytes capable of controlling autoimmune diseases. The present study was performed to explore the mechanism of NOR in the view of cellular metabolism. A global metabolomic analysis indicated that NOR preferentially altered the fatty acid oxidation (FAO) pathway and elevated the content of related metabolites during Treg cell differentiation. The detection of oxygen consumption rate (OCR) and mRNA expression of FAO-related enzymes demonstrated that NOR promoted FAO in the early stage of Treg cell differentiation. Consistently, pharmacological or genetic inhibition of FAO markedly diminished the induction of NOR on Treg cell differentiation. Furthermore, NOR was shown to elevate the level of acetyl-CoA derived from FAO and acetylation of lysine 27 on histone 3 (H3K27) at the Foxp3 promoter and CNS2 regions. A knockdown of CPT1, the rate-limiting enzyme of FAO, weakened the promotion of NOR on the development, acetyl-CoA level, and acetylation of H3K27 of Treg cells in vitro and in the mice with collagen-induced arthritis, and attenuated the anti-arthritic effect of NOR. These findings demonstrate that NOR induces the development of Treg cells through promoting FAO, therefore, facilitating gene transcription of Foxp3 via acetyl-CoA-mediated H3K27 acetylation modification, and FAO might serve as a novel target to induce Treg cell development.

Tetrandrine, an immunosuppressive alkaloid isolated from Steohania tetrandra S. Moore, induces the generation of Treg cells through enhancing fatty acid oxidation.

Our previous studies have demonstrated that tetrandrine can induce the generation of regulatory T (Treg) cells in vitro and in vivo. But, the underlying mechanism of tetrandrine remains obscure. Naïve CD4+ T cells are isolated from the mesenteric lymph nodes of mice for the differentiation of Treg cells. Flow cytometry is used to detect the frequencies of Treg cells. Non-targeted metabolomics analysis based on UHPLC-QTOF/MS is performed to assess the intracellular metabolic profiles. ChIP-PCR analysis is conducted to detect the level of H3K27ac at Foxp3 promoter and CNS regions. Tetrandrine treatment alters the metabolic profile of Treg cells, and pathway enrichment of differential metabolites mainly involves fatty acid oxidation (FAO). Tetrandrine promotes the mRNA expression of carnitine palmitoyl transferase-1, and increases the level of acetyl coenzyme A (acetyl-CoA) and the intracellular oxygen consumption rate. Either CPT1 inhibitor (etomoxir) or siRNA markedly diminishes the promotion of tetrandrine on Treg cell differentiation. Furthermore, tetrandrine enhances the acetylation of H3K27 in the promoter and CNS1 regions of Foxp3 through the acetyl-CoA derived from FAO. In the mice with collagen-induced arthritis, tetrandrine also induces Treg cell generation through FAO pathway. In addition, tetrandrine enhances the immunosuppressive function of Treg cells both in vitro and in vivo. The findings indicate that tetrandrine promotes Treg cell differentiation by enhancing FAO-mediated Foxp3 acetylation, and the CPT1-mediated FAO can serve as the target for the discovery of novel inducers of Treg cell generation.

Tetrandrine attenuates intestinal epithelial barrier defects caused by colitis through promoting the expression of Occludin via the AhR-miR-429 pathway.

The elevated intestinal permeability due to mucosal barrier defects is not only secondary to inflammatory bowel disease but also precedes enteritis. Tetrandrine, a bisbenzyl isoquinoline alkaloid isolated from the dried roots of Stephamis tetlandra S. Moor, was previously demonstrated to ameliorate colitis induced by dextran sulfate sodium (DSS) in mice. Here, we investigate whether and how tetrandrine protects against the disruption of the intestinal epithelial barrier under colitis condition. The data show that oral administration of tetrandrine significantly counteracted the increase of intestinal permeability in DSS-treated mice, enhanced the mRNA and protein expression of Occludin and Claudin1 in the colon, but hardly affected the expression of ZO-1 and Mucin2. In vitro, tetrandrine treatment rescued the decrease of monolayer transmembrane resistance and the increase of epithelial cell permeability induced by TNF-α, upregulated the expression of Occludin, and downregulated the expression of Claudin1 but did not affect the expression of ZO-1. The siRNA of Occludin largely weakened the protective effect of tetrandrine on the epithelial barrier function in Caco-2 cells. MiR-429 mimic obviously counteracted the upregulation of tetrandrine on the expression of Occludin and the amelioration on epithelial barrier defects, in contrast, miR-429 inhibitor showed the opposite effects. The antagonist (CH223191) and siAhR of aryl hydrocarbon receptor (AhR) nearly completely diminished the effects of tetrandrine, including inhibition of the miR429 expression, the upregulation of Occludin expression, and amelioration of intestinal epithelial barrier defects in Caco-2 cells. In colitis mice, CH223191 significantly weakened the protective effect of tetrandrine on colitis and intestinal mucosal barrier and diminished the downregulation on miR-429 expression and the promotion on Occludin expression in the colon. In summary, tetrandrine can attenuate the intestinal epithelial barrier defects in colitis through promoting Occludin expression via the AhR/miR-429 pathway, and it might be used to treat colitis as a barrier protector.

Age-dependent alterations in the coordinated development of subcortical regions in adolescents with social anxiety disorder.

Subcortical brain regions play essential roles in the pathology of social anxiety disorder (SAD). While adolescence is the peak period of SAD, the relationships between altered development of the subcortical regions during this period and SAD are still unclear. This study investigated the age-dependent alterations in structural co-variance among subcortical regions and between subcortical and cortical regions, aiming to reflect aberrant coordination during development in the adolescent with SAD. High-resolution T1-weighted images were obtained from 76 adolescents with SAD and 67 healthy controls (HC), ranging from 11 to 17.9 years. Symptom severity was evaluated with the Social Anxiety Scale for Children (SASC) and the Depression Self Rating Scale for Children (DSRS-C). Structural co-variance and sliding age-window analyses were used to detect age-dependent group differences in inter-regional coordination patterns among subcortical regions and between subcortical and cortical regions. The volume of the striatum significantly correlated with SAD symptom severity. The SAD group exhibited significantly enhanced structural co-variance among key regions of the striatum (putamen and caudate). While the co-variance decreased with age in healthy adolescents, the co-variance in SAD adolescents stayed high, leading to more apparent group differences in middle adolescence. Moreover, the striatum's mean structural co-variance with cortical regions decreased with age in HC but increased with age in SAD. Adolescents with SAD suffer aberrant developmental coordination among the key regions of the striatum and between the striatum and cortical regions. The degree of incoordination is age-dependent, which may represent a neurodevelopmental trait of SAD.

Phytoestrogen arctigenin preserves the mucus barrier in inflammatory bowel diseases by inhibiting goblet cell apoptosis via the ERß/TRIM21/PHB1 pathway.

Intestinal mucus barrier dysfunction is closely involved in the pathogenesis of inflammatory bowel diseases (IBD). To investigate the protective effect and underlying mechanism of arctigenin, a phytoestrogen isolated from the fruits of Arctium lappa L., on the intestinal mucus barrier under colitis condition. The role of arctigenin on the intestinal mucus barrier and the apoptosis of goblet cells were examined by using both in vitro and in vivo assays. Arctigenin was demonstrated to promote the mucus secretion and maintain the integrity of mucus barrier, which might be achieved by an increase in the number of goblet cells via inhibiting apoptosis. Arctigenin selectively inhibited the mitochondrial pathway-mediated apoptosis. Moreover, arctigenin elevated the protein level of prohibitin 1 (PHB1) through blocking the ubiquitination via activation of estrogen receptor ß (ERß) to competitively interact with PHB1 and disrupt the binding of tripartite motif 21 (TRIM21) with PHB1. ERß knock down in the colons of mice with DSS-induced colitis resulted in significant reduction of the protection of arctigenin and DPN against the mucosal barrier. Arctigenin can maintain the integrity of the mucus barrier by inhibiting the apoptosis of goblet cells through the ERß/TRIM21/PHB1 pathway.

Pharmacological activation of ERß by arctigenin maintains the integrity of intestinal epithelial barrier in inflammatory bowel diseases.

Intestinal epithelial barrier dysfunction is deeply involved in the pathogenesis of inflammatory bowel diseases (IBD). Arctigenin, the main active constituent in Fructus Arctii (a traditional Chinese medicine), has previously been found to attenuate colitis induced by dextran sulfate sodium (DSS) in mice. The present study investigated whether and how arctigenin protects against the disruption of the intestinal epithelial barrier in IBD. Arctigenin maintained the intestinal epithelial barrier function of mice with DSS- and TNBS-induced colitis. In Caco-2 and HT-29 cells, arctigenin lowered the monolayer permeability, increased TEER, reversed the abnormal expression of tight junction proteins, and restored the altered localization of F-actin induced by TNF-α and IL-1ß. The specific antagonist PHTPP or shRNA of ERß largely weakened the protective effect of arctigenin on the epithelial barrier function of Caco-2 and HT-29 cells. Molecular docking demonstrated that arctigenin had high affinity for ERß mainly through hydrogen bonds as well as hydrophobic effects, and the protective effect of arctigenin on the intestinal barrier function was largely diminished in ERß-mutated (ARG346 and/or GLU305) Caco-2 cells. Moreover, arctigenin-blocked TNF-α induced increase of the monolayer permeability in Caco-2 and HT-29 cells and the activation of myosin light chain kinase (MLCK)/myosin light chain (MLC) pathway in an ERß-dependent manner. ERß deletion in colons of mice with DSS-induced colitis resulted in a significant attenuation of the protective effect of arctigenin on the barrier integrity and colon inflammation. Arctigenin maintained the integrity of the intestinal epithelial barrier under IBD by upregulating the expression of tight junction proteins through the ERß-MLCK/MLC pathway.

Synthesis of norisoboldine derivatives and bioactivity assay for inducing the generation of regulatory T cells.

In this study, we used chemical modification to improve the pharmacological activity of norisoboldine (NOR). A new NOR-benzoic acid derivative, named DC-01, showed more potent induction of Treg cell differentiation than NOR. The in vitro effective concentration of DC-01 (1 µM) is about an order of magnitude lower than that of NOR (10 µM). DC-01 (28, 56 mg/kg) showed better amelioration of dextran sodium sulfate-induced colitis in mice than NOR (20, 40 mg/kg), and DC-01 (28 mg/kg) increased the number of Treg cells slightly better than NOR (20 mg/kg). In summary, DC-01 exerts more potent induction of Treg cell generation, which might be a candidate drug for the treatment of inflammation- and immune-related diseases.

Oral administration of curcumin ameliorates pulmonary fibrosis in mice through 15d-PGJ2-mediated induction of hepatocyte growth factor in the colon.

Oral administration of curcumin has been shown to inhibit pulmonary fibrosis (PF) despite its extremely low bioavailability. In this study, we investigated the mechanisms underlying the anti-PF effect of curcumin in focus on intestinal endocrine. In bleomycin- and SiO2-treated mice, curcumin (75, 150 mg· kg-1 per day) exerted dose-dependent anti-PF effect when administered orally or rectally but not intravenously, implying an intestinal route was involved in the action of curcumin. We speculated that curcumin might promote the generation of gut-derived factors and the latter acted as a mediator subsequently entering the lungs to ameliorate fibrosis. We showed that oral administration of curcumin indeed significantly increased the expression of gut-derived hepatocyte growth factor (HGF) in colon tissues. Furthermore, in bleomycin-treated mice, the upregulated protein level of HGF in lungs by oral curcumin was highly correlated with its anti-PF effect, which was further confirmed by coadministration of c-Met inhibitor SU11274. Curcumin (5-40 µM) dose-dependently increased HGF expression in primary mouse fibroblasts, macrophages, CCD-18Co cells (fibroblast cell line), and RAW264.7 cells (monocyte-macrophage cell line), but not in primary colonic epithelial cells. In CCD-18Co cells and RAW264.7 cells, curcumin dose-dependently activated PPARγ and CREB, whereas PPARγ antagonist GW9662 (1 µM) or cAMP response element (CREB) inhibitor KG-501 (10 µM) significantly decreased the boosting effect of curcumin on HGF expression. Finally, we revealed that curcumin dose-dependently increased the production of 15-deoxy-Δ12, 14-prostaglandin J2 (15d-PGJ2) in CCD-18Co cells and RAW264.7 cells, which was a common upstream of the two transcription factors. Moreover, both the in vitro and in vivo effects of curcumin were diminished by coadministration of HPGDS-inhibitor-1, an inhibitor of 15d-PGJ2 generation. Together, curcumin promotes the expression of HGF in colonic fibroblasts and macrophages by activating PPARγ and CREB via an induction of 15d-PGJ2, and the HGF enters the lungs giving rise to an anti-PF effect.

Effect and underlying mechanism of morin on the pharmacokinetics of diclofenac sodium in rats.

1. Morin, a natural flavonol, is present in many plants. It has anti-inflammatory and immunomodulatory activities and is often used as an adjuvant treatment for arthritis. Diclofenac sodium is the first-choice drug in the treatment of rheumatoid arthritis. However, the herb-drug interaction (HDI) between morin and diclofenac sodium remains unclear.2. The aim of the present research was to investigate whether and how morin affect the pharmacokinetic profile of diclofenac sodium.3. The enzyme kinetic and pharmacokinetic studies showed that morin significantly accelerated the metabolism and reduced systemic exposure of diclofenac sodium. Interestingly, the effect of morin on the pharmacokinetic profile of diclofenac sodium was not in a dose-dependent manner. Therefore, the effect of morin on P-glycoprotein (P-gp) was further investigated.4. The results implied that the influence mechanism of morin on the pharmacokinetic of diclofenac sodium might be related to CYP2C9 and P-gp. Attention should be paid to the risk of HDI between morin and diclofenac sodium in clinical practice.

The gut microbiota modulator berberine ameliorates collagen-induced arthritis in rats by facilitating the generation of butyrate and adjusting the intestinal hypoxia and nitrate supply.

The commensal microbiota is one of the environmental triggers of rheumatoid arthritis (RA). Recent studies have identified the characteristics of the gut microbiota in patients with RA. However, it is still unclear how the microbiota can be modulated to slow down disease progression. In the present study, berberine, a modulator of gut microbiota with substantial anti-RA effect, was chosen to explore the mechanisms by which the microbiota modulators ameliorate RA. The results showed that oral administration of berberine alleviated collagen-induced arthritis (CIA) in rats in a gut microbiota-dependent manner. Berberine down-regulated the diversity and richness of the gut bacteria, reduced the abundance of Prevotella, and elevated the abundance of butyrate-producing bacteria in CIA rats as determined by the 16S rRNA gene sequence, which might function through limiting the generation of nitrate and stabilizing the physiologic hypoxia in the intestine. Moreover, berberine treatment significantly increased the intestinal butyrate level and promoted the expression and activity of butyryl-CoA:acetate-CoA transferase (BUT). The coadministration of a BUT inhibitor largely diminished the adjustment of intestinal environment and the antiarthritic effect of berberine. In conclusion, modulators of the gut microbiota might serve as therapeutic agents for RA by inducing the butyrate generation through promoting the expression and activity of BUT.-Yue, M., Tao, Y., Fang, Y., Lian, X., Zhang, Q., Xia, Y., Wei, Z., Dai, Y. The gut microbiota modulator berberine ameliorates collagen-induced arthritis in rats by facilitating the generation of butyrate and adjusting the intestinal hypoxia and nitrate supply.

Effects of the ABCB1 and ABCG2 polymorphisms on the pharmacokinetics of afatinib in healthy Chinese volunteers.

1. Afatinib is an oral, selective tyrosine kinase inhibitor (TKI) primarily transported by P-glycoprotein (MDR1, gene code ABCB1) and breast cancer resistance protein (BCRP, gene code ABCG2). In the present study, the effects of ABCB1 and ABCG2 genetic polymorphisms on the pharmacokinetics of afatinib in healthy Chinese were investigated.2. Blood samples from 24 healthy participants who received afatinib were used for genotyping ABCB1 (1236C>T, 2677G > T/A, 3435C>T) and ABCG2 (34G>A, 421C>A) polymorphisms. Subsequently, the association between afatinib plasma concentrations and target single-nucleotide polymorphisms (SNPs) was analyzed.3. Among the five polymorphisms, plasma concentrations of afatinib in healthy subjects with ABCB1 1236CC-3435CC were remarkably higher than in other genotype subjects. No significant differences of afatinib exposure were found between the ABCG2 wild-type and heterozygous groups.4. The ABCB1 genetic polymorphism influenced the plasma exposure of afatinib, and gene testing before drug administration may be useful for clinically individualized use of afatinib. Our data suggest the usefulness of afatinib pharmacogenetics in treatment optimization.

miR-125a-3p inhibits ERα transactivation and overrides tamoxifen resistance by targeting CDK3 in estrogen receptor-positive breast cancer.

Tamoxifen (TAM) is a major adjuvant therapy for patients who are diagnosed with estrogen receptor-α (ER)-positive breast cancer; however, TAM resistance occurs often during treatment and the underlying mechanism is unclear. Here, we report that miR-125a-3p inhibits ERα transcriptional activity and, thus, ER+ breast cancer cell proliferation, which causes cell-cycle arrest at the G1/S stage, inducing apoptosis and suppressing tumor growth by targeting cyclin-dependent kinase 3 (CDK3) in vitro and in vivo. In addition, CDK3 and miR-125a-3p expression levels were measured in 37 cancerous tissues paired with noncancerous samples, and their expression levels were negatively associated with miR-125a-3p level. Of interest, miR-125a-3p level is down-regulated in MCF-7 TAM-resistant (TamR) cells. Of more importance, up-regulation of miR-125a-3p resensitizes MCF-7 TamR cells to TAM, which is dependent on CDK3 expression. These results suggest that miR-125a-3p can function as a novel tumor suppressor in ER+ breast cancer by targeting CDK3, which may be a potential therapeutic approach for TamR breast cancer therapy.-Zheng, L., Meng, X., Li, X., Zhang, Y., Li, C., Xiang, C., Xing, Y., Xia, Y., Xi, T. miR-125a-3p inhibits ERα transactivation and overrides tamoxifen resistance by targeting CDK3 in estrogen receptor-positive breast cancer.

Curcumin attenuates collagen-induced inflammatory response through the "gut-brain axis".

BACKGROUND: Previous studies have demonstrated that oral administration of curcumin exhibited an anti-arthritic effect despite its poor bioavailability. The present study aimed to explore whether the gut-brain axis is involved in the therapeutic effect of curcumin. METHODS: The collagen-induced arthritis (CIA) rat model was induced by immunization with an emulsion of collagen II and complete Freund's adjuvant. Sympathetic and parasympathetic tones were measured by electrocardiographic recordings. Unilateral cervical vagotomy (VGX) was performed before the induction of CIA. The ChAT, AChE activities, and serum cytokine levels were determined by ELISA. The expression of the high-affinity choline transporter 1 (CHT1), ChAT, and vesicular acetylcholine transporter (VAChT) were determined by real-time PCR and immunohistochemical staining. The neuronal excitability of the vagus nerve was determined by whole-cell patch clamp recording. RESULTS: Oral administration of curcumin restored the imbalance between the sympathetic and parasympathetic tones in CIA rats and increased ChAT activity and expression of ChAT and VAChT in the gut, brain, and synovium. Additionally, VGX eliminated the effects of curcumin on arthritis and ACh biosynthesis and transport. Electrophysiological data showed that curcumin markedly increased neuronal excitability of the vagus nerve. Furthermore, selective α7 nAChR antagonists abolished the effects of curcumin on CIA. CONCLUSIONS: Our results demonstrate that curcumin attenuates CIA through the "gut-brain axis" by modulating the function of the cholinergic system. These findings provide a novel approach for mechanistic studies of anti-arthritic compounds with low oral absorption and bioavailability.

Asiaticoside hinders the invasive growth of keloid fibroblasts through inhibition of the GDF-9/MAPK/Smad pathway.

Higher expression of growth differentiation factor-9 (GDF-9) in keloids compared with hypertrophic scars and normal skin tissues has been reported recently. The present study was performed to investigate the role of GDF-9 in keloid pathogenesis, and to elucidate its implication for asiaticoside in the keloid management. The data showed that GDF-9 could enhance the proliferation, migration, and invasion of keloid fibroblasts (KFs), while it only slightly elevated collagen expression, indicating that the effect of GDF-9 was opposite to that of TGF-ß1. The bioactivity difference between GDF-9 and TGF-ß1 could be explained by the different phosphorylated sites on the downstream Smad2/3. Moreover, asiaticoside could inhibit GDF-9-induced activation of MAPKs and Smad pathway in KFs. In conclusion, GDF-9 enhanced the invasive growth of KFs, which was achieved by phosphorylation of Smad 2/3 at the linker region through activation of MAPKs pathway. Asiaticoside hindered the invasive growth of KFs by inhibiting the GDF-9/MAPK/Smad pathway.

The absorption enhancement of norisoboldine in the duodenum of adjuvant-induced arthritis rats involves the impairment of P-glycoprotein.

Lindera aggregata (Sims) Kosterm root has been used in traditional Chinese medicine for the treatment of rheumatism palsy, dyspepsia and frequent urination for a long time. Norisoboldine, the main active constituent of this herb drug, possesses outstanding anti-arthritis activity. However, the in vivo disposition of norisoboldine is known to a limited extent, especially under the pathological condition of rheumatoid arthritis (RA). The aim of this study is to investigate whether and how the absorption of norisoboldine is altered in adjuvant-induced arthritis (AIA) rats. Comparative studies of the intestinal absorption of norisoboldine in normal and AIA rats at different pathological stages of the arthritis were performed using in situ single-pass intestinal perfusion, and the effects of an inhibitor of efflux proteins were also investigated. Norisoboldine was shown to be a substrate of P-glycoprotein (P-gp), as P-gp inhibitor verapamil markedly increased the permeability coefficient (Peff ) of norisoboldine by 88% in the intestine of normal rats. Compared with normal rats, AIA rats displayed increased Peff values of norisoboldine by 84% and 86% on day 5 and day 10 after the appearance of the secondary response of arthritis, respectively. Verapamil could eliminate the difference of intestinal absorption of norisoboldine between normal and AIA rats. Further studies showed that impaired expression and activity of P-gp in AIA rats play a decisive role in the absorption enhancement of norisoboldine. Notably, the impairment of P-gp function positively correlated with the severity of arthritis. Copyright © 2016 John Wiley & Sons, Ltd.

Kinetic study of Reactive Black 5 degradation by Fe2+/S2O82- process via interactive model-based response surface methodology.

This study aimed to kinetically discover optimal conditions on characteristics of Reactive Black 5 decolorization/degradation via ferrous (Fe2+)-activated potassium persulfate (PS). Monod-like kinetics and interactive model-based response surface methodology (RSM) were applied to fitting and predict optimize treatment. Biodegradability of the intermediates was also tested by shaking culture with two species (Proteus hauseri ZMd44 and Shewanella sp. WLP72). Results showed that the optimal degradation efficiency was predicted (through RSM) as pH 3.72, (PS) = 0.39 mM, and (Fe2+) = 0.29 mM. The transformation products (dl-4-hydroxymandelic acid, benzoic acid, benzene, formic acid, oxalic acid and acetic acid) were less toxic than the original dye solution. According to those results, clean-up of dye pollutants by the Fe2+/S2O82- process is feasible as a pre-processing for the biodegradation, and the predicted optimal conditions are meaningful for further industry utilization.

Sinomenine induces the generation of intestinal Treg cells and attenuates arthritis via activation of aryl hydrocarbon receptor.

Sinomenine (SIN), an anti-arthritis drug, has previously been proven to exert immunomodulatory activity in rats by inducing intestinal regulatory T-cells (Treg cells). Here, we assessed the effect of SIN on the generation and function of Treg cells in autoimmune arthritis, and the underlying mechanisms in view of aryl hydrocarbon receptor (AhR). The proportions of Treg cells and IL-17-producing T-cells (Th17 cells) differentiated from naive T-cells were analyzed by flow cytometric analysis. The AhR agonistic effect of SIN was tested by analyzing the activation of downstream signaling pathways and target genes. The dependence of intestinal Treg cell induction and arthritis alleviation by SIN on AhR activation was confirmed in a mouse collagen-induced arthritis (CIA) model. SIN promoted the differentiation and function of intestinal Treg cells in vitro. It induced the expression and activity of AhR target gene, promoted AhR/Hsp90 dissociation and AhR nuclear translocation, induced XRE reporter activity, and facilitated AhR/XRE binding in vitro, displaying the potential to be an agonist of AhR. In CIA mice, SIN induced the generation of intestinal Treg cells, and facilitated the immunosuppressive function of these Treg cells as shown by an adoptive transfer test. In addition, the induction of intestinal Treg cells and the anti-arthritic effect of SIN in CIA mice could be largely diminished by the AhR antagonist resveratrol. SIN attenuates arthritis by promoting the generation and function of Treg cells in an AhR-dependent manner.

Paeoniflorin suppresses TGF-ß mediated epithelial-mesenchymal transition in pulmonary fibrosis through a Smad-dependent pathway.

AIM: Paeoniflorin has shown to attenuate bleomycin-induced pulmonary fibrosis (PF) in mice. Because the epithelial-mesenchymal transition (EMT) in type 2 lung endothelial cells contributes to excessive fibroblasts and myofibroblasts during multiple fibrosis of tissues, we investigated the effects of paeoniflorin on TGF-ß mediated pulmonary EMT in bleomycin-induced PF mice. METHODS: PF was induced in mice by intratracheal instillation of bleomycin (5 mg/kg). The mice were orally treated with paeoniflorin or prednisone for 21 d. After the mice were sacrificed, lung tissues were collected for analysis. An in vitro EMT model was established in alveolar epithelial cells (A549 cells) incubated with TGF-ß1 (2 ng/mL). EMT identification and the expression of related proteins were performed using immunohistochemistry, transwell assay, ELISA, Western blot and RT-qPCR. RESULTS: In PF mice, paeoniflorin (50, 100 mg·kg(-1)·d(-1)) or prednisone (6 mg·kg(-1)·d(-1)) significantly decreased the expression of FSP-1 and α-SMA, and increased the expression of E-cadherin in lung tissues. In A549 cells, TGF-ß1 stimulation induced EMT, as shown by the changes in cell morphology, the increased cell migration, and the increased vimentin and α-SMA expression as well as type I and type III collagen levels, and by the decreased E-cadherin expression. In contrast, effects of paeoniflorin on EMT disappeared when the A549 cells were pretreated with TGF-ß1 for 24 h. TGF-ß1 stimulation markedly increased the expression of Snail and activated Smad2/3, Akt, ERK, JNK and p38 MAPK in A549 cells. Co-incubation with paeoniflorin (1-30 µmol/L) dose-dependently attenuated TGF-ß1-induced expression of Snail and activation of Smad2/3, but slightly affected TGF-ß1-induced activation of Akt, ERK, JNK and p38 MAPK. Moreover, paeoniflorin markedly increased Smad7 level, and decreased ALK5 level in A549 cells. CONCLUSION: Paeoniflorin suppresses the early stages of TGF-ß mediated EMT in alveolar epithelial cells, likely by decreasing the expression of the transcription factors Snail via a Smad-dependent pathway involving the up-regulation of Smad7.