AhR Expression Research Articles

Evaluation of the expression of FLG, AHR and ARNT genes in the skin of patients with atopic dermatitis after phototherapy

Background: Ultraviolet irradiation of the skin can activate the cytoplasmic aryl hydrocarbon receptor AhR, which, in combination with its nuclear translocator ARNT binds to the promoter of the FLG gene encoding filaggrin, a protective skin barrier protein. This suggests that the therapeutic effect of phototherapy may be due not only to the immunosuppressive effect, but also to stimulation of filaggrin production. Aims: to evaluate the effect of ultraviolet irradiation used for various phototherapy methods on the expression levels of the FLG, AHR and ARNT genes in the skin of patients with atopic dermatitis. Materials and methods: The expression levels of the FLG, AHR and ARNT genes were determined using real-time PCR. To define the severity of the disease, the SCORAD index was calculated. Results: 76 patients with atopic dermatitis were included in the study. 37 patients underwent narrow-band phototherapy; 39 – UFA1 therapy. Both methods of phototherapy were effective. After narrow-band phototherapy, the level of expression of the FLG, AHR and ARNT genes significantly increased. After UFA1 therapy, the expression of the AHR and ARNT genes increased, and no changes in the expression of the FLG gene were observed. Conclusions: Data have been obtained indicating that the therapeutic effect of narrow-band phototherapy in atopic dermatitis may be due to stimulation of the expression of the FLG gene in the skin. The revealed changes in the expression of the AHR and ARNT genes indicate the possible involvement of their protein products AhR and ARNT in the pathogenesis of the disease.

IDO1 inhibits ferroptosis by regulating FTO-mediated m6A methylation and SLC7A11 mRNA stability during glioblastoma progression

Indoleamine 2, 3-dioxygenase 1 (IDO1) has been recognized as an enzyme involved in tryptophan catabolism with immunosuppressive ability. This study determined to investigate the impact of IDO1 on glioblastoma multiforme (GBM) cells. Here, we showed that the expression of IDO1 was markedly increased in patients with glioma and associated with GBM progression. IDO1 overexpression suppressed ferroptotic cell death, reduced ROS and lipid peroxide generation in GBM cells. IDO1 expression increased the SLC7A11 mRNA stability through FTO-dependent m6A methylation. Mechanistically, IDO1 promoted the AhR expression and nuclear translocation, thus facilitating AhR recruitment at the promoter regions of FTO gene and negatively regulating its transcription. These findings demonstrate that IDO1 facilitates GBM progression by inhibiting SLC7A11-dependent ferroptosis through an IDO1-AhR-FTO axis-mediated m6A methylation mechanism.

Studies on the alleviating effect of Bifidobacterium lactis V9 on dextran sodium sulfate-induced colitis in mice

BackgroundInflammatory bowel disease (IBD) has become a global public health problem with complex pathogenesis and limited therapeutic options. We aimed to investigate the potential mechanisms by which Bifidobacterium lactis V9 (V9) alleviated colitis in a dextran sodium sulfate-induced colitis model mice.MethodsMice were induced to develop colitis by drinking DSS solution to induce colitis. The expression of the relevant factors in the blood supernatant of the mice was determined by ELISA. RT-qPCR and Western blotting were used to detect mRNA and protein expression of target genes. The fecal microbiota was analyzed by 16S rRNA sequencing. Intestinal metabolites were analyzed by untargeted metabolomics;ResultsV9 effectively improved the overall symptoms of the colitis model mice. H&E showed that V9 re-stored the intestinal tissue structure. ELISA showed that V9 decreased the levels of IL-6, IL-22, and TNF-α and increased IL-10, SP, VIP, and 5-HT. V9 increased the expression of AHR, CYP1A1, MUC2, Claudin-3, Occludin, and ZO-1, and decreased 5-hydroxytryptamine transporter and Claudin-2. V9 increased the abundance of gut microbiota in colitis mice to promote the growth of beneficial bacteria. V9 increased tryptophan metabolites, and short-chain fatty acids, and improved gut inflammation.ConclusionV9 attenuates intestinal inflammation, improves the mucosal barrier, modulates intestinal microecology and exerts a protective effect in a mouse model of DSS-induced colitis.

The Aryl Hydrocarbon Receptor (AhR) Is a Novel Gene Involved in Proper Physiological Functions of Pancreatic β-Cells.

The Kynurenine pathway is crucial in metabolizing dietary tryptophan into bioactive compounds known as kynurenines, which have been linked to glucose homeostasis. The aryl hydrocarbon receptor (AhR) has recently emerged as the endogenous receptor for the kynurenine metabolite, kynurenic acid (KYNA). However, the specific role of AhR in pancreatic β-cells remains largely unexplored. This study aimed to investigate the expression of AhR in human pancreatic islets using publicly available RNA-sequencing (RNA-seq) databases and to explore its correlations with various metabolic parameters and key β-cell markers. Additionally, functional experiments were conducted in INS-1 cells, a rat β-cell line, to elucidate the role of Ahr in β-cell biology. RNA-seq data analysis confirmed the expression of AHR in human islets, with elevated levels observed in pancreatic islets obtained from diabetic and obese donors compared to non-diabetic or lean donors. Furthermore, AHR expression showed an inverse correlation with the expression of key β-cell functional genes, including insulin, PDX-1, MAFA, KCNJ11, and GCK. Silencing Ahr expression using siRNA in INS-1 cells decreased insulin secretion, insulin content, and glucose uptake efficiency, while cell viability, apoptosis rate, and reactive oxygen species (ROS) production remained unaffected. Moreover, Ahr silencing led to the downregulation of major β-cell regulator genes, Ins1, Ins2, Pdx-1, and Glut2, at both the mRNA and protein levels. In summary, this study provides novel insights into the role of AhR in maintaining proper β-cell function. These findings suggest that AhR could be a potential target for future therapeutic strategies in treating type 2 diabetes (T2D).

Human Umbilical Cord Mesenchymal Stem Cell-Derived Exosomes Loaded Mir-29-3p Targets AhR to Improve Juvenile Idiopathic Arthritis via Inhibiting the Expression of IL-22 in CD4+ T Cell.

Juvenile idiopathic arthritis (JIA) is one of the most common chronic inflammatory rheumatic diseases in children. Human umbilical cord mesenchymal stem cells (HUCMSCs)-derived exosomes (HUCMSCs-Exos) are involved in autoimmune diseases. This study investigates the mechanism of HUCMSC-Exos in improving JIA by targeting AhR through delivery of miR-29-3p to inhibit IL-22 expression in CD4+ T cells. Collagen induced arthritis (CIA) mouse model was established, and mice were treated with HUCMSCs-Exos and miR-29-3p antagomir, respectively. CD4+ T cells from JIA patients were used for cell experiments. The mechanism was elucidated by histopathological staining, transmission electron microscopy (TEM), immunohistochemistry, CCK-8 assay, flow cytometry, Western blotting, real-time PCR, and enzyme-linked immunosorbent assay (ELISA), laser confocal microscopy, and luciferase assay. JIA-CD4+ T cells showed higher expression of IL-22 and lower the levels of miR-29-3p, while HUCMSCs-Exos significantly inhibited the expression of IL-22 and increased the levels of miR-29a-3p, miR-29b-3p, and miR-29c-3p in CD4+ T cells from JIA patients. The expression of miR-29a-3p, miR-29b-3p, miR-29c-3p, AhR, and IL-22 in CD4+ T cells was significantly reversed when co-cultured with HUCMSCs transfected with miR-29-3p mimic or miR-29-3p inhibitor. In vivo experiment, HUCMSCs-Exos ameliorated CIA mice by delivering miR-29-3p to inhibit AhR, IL-22, IL-22R1, MMP3, and MMP13 expression. Furthermore, HUCMSCs-Exos also deliver miR-29-3p targeting AhR expression to inhibit IL-22 in JIA-CD4 + T cells through alleviating arthritic synovial fibroblast activation. HUCMSCs-Exos loaded miR-29-3p targets AhR to improve JIA via inhibiting the expression of IL-22 in CD4+ T cell, which provides a scientific basis for the treatment of JIA.

Indigo alleviates psoriasis through the AhR/NF-κB signaling pathway: an in vitro and in vivo study.

Psoriasis is a chronic inflammatory skin disease. A strong association between the AhR/ NFκB axis and the inflammatory response in psoriasis. Indigo (IDG) has demonstrated significant anti-inflammatory properties. This study aimed to assess the anti-psoriatic efficacy of IDG while investigating the underlying mechanisms involved. In the in vitro experiments, cell viability was assessed using the CCK-8. qRT-PCR was employed to measure the mRNA levels of NF-κB, TNF-α, IL-1β, AhR, and CYP1A1. Western blotting was conducted to examine alterations in cytoplasmic and nuclear AhR protein levels. Additionally, an IDG nanoemulsion (NE) cream was prepared for the in vivo experiments. A psoriasis-like skin lesion mice model was induced using IMQ (62.5 mg/day for 7 days). The severity of psoriasis was evaluated using PASI, and skin lesions were scored while epidermal thickness was assessed via HE staining. The expression of inflammatory markers, including IL-6, IL-13, IL-17A, MCP-1, and TNF-α, was detected in skin lesions using Luminex. The levels of CYP1A1, p65, and p-p65 proteins were determined by Western blotting. LPS stimulation significantly elevated TNF-α, IL-6, and NF-κB mRNA levels, which were notably reduced by IDG treatment. Additionally, IDG significantly enhanced the expression of AhR and CYP1A1 mRNA. Further investigation revealed that IDG facilitated AhR translocation from the cytoplasm to the nucleus. In the IMQ-induced psoriasis-like mouse model, IDG NE substantially ameliorated the severity of skin lesions. Moreover, IDG NE treatment reduced the upregulation of inflammatory cytokines such as IL-6, IL-17A, MCP-1, and TNF-α in IMQ-induced skin lesions. It was also observed that IDG NE treatment increased CYP1A1 protein expression while inhibiting p65 and p-p65 protein expression. IDG emerges as a promising treatment for psoriasis, demonstrating effective therapeutic outcomes. Its mechanism of action is likely linked to the modulation of the AhR/NFκB signaling pathway.

Rifaximin ameliorates influenza A virus infection-induced lung barrier damage by regulating gut microbiota

Prior research has indicated that the gut-lung-axis can be influenced by the intestinal microbiota, thereby impacting lung immunity. Rifaximin is a broad-spectrum antibacterial drug that can maintain the homeostasis of intestinal microflora. In this study, we established an influenza A virus (IAV)-infected mice model with or without rifaximin supplementation to investigate whether rifaximin could ameliorate lung injury induced by IAV and explore the molecular mechanism involved. Our results showed that IAV caused significant weight loss and disrupted the structure of the lung and intestine. The analysis results of 16S rRNA and metabolomics indicated a notable reduction in the levels of probiotics Lachnoclostridium, Ruminococcaceae_UCG-013, and tryptophan metabolites in the fecal samples of mice infected with IAV. In contrast, supplementation with 50 mg/kg rifaximin reversed these changes, including promoting the repair of the lung barrier and increasing the abundance of Muribaculum, Papillibacter and tryptophan-related metabolites content in the feces. Additionally, rifaximin treatment increased ILC3 cell numbers, IL-22 level, and the expression of RORγ and STAT-3 protein in the lung. Furthermore, our findings demonstrated that the administration of rifaximin can mitigate damage to the intestinal barrier while enhancing the expression of AHR, IDO-1, and tight junction proteins in the small intestine. Overall, our results provided that rifaximin alleviated the imbalance in gut microbiota homeostasis induced by IAV infection and promoted the production of tryptophan-related metabolites. Tryptophan functions as a signal to facilitate the activation and movement of ILC3 cells from the intestine to the lung through the AHR/STAT3/IL-22 pathway, thereby aiding in the restoration of the barrier.Key points• Rifaximin ameliorated IAV infection-caused lung barrier injury and induced ILC3 cell activation.• Rifaximin alleviated IAV-induced gut dysbiosis and recovered tryptophan metabolism.• Tryptophan mediates rifaximin-induced ILC3 cell activation via the AHR/STAT3/IL-22 pathway.

Kynurenine Attenuates Ulcerative Colitis Mediated by the Aryl Hydrocarbon Receptor.

The higher prevalence of ulcerative colitis (UC) and the side effects of its therapeutic agents contribute to finding novel treatments. This study aimed to investigate whether kynurenine (KYN), a tryptophan metabolite, has the possibility of alleviating UC and further clarifying the underlying mechanism. The effect of KYN on treating UC was evaluated by intestinal pathology, inflammatory cytokines, and tight-junction proteins in colitis mice and LPS-stimulated Caco-2 cells. Our results revealed that KYN relieved pathological symptoms of UC, improved intestinal barrier function, enhanced AhR expression, and inhibited NF-κB signaling pathway activation in the colon of colitis mice. Moreover, the improved intestinal barrier function, the decreased inflammasome production, and the inhibited activation of the NF-κB signaling pathway by KYN were dependent on AhR in Caco-2 cells. KYN could trigger AhR activation, inactivate the NF-κB signaling pathway, and inhibit NLRP3 inflammasome production, thus alleviating intestinal epithelial barrier dysfunction and reducing intestinal inflammation. In conclusion, the present study reveals that KYN ameliorates UC by improving the intestinal epithelial barrier and activating the AhR-NF-κB-NLRP3 signaling pathway, and it can be a promising therapeutic agent and dietary supplement for alleviating UC.

Unraveling the chemotherapeutic potential of taxifolin ruthenium-p-cymene complex in breast carcinoma: Insights into AhR signaling pathway in vitro and in vivo

BackgroundMammary carcinoma is the most frequently diagnosed form of carcinoma in women worldwide. The organometallic compounds showed a prospective anticancer activity. This research explored the anticancer efficacy of taxifolin ruthenium-p-cymene counter to breast cancer. MethodsThe anticancer efficacy of the novel organometallic compound was investigated via various in vitro and in vivo techniques using breast cancer cell lines and breast cancer model of rat. ResultsTarget proteins were identified via pharmacophore analysis, which revealed a high binding affinity towards AhR, EGFR, and β-catenin. The compound induced apoptotic events and prevented cancer cell colony formation. Furthermore, decreased expression of AhR, EGFR, and N-cadherin inhibited cancer cell growth, migration, and proliferation. The compound provoked the cell cycle arrest at sub G0/G1 phase, S phase and G2/M phase and inaugurated the caspase-3 dependent apoptotic events. The in-vivo experimentation displayed the fruitful restoration of breast tissue since the complex treatment in DMBA persuaded breast carcinoma in rat. Moreover, the upstream of p53 and caspase-3 expression along with substantially downstream of vimentin, β-catenin, m-TOR and Akt expression. ConclusionsIn conclusion, the compound repressed the cancerous cellular viability, migration, and EMT via modulating the AhR/EGFR/ PI3K transduction pathway and the expression of EMT biomarkers such as N-cadherin, E-cadherin, thus eventually revoked the EMT facilitated metastasis of malignant cells.

Impact of Skin Exposure to Benzo[a]pyrene in Rat Model: Insights into Epidermal Cell Function and Draining Lymph Node Cell Response.

The skin is a direct target of the air pollutant benzo[a]pyrene (BaP). While its carcinogenic qualities are well-studied, the immunotoxicity of BaP after dermal exposure is less understood. This study examines the immunomodulatory effects of a 10-day epicutaneous BaP application, in environmentally/occupationally relevant doses, by analyzing ex vivo skin immune response (skin explant, epidermal cells and draining lymph node/DLN cell activity), alongside the skin's reaction to sensitization with experimental hapten dinitrochlorobenzene (DNCB). The results show that BaP application disrupts the structure of the epidermal layer and promotes immune cell infiltration in the dermis. BaP exposure led to oxidative stress in epidermal cells, characterized by decreased reduced glutathione and increased AHR and Cyp1A1 expression. Production and gene expression of proinflammatory cytokines (TNF, IL-1β) by epidermal cells decreased, while IL-10 response increased. Decreased spontaneous production of IFN-γ and IL-17, along with unchanged IL-10, was observed in DLC cells, whereas ConA-stimulated production of these cytokines was elevated. Local immunosuppression caused by BaP application seems to reduce the skin's response to an additional stimulus, evidenced by decreased effector activity of DLN cells three days after sensitization with DNCB. These findings provide new insight into the immunomodulatory effects and health risks associated with skin exposure to BaP.

Elastin-derived peptides (EDPs) affect gene and protein expression in human mesenchymal stem cells (hMSCs) – preliminary study

During the aging process, elastin is degraded and the level of elastin-derived peptides (EDPs) successively increases. The main peptide released from elastin during its degradation is a peptide with the VGVAPG sequence. To date, several papers have described that EDPs or elastin-like peptides (ELPs) affect human mesenchymal stem cells (hMSCs) derived from different tissues. Unfortunately, despite the described effect of EDPs or ELPs on the hMSC differentiation process, the mechanism of action of these peptides has not been elucidated. Therefore, the aim of the present study was to evaluate the impact of the VGVAPG and VVGPGA peptides on the hMSC stemness marker and elucidation of the mechanism of action of these peptides. Our data show that both studied peptides (VGVAPG and VVGPGA) act with the involvement of ERK1/2 and c-SRC kinases. However, their mechanism of activation is probably different in hMSCs derived from adipose tissue. Both studied peptides increase the KI67 protein level in hMSCs, but this is not accompanied with cell proliferation. Moreover, the changes in the NANOG and c-MYC protein expression and in the SOX2 and POU5F1 mRNA expression suggest that EDPs reduced the hMSC stemness properties and could initiate cell differentiation. The initiation of differentiation was evidenced by changes in the expression of AhR and PPARγ protein as well as specific genes (ACTB, TUBB3) and proteins (β-actin, RhoA) involved in cytoskeleton remodeling. Our data suggest that the presence of EDPs in tissue can initiate hMSC differentiation into more tissue-specific cells.

Colistin Induces Oxidative Stress and Apoptotic Cell Death through the Activation of the AhR/CYP1A1 Pathway in PC12 Cells.

Colistin is commonly regarded as the "last-resort" antibiotic for combating life-threatening infections caused by multidrug-resistant (MDR) gram-negative bacteria. Neurotoxicity is a potential adverse event associated with colistin application in clinical settings, yet the exact molecular mechanisms remain unclear. This study examined the detrimental impact of colistin exposure on PC12 cells and the associated molecular mechanisms. Colistin treatment at concentrations of 0-400 μM decreased cell viability and induced apoptotic cell death in both time- and concentration-dependent manners. Exposure to colistin triggered the production of reactive oxygen species (ROS) and caused oxidative stress damage in PC12 cells. N-acetylcysteine (NAC) supplementation partially mitigated the cytotoxic and apoptotic outcomes of colistin. Evidence of mitochondrial dysfunction was observed through the dissipation of membrane potential. Additionally, colistin treatment upregulated the expression of AhR and CYP1A1 mRNAs in PC12 cells. Pharmacological inhibition of AhR (e.g., using α-naphthoflavone) or intervention with the CYP1A1 gene significantly decreased the production of ROS induced by colistin, subsequently lowering caspase activation and cell apoptosis. In conclusion, our findings demonstrate, for the first time, that the activation of the AhR/CYP1A1 pathway contributes partially to colistin-induced oxidative stress and apoptosis, offering insights into the cytotoxic effects of colistin.

Targeting mitochondrial dysfunction in atopic dermatitis with trilinolein: A triacylglycerol from the medicinal plant Cannabis fructus

BackgroundAtopic dermatitis (AD) is a common skin condition that causes chronic and recurring eczema lesions. Prior research has indicated that Cannabis fructus, the mature fruit of Cannabis sativa, has an antioxidant effect. Historically, Cannabis fructus has been used in cosmetics and medicine. However, there is limited knowledge regarding its biological components and the mechanisms by which it prevents and treats AD. ObjectivesHPLC-ESI-MS/MS analysis was utilized to identify the main compounds of Cannabis fructus, and trilinolein was extracted using chromatographic techniques. The potential of trilinolein in the prevention of AD was assessed, and its underlying mechanisms of action were elucidated. MethodsThe distribution of distinct cellular subpopulations and the principal biological processes implicated in the pathogenesis of AD were assessed through a comparative study involving chronic AD patients and healthy controls (HCs). Differential gene expression was validated in clinical samples from the lesions of AD patients and the healthy skin of controls. The pharmacodynamic activity of trilinolein was validated in dinitrochlorobenzene (DNCB)-induced BALB/c mice and in IL-4- and TNF-α-induced HaCaT cells. Proteomics analyse was employed to investigate its mechanisms. ResultsSingle-cell transcriptome analysis revealed that chronic AD is characterized by abnormal keratinocyte differentiation and oxidative stress damage. When topically applied, trilinolein can effectively improve AD-like skin lesions induced by DNCB. It increases the expression of terminal differentiation proteins and decreases the expression of NADPH oxidase 2 (NOX2), with a therapeutic effect comparable to that of the positive control drug crisaborole. Additionally, trilinolein reduced ROS fluorescence intensity, restored mitochondrial morphology and membrane potential, and decreased mitochondrial DNA (mtDNA) release in keratinocytes stimulated with IL-4 and TNF-α. Moreover, trilinolein increased the protein expression of AhR, CYP1A1, and Nrf2 in a dose-dependent manner. The effect of trilinolein on keratinocyte terminal differentiation proteins and ROS levels was blocked by the addition of an AhR inhibitor. ConclusionThe study suggests that trilinolein from Cannabis fructus alleviates NOX2-dependent mitochondrial dysfunction and repair the skin barrier via AhR-Nrf2 pathway, making it a promising agent for the prevention and treatment of AD.

Dysregulated tryptophan metabolism and AhR pathway contributed to CXCL10 upregulation in stable non-segmental vitiligo

BackgroundTryptophan metabolism dysregulation has been observed in vitiligo. However, drawing a mechanistic linkage between this metabolic disturbance and vitiligo pathogenesis remains challenging. ObjectiveAim to reveal the characterization of tryptophan metabolism in vitiligo and investigate the role of tryptophan metabolites in vitiligo pathophysiology. MethodsLC-MS/MS, dual-luciferase reporter assay, ELISA, qRT-PCR, small interfering RNA, western blotting, and immunohistochemistry were employed. ResultsKynurenine pathway activation and KYAT enzyme-associated deviation to kynurenic acid (KYNA) in the plasma of stable non-segmental vitiligo were determined. Using a public microarray dataset, we next validated the activation of kynurenine pathway was related with inflammatory-related genes expression in skin of vitiligo patients. Furthermore, we found that KYNA induced CXCL10 upregulation in keratinocytes via AhR activation. Moreover, the total activity of AhR agonist was increased while the AhR concentration per se was decreased in the plasma of vitiligo patients. Finally, higher KYAT, CXCL10, CYP1A1 and lower AhR expression in vitiligo lesional skin were observed by immunohistochemistry staining. ConclusionThis study depicts the metabolic and genetic characterizations of tryptophan metabolism in vitiligo and proposes that KYNA, a tryptophan-derived AhR ligand, can enhance CXCL10 expression in keratinocytes.

Modulatory Roles of AHR, FFAR2, FXR, and TGR5 Gene Expression in Metabolic-Associated Fatty Liver Disease and COVID-19 Outcomes.

We investigated gene expression levels of AHR, FFAR2, FXR, and TGR5 in patients with MAFLD and COVID-19 compared to controls. We examined associations between gene expression and clinical outcomes. COVID-19 patients displayed altered AHR expression, potentially impacting immune response and recovery. Downregulated AHR in patients with MAFLD correlated with increased coagulation parameters. Elevated FFAR2 expression in patients with MAFLD was linked to specific immune cell populations and hospital stay duration. A significantly lower FXR expression was observed in both MAFLD and severe COVID-19. Our findings suggest potential modulatory roles for AHR, FFAR2, and FXR in COVID-19 and MAFLD.

Role of 4-Thiazolidinone-Pyrazoline/Indoline Hybrids Les-4369 and Les-3467 in BJ and A549 Cell Lines.

Cancer is one of the most important problems of modern societies. Recently, studies have reported the anticancer properties of rosiglitazone related to its ability to bind peroxisome proliferator receptor γ (PPARγ), which has various effects on cancer and can inhibit cell proliferation. In this study, we investigated the effect of new 4-thiazolidinone (4-TZD) hybrids Les-4369 and Les-3467 and their effect on reactive oxygen species (ROS) production, metabolic activity, lactate dehydrogenase (LDH) release, caspase-3 activity, and gene and protein expression in human foreskin fibroblast (BJ) cells and lung adenocarcinoma (A549) cells. The ROS production and caspase-3 activity were mainly increased in the micromolar concentrations of the studied compounds in both cell lines. Les-3467 and Les-4369 increased the mRNA expression of PPARG, P53 (tumor protein P53), and ATM (ATM serine/threonine kinase) in the BJ cells, while the mRNA expression of these genes (except PPARG) was mainly decreased in the A549 cells treated with both of the tested compounds. Our results indicate a decrease in the protein expression of AhR, PPARγ, and PARP-1 in the BJ cells exposed to 1 µM Les-3467 and Les-4369. In the A549 cells, the protein expression of AhR, PPARγ, and PARP-1 increased in the treatment with 1 µM Les-3467 and Les-4369. We have also shown the PPARγ modulatory properties of Les-3467 and Les-4369. However, both compounds prove weak anticancer properties evidenced by their action at high concentrations and non-selective effects against BJ and A549 cells.

Kynurenine acts as a signaling molecule to attenuate pulmonary fibrosis by enhancing the AHR-PTEN axis

IntroductionPulmonary fibrosis (PF) is a fatal fibrotic lung disease without any options to halt disease progression. Feasible evidence suggests that aberrant metabolism of amino acids may play a role in the pathoetiology of PF. However, the exact impact of kynurenine (Kyn), a metabolite derived from tryptophan (Trp) on PF is yet to be addressed. ObjectivesThis study aims to elucidate the role of kynurenine in both the onset and advancement of PF. MethodsLiquid chromatography–tandem mass spectrometry was employed to assess Kyn levels in patients with idiopathic PF and PF associated with Sjögren’s syndrome. Additionally, a mouse model of PF induced by bleomycin was utilized to study the impact of Kyn administration. Furthermore, cell models treated with TGF-β1 were used to explore the mechanism by which Kyn inhibits fibroblast functions. ResultsWe demonstrated that high levels of Kyn are a clinical feature in both idiopathic PF patients and primary Sjögren syndrome associated PF patients. Further studies illustrated that Kyn served as a braking molecule to suppress fibroblast functionality, thereby protecting mice from bleomycin-induced lung fibrosis. The protective effects depend on AHR, in which Kyn induces AHR nuclear translocation, where it upregulates PTEN expression to blunt TGF-β mediated AKT/mTOR signaling in fibroblasts. However, in fibrotic microenviroment, the expression of AHR is repressed by methyl-CpG-binding domain 2 (MBD2), a reader interpreting the effect of DNA methylation, which results in a significantly reduced sensitivity of Kyn to fibroblasts. Therefore, exogenous administration of Kyn substantially reversed established PF. ConclusionOur studies not only highlighted a critical role of Trp metabolism in PF pathogenesis, but also provided compelling evidence suggesting that Kyn could serve as a promising metabolite against PF.

Protective Potential of a Botanical-Based Supplement Ingredient against the Impact of Environmental Pollution on Cutaneous and Cardiopulmonary Systems: Preclinical Study.

Air pollution is a growing threat to human health. Airborne pollution effects on respiratory, cardiovascular and skin health are well-established. The main mechanisms of air-pollution-induced health effects involve oxidative stress and inflammation. The present study evaluates the potential of a polyphenol-enriched food supplement ingredient comprising Lippia citriodora, Olea europaea, Rosmarinus officinalis, and Sophora japonica extracts in mitigating the adverse effects of environmental pollution on skin and cardiopulmonary systems. Both in vitro and ex vivo studies were used to assess the blend's effects against pollution-induced damage. In these studies, the botanical blend was found to reduce lipid peroxidation, inflammation (by reducing IL-1α), and metabolic alterations (by regulating MT-1H, AhR, and Nrf2 expression) in human skin explants exposed to a mixture of pollutants. Similar results were also observed in keratinocytes exposed to urban dust. Moreover, the ingredient significantly reduced pollutant-induced ROS production in human endothelial cells and lung fibroblasts, while downregulating the expression of apoptotic genes (bcl-2 and bax) in lung fibroblasts. Additionally, the blend counteracted the effect of urban dust on the heart rate in zebrafish embryos. These results support the potential use of this supplement as an adjuvant method to reduce the impact of environmental pollution on the skin, lungs, and cardiovascular tissues.

AHRR and SFRP2 in primary versus recurrent high-grade serous ovarian carcinoma and their prognostic implication

BackgroundThe aim of this study was to analyse transcriptomic differences between primary and recurrent high-grade serous ovarian carcinoma (HGSOC) to identify prognostic biomarkers.MethodsWe analysed 19 paired primary and recurrent HGSOC samples using targeted RNA sequencing. We selected the best candidates using in silico survival and pathway analysis and validated the biomarkers using immunohistochemistry on a cohort of 44 paired samples, an additional cohort of 504 primary HGSOCs and explored their function.ResultsWe identified 233 differential expressed genes. Twenty-three showed a significant prognostic value for PFS and OS in silico. Seven markers (AHRR, COL5A2, FABP4, HMGCS2, ITGA5, SFRP2 and WNT9B) were chosen for validation at the protein level. AHRR expression was higher in primary tumours (p < 0.0001) and correlated with better patient survival (p < 0.05). Stromal SFRP2 expression was higher in recurrent samples (p = 0.009) and protein expression in primary tumours was associated with worse patient survival (p = 0.022). In multivariate analysis, tumour AHRR and SFRP2 remained independent prognostic markers. In vitro studies supported the anti-tumorigenic role of AHRR and the oncogenic function of SFRP2.ConclusionsOur results underline the relevance of AHRR and SFRP2 proteins in aryl-hydrocarbon receptor and Wnt-signalling, respectively, and might lead to establishing them as biomarkers in HGSOC.

The Garlic Compound, Diallyl Trisulfide, Attenuates Benzo[a]Pyrene-Induced Precancerous Effect through Its Antioxidant Effect, AhR Inhibition, and Increased DNA Repair in Human Breast Epithelial Cells.

Exposure to B[a]P, the most characterized polycyclic aromatic hydrocarbon, significantly increases breast cancer risk. Our lab has previously reported that diallyl trisulfide (DATS), a garlic organosulfur compound (OSC) with chemopreventive and cell cycle arrest properties, reduces lipid peroxides and DNA damage in normal breast epithelial (MCF-10A) cells. In this study, we evaluated the ability of DATS to block the B[a]P-induced initiation of carcinogenesis in MCF-10A cells by examining changes in proliferation, clonogenic formation, reactive oxygen species (ROS) formation, 8-hydroxy-2-deoxyguanosine (8-OHdG) levels, and protein expression of ARNT/HIF-1β, CYP1A1, and DNA POLβ. The study results indicate that B[a]P increased proliferation, clonogenic formation, ROS formation, and 8-OHdG levels, as well as increasing the protein expression of ARNT/HIF-1β and CYP1A1 compared to the control. Conversely, DATS/B[a]P co-treatment (CoTx) inhibited cell proliferation, clonogenic formation, ROS formation, and 8-OHdG levels compared to B[a]P alone. Treatment with DATS significantly inhibited (p < 0.0001) AhR expression, implicated in the development and progression of breast cancer. The CoTx also attenuated all the above-mentioned B[a]P-induced changes in protein expression. At the same time, it increased DNA POLβ protein expression, which indicates increased DNA repair, thus causing a chemopreventive effect. These results provide evidence for the chemopreventive effects of DATS in breast cancer prevention.