Systemic neutralization of IL-17A significantly reduces breast cancer associated metastasis in arthritic mice by reducing CXCL12/SDF-1 expression in the metastatic niches

BACKGROUND: IL-17A is a pro-inflammatory cytokine that is normally associated with autoimmune arthritis and other pro-inflammatory conditions. Recently, IL-17A has emerged as a critical factor in enhancing breast cancer (BC)-associated metastases. We generated immune competent arthritic mouse models that develop spontaneous BC-associated bone and lung metastasis. Using these models, we have previously shown that neutralization of IL-17A resulted in significant reduction in metastasis. However, the underlying mechanism/s remains unknown. METHODS: We have utilized two previously published mouse models for this study: 1) the pro-arthritic mouse model (designated SKG) injected with metastatic BC cell line (4T1) in the mammary fat pad, and 2) the PyV MT mice that develop spontaneous mammary gland tumors injected with type II collagen to induce autoimmune arthritis. Mice were treated with anti-IL-17A neutralizing antibody and monitored for metastasis and assessed for pro-inflammatory cytokines and chemokines associated with BC-associated metastasis. RESULTS: We first corroborate our previous finding that in vivo neutralization of IL-17A significantly reduced metastasis to the bones and lungs in both models. Next, we report that treatment with anti-IL17A antibody significantly reduced the expression of a key chemokine, CXCL12 (also known as stromal derived factor-1 (SDF - 1)) in the bones and lungs of treated mice. CXCL12 is a ligand for CXCR4 (expressed on BC cells) and their interaction is known to be critical for metastasis. Interestingly, levels of CXCR4 in the tumor remained unchanged with treatment. Consequently, protein lysates derived from the bones and lungs of treated mice were significantly less chemotactic for the BC cells than lysates from untreated mice; and addition of exogenous SDF-1 to the lysates from treated mice completely restored BC cell migration. In addition, cytokines such as IL-6 and M-CSF were significantly reduced in the lung and bone lysates following treatment. The data presented suggests that systemic neutralization of IL-17A can block the CXCR4/SDF-1 signaling pathway by reducing the expression of SDF-1 in the metastatic niches and significantly reducing metastasis in both mouse models. CONCLUSION: In our model, neutralization of IL-17A regulates SDF-1 expression in the metastatic niches either directly or indirectly via reducing levels of IL-6 and M-CSF

Suppressing miR-21 activity in tumor-associated macrophages promotes an antitumor immune response

microRNA-21 (miR-21) is the most commonly upregulated miRNA in solid tumors. This cancer-associated microRNA (oncomiR) regulates various downstream effectors associated with tumor pathogenesis during all stages of carcinogenesis. In this study, we analyzed the function of miR-21 in noncancer cells of the tumor microenvironment to further evaluate its contribution to tumor progression. We report that the expression of miR-21 in cells of the tumor immune infiltrate, and in particular in macrophages, was responsible for promoting tumor growth. Absence of miR-21 expression in tumor- associated macrophages (TAMs), caused a global rewiring of their transcriptional regulatory network that was skewed toward a proinflammatory angiostatic phenotype. This promoted an antitumoral immune response characterized by a macrophage-mediated improvement of cytotoxic T-cell responses through the induction of cytokines and chemokines, including IL-12 and C-X-C motif chemokine 10. These effects translated to a reduction in tumor neovascularization and an induction of tumor cell death that led to decreased tumor growth. Additionally, using the carrier peptide pH (low) insertion peptide, we were able to target miR-21 in TAMs, which decreased tumor growth even under conditions where miR-21 expression was deficient in cancer cells. Consequently, miR-21 inhibition in TAMs induced an angiostatic and immunostimulatory activation with potential therapeutic implications

Inhibition of profibrotic microRNA-21 affects platelets and their releasate.

Fibrosis is a major contributor to organ disease for which no specific therapy is available. MicroRNA-21 (miR-21) has been implicated in the fibrogenetic response, and inhibitors of miR-21 are currently undergoing clinical trials. Here, we explore how miR-21 inhibition may attenuate fibrosis using a proteomics approach. Transfection of miR-21 mimic or inhibitor in murine cardiac fibroblasts revealed limited effects on extracellular matrix (ECM) protein secretion. Similarly, miR-21-null mouse hearts showed an unaltered ECM composition. Thus, we searched for additional explanations as to how miR-21 might regulate fibrosis. In plasma samples from the community-based Bruneck Study, we found a marked correlation of miR-21 levels with several platelet-derived profibrotic factors, including TGF-β1. Pharmacological miR-21 inhibition with an antagomiR reduced the platelet release of TGF-β1 in mice. Mechanistically, Wiskott-Aldrich syndrome protein, a negative regulator of platelet TGF-β1 secretion, was identified as a direct target of miR-21. miR-21-null mice had lower platelet and leukocyte counts compared with littermate controls but higher megakaryocyte numbers in the bone marrow. Thus, to our knowledge this study reports a previously unrecognized effect of miR-21 inhibition on platelets. The effect of antagomiR-21 treatment on platelet TGF-β1 release, in particular, may contribute to the antifibrotic effects of miR-21 inhibitors

Osteoblasts Express NLRP3, a Nucleotide-Binding Domain and Leucine-Rich Repeat Region Containing Receptor Implicated in Bacterially Induced Cell Death

Bacterially induced osteoblast apoptosis may be a major contributor to bone loss during osteomyelitis. We provide evidence for the functional expression in osteoblasts of NLRP3, a member of the NLR family of cytosolic receptors that has been implicated in the initiation of programmed cell death

Effect of Oral Morphine Consumption in Female Rats on Development of Brain Cavities, Central Canal and Choroid Plexus of Their Embryos

Objective: Previous studies have shown that morphine consumption during pregnancymay delay embryo development or cause abnormal nervous system function. The presentstudy focused on the effects of maternal morphine consumption on brain cavities andcentral canal development in Wistar rats.Materials and Methods: In this study Wistar rats (average weight: 170-200 g) were used.The experimental group, after pregnancy, received 0.05 mg/ml of morphine by tap waterwhile the control group received water. On the 17th day of pregnancy, the pregnant animalswere anesthetized by chloroform and embryos were surgically removed. The sampleswere fixed in 10% formalin for four weeks. Then, tissues were processed and sectioned.Sections were stained with hematoxylin and eosin (H&E) and examined for ventricle, centralcanal and choroid plexus development by light microscopy and MOTIC software.Results: Severe reductions of the third and lateral ventricles were observed in the experimentalgroup. In addition, an increase in the choroid plexus (CP) area in the experimentalgroup with regards to the control group was identified.Conclusion: The study showed that oral morphine consumption lead to reduction in thethird and lateral brain cavities and an increase in the CP area. This defect may cause behavioralchanges observed in the F1 generation from addicted pregnant animals

The effect of morphine consumption on plasma corticosteron concentration and placenta development in pregnant rats

Background: Previous studies have shown that morphine consumption during pregnancy may delay embryo development or cause abnormal nervous system function. Objective: The present study focused on the effect of maternal morphine consumption on development of placenta and blood corticosteron concentration in addictive pregnant mothers.Materials and Methods: 24 female rats, 170-200g weight, were used. The experimental groups after pregnancy received an oral dose of 0.05 mg/ml of morphine by tap water while the control group received only tap water. On 10th and 14th day of pregnancy, rats were anesthetized and placenta removed surgically, 1ml blood was collected from each pregnant mother from retro-orbital sinus, the concentration of blood corticosteron was determined by corticosteron Elisa kit after centrifugation. The fixed tissue was processed, sectioned and stained with hematoxylin and eosin. Placenta was studied microscopically according to the thickness of layers, area of blood cisterns, and the number of cells.Results: Comparing the plasma corticosteron concentration of the treatment and the control groups, not only a severe increase in the treatment group was detected, but also the thickness of maternal and embryonic portions of the placenta at day 10th and 14th of gestation was different significantly (p≤0.05). Furthermore, an increase in number of cells in maternal and embryonic portion of placenta and a decrease in blood cistern area were demonstrated in both the experimental and the control groups.Conclusion: The effects of morphine, including an increase in blood concentration of corticosteron, in dependent pregnant mothers were seen. Development of placenta in the experimental group was delayed

The effect of morphine consumption on plasma corticosteron concentration and placenta development in pregnant rats

Background: Previous studies have shown that morphine consumption during pregnancy may delay embryo development or cause abnormal nervous system function. Objective: The present study focused on the effect of maternal morphine consumption on development of placenta and blood corticosteron concentration in addictive pregnant mothers. Materials and Methods: 24 female rats, 170-200g weight, were used. The experimental groups after pregnancy received an oral dose of 0.05 mg/ml of morphine by tap water while the control group received only tap water. On 10th and 14th day of pregnancy, rats were anesthetized and placenta removed surgically, 1ml blood was collected from each pregnant mother from retro-orbital sinus, the concentration of blood corticosteron was determined by corticosteron Elisa kit after centrifugation. The fixed tissue was processed, sectioned and stained with hematoxylin and eosin. Placenta was studied microscopically according to the thickness of layers, area of blood cisterns, and the number of cells. Results: Comparing the plasma corticosteron concentration of the treatment and the control groups, not only a severe increase in the treatment group was detected, but also the thickness of maternal and embryonic portions of the placenta at day 10th and 14th of gestation was different significantly (p≤0.05). Furthermore, an increase in number of cells in maternal and embryonic portion of placenta and a decrease in blood cistern area were demonstrated in both the experimental and the control groups. Conclusion: The effects of morphine, including an increase in blood concentration of corticosteron, in dependent pregnant mothers were seen. Development of placenta in the experimental group was delayed

Evaluating the Effects of Oral Morphine on Embryonic Development of Spinal Cord in Wistar Rats

Introduction: In the present research, the effect of morphine consumption during pregnancy on the development of the embryo’s spinal cord was studied in Wistar rat. Methods: Female Wistar rats (Wt: 250-300 g) were mated with males. The test group received morphine (0.01 mg/ml) in their drinking water. Pregnant rats were later killed with chloroform on the 12th, 13th and 14th days of pregnancy, and the embryos were taken out surgically. The embryos were fixed in formalin 10% for 2 weeks. Then, the weight of fixed embryos was calculated by a scale. In addition, several animals’ sizes including fronto-posterior and lateral length were measured by a caliper. Tissue processing, sectioning and hematoxylin and eosin (H&E) staining were applied for the embryos. The sections were examined for spinal cord development by light microscope and MOTIC software. Results: Significant decrease was observed in the fronto-posterior and lateral length and the weight of the embryos in the test groups. The thickness of the white matter layer decreased on the 12th, 13th and 14th embryonic days. The thickness of the spine's grey layer was also less than the control group, on the same days. Increase in the length of the ependimal duct observed as well. Number of grey substance cells decreased compared to the control group within the same days. Meanwhile, thickness of the germinal layer reduced in comparison to the control group on the mentioned days. Discussion: In conclusion, morphine consumption during pregnancy causes defects in growth and completion of the spinal cord