HIF-α Activation Impacts Macrophage Function during Murine Leishmania major Infection

Leishmanial skin lesions are characterized by inflammatory hypoxia alongside the activation of hypoxia-inducible factors, HIF-1α and HIF-2α, and subsequent expression of the HIF-α target VEGF-A during Leishmania major infection. However, the factors responsible for HIF-α activation are not known. We hypothesize that hypoxia and proinflammatory stimuli contribute to HIF-α activation during infection. RNA-Seq of leishmanial lesions revealed that transcripts associated with HIF-1α signaling were induced. To determine whether hypoxia contributes to HIF-α activation, we followed the fate of myeloid cells infiltrating from the blood and into hypoxic lesions. Recruited myeloid cells experienced hypoxia when they entered inflamed lesions, and the length of time in lesions increased their hypoxic signature. To determine whether proinflammatory stimuli in the inflamed tissue can also influence HIF-α activation, we subjected macrophages to various proinflammatory stimuli and measured VEGF-A. While parasites alone did not induce VEGF-A, and proinflammatory stimuli only modestly induced VEGF-A, HIF-α stabilization increased VEGF-A during infection. HIF-α stabilization did not impact parasite entry, growth, or killing. Conversely, the absence of ARNT/HIF-α signaling enhanced parasite internalization. Altogether, these findings suggest that HIF-α is active during infection, and while macrophage HIF-α activation promotes lymphatic remodeling through VEGF-A production, HIF-α activation does not impact parasite internalization or control.

A Critical Review on Avipathi Choorna- A Unique Formulation for Peptic Ulcer Disease

Peptic-ulcer-disease is the ulceration of gasrtric or duodenal mucosa due to the digestive action of pepsin and stomach acid. Gastritis, gastric ulcer and duodenal ulcer are included under this. It can be correlated with the condition Parinamasoola mentioned in Ayurveda. Avipathichoornam is a famous Ayurvedic formulation, mentioned in the texts Ashtanga Hridaya and Sahasrayoga. Avipathi choorna exerts its effect in Peptic ulcer disease probably through Deepana, Pachana and Saraka actions by virtue of the pharmacological properties of the ingredients with which the vitiated Pitta can get normalized. It can be deducted that Avipathi choorna probably neutralize the excess acid secretion in the gastrointestinal tract and maintain a healthy pH. The formulation also probably acts by the anti inflammatory property of most of the ingredients which can help pacify the inflamed tissue layer of the gut. The aim of this paper is to demonstrate mode of action of Avipathi choorna in peptic ulcer disease by critically analyzing the pharmacological properties as well as chemical constituent of the ingredients.

HIF-alpha Activation Impacts Macrophage Function During Murine Leishmania major Infection

Leishmanial skin lesions are characterized by inflammatory hypoxia alongside the activation of hypoxia inducible factors, HIF-1a and HIF-2a, and subsequent expression of the HIF-a target VEGF-A during Leishmania major infection. However, the factors responsible for HIF-a activation are not known. We hypothesize hypoxia and pro-inflammatory stimuli contribute to HIF-a activation during infection. RNASeq on leishmanial lesions found transcripts associated with HIF-1a signaling are induced. To determine whether hypoxia contributes to HIF-a activation, we followed the fate of myeloid cells infiltrating from the blood and into hypoxic lesions. Recruited myeloid cells experience hypoxia when they enter inflamed lesions, and the length of time in lesions increases their hypoxic signature. To determine whether pro-inflammatory stimuli in the inflamed tissue can also influence HIF-a activation, we subjected macrophages to various pro-inflammatory stimuli and measured VEGF-A. While parasites alone did not induce VEGF-A, and pro-inflammatory stimuli only modestly induce VEGF-A, HIF- stabilization increases VEGF-A during infection. HIF-a stabilization does not impact parasite entry, growth or killing. Alternatively, the absence of ARNT/HIF- signaling enhances parasite internalization. Altogether, these findings suggest HIF-a is active during infection, and while macrophage HIF-a activation promotes lymphatic remodeling through VEGF-A production, HIF-a activation does not impact parasite internalization or control.

Molecular Insights Into Neutrophil Biology From the Zebrafish Perspective: Lessons From CD18 Deficiency

Neutrophils are key players in innate immunity and originate from the bone marrow of the adult mammalian organism. In mammals, mature neutrophils are released from the bone marrow into the peripheral blood where they circulate until their recruitment to sites of inflammation in a multistep adhesion cascade. Here, adhesion molecules of the β2 integrin family (CD11/CD18) are critically required for the initial neutrophil adhesion to the inflamed endothelium and several post-adhesion steps allowing their extravasation into the inflamed tissue. Within the mammalian tissue, interstitial neutrophil migration can occur widely independent of β2 integrins. This is in sharp contrast to neutrophil recruitment in zebrafish larvae (Danio rerio) where neutrophils originate from the caudal hematopoietic tissue and mainly migrate interstitially to sites of lesion upon the early onset of inflammation. However, neutrophils extravasate from the circulation to the inflamed tissue in zebrafish larvae at later-time points. Although zebrafish larvae are a widely accepted model system to analyze neutrophil trafficking in vivo, the functional impact of β2 integrins for neutrophil trafficking during acute inflammation is completely unknown in this model. In this study, we generated zebrafish with a genetic deletion of CD18, the β subunit of β2 integrins, using CRISPR/Cas9 technology. Sequence alignments demonstrated a high similarity of the amino acid sequences between zebrafish and human CD18 especially in the functionally relevant I-like domain. In addition, the cytoplasmic domain of CD18 harbors two highly conserved NXXF motifs suggesting that zebrafish CD18 may share functional properties of human CD18. Accordingly, CD18 knock-out (KO) zebrafish larvae displayed the key symptoms of patients suffering from leukocyte adhesion deficiency (LAD) type I due to defects in ITGB2, the gene for CD18. Importantly, CD18 KO zebrafish larvae showed reduced neutrophil trafficking to sites of sterile inflammation despite the fact that an increased number of neutrophils was detectable in the circulation. By demonstrating the functional importance of CD18 for neutrophil trafficking in zebrafish larvae, our findings shed new light on neutrophil biology in vertebrates and introduce a new model organism for studying LAD type I.

Endothelial junctional membrane protrusions serve as hotspots for neutrophil transmigration

Upon inflammation, leukocytes rapidly transmigrate across the endothelium to enter the inflamed tissue. Evidence accumulates that leukocytes use preferred exit sites, though it is not yet clear how these hotspots in the endothelium are defined and how they are recognized by the leukocyte. Using lattice light sheet microscopy, we discovered that leukocytes prefer endothelial membrane protrusions at cell junctions for transmigration. Phenotypically, these junctional membrane protrusions are present in an asymmetric manner, meaning that one endothelial cell shows the protrusion and the adjacent one does not. Consequently, leukocytes cross the junction by migrating underneath the protruding endothelial cell. These protrusions depend on Rac1 activity and by using a photo-activatable Rac1 probe, we could artificially generate local exit-sites for leukocytes. Overall, we have discovered a new mechanism that uses local induced junctional membrane protrusions to facilitate/steer the leukocyte escape/exit from inflamed vessel walls.

Inflammation induces pro-NETotic neutrophils via TNFR2 signaling

Cytokines released during chronic inflammatory diseases induce pro-inflammatory properties in polymorphonuclear neutrophils (PMN). Here we show that in vitro cytokine treatment leads to the development of a subgroup of human PMN expressing CCR5, termed CCR5+ cytokine-induced PMN (CCR5+ cPMN). Auto/paracrine TNF signaling increases intracellular neutrophil elastase (ELANE) abundance and induces NETosis in CCR5+ cPMN. Triggering of CCR5 amplifies NETosis. Membranous TNF (mTNF) outside-in signaling induces the formation of reactive oxygen species, a known activator of NETosis. In vivo, we find an increased number of CCR5+ cPMN in the peripheral blood and inflamed lamina propria of patients with ulcerative colitis (UC) but not Crohn's disease (CD). Notably, failure of anti-TNF therapy is associated with higher frequencies of CCR5+ cPMN. In conclusion, we identify a phenotype of pro-NETotic, CCR5 positive PMN present in inflamed tissue in vivo and inducible in vitro. These cells may reflect an important component of tissue damage during chronic inflammation and could be of diagnostic value.

Effect of Glabridin on Microvascular Permeability of Plasma Proteins Induced by Carrageenan

In the present study, investigate the anti-inflammatory effects of glabridin (GLA) in the carrageenan-induced paw edema test of rats. Inflammation is an answer to the body's immune response to various stimuli such as physical trauma, various antigens, chemicals, microorganisms, radiation-damaged tissues. The cause of this edema is the increase of vascular permeability, an increase in local blood flow, as well as the penetration of neutrophils and macrophages into the inflamed tissue. The current study aimed to determine the mechanism of microvascular leakage on carrageenan (CAR)-induced paw edema of GLA. Therefore, 10, 20 and 40 mg / kg doses of GLA were given intraperitoneal 3 days before intraplantar administration of CAR by using Evans blue (EB) method and by measuring paw thickness with electronic digital calipers. As a result, GLA inhibited both edema and microvascular leak. The results of our study suggest that pretreat-GLA to CAR-induced paw edema of rats via anti-inflammatory potential through inhibition of parameters such as microvascular escape and anti-edematous effect. These findings may be a new treatment of inflammation by anti-protein leakage of GLA.

Recurrent epistaxis from inflamed granulated tissue and an associated pseudoaneurysm of the internal carotid artery: case report

Background Chronic inflamed tissue in nasal cavity is a rare complication of transsphenoidal approach (TSA). Inflamed tissue is rich in blood vessels, which can lead to frequent nosebleeds. In addition, chronic inflammation can cause pseudoaneurysm, whose rupture results in massive epistaxis. There have been few reported cases of pseudoaneurysm of ICA occurring more than 10 years after TSA surgery. Case presentation We report a case of a patient who had recurrent epistaxis for over a decade after TSA surgery, and analyzed the causes of the nosebleeds. The aspect of occurrence of the nosebleeds and the result of biopsy and imaging tests suggest that the nosebleeds were due to chronic inflamed tissue and an associated pseudoaneurysm. The rupture of pseudoaneurysm recurred after treatment with stent placement, and brain abscess was developed. After removing the inflamed tissue by endoscopic resection, the patient no longer had recurrence of ruptured pseudoaneurysm or nosebleeds. Conclusions In patients with recurrent nosebleeds, the possibility of intranasal inflammation and subsequent pseudoaneurysm should be considered. Therefore, people who consistently have epistaxis after TSA, even if the bleeding is not in large amount, should be actively screened and treated for nasal chronic inflammation.

Relationship between Metalloprotease-7 and -14 and Tissue Inhibitor of Metalloprotease 1 Expression by Mucosal Stromal Cells and Colorectal Cancer Development in Inflammatory Bowel Disease

Colorectal carcinoma (CRC) associated with inflammatory bowel disease (IBD) is an example of an inflammation-related cancer. Matrix metalloproteases (MMP) are known to be associated with both processes. The aim of the study was to compare the expression of MMP-7, MMP-14 and tissue inhibitor of metalloproteases-1 (TIMP-1) in sporadic CRC- and IBD-associated CRC, and to compare the expression in inflamed and non-inflamed colonic tissue samples from IBD patients without or with associated CRC. An immunohistochemical study of MMP-7, -14 and TIMP-1 was performed on sporadic CRC (n = 86), IBD-associated CRC (n = 23) and colorectal mucosa of non-tumor samples from IBD patients without (n = 47) and with (n = 23) associated CRC. These factors were more frequently expressed by cancer-associated fibroblasts (CAF) from IBD-associated CRC than by CAF from CRC not associated with IBD. Regarding the inflamed tissue of IBD patients, Crohn’s disease (CD) patients with CRC development showed a higher expression of MMP-14 by fibroblasts and by mononuclear inflammatory cells (MICs) than CD patients without CRC development. In non-inflamed tissue samples, MMP-7 associated with fibroblasts and MICs, and TIMP-1 associated with MICs, were more frequently expressed in CD patients with CRC development than in CD patients without CRC development. Our data suggest that these factor expressions by stromal cells may be biological markers of CRC development risk in IBD patients.

An Hypothesis for CXCL1/CXCR2 Signaling Regulating Neutrophil-Derived Opioid Peptides Involved in Acupuncture for Inflammatory Pain

Increasing evidences demonstrate that acupuncture is effective in treating inflammatory pain. Recent studies have found that peripheral endogenous opioid peptides in the area of inflammation are involved in acupuncture-treating inflammatory pain. However, the source of endogenous opioid peptides in local area of inflammation and the mechanism of acupuncture regulating these opioid peptides remain unclear. Studies have demonstrated that neutrophils infiltrated in the inflamed tissue contain and release opioid peptides. Chemokine (C-X-C motif) ligand 1 (CXCL1) is one of the key neutrophil chemokines and can promote the blood neutrophil recruitment to the area of inflammation. In our previous experiments, we found that acupuncture could alleviate inflammatory pain and significantly increase the concentration of chemokine CXCL1 in the blood of rats with inflammatory pain. So we suppose that increased concentration of CXCL1 by acupuncture could activate the blood opioid-containing neutrophils via its main receptor chemokine receptor type 2 (CXCR2) and promote them recruit to the inflamed tissue to release opioid peptides, participating in the analgesic effect of acupuncture.